What’s up?
From Hermann Burchard:
George,
here is a simple model to explain the vapor trail’s observed symmetry:
Partial cloudlets each side, North & South,
have almost identical ones opposite.
1. The Bos’ blowtorch momentum sims and video blow-ups from Steve Garcia’s
posts indicate that the explosive ablations shoot debris ahead in the
direction of motion, both vapors and frags.
2. The vapors immmediately begin to rise initially as whole cloudlets.
3. By the time the main body of the meteoroid catches up with a cloudlet,
this will have risen a bit, so its bottom is hit off-center.
4. The meteoroid pierces the cloudlet at its bottom leaving clear air
behind, creating the impression that there are two parts.
5, Indeed, there appears to be a top part connecting North and South.
…As to the ablation throwing pieces out front and them creating the trail, then the object blowing through the trail and splitting it, it is a pretty decent insight, but the wake of the object would strongly tend to suck the trails into the vortex behind the object. We really don’t see that having happened, do we? It couldn’t really leave clear air, could it?
Ok, a glimmer of light, maybe…
– The pilot and co-pilot of the airliner said they saw THREE objects.
– The videos of the object seemed to clearly show ONE.
– The trails are twin trails.
This won’t be any final word, but when I look at each of those separate trails, I see them spiraling. To me that suggests that there WERE two objects, and that each of them was spinning.
And right before the big burst, the spirals seem to have gotten bigger. What does that suggest? Could one of the pair of spiraling objects have jetted out enough to trigger a disintegration of the other – which then disintegrated the first one in return?
Note also that immediately after the big burst, the smaller trails are NOT centered on the previous trails, but are lower. It appears that the big blast was asymmetrical, outward toward the top. Could this have blown out the top part and left the bottom, smaller, part intact?
It seems that smaller part first began to go downward, but then resumed its course, but as some have observed, its trajectory after that WAS more downward.
But it ALSO shifted the centers of the trails closer together, as if the downward push was not directly down but skewed toward the middle – of BOTH or maybe
Therefore I suggest this (refer to the image above):
– The big burst for both was more on top than centered.
– The remaining part of each one was driven down and toward the other
– That pushed each smaller part down – and possibly even BACKWARD, relative to the direction of travel (but, because of the forward velocity, it could appear to us to have been forward) – but only for a short moment. This gave a Z-axis motion to it, but only for a moment.
– The air resistance slowed each one down very quickly, eventually to almost nothing. (This is the “kink” in the paths of the smaller ones, when this vector decreased.)
– The forward momentum continued to move the smaller parts forward
– By vector addition, the smaller parts were now on a slightly downward track from before the big burst
On THIS video http://www.youtube.com/watch?feature=player_embedded&v=3kc274wZgMg
what seems to happen with the main twin trails is two-fold:
a.) that the two trails are corkscrewing, apparently from outgassing
b.) that the two trails are ALSO slightly separating
Yes, b.) could be a matter of perspective. But look at this one, too (tip of the hat to Hermann) http://www.youtube.com/watch?v=GL9JPuZKrbM
I THINK I see in both videos that the trails are separating.
I think that b.) is a natural consequence of a.)
If both are corskcrewing, then during part of the spiraling the outgassing is aimed toward the other one. Thus, this would push them apart.
If true, this could be seen as stutters in the paths, when each gets blasted by the outgassing of the other.
At the same time, if there is outgassing, then there should be no (N.O.) massive build-up of internal pressure with which to “explode” the objects.
This internal build-up is an assumed condition, not necessarily fact. Two things mitigate against this build-up (not even counting this corkscrewing that I think we can see):
1.) The vast majority of the heat is on the frontal face, which is what causes the ablation (look it up, this is NORMAL behavior for meteors in the atmosphere). This heat does NOT extend deeply into a large body. It is what causes “Fusion crust” on meteors, and this is only a few cm deep.
2.) Thus, the “heat build-up” is not what really happens. The ablation actually REMOVES most of the heat from the frontal face, when the terrifically heated ablated material “sloughs off.”
Still, in and behind the ablating material, there is outgassing occurring, called “ablation vapors”. Some of this outgassing will be jetting at higher velocities than other outgassings.
I think what was happening was this, then:
– The two objects hit the atmosphere.
– If the weren’t split up already, the impact shock with the atmosphere breaks them up
– The heated compressed air ahead of each one creates a glow
– The two glows are so close together that they appear to be one glow
– They begin spinning from their lack of aerodynamics
– They also begin jetting/outgassing (which may assist the spinning)
– As each outgassing side faces the other (on each spin around), the two are pushed apart
– The outgassing on each one looks like a corkscrew
—– This can be seen in the videos
—– It SHOULD have a regular “pitch” to it for each one
—– The two probably would not be “in phase” with each other
– As pieces ablate (slough off), we should – and DO – see flare-ups. Bigger pieces make for bigger flare-ups
—– This should also be sensed as being LOUD, with both the breaking off and the new outgassing (as the cooler layer is exposed) being able to create a loud noise
– The braking by air resistance continues as the object gets deeper into the atmosphere, slowing the velocity at an increased rate (I honestly do not know for sure if the heat gets greater, but I think it does)
– When the one of the internal imperfections (cracks) is exposed to the heated compressed air which causes ablation, one of the objects suddenly breaks apart again
– This break-up also impacts the other one, breaking it up, too
– The break-up of the second one contributes to the further break-up of the first one
– The remainder of each one continues on as described above
All of this suggests that the original body was fairly friable. A 10-meter body should be able to withstand the shock of atmospheric entry better than the smaller ones seen in the past.
Why couldn’t it have simply been two objects in the first place? Couldn’t the original body have simply broken up out in space, due to Earth’s gravity?
Yes, it might have broken up early. But I think the two would have had some perceivable distance between them at the radiant point. Maybe not.
Steve,
“Yes, it might have broken up early. But I think the two would have had some perceivable distance between them at the radiant point. Maybe not.”
You are correct, it didn’t break up before starting to fluoresce, otherwise it would have appeared as multiple glowing dots instead of one.
Realize that the fireballing segment and the other bright object(s) that kept going were all quite hypersonic. They bore a Tunnel – shock tube or shock sheath – through sea of atmosphere as they penetrate. As soon as fragmentation occurs, different ballistic coefficient separate different particles like a cracking tower in a refinery, only not vertically but along the trajectory axis. This happens quickly, as the lighter particles experience many G’s decel while the heavier one punch on with less deterrence from our friend Mr. Atmosphere.
So as soon as the lower density chunks separate from Mr. Heavy, they are gone from his shock tube and out on their own (typically behind and below as ballistics are overcome by frictional loss) in an instant. They are decelerating from 15 km/sec to something like a few hundred meters per second in a matter of about 10 seconds. Calculate that in G’s. Its lots of G’s. They don’t affect the Mr. Heavy chunk at all save the relatively small momentum change from the separation velocity, which typically pale compared to flyby speed.
Once the lower density pieces do break out on their own to look for their own apartment, life heats up quick.
“- The braking by air resistance continues as the object gets deeper into the atmosphere, slowing the velocity at an increased rate (I honestly do not know for sure if the heat gets greater, but I think it does)”
The heat released for any bit of meteor mass depends on how much velocity it loses. Don’t confuse heat with temperature. Heat has units of energy, which actually makes life very simple when you look at everything through that lens. Temperature is a Kinetic energy measurement of the average velocity of the particles within the matter being measured. Temperature essentially represents “amplitude of oscillation” of thermal vibration.
During fragmentation, bigger chunks break into smaller chunks, exposing geometrically more surface area as the process continues. In our case, the bright flare was the result of that increasing surface area allowing for a surge in the energy transfer rate from bolide to heat/light. The hotter the temp the whiter the light. Important to understand, the fireball was still supersonic likely till around the same time in the process as when most or all of the luminosity went out of it. It looks slow and graceful, not like a shock generating detonation you are used to seeing the science channel. When the fireball slows down to subsonic is when it finally sheds the shock wave, which then travels on to wherever its aimed.
This is easier to understand when you realize that the Chelyabinsk fireball of the bright flare, as it travels horizontally, goes about 50 km and is about 8 km across. Count the seconds of the bright flashes and assume constant decel from 15 km/s to zero (first approx only). So average speed of 7.5 km/s during decel flash phase for 5 or 7 seconds duration of those flashes? You make the call. 35 or 50 km horizontal distance?
Convection is quite obvious in the meteor plume, making any glider pilot drool for an aero tow to that altitude (and a pressure suit and a pressure cabin to handle the height)…
The entire plume contains heat released by the astronomical passer by, and this is especially true in the case of the fireballing portion. Vorticity on both sides of the plume are the natural result of the linear nature of the heated plume. Vorticity in fluid often results when two potential gradients are at right angles to each other within that fluid. The atmosphere has a pressure/density potential, aligned vertically. The meteor plume has another potential gradient, getting hotter as you approach the core and then cooler again as you move past the core to the other side, moving in a horizontal direction.
The thermal gradient of the plume reverses at the center of the track. When you cross (vector multiply) the plume’s thermal gradient (horizontally aligned) with the vertical potential field of atmospheric pressure, you get a Vorticity vector parallel to the plume, but opposite in sense (sign) on either side of plume centerline since that thermal gradient slopes down in opposite directions going away from meteor track center line.
TH
Hi TH –
I suggest some corrections:
“In our case, the bright flare [bolide] was the result of that increasing surface area
xxxallowingx forxaxsurgexinxthexenergy transferxratexfromxbolide toxheat/lightxxx.
creating enough energy to break the binding forces of the meteroid.
xxxThe hotter the temp the more whiter the light.xxx
The higher the energy the more intense the light.
Important to understand, the fireball was still
xxxsupersonicxlikelyxtill aroundxthexsamextimexin thexprocessxasxwhenxxx
was still hypersonic until the bolide.
Or “was still moving at hypervelocity until the bolide.”
Steve – The “appearance” of the bolide in the fireball was actually an artifact of the video recorder electronics.
Hermann – You are looking through the walls of a tube. Use area integration formulas.
Hi Hermann –
Also. at hypersonic velocities each video frame is an integration of events.
Finally, you have atmospheric density and that is always lower the higher the plume goes.
Hahaha –
How many Bosloughs does it take to screw in a lightbulb?
From https://share.sandia.gov/news/resources/releases/2007/asteroid.html “Sandia supercomputers offer new explanation of Tunguska disaster”
Smaller asteroids may pose greater danger than previously believed
““There’s actually less devastation than previously thought,” says Boslough, “but it was caused by a far smaller asteroid. Unfortunately, it’s not a complete wash in terms of the potential hazard, because there are more smaller asteroids than larger ones.”
Oh, let’s see – ” a far smaller asteroid”?
Tunguska was about 100 m across.
Far smaller – what does that mean? Is that a scientific term? Or a scientific “I don’t know”?
Simply “smaller” would imply maybe half as big – 50 m.
“Much smaller” would imply maybe 1/4 as big.
“Far smaller” – what do you think? Maybe 75%-90% smaller?
Like 10 meters across?
Tunguska’s damage area was a bit over 2,000 sq km.
Hey, Bos! Where is the devastated forest near Chelyabinsk? Heck, we will even take like 350 square km, dude. We aren’t picky.
How many broken windows count as one tree? Even the weakened trees Bos asserts – with no evidence at all except his cartoon machine.
But look at his “visual sound bite” images he poses in front of.
Bos! Hey, Bos! Where is the 7 gazillion degree down blast? Where are the melted quartz blobs?
/snarc
Seriously, folks.
As a kid we used to have commercials for all kinds of pills, like Tums – “Tums for the Tummy” and such. Some of those commercials had high-tech animations, high-tech for those days, at least. Those animations showed pills descending the esophagus and entering the stomach and coating the stomach. And they didn’t prove anything. It was just some artist’s rendering.
You can draw anything. It doesn’t make it true.
Scientific models are only much fancier drawings. I worked with CAD – computer-aided drawing – for two decades. I know that you can draw anything. Just because other people think it looks cool doesn’t mean anything. Just because you can draw it doesn’t make it real.
People have been saying since the advent of the computer: Garbage in, garbage out.
So how do we know if we are putting “garbage in” or not?
Well, sometimes we do, and sometimes we don’t know. When it is repeatable technology, when people have proven out – in the REAL world – time after time after time, then you should be able to discern “garbage in” or not. It STILL doesn’t mean that the programmer or program operator input the right code or values, but it means that somone ELSE can tell if the wrong code or values have been input.
When someone is doing models that only they know what is going on — folks, it ain’t science yet., It is one guy’s code and values – that HE may think are all correct and valid. It may make the bestest, most prettiest animations since Tums. But if the assumptions and code and values aren’t replicatable, it ain’t real.
And if the possible “garbage in” comes from a guy whose assertions that Tunguska was “far smaller” – and then Chelyabinsk comes along and doesn’t do ANYTHING that Mr Bos says it would be capable of – are we obligated to believe his pretty animations?
Even when his animations look like really cool dragon’s breath?
You know, Bos right now should be quaking in his boots, wondering if anyone realizes he is busted.
Disney Studios – do you folks need a good animator? Maybe for a sequel to “Roger Rabbit”, with its toons that keep on coming back after death-dealing hammer blows or being run over by toon cars and real cars?
I am being facetious about Roger Rabbit, but MODELS ARE NOT REALITY. And the less KNOWN, solid science behind them, the less real they can be expected to be.
LITERALLY, Bos – where is the downward Bos plume at Chelyabinsk?
For that matter, where is the evidence at Tunguska of your Bos plume? Heat to melt quartz, with that downward force, should have not only stripped those trees but turned them into charred nothings.
I have a friend who has a controversial hypothesis about the ancient Egyptians. He has some graphics software that allows his presentations to really WOW his audience.
Most of the people watching his presentations don’t really know what he is talking about. They watch the slides and animations, and they come away very sufficiently impressed.
I watch his presentations, and I KNOW what he is talking about. I am an engineer, and so is he, and I can follow (even anticipate) where he is going with his presentation and his ideas. And I can tell you that his ideas are as sound as 1/4″-20 Hex Head Cap Screws. His ideas are measuring real things with real tools – and anyone else is welcome to test out what he is saying.
I DO question everything he says, and what I come up with is hat he is correct.
If all his audience were the “lay public,” my friend could be The Man Behind The Curtain. But they aren’t. SOME of his audience is like me – capable of comparing his “garbage out” and determining that it is not garbage at all. BUT WE ARE OBLIGATED TO TRY to find out where the garbage is.
Boslough is like that friend, if the friend’s audience were country bumpkins. Bos has one program that he wrote. Bos puts in the values. No one can see what he programmed. And his assumptions and formulas may be as inaccurate as his downward plume at Tunguska.
After Chelyabinsk, Bos now has a world that has seen that his downward plume is a figment of his imagination.
And what does that tell us?
GIGO
The other scientists who question his Libyan Desert Glass scenario ought soon to be all over his cartoonist rear end.
Scratch one LDG hypothesis. It has met reality and failed. Heck, it only knocked down one poorly-built building. And no one’s eyebrows were even singed.
Lots of people just about crapped in their pants. Actually, maybe a few did have stinky downward plumes. You don’t think he mistook a sonic boom for a plume, do you?
Richard Feynman’s video on the Scientific method.
So, am I precipitous in saying that Boslough’s guess about air bursts is wrong? That Chelyabinsk isn’t large enough to be “far smaller” that Tunguska?
Oops! Sent too early.
Continuing…
I simply think that Chelyabinsk IS a test of Bos’s air burst model. And since the model IS his “computation” (Feynman’s word), it did not agree with experiment/experience, and thus his model is wrong.
Wrong enough to need better computation, at the least. I.e., a better model. Bos should no longer be able to prance around and brag that he has solved the LDG mystery – or that he is THE expert on air bursts.
I love the Feynman passage, “It doesn’t make any difference how SMART you are, who made the guess, or what his NAME is. If it disagrees with experiment, it’s wrong.”
Recall that Einstein’s Relativity was not widely accepted as real until 1919 when Arthur Eddington measured the light bending around the Sun during an eclipse.
The principle of falsifiablity is the bedrock of scientific thought. A hypothesis must make predictions. That hypothesis should – as Feynman says – have included within it – or lead to -computations that can predict a specific result. That prediction needs to be precise enough that the hypothesis can be seen to be true or false.
If a hypothesis does not have such precise predictions – if it is too vague – then it normally will not be seen to be scientific, though in astronomy and cosmology are in particular given wide latitude, since planetary. stellar, galactic, and cosmological ideas can hardly be studied in a laboratory.
But Bos’ models are an exception to that. From time to time the WORLD is his lab, and objects DO enter the atmosphere. Real-world data CAN be collected to compare with his models’ predictions.
Steve –
You have seen video of exactly 1 bolide. There are many videos of many different bolides out there on the net.
As far as “B.” goes, when he refers to the “asteroid” that hit at Tunguska, that shows that he does not know what he is talking about, and one does not need to go any further.
Another weird observation. . .
I gotta ask – Like water diffraction of light, s it first enters the atmosphere, does the object get dragged down – bottom first – onto a different angle as it enters the atmosphere.
Or does it begin spinning over-the-top from the greater drag on its lower side?
Is that why the two trails are at the side midpoints? Is the thing spinning?
Did you ever see the WWII film about the round bouncing British bombs that were used on one mission to take out dams in Germany? They were released from under ten feet, and the moment they hit the water, they were spinning like crazy.
I mean, why WOULDN’T they spin?
Steve, Hermann –
Both of you have been assuming that the meteoroid was spherical.
May I recommend to both of you reading Peter Norton’s “Rocks from Space”, so that you could learn the correct technical terms to use in discussion?
Ed –
Not even close. We are not idiots.
Ed,
Is this the book you are talking about?
http://www.amazon.com/Rocks-Space-Meteorites-Meteorite-Astronomy/dp/0878423737/ref=sr_1_1?s=books&ie=UTF8&qid=1363344707&sr=1-1&keywords=%22Rocks+from+Space%22
Rocks from Space: Meteorites and Meteorite Hunters (Astronomy) [Paperback]
O. Richard Norton (Author), Dorothy S. Norton
Review —
5.0 out of 5 stars Excellent Book. April 22, 2007
By Gary Peterson TOP 500 REVIEWER
Format:Paperback|Amazon Verified Purchase
I purchased the book “Rocks From Space (Second Edition)” about seven years ago. My main interest in space is in the field of planetary geology and I have a need to be reasonably conversant with the subscience of meteoritics. The “Rocks From Space” book was recommended by several colleagues, and I also noted that it had received good reviews.
In general, I find “popular” books directed to the interests of amateurs to be shallow and even corny. “Rocks From Space” is an exception. This book is outstanding. It provides a concise but excellent introduction to the subjects of meteorites, asteroids, comets, meteors and impact sites. It is presented in a way that amateur collectors, amateur astronomers or anyone interested in these space-related subjects can easily read and understand, but, at the same time, it is very informative and authoritative. I would not hesitate to recommend the book to anyone who was interested in meteorites and other space debris. In fact, I have recommended it to countless individuals as an excellent place to start.
“Rocks From Space” is well written, well illustrated and interesting to read. It has achieved a permanent and respected place in my reference book collection. I give talks on planetary geology to groups of geologists and astronomers and I use some of the illustrations in my presentations. For people who are interested is collecting meteorites, Norton presents a series of guidelines, anecdotes and useful information including a list of laboratories where one might get an identification confirmed. For a small and inexpensive paperback, this book contains a wealth of information.
Gary Peterson
The question still remains to be answered, why is there a laterally symmetric outcome, and why the vortex stream “corkscrewing” description that makes sense: Why are there two parallel corkscrews at the same altitude. For this to occur in a 3D, three dimensional, set-up does require an explanation which so far has not been offered. The “separated at birth” name refers to the coherence of the two vortex streams, they are far too similar to each other plausibly to have separate causes.
The observed configuration is 2D, two dimensional, in a sense, which is a surprise. A 2D model in x,y co-ordinates, with no z-variable, may predict two vortex streams, but would not help to explain the Chelyabinsk vapor trail. It begs the question: We need x,y,z coordinates and of course time t is also to be considered.
The only cause for the two trails at equal altitude that I can come up with is the air density decreasing with altitude or height above ground. The diameter of the trail is fairly large,perhaps two kilometers, possibly larger. So, the density gradient is not inconsiderable.
The pilots of the passenger plane most likely never saw the main stone, which presumably was covered in plasma. What they saw were the ablated frags shooting out ahead, with the explosion adding extra momentum, as can be seen in the doctored videos that you Steve found.
This may be an example of what the physicists call “symmetry breaking.” The physical phenomena take place in 3D, so we would expect a resulting vapor trail that is spherically symmetric about each point of the trajectory. However the phenomena don’t bear this out: We observe two parallel, coherent vapor trails at equal altitude, the 3D symmetry fails, it has been broken. Answers would seem to require dependence on altitude with gravity and the resulting air pressure or density gradients breaking the 3D symmetry.
Hermann and Ed –
I don’t think that paper is applicable. It is talking about vortexes at the downwind edge of flat plates, and the vortexes are Z- and Y-axis cortexes – 90° different from the corkscrewing Hermann and I are talking about. The Russian double vortexes are X- and Y-axis vortexes.
Now, if the meteor had cooperated and been a flat chondrite flying through the air like a table top, that paper would apply.
One last thing: Models are not real. They are made up of what the scientist told the code writer reality is assumed to be. Models used at the leading edge of science are WAY more often wrong than right – simply because the scientist assumed things that aren’t true, and the code writer put them in for his customer. The customer is NOT always right.
As I’ve stated elsewhere here, models for technology that is fully known are fine, because there are no assumptions that need to be made. In those cases, everything known has been turned into repeatable and replicatable equations – and the output from those equations are fully verifiable IN THE REAL WORLD. Models are speculations – until real world experience has shown them to be correct. And if they are correct, where are the papers showing that to be the case? Right now, all I see is someone drawing cartoons and claiming that something in the cartoons tells us something. Where is the paper that says, “Yeah, we repeated this with lab experiments, and found it to be true”? Just because their sketches resemble vortexes doesn’t mean a whole lot. And if the vortexes were about solid objects, that would be nice, too – BUT STILL A MODEL. GIGO.
Ed, throwing some hand-sketched academic paper at us isn’t helping – especially when it doesn’t apply and is about models, of all things.
Hi Trent –
Thank you. That is exactly the book. Perhaps Steve and Hermann will be encouraged to follow your recommendation.
Steve, Hermann, why are you expecting and demanding my views on hypersonics? Don’t either of you know any dynamicists you cold bother?
It is as bad as people sending me their papers, and then taking that as some kind of endorsement. (Of course, what is even funnier is someone quoting you won work back to you as if it were there own.)
Both of you are seeking confirmation from me on your views. Feel free to speculate on this, but since I don’t care about your speculations right as I have some pressing matters to take care of right now, would you please stop it?
Hermann,
I already explained the twin, laterally symmetric vorticity in a post above. Its due to the convection of the hot trial left by the passing object. The cross section of the plume (perpendicular to track) is the same as a cross section of a thermal.
Pressure/density vertical gradient crossed with horizontal thermal gradient (opposite slope on each side of the hot trail) gives vorticity vector(s) parallel to track, opposite sense vorticity on either side of track.
We need to let Ed work.
TimH
Ed –
No. We are not seeking confirmation from you on our views. You are missing the point. We ARE asking for some feedback, which you are too high and mighty to give. All you say is, “Go read 30 books on this and then we can talk.” Like you, neither one of us has unlimited time left in our lives. And this is NOT MIT or CalTech. It is a BLOG, in which people sometimes ask others WHO ARE MORE KNOWLEDGEABLE (yes you are) to please respond with something other than blowing us off.
TH –
You saying the it is due to the convection of a hot trail left by the passing of an object does not either make that statement true. You flatter yourself that you are an expert on something even the real experts are having so much trouble on that they haven’t gotten it yet.
Nor does your “thermal” fit the observed twin trail. A thermal does not have two vortexes. And a thermal does not have a hyper-velocity object going up or down its axis. Thermals are solely convection events. This has as much in common with a convection event as a tornado does to a slowly warming pot of water.
The vorticity was not parallel to the track. It was perpendicular to it. You have your X, Y, and Z axes confused. Your explanation is a bunch of gobbledegook buzz words.
Steve,
TH has the vapor trail model about right, just a slight correction on my primitive model: The center of the vapor trail, which he claims is up to 8 km diameter, is much hotter than the outer parts, so rises up “like a plume,” although you, SG, criticize that expression. So, the hollow at center bottom is simply
the void left when the hot core rises rapidly, dragging with it denser, cooler, or not-as-hot air beneath and thus creates the bottom “separated at birth” channe; seen in the videos. None of these show the trail during the mere fraction of a second when it was forming.
TH also of course explains the corkscrews on both sides of the
trail bottom, proving to be a better applied mathematician than myself. Gotta check his vorticity cross products though, he’s talking DFxDG when F.G=0 (D=Del), if I red him right? In Calculus, we usually only teach vorticity=Dx[u,v,w] for a single vector [u,v,w].
Hermann, the ablation products all come out as melt droplets, which vaporize, and they are not preferential as to direction. Gravity is a flea on an elephant’s butt compared to the other forces occurring. TH’s vorticity is driven by convection? Convection is even a weaker force than gravity, as it is the delta between two fluids, both driven by gravity and one less so. Not hardly. Those vortices are fully formed within one minute – with blue sky visible in between. TH is declaring that the convection has happened over 8 KILOMETERS within one minute? He is giving convection more capabilities than it possesses. And not only does he say 8 km gap, but it has also wound completely around the corkscrew (pi times 8 km) besides? And no one sees this high velocity roiling around. Not possible. 25 km circumference in one minute? That is 1500 km per hour, THAT alone would be supersonic and creating sonic booms. No. SOMEONE would have seen and commented on it and it would have been more than noticeable in any of the underside videos. And the basic idea of convection driving it and splitting the two – not gonna happen.
I worked with and around 3000 F, and such powreful convection isn’t even close to reality. Yes, I know, 3000 F is not 3000 C, But convection is pretty linear. This is a mechanism out of a fantasy.
The ablation vapors are what is seen, and the most powerful force in them is expansion. Massive expansion. If I remember right, expansion of water into steam is ~1,000 times the liquid volume, at only just above boiling temperature. For molten rock vaporizing it has to be much more than 1,000. Like I said, convection-driven vorticity is the very weakest thing going on – by at least 4-6 magnitudes, seriously weak. Literally a fart in a windstorm. The ablation vapors are happening 360° around the object.
If there were vorticity it doesn’t explain why only on the sides, nor for only this object. Anybody ever see this before? With other trails?
Your speculation earlier that it has to do with delta P at different altitudes – same argument here: Compared to explosively expanding molten rock ablation vapors, those deltas don’t mean anything. They are <<< in comparison.
E.P. Grondine wrote, March 13, 2013 at 9:57 pm
“you have been assuming that the meteoroid was spherical.”
Hermann Burchard wrote, March 16, 2013 at 3:29 pm
“Why are there two parallel corkscrews at the same altitude.”
So, could a single large, nonspherical object to leave two distinct vortices in its wake?
It happens all the time:
http://wallpapersus.com/wp-content/uploads/2012/06/physics-airliners-vortex-contrails.jpg
Popular Science Magazine showed why, in this 1947 article:
http://conspiracies.skepticproject.com/images/articles/chemtrails/popscicontrails-full.jpg
Note, the vortexes are not formed through hotter air rising in the center; the air is pushed into circular motion by the shape of the airflow over the left and right tips.
So if it’s much wider than it is tall, with sorta pointy ends left and right when in a given attitude, one nonrotating bolide might be able to produce two counter-rotating trails. Outgassing would not be necessary, the ablated material would get sucked into the vortices and make them visible. It sounds farfetched that a bolide would just happen to be shaped like that, but maybe its hellacious speed could compensate and produce the double-vortex phenomenon even with a shape that is merely jagged.
Having produced a double vortex, why would the two trails separate and then come back together?
It happens all the time:
http://commons.wikimedia.org/wiki/File:Contrail_with_crow_instability.jpg
See also the last two photos in this set:
http://metabunk.org/threads/929-Hybrid-Contrails-Was-Different-evolution-of-symmetric-and-asymmetric-contrails
Of course, trying to understand this monster through simple analogies to aircraft might be as worthless as trying to understand the effects of a tsunami with analogies to a squirt gun. Still, at least it’s an analogy to a real, known phenomenon, rather than just a model. Maybe someone who works with hypersonic wind tunnels could shed some better light on it.
If I understand the forces here correctly, we are looking at a multiple kilometer diameter solid object at near zero temperature being heated to a plasma in the space of a few tens of seconds with a 500kt energy budget.
What I do not understand is Boslough claiming plasma _conserves_directional_momentum_ and goes deep into an atmosphere after converting wholly to plasma.
Plasma is highly energetic, highly electrically charged and not very dense. Unless there are a lot of magnetic or gravitational forces involved, it strongly repels from a like electrical charged plasma and denser matter states.
Plasma wants to -expand-, not _penetrate_directionally_ into a denser material.
I keep coming back to armor penetration as a model here. Armor perpetrators have to be more dense than the material it penetrates to achieve depth of penetration in the armor material.
The biggest problem with both low density perpetrators facing high density armor at slower velocities and even depleted uranium (DU) armor piercing fin stabilized discarding sabot (APFSDS) projectiles at hyper velocity [5km (+) per sec] is that the perpetrators structurally fail, converting their momentum energy into heat & light energy during structural failure, leaving a crater in the armor with both projectile & armor fragments flying out on radically different vectors from the crater.
A meteor is in no way shaped like either a arrow-like APFSDS projectile or a bunt tipped and conical Mark 12 nuclear reentry vehicle.
How does one expect a complete plasma spawned by an irregularly shaped and disintegrating meteor to retain a directional momentum into a denser gas or solid over tens of kilometers, when minus those intense magnetic and gravitational forces, it can expand elsewhere?
Especially with the multiple vacuum paths the disintegrating solid meteor is creating for the plasma to expand in the atmosphere behind it?
Plasma at the surface of the Earth will come from a solid object converting to plasma at impact or from a very low altitude air burst, where there is no place else for the plasma to expand into.
I’m thinkin’ you’ve got “perpetrator” confused with “penetrator” Trent.
Dennnis, the guys inside the tank are thinking perpetrator.
Dennis —
Gah!
Spell check isn’t always you friend.
I hit the wrong word in my spell check list there.
Robert —
You got that right.
On a more serious note, you guys are a panic! LOL.
As always, Dr. Burchard is my hero. I will now defend myself against unwarranted and vicious attack….
Steve,
Steve, Steve, Steve…..
Easy bud. I’m just going on what I see, what I’ve flown through, what I’ve written and studied the math for, and what I know about shock and heat transfer from a BS in Engineering Science and Mechanics. No advanced degree, just lots of graduate level courses before and after getting my BS. Some of that from industry after getting spacecraft jobs. One of those jobs with all those “Engineering B Courses” was with the guys at GE who all did reentry before I got there in the early 90’s. ComSat Fleet Ops Gobbledegook. And I’m using that with a capital “G” because I like the word!
So ablation causes rapid expansion, faster than the shock speed. Yes, faster, so in this phase the shock builds and piles up in front of the expansion at first. Shock front formation and fortification. But eventually as the expanding stuff radiates outward the heated matter slows, and eventually during this slowing process the shock sheds from that bit of fluid and propagates onward and away from that hot blast that so lovingly enabled its existence.
Now, be aware that this is in a vast either of Gobbledegook, so that effects everything we’re talking about.
Think about the progression, from super hot and pressurized to expanding and cooling and slowing in that expansion. One continuous process, and eventually the shock separates from the plume as the expansion rate slows. We know this since the plume is still up in the sky when the shock hits the ground at Chelyabinsk. Its in the video. And I spelled Chelyabinsk!
Now you have a warm trail that lofts long after the shock has cleaved from it. It will still expand after shedding the shock. Depending on its expanding momentum and some heat transfer issues, it may also contract a bit after it finishes expanding, but most likely not much even if it does contract at all (case of rapid cooling and associated pressure drop). Most likely monotonic expansion once set in motion. It is clearly convecting as the large fireball plume actually bends the trailing edge of the rest of the slightly higher transit plume while it rises, pulling up large atmospheric volumes around it. Its very visible in the videos. Mass transport. Convectively dominated. Large scale. Clearly.
In high school I thermal soared a full scale sailplane solo for 4 hrs 15 minutes. That was by understanding convection. But back to the passage of the bolide first.
Yes gravity doesn’t have much say in the immediate direction of the hypersonic portion of bolide ignimbrite, even while it becomes the plasma momentum current. Remember also that these things happen as a continuous process. Fragmentation produces more exposed surface area which cause faster conversion of the hypersonic mass to plasma, causing still faster fragmentation, faster burning, etc. This is typically all happening at great altitude where most of (a very large fraction of) Earth’s atmosphere still lies below. The deceleration is still many hundreds of G’s (or few thousands) as the particles get smaller and there is tremendous frictional heating, the extreme Kinetic (remember KE varies with the square of the astronomically large velocity) is absorbed by all those unlucky molecules or ions in harm’s way.
Explosive heating. That is what drives the expansion and resulting shock formation and fortification.
Penetration of the troposphere by the bolide just speeds things up, pushing the frag and fireball process into the range of faster time scales. Just realize that the period while shock is being generated, as the bolide is passing and the wicked hot trail starts to expand out behind it, is relatively brief. Likewise while the detached fragment disintegrates and fireballs, it builds a shock for that brief fragmentary detonation. Then the trail (or the fireball) sheds the shock and the shock propagates away. While this happens, the trail still expands, but the rate of expansion is not fast enough any more to continue generating shock. In the fireball case, the expansion lasts longer than it does for the passing fragment. Longer rapid expansion builds bigger shock.
The fireballing (absorbed) portion of the bolide generates a very high energy shock vs that of the chunk that continues on by. This is because the astronomical KE is delivered to the atmosphere in the fireball case, but not in the pass by case.
Also interesting here is that the larger the overpressure of the step discontinuity (shock wave), the higher above the speed of sound a shock wave will travel. So the strongest shock is the one you hear first in this case, and typically in cases where there are multiple or continuous shock sources in a concentrated area at distance from the observer. Yes. Shock waves travel faster than the speed of sound in the medium in which they travel. That’s why they’re shock waves and not sonic or sound (harmonic) waves. Degree of overspeed depends on degree of overpressure.
Regarding course or trajectory change:
The hypersonic momentum of the bolide is what largely limits the angle through with any bit may diverge from the original vector. A given change in trajectory requires geometrically higher normal (perpendicular to trajectory) force at higher speed. Just to be clear, while the convection is dominant in the motion of the plume is only long after the passage of the bolide and/or fireball and also after shock shedding from that plume after passage. Two entirely different phases, two entirely different processes. Two entirely different time scales.
Don’t get caught mixing the two realms. Its easy to do without a sound basis in whatever the governing mechanics (my Engineering Science degree)
Kind of like the contacting phase and then the crater excavation phase in a shallow angle impact problem. Two totally different processes at two totally different time scales. Don’t get caught mixing them. Easy to do.
How far do you guess 500 ktons of heat released in 5 or 7 seconds is going to rise in the first minute after release? Think about it. How far does a fractional megaton mushroom cloud go up in 60 seconds? Does it loft any neighboring atmosphere? Yes. There is large scale mass transport due to overwhelming convective instability. Dominant convection. Fractional megaton heat release. Atomic bomb scale.
And I think you’ll find my math quite reasonable. Cross the vertical density potential gradient of the exponential atmosphere (always vertical) by the horizontal thermal gradient direction of the plume’s cross track section (this is a horizontal line at a right angle to the trajectory), and you get a resultant vorticity vector parallel to the plume which is the core of the vortex on either side of the plume. Pretty simple. No offense.
Maybe I wasn’t clear. The math is very clear. So is the convection. And I’m not telling you to read any books to learn about it. I’m giving you the answer. Because I can. Slope of heat gradient is opposite on opposite sides of plume. So is vorticity. (Dr. Burchard can check this at his turbo brain leisure…!)
For Shock I studied under Dr. M. S. Cramer at VA Tech. We did discrete and continua and nonlinear and Lagrangian Potential methods and a bunch of stuff I don’t remember many of the details of 25 years later. The dynamics and fluids folks in that department are pretty good. The MechE department there was also top shelf. They punished us with Thermo for Majors, and made us work problems in Imperial units instead of SI when we slacked on the homework. I cried and thought of quitting. And then I got busy and aced the final.
“explanation is a bunch of gobbledegook buzz words” Yeah, just like the kind those experts who taught ’em to me used all the time.
I accept and respect your diverse postings and your beautiful interest in these fascinating topics, Steve G. Please show similar respect. Many of the folks posting here have a broad knowledge base beneath an otherwise nondescript appearance. I haven’t designed, built and flown spacecraft, rotorcraft, aircraft and parachutes without actually learning something about physical mechanics. That’s why I’m still alive. And so are all the pilots I worked flight test with. And all the people I packed parachutes for. And flew helicopters with. And built airplanes with. And BASE jumped with.
I think you get it.
So I’m the guy who gets to use Gobbledegook whenever its in my field, which is plenty often on this forum. I’ll shut up about Geochem, or Archaeology. But don’t get me started on shock or orbits or heat or mass transfer or thermodynamics. I studied intuitively, so I can often work it though largely without the math for a first guess in many of these topics. I had to learn it that way because I have trouble reading.
Got my Gobbledegook badge now, capital G. No one can take that away from me. I have too much BASE free fall and am now officially a lifetime Goggledegook-er. So don’t ever ask a dynamicist “why…?” because now you see what happens….
At VA Tech in the ESM dept. Dr. L. Glenn Craig taught me Vector Product graphical solution technique for multi-jointed mechanisms dynamics problems. I already understood that marvelous method and had taught it to myself as a shortcut to check answers in those complicated problems. Its very unusual, but that’s the way my head works. I think that way naturally. Gobbledegook-ly like.
I’m not makin’ this stuff up, I promise!
Did you figure out why the Chelyabinsk trail kinks early on in the descent yet? It’s right there in the videos….
Where does turbulence come from at 150K ft altitude? (or 300 k ft or 200 or whatever) Isn’t stratospheric flow always supposed to be laminar, especially over the Urals in Winter? My boss on my Mars Observer program job was a PhD Meteorologist. I think he told me that laminar thing in 1989.
So to review, shock wave brew ha during hypersonic bolide passage, and convection brew ha of thermal plume from after bolide passage are not to be confused. They are two largely different processes and happen over two largely different time scales. True they are both ultimately part of the same evolution above Chelyabinsk. Mainly, however, they are entirely different families of brew ha.
What else can I help with?
TimH.
Gobbledegook. –
I read and keep on reading papers on meteors and ablation and the processes going on, and NONE of them talk about shock, overspeed, overpressure, or contact phase, or crater excavation or any of your other flowery phrases. You are making it up as you go along, and I guess you are convincing yourself, but not me.
The air in front gets compressed and super heated. That air in a bolide (not in very small meteors) creates a film of air that allows (somewhat) the compressed air to flow around the bolide. The heating of the frontal face melts the materials. The drops of melted material flows away with the air, carrying heat with it, but not before it vaporizes. This material/vapor is what we see as a luminous tail. And then as a “smoky trail.” The meteor is, drop by vaporized/ablated drop, left behind in that smoky trail. And its energy, too.
There is almost no fragmentation as we normally conceive it. Almost all of the material is ablated and vaporized, until the remaining structure of the bolide cannot withstand the reaction force of the compressed air, at which THEN the body disintegrates and appears to “explode”, but it is actually just more surface area being exposed, creating a physically larger luminous body – for an instant.
There was no 500 kt explosion. The energy was being released as the material was being ablated, all along the track.
About the only thing that doesn’t sound wrong is that when it hits the troposphere there would be another impact, and THAT impact may have been what the big flare-up was about, having triggered the disintegration. But it was not a 500 kt explosion.
I predict that VERY few fragments will ever be found – because they don’t exist. The material had been melted into slag droplets. They couldn’t be larger than droplets because of the turbulence and force – and HEAT – of the compressed air. They then vaporized and were pushed back and around the bolide, to be left behind.
I predict that the solid pieces of the meteor will all be ones from after it stopped being luminescent – toward Lake Chebarkul.
The trail was still expanding for some minutes, but not convectively to any appreciable degree, not upward in any sizable way, and not only in the center, not compared to the pressure expansion. Geez, the expansion pressure was magnitudes greater than convection. Convection is SO small a force.
There is no reason that the convection would drag the inside perimeter of each of those around and cause the outside perimeter to go down. And not in a corksrew fashion like is obvious. There is a regular pitch to that corkscrew. A convective upward flow would affect the inside perimeter, but not the outside perimeter, and it would not round off the top and bottom.
Your horizontal plane thing is not valid as anything. YES, the air pressure above it was less than below. That is what convection is, after all. That doesn’t mean anything. Perhaps 0.25%, I’d say. A tiny refinement of the massive things going on. As a driving force in all the HUGE forces taking place, pushing things outward all over the place? I repeat – a fart in a windstorm.
You claim the vortices are some km large. No convection could possibly work in that one minute on a vertical scale that large. Remember that convection has to push up and displace the denser air above in the process. There WOULD be roiling, visible roiling, but not in the time window of one minute or so. X km per minute vertically WHILE it is pushing that air aside? I’d like to check the math on that one.,
As to atomic explosions, you and I both know a lot of that mushroom cloud is from reflection off the ground plus expansion upward. Without the ground there is no mushroom cloud to speak of. In space, for example. . . well, you know that.
Stratospheric flow being laminar? That would depend on the values plugged in and the Reynold’s Number of the air up there. And the velocities. Evidently the velocities are inadequate to cross the RN threshold into turbulence. if the velocities were greater turbulence would occur. Your boss would have known that, evidently. Probably simply a function of the thin atmosphere. I haven’t worked with the formulas in so long I can only remember the general principles.
Thomas, Steve,
If I understand you both correctly, you both agree we are looking at a non-instantaneous and non-spherical energy release.
That being the case, how can the Infra-sound detectors keyed to nuclear blasts with those characteristics be correct in calling the Chelyabinsk energy yield?
Trent –
I am SO doubtful about the 500kt number you can’t believe.
If it DOES happen to be true, it was all released along its trail, from radiant point to final disintegration (that most people call its air burst), which, by itself had the immensely, gigundous, tremendous power to (WOW!) blow out windows and knock down a building that was likely going to collapse in the next two snow seasons.
A 500kt nuke at that height would have offed thousands of Chelyabinskians.
From what I could tell, the infrasound detectors could only tell the direction. The stuff I read on it didn’t discuss its power.
This meteor has made me think a LOT less about the power of an airburst to do anything. My sense is that even Tunguska was probably about in the top 10 percentile of airbursts. It seems to have burst at an optimal height for energy to be directed down.
At least for low angle trajectory objects. Something coming in directly – more vertically – with less atmosphere to give up its energy to – perhaps.
I furthermore discount just about all that Bos has in his model as GIGO.
I furthermore have come to think an air burst was completely inadequate for the Y-D event. IMHO at this time, I am certain it had to be a ground impact (on ice, yes).
A meteor is much denser than what is thought of as a comet, and if its density isn’t enough to do squat but break glass. . . blah, blah, blah. You get the gist.
But a comet does have much more velocity, and it would hit us broadside, increasing its geocentric velocity (i.e., energy), so perhaps that is a different ball of wax.
But for right now, I am not impressed at all with the destructive capacity of their “500kt meteor blast.” More like the final disintegration was 15 kt, tops.
From my reading on meteor papers, everyone says most of the energy is expended along its trail, ablating and ablating: Compressed air > melting > vaporizing > bleeding off energy. Till the thing has so little integrity left it falls apart from the reaction force of the air. At that point more surface is exposed, and it is just bigger in area that we see, but in psi I don’t think it is any greater. And look at the puny pieces left or driven off.
>>If it DOES happen to be true, it was all released along its trail, from
>>radiant point to final disintegration (that most people call its air burst),
>>which, by itself had the immensely, gigundous, tremendous power to (WOW!)
>>blow out windows and knock down a building that was likely going to collapse
>>in the next two snow seasons.
This is part of the reason I keep coming back to the armor penetrator analogy.
Most of the energy of a penetration is expended on the shoulders and not the tip in the event.
That is why armor designers spend so much effort in chobham arrays to put hard/brittle, tough, and ductile materials of varying densities into a matrix to destabilize the penetration laterally, and cause the energy to be shifted to penetrator break-up/failure and not armor failure.
Do you think the designers of Earth designed the atmosphere that way, too? . . . .LOL
You do have to admit, the atmosphere is a fair shield.
BTW, I had no idea about how ablation worked in meteors (and I assume comets, too). The ablation material I’d dealt with doesn’t melt or burn, but chars – and then flakes off. I originally assumed ablation in meteors was the same process, but it does not seem to be.
The melting > vaporizing is a very interesting process and one I can understand its workings.
I had to leave my engineering experience behind for once and bow to the experience of the meteor experts, some from way back.
What I came away with is a completely different view of what happens in the atmosphere.
Whether – or how much – it applies to steeper slopes I cannot yet absorb, in terms of ground impacts vs air bursts. There seems to be no reason the same processes occur, but with more rapidly rising air density, things happen faster. For me it leaves the question of how much energy is left at ground impact. MANY meteors found would appear to have not impacted the ground with sizable force. This is especially true f the melt fusion samples, which have fairly brittle crusts, yet they had not cast off the crusts upon landing. I haven’t yet had time to look into really large bolides.
To me it seems quite odd that while many impact people talk about low angle entries being rare, so many of the videos everywhere show low, almost grazing, objects. With the atmosphere being so small an annular ring (only ~100 km on a body around 13,000 km across) presented as a target for incomers, it amazes me at the high number that enter the annular ring instead of impacting directly.
Hi Steve –
Most of the experts on this will be presenting during a session at the next Asteroids, Comets, and Meteorites (ACM) annual meeting. Not only do I not know where it will be or hoe much it will cost to attend, I don’t know if anyone would actually be willing to share with you yourself where their data and estimates on explosive equivalent force came from.
I know you find this frustrating, but that is just the way it is.
Ed –
Thanks for that take on things.
They do have to inform each other, don’t they? And have it published somewhere?
In case you had not seen this:
That is from http://impact.arc.nasa.gov/news_archive.cfm?year=now
I am sure with Morrison in charge, a lot of “Move on! There is nothing to see here!” will occur.
Actually the article is at http://impact.arc.nasa.gov/news_detail.cfm?ID=186
I’ve been involve in the discussion at Tallbloke about a possible link between Chebarkul and 2012DA14.
I’ve not been able to get anyone else to comment here on my concerns, and it hasn’t happened much there, either.
My main point is that Chebarkul was so far north of the C.G. of the Earth that the C.G., being the mathematical gravitational attractor, could not have put an object from the Columbians’ orbit into THAT approach to Chebarkul.
On the other hand, it has turned out that the 2012DA14 orbit is a good candidate orbit. If not that exact orbit, then a closely parallel one. The great circle arc back from the Chebarkul object, through its radiant, passes over China, New Guinea and New Zealand – and SOUTH, right where 2012DA14 came from.
The Morrison web page above says this:
WRONG. Its final – after wrap-around – path was from thee east – but an east HIGH above the C.G of the Earth, which means that its approach BEFORE that was wrapped around FROM the south. The object could not have done an east>west path that started and finished at that latitude. It is physically impossible.
As to 2012DA14, it passed 28,000 km from Earth (only about two diameters), and to have another object only ~28,000 km from that one in a final path that can be easily fitted to 2012DA14 – well, folks, it is a bloody damned big solar system and 28,000 km is NOT likely by chance.
Is there anybody here who even GETS what I’ve been saying for 6 weeks?
>>Do you think the designers of Earth designed the atmosphere that way, too? . . . .LOL
No, I think armor designers are trying hard to replicate nature. 😉
More seriously, the only way that armor designers can get their computer simulations to match their flash x-ray radiography is to use computational fluid dynamics with two liquids of different densities.
And we know more about the surface of the Moon than we know about upper atmospheric weather, AKA density variation.
What a earth-type planetary atmosphere looks to a space rock at 15 klicks a second might be somewhat close to what a depleted uranium (DU) armor looks to a 1.7 klick a second velocity APFSDS DU penetrator, from a CFD representational point of view.
Hi:
My name is Peter and I enjoy reading your Cosmic Tusk blog. As a layman I got interested in this subject when I saw the
PBS Nova program Megabeasts’ Sudden Death. I searched for more info on it and found your blog. I have been reading it ever since. Anyways I wanted to alert you to the fact that PBS Nova has just aired a program called Meteor Strike that examines the recent Russian meteorite incident. It features Mr. Boslough. Inexplicably the Titantv.com listing for that episode listed it as NOVA “Hunting the Elements”. According to Titantv.com a repeat of “Hunting the Elements” is slated for friday march 29
at 12 am. I’m guessing that it will be repeat of the Meteor Strike episode rather than “Hunting the Elements”. I thought you might be interested since it relates to the discussion that has been happening here for the last little while.
Thanks/Peter
P.S. I wasn’t sure where to post this so I hope posting here is ok. I also apologize if this doesn’t format right when I post it.
And speaking of media reports on impacts, my wife pointed me to this Science Daily article on the Chicxulub impact in Mexico’s Yucatan Peninsula. The points about impact heat loading and “correcting the data for sedimentation rates” of charcoal deposits should be of extreme interest here —
http://www.sciencedaily.com/releases/2013/03/130327144249.htm
New Evidence Ancient Asteroid Caused Global Firestorm On Earth
Mar. 27, 2013 — A new look at conditions after a Manhattan-sized asteroid slammed into a region of Mexico in the dinosaur days indicates the event could have triggered a global firestorm that would have burned every twig, bush and tree on Earth and led to the extinction of 80 percent of all Earth’s species, says a new University of Colorado Boulder study.
and
The CU-led team developed an alternate explanation for the fact that there is little charcoal found at the Cretaceous-Paleogene, or K-Pg, boundary some 66 million years ago when the asteroid struck Earth and the cataclysmic fires are believed to have occurred. The CU researchers found that similar studies had corrected their data for changing sedimentation rates. When the charcoal data were corrected for the same changing sedimentation rates they show an excess of charcoal, not a deficiency, Robertson said.
“Our data show the conditions back then are consistent with widespread fires across the planet,” said Robertson, a research scientist at CIRES, which is a joint institute of CU-Boulder and the National Oceanic and Atmospheric Administration. “Those conditions resulted in 100 percent extinction rates for about 80 percent of all life on Earth.”
and
Geological evidence indicates the asteroid collided with Earth about 66 million years ago and carved the Chicxulub crater in Mexico’s Yucatan Peninsula that is more than 110 miles in diameter. In 2010, experts from 33 institutions worldwide issued a report that concluded the impact at Chicxulub triggered mass extinctions, including dinosaurs, at the K-Pg boundary.
The conditions leading to the global firestorm were set up by the vaporization of rock following the impact, which condensed into sand-grain-sized spheres as they rose above the atmosphere. As the ejected material re-entered Earth’s atmosphere, it dumped enough heat in the upper atmosphere to trigger an infrared “heat pulse” so hot it caused the sky to glow red for several hours, even though part of the radiation was blocked from Earth by the falling material, he said.
But there was enough infrared radiation from the upper atmosphere that reached Earth’s surface to create searing conditions that likely ignited tinder, including dead leaves and pine needles. If a person was on Earth back then, it would have been like sitting in a broiler oven for two or three hours, said Robertson.
The amount of energy created by the infrared radiation the day of the asteroid-Earth collision is mind-boggling, said Robertson. “It’s likely that the total amount of infrared heat was equal to a 1 megaton bomb exploding every four miles over the entire Earth.”
Whoops, see this for where the paper, as opposed to the science daily story, is —
“A paper on the subject was published online this week in the Journal of Geophysical Research-Biogeosciences, a publication of the American Geophysical Union.
Co-authors on the study include CIRES Interim Director William Lewis, CU Professor Brian Toon of the atmospheric and oceanic sciences department and the Laboratory for Atmospheric and Space Physics and Peter Sheehan of the Milwaukee Public Museum in Wisconsin.”
Does anyone here know the professional reputations of CU Professor Brian Toon and this Peter Sheehan of the Milwaukee Public Museum in Wisconsin?
And now Science Daily spit up their article for your space object impact education —
http://www.sciencedaily.com/releases/2013/03/130325185237.htm
Moon and Asteroids Share History, NASA Scientists Find
Mar. 25, 2013 — NASA and international researchers have discovered that Earth’s moon has more in common than previously thought with large asteroids roaming our solar system.
cientists from NASA’s Lunar Science Institute (NLSI) in Moffett Field, Calif., discovered that the same population of high-speed projectiles that impacted our lunar neighbor four billion years ago, also hit the giant asteroid Vesta and perhaps other large asteroids.
The research unveils an unexpected link between Vesta and the moon, and provides new means for studying the early bombardment history of terrestrial planets. The findings are published in the March issue of Nature Geoscience.
“It’s always intriguing when interdisciplinary research changes the way we understand the history of our solar system,” said Yvonne Pendleton, NLSI director. “Although the moon is located far from Vesta, which is in the main asteroid belt between the orbits of Mars and Jupiter, they seem to share some of the same bombardment history.”
The findings support the theory that the repositioning of gas giant planets like Jupiter and Saturn from their original orbits to their current location destabilized portions of the asteroid belt and triggered a solar system-wide bombardment of asteroids billions of years ago, called the lunar cataclysm.
Left unsaid in the article is that the same gas giant spawned asteroid belt bombardment hitting Luna and Vesta would also be hitting the Earth.
I wonder if there is the same paradigm blindness in the paper in the March 2013 issue March issue of Nature Geoscience this article was extracted from?
I would bet _YES!_ on that one.
Do these scientist know how to speak clearly? Or is it the journalist who doesn’t know an ambiguous statement when he/she hears it? – – –
“Those conditions resulted in 100 percent extinction rates for about 80 percent of all life on Earth.”
If this means 80% of all species died, they should say so. If it isn’t saying that, I am confused.
“It’s likely that the total amount of infrared heat was equal to a 1 megaton bomb exploding every four miles over the entire Earth.”
What the hell does THAT mean?! Every four miles vertically? E-W? N-S? E-W AND N-S? Every 4 SQUARE miles?
Talk about geeks that can’t communicate, WOW. If it is the journalist, the dude aught to get a job flipping burgers. He’s almost as bad at that as Bos is at air bursts (as opposed to ‘Marlboro Man’ posing).
Trent –
I’ve been to the Milwaukee Public Museum, but don’t know about those two guys.
The Museum is ‘pap for the masses’ stuff – aimed at 3rd and 4th graders – so who knows what level of work those two do.
I am MUCH put off by the fact that two papers at the same time can draw such diametrically opposite conclusions. It just points out the uncertainty of anything they know about 66 million years ago – which is, of course, the truth of the matter.
But it is an unusual ‘event’ that the two came out at the same time. If either of those papers had come out without the other one, the authors would be pontificating about how it all certainly meant this or that.
It DOES go to show that little is really known and that science about non-testable subject matter is 98% interpretation.
Them talking about SEDIMENTATION 66 million years ago struck me as extremely odd, too. As they solidified into (probably) limestone, the layers are ‘muddied up’ – mixed, mushed, and crushed, so sedimentation has to be really ambiguous in what can be read into it. It is bad enough with tree rings in the last 500-600 years. Extremely sparse evidence is bad enough, but muddled up evidence has to increase the uncertainty by a magnitude or more.
But 66 million with sedimentation? Interpret away, folks! But their conclusions are no more likely to be correct in the long term than me winning the lotto.
“[S]cientists from NASA’s Lunar Science Institute (NLSI) in Moffett Field, Calif., discovered that the same population of high-speed projectiles that impacted our lunar neighbor four billion years ago, also hit the giant asteroid Vesta and perhaps other large asteroids.”
You’ve GOT to be kidding.
Some agency actually paid (non-Monopoly) MONEY for this study?
I don’t even know how to express the ridiculousness of studying something that is so patently obvious. What did they think impacted the Moon? Bubbles from Mars?
That is like discovering that the same thing that covers dogs (fur) is the same thing cats have covering them, too.
“The findings support the theory that the repositioning of gas giant planets like Jupiter and Saturn from their original orbits to their current location destabilized portions of the asteroid belt and triggered a solar system-wide bombardment of asteroids billions of years ago, called the lunar cataclysm.”
Speculation piled on speculation.
And they have the nerve to say that the exploding planet hypothesis of the asteroid belt and meteors and comets is silly.
And I can’t pass up commenting on such statements as this:
“It’s always intriguing when interdisciplinary research changes the way we understand the history of our solar system,…”
WTF other possible explanation could they have fallen for before? Not ONE of them predicted this sort of evidence? Literally – did they think the Moon was hit by different stuff than the asteroids? If so, god help the field of astronomy.
“Paradigm blindness,” indeed, Trent.
Maybe they should try to attract students with 3-digit IQs in the future. Or stop kicking out the students who show some intelligence and independence.
Okay, I am in a bitchy mood today, guys.
That Science Daily article starts out,
“A new look at conditions after a Manhattan-sized asteroid slammed into a region of Mexico in the dinosaur days …”
What does “Manhattan-sized” mean? Egocentricity? Diameter equal to the length of Manhattan? The width? The mass? If mass, how much depth do they include? Does it include the buildings?
Or are they just pandering to the NYC market? (Naw, that couldn’t happen. No one has ever done that!)
/snarc
Sorry, but one more here:
IT’S A MODEL. It is not real. It is based on THEIR assumptions, which could throw the results off by magnitudes and magnitudes – and even give it the wrong sign. (Trust me – it has happened…)
There is no more evidence in a model than in a Bugs Bunny cartoon.
UNLESS…
Unless it is in a scientific area that has been well-verified by real-world experience and ALL equations – and limitations – are known. For example, a model of a building you can trust, because all the factors have been worked out long ago.
But scientific areas in which variables have to be guessed at – no one should even SLIGHTLY accept the results. Every guess has huge uncertainties in its input values – many times much larger than the guess itself. As to PROCESSES, Katy Bar The Door, because each researcher has his idea of what the processes were/are.
Seriously, un-aligned observers are only just now waking up to the fact that the dozens of climate models that the UN IPCC bases its forecasts on to the year 2100 – NONE of those models is worth a dime, in terms of how it replicates nature. I won’t go into the known fudges the modelers input, but some of them are single-value guesses representing very complex processes. In fact, the processes are so complex no one can model the individual processes, much less incorporate the processes into the bigger GCM models.
In other words, if you can’t verify a model’s outputs/results, in order to TEST the model, then don’t trust the model. It is, after all, just a program, one that can have wrong inputs, wrong formulae, and wrong coding.
They DO make pretty pictures, though. Mostly, anyway.
[Steve Garcia March 23, 2013 at 6:29 pm:]
Trent – I am SO doubtful about the 500kt number you can’t believe. If it DOES happen to be true, it was all released along its trail, from radiant point to final disintegration (that most people call its air burst), which, by itself had the immensely, gigundous, tremendous power to (WOW!) blow out windows and knock down a building that was likely going to collapse in the next two snow seasons. A 500kt nuke at that height would have offed thousands of Chelyabinskians.
True! But just imagine tilting that long vapor trail to a steeper angle, the exploding double tubular structure incoming at a 20 degree angle, and make it nearly vertical, the blow torch forward momentum flame thrower likely would have been in effect to wipe out a city, except it would have been Korkino or Roza across the pit mine.
[Am off-Tusk on rush projects for a while.]
I might be wrong, but it seems they gauged the 500kt solely on its mass and didn’t consider the low inclination and the energy losses.
I agree, Hermann, that a steeper slope would have been a different story. But its not like they predicted the 500kt before the fact. They all came up with that number after the fact.
If THAT puny bang was 500kt, what were we so worried about during the Cold War?
BTW, I haven’t been able to find out the infrasound data used to make determinations about its kt.
Anybody?
From Space Daily regarding the dinosaur extinction event 66M/65M ybp
“CU study provides new evidence ancient asteroid caused global firestorm on Earth”
http://www.spacedaily.com/reports/CU_study_provides_new_evidence_ancient_asteroid_caused_global_firestorm_on_Earth_999.html
Interesting quotes regarding ejecta morphology and heat transport. In the case of Carolina Bays, if a shallow angle impact did take place at the Saginaw trench, the sandstone launched during cratering of that trench is Michael Davias’ proposed source for the sand of the CBays. That shallow angle strike idea does give good causality for lots of terrestrial melt drops being formed (and purified) in “astronomic” volumes during such crater ejecta process, especially if you look at the layer of sandstone that is part of the missing strata of the Saginaw trench. What Mr. Davias is at a loss to explain so far is the particular shape of the bays and their remarkable uniform regional orientation across wide ranging temperate latitudes of vastly varying weather, which is a detractor of the wind/water formative process proposed by Geologists in the Uniformitarian camp of that science I.M.H.O.
But back to dinosaur extinction…
“The conditions leading to the global firestorm were set up by the vaporization of rock following the impact, which condensed into sand-grain-sized spheres as they rose above the atmosphere. As the ejected material re-entered Earth’s atmosphere, it dumped enough heat in the upper atmosphere to trigger an infrared “heat pulse” so hot it caused the sky to glow red for several hours, even though part of the radiation was blocked from Earth by the falling material, he said.”
“But there was enough infrared radiation from the upper atmosphere that reached Earth’s surface to create searing conditions that likely ignited tinder, including dead leaves and pine needles. If a person was on Earth back then, it would have been like sitting in a broiler oven for two or three hours, said Robertson.
The amount of energy created by the infrared radiation the day of the asteroid-Earth collision is mind-boggling, said Robertson. “It’s likely that the total amount of infrared heat was equal to a 1 megaton bomb exploding every four miles over the entire Earth.”
It really does sound eerily like fire and brimstone, as if Humanity really has witnessed such horror at some time(s) in the orally recorded past.
Also for a violent enough shallow angle strike to excavate the saginaw trench from under the mile or two mile thick Laurentide Ice Sheet would have required an impactor typically larger than that ice thickness dimension. Mr. Davias has isolated the likely epoch of formation of the CBays as between 100k and 200k years before present, so can not directly be the Younger Dryas Lower Boundary impact suspect. All of these impactor issues, however, are related for that very reason.
Steve G.
That 500 kTons was spread out over a large horizontal distance and, more importantly I believe, released at substantial altitude. Realize that the energy was delivered into extremely thin atmosphere where the impedance is relatively low to things like passing hypersonic objects, shock waves, spreading fireballs, and convection. Now this is a relative term but I’m talking about far less impedance than anything anywhere near the surface where the atmosphere is exponentially more dense and therefore higher impedance. So on a relative basis….
Low impedance.
The shock in the Chelyabinsk case apparently traveled for nearly 1.5 minutes before first detection on the ground near directly underneath (point of first ground contact by shock wave). This is a substantial time to allow for geometric dissipation of shock front intensity. This time delay alone, combined with the tenuous nature of the high altitude medium of delivery, mean that the folks of Chelyabinsk were exceptionally lucky that day.
Exceptionally lucky. High fry-ability of the component that fire-balled is also responsible for the high altitude cook-off, as is likely the shallow angle approach as well.
The infrasound detection technique uses long wave acoustic energy waves to estimate energy at the source assuming some known distance. Infrasound is just sonic instead of RF spectrum, very low low low in the sonic range. A sensor array at the detection station gives a direction, which they compare to other stations. Then the triangulated distance estimate is used to estimate the yield or energy released by the event. It does rely on mechanical models to use in the computation, but the models are well correlated to known events. Because as we know, if the model is garbage so are the results. Likewise even with a good model (well calibrated or correlated), garbage in will still give garbage out. My degree is basically in modeling of mechanical systems, so I’m very familiar with the garbage model concept. Pitfall of endless manpower and resource. Always beware the model. And as a practicing dynamicst on a developmental flight test program for the V-22 Tiltrotor, I was always one to trust measured values above all others, be those others calculated, implied, inferred by management or specification, or whatever their source. Measure and compare. 7th grade shop. 4th grade science.
The distance is estimated by triangulation from a number of detectors. In the Chelyabinsk case many stations detected the event, w/ the nearest detection station apparently Alaska, some 6k miles from the event. At this great range, the dispersion of various wave lengths within a wave packet from an impulsive event (weather is be a focused explosion or one released briefly over a distance as in our hypersonic Chelyabinsk case) will tend to make the energy values similar in either case. What is different is the actual shape of the wave (more properly the “wave train”), which probably explain the scatter in the actual triangulation estimations shown in some of the graphics presented after detection of that event. I have an idea of this because I’m a dynamicist by training and by profession, and I’ve studied these type systems both in school and in many different cases at work on both Spacecraft and Aircraft. (FYI S.G.)
And further, due to the low atmospheric pressure ~~ .0001 to .01 Atm along the luminous trail’s varying altitude of 300,000 feet down to 80,000 feet at the point of maximum energy output and radiative brightness, effects are almost as if it exploded in vacuum outside air ocean, half lost to space as EM radiation, much of it in the IR spectrum.
Most of the energy of 440 kilotons, according to Wikipedia (revised), was absorbed by the air, as seems plausible (more correctly, half lost to space).
And, at the distance of more than 15 miles, would not a 440 kiloton explosion at a height of 2500 feet (or so) have been survivable by people on the ground?
BTW, as I just verified on my calculator, the 440 kilotons or .44 Megaton TNT estimated energy equate to
.44 Mt = 1.8×10^9 kilojoules,
and this is the exact kinetic energy of the space rock, 11,000 tons moving at 18 km/s.
For the definition of Mt unit = 1 Megaton of TNT, see here:
http://www.unc.edu/~rowlett/units/
Not stated there, apparently the nuke physicists (sneaky guys) have defined
somewhat arbitrarily
1 Mt of TNT = 10^12 Cal,
where 1 Cal is the “large” or kilo calorie used by dieters.
In other units:
1 Mt of TNT = 1.00 x 10^12 Cal
= 4.18 x 10^12 kilojoules
= 1.16 x 10^9 kwh
= 3.97 10^12 Btu
[Better check these figures for yourself, as this is a sleepy mathematical philosopher.]
I’m guessing the CU folks used the proposed energy delivered by the bolide divided by the area of Earth and got that megaton per square mile number.
Infrasound detection of Chelyabinsk event, shows data in the form of strip chart traces
http://www.space.com/19860-russia-meteor-explosion-largest-detected.html
Oops Space dot com has more goodies on Chelyabinsk, published early after the event?
http://www.space.com/19829-russian-fireball-meteor-blast-infographic.html
TH –
Yes, I saw those strip chart traces. Amazing that anyone uses those anymore. 1940s technology updated to the 2010’s? Just for public consumption?
The 2nd link is a real pap for the masses PR department effort to put out some eye candy and look like they are on top of things.
They certainly do NOT have the final path aligned correctly.
I may not know all the technical things, but I DO want to know it, and you can see I am not afraid of asking questions that might show my lack of knowledge. But I also don’t want to be insulted.
When will any science institution realize that not everyone is a 4th grader? It would be awfully nice to see them produce something with some beef in it. You can almost see them patting us all on the head and saying, “Run along Sonny, nothing to see here.”
Three more levels would be nice – one for high school grads, one for general college folks/grads, and one for people in the sciences and engineering. Them talking down to EVERYONE and assuming no one can understand any of it above “See Moon; See Moon orbit” level is pathetic.
>“[S]cientists from NASA’s Lunar Science Institute (NLSI) in Moffett Field, Calif.,
>discovered that the same population of high-speed projectiles that impacted our
>lunar neighbor four billion years ago, also hit the giant asteroid Vesta and
>perhaps other large asteroids.”
>
>You’ve GOT to be kidding.
>
>Some agency actually paid (non-Monopoly) MONEY for this study?
>
>I don’t even know how to express the ridiculousness of studying something that is
>so patently obvious. What did they think impacted the Moon? Bubbles from Mars?
Steve,
Confirming the blindingly obvious with hard data is also part of the scientific method…plus it lets them get paid to eat regular and sleep indoors.
>What the hell does THAT mean?! Every four miles vertically? E-W? N-S? E-W AND N-S?
>Every 4 SQUARE miles?
>
>Talk about geeks that can’t communicate, WOW. If it is the journalist, the dude
>aught to get a job flipping burgers. He’s almost as bad at that as Bos is at air
>bursts (as opposed to ‘Marlboro Man’ posing).
This was likely the Science Daily editorial staff butchering the press release hand out.
My wife did technical writing in a former job and twits the S.D. writers work to me regularly.
Actually, the late lunar heavy bombardment has been an outstanding mystery and controversy for some time, and insight into this phenomenon was gained through the giant gas planet migration by looking at both extrasolar systems and the scattered disk of trans-Neptunians and Kuiper belt objects, in addition to simulations which are able to reproduce some aspects of the asteroid belt. By looking at the cratering and dark thin organic layer at the surface of Vesta, a large and relatively pristine object in the asteroid belt, some confirmation of the models were thus obtained. There were a lot of other competing hypotheses that didn’t pan out at the end of this.
>IT’S A MODEL. It is not real. It is based on THEIR assumptions, which could throw
>the results off by magnitudes and magnitudes – and even give it the wrong sign.
>(Trust me – it has happened…)
>
>There is no more evidence in a model than in a Bugs Bunny cartoon.
Why are you surprised by this.
Any successful scam — UN Climate change modeling for instance — breed’s imitators.
Thomas Harris said —
>Infrasound is just sonic instead of RF spectrum, very low low low in the sonic
>range. A sensor array at the detection station gives a direction, which they
>compare to other stations. Then the triangulated distance estimate is used to
>estimate the yield or energy released by the event. It does rely on mechanical
>models to use in the computation, but the models are well correlated to known
>events. Because as we know, if the model is garbage so are the results. Likewise
>even with a good model (well calibrated or correlated), garbage in will still give
>garbage out.
This gets us back to the point that atmospheric disturbance infrasound models of nuclear detonations are “well correlated to known events.”
The atmospheric disturbance(s) from a “High fry-ability object” breakibng up upon impact in on our atmopshere are not “well correlated to known events.”
You need 20 of anything to even begin a statistical analysis.
How many 100 KT plus energy release atmospheric impacts of extraterrestrial objects have these infrasound detectors measured?
Models and the computers that run them are ‘analytical tools’. You guys need to try and wrap your minds around the concept of ‘multiple lines of evidence’ and ’empirical observations’ and well as ‘mathematical theory’ and ‘unviable hypotheses’. You may now return to your wild speculations and conspiracy theories.
Speaking of conspiracy:
http://lablemminglounge.blogspot.com/2013/04/why-deflecting-asteroids-is-really-bad.html
Trent –
I had posted this:
“[S]cientists from NASA’s Lunar Science Institute (NLSI) in Moffett Field, Calif.,
>discovered that the same population of high-speed projectiles that impacted our
>lunar neighbor four billion years ago, also hit the giant asteroid Vesta and
>perhaps other large asteroids.”
Actually, the real deal with that is this:
If the both the asteroid belt and the Moon were pelted by that population of projectiles, then so was the Earth.
Duh.
Oh, excuse me, GOD protects the Earth. God and the Uniformitarians who say (…altogether now, class…) “It can’t happen here!”
TH –
Models are not viable “lines of evidence.” Models are not evidence. Models are not empirical. Models are guesses, guesses with pretty pictures. Models are not real.
I say all that in re research. Models for engineering are SOLID and are replicatable – and ARE.
Models for research are – in this area especially – figments of the imagination. And don’t say they are based on “the best information possible,” because the history of science is rife with the skeletons of “reasonable” guesses that empircally were proven wrong. Reasonable is not science. Reasonable is still guesses.
These are the best minds, so their reasonable guesses are more than just reasonable guesses? Watch Richard Feynman’s lecture on the scientific method on YouTube.
No. Until backed up by empirical evidence, models are only guesses. Guesses accompanied by cartoons.
Ask ANY climate modeler to reproduce the last 40 years, even the last 20 years. In fact, ask ALL of them to do so. If you ask 15 of them, you will get AT LEAST 15 different hindcasts – and NONE of them will agree with actual climate records.
All of those models are based on “reasonable” assumptions – and all of them fail Feynman’s test of “comparing to experience.”
So don’t be bringing models in here and claiming they are “lines of EVIDENCE.” They are lines of assumptions.
In fact, an argument can be made that models themsleves are “unviable hypotheses” and “speculations and conspiracy theories.”
Sorry if that steps on your modeler’s toes, but models can only reflect (at best) the assumptions that go into them. And HOW does that make them anything more than guesses?
I side with Robert Hooke, who insisted (but lost) the argument with Newton that only empirical evidence should be allowed in the Royal Society confabs. Models are not empirical, no matter how much you may think so.
On of the big problems with the global warming thing is that modelers have come to confuse their models with reality – and take an entire science and almost took the world’s policymakers with them, down a Yellow Brick Road of imaginary science.
Guesses are the first step toward scientific understanding. But without the REAL lines of evidence – experience and experiment – they are no better than what reasonable guesses come out of our heads. And in areas where experiments cannot be done, models need to be considered VERY carefully, because, like in global warming, they can lead people down imaginary alarmist blind alleys.
And considering that impact is ALSO an alarmist direction, we HERE need to be especially wary of what we can “prove” with models.
Look at Boslough, for example… Then compare to Chebarkul. Where was the downward blast? Somewhere he got his model wrong. Pretty cartoons, though.
Maybe we can consider models to be Beta versions of reality – mostly correct, but you never know when the results will be something not necessarily correct.
Again, I give you climate models. There are a LOT of people who actually believe models that can’t hindcast worth a damn or predict climate for the next year or five or ten are capable of telling us – within 0.1°C – what the climate will be in the year 2100.
One can forgive the people like policymakers who depend on scientists to advise them on such things. After all, what do they know?
But the scientists themselves – the climate modelers in particular – how can they look themselves in the mirror, knowing they are bullshi**ing the world?
TH – I DO believe that SOME DAY models of such complex things as impacts and climate will be understood enough that the models will give reliable results. You and I both know that in those areas that day is not today. Too many unknowns. To many assumptions. Too many uncertainties.
Chebarkul should increase our knowns. That is a good thing, and it should make our models better – but only if the knowns are really knowns. Again, I bring up the Columbians’ impossible Apollo asteroid orbit. If that is allowed to stand, models will have an error included in them. And nobody is even aware there is a problem.
I am still communicating with the two guys working over at Tallbloke’s page about that. They are getting closer and closer – using a model – to showing that there is SOME reason to think that DA14 and the Russian object were part of a shower of sorts. Using the models they have – which I take with a grain of sand – they show this – and it goes more or less 90° from what the Columbians show. But they at least tie the radiant point and heading to the orbit they propose. There is nothing in the available non-paywalled literature about the Columbian’s orbit that shows how the orbit and the radiant and heading are connected.
Are the two correct? Not yet. But I think there is enough known about orbits that a model is worth looking at. In THAT regard, this is a model based on much known material, basically at an engineering level.
And if two models disagree? Obviously one of them would be wrong. It is almost certainly the tow over at Tallbloke’s who are wrong. But so far their model can put the object on the right heading at the radiant. At the same time, I freely admit that it is HIGHLY likely that I am overlooking something, and that the Columbians are correct. But dammit if I can tell what it is.
hahah – the model in my head says the Columbians are wrong, and the other model (at Tallbloke’s) not only agrees with me, but it places the object exactly where I think it should be. Of all the places where their model could have said the object came from, it is remarkable that they put it there. So, am I agreeing with them just because their model agrees with me? Nope. But I think it opens up the possibility that I my brain model is right. And they are using a known, well-proven model as far as I know.
So, do I only agree with models when they agree with my conclusions? No. I agree with engineering models – which includes NASA orbital models, which have been proven out in the real world. The farther from the real engineering world a model is, I simply think the more we should be wary of its output. In those cases, they are reasonable guesses, but reasonable guesses have enough of a history of being wrong that we should use them with caution.
TH – You have never done a model that used assumptions that proved to be wrong? You never had to tweak your models, based on results not agreeing with experience or experiment? You always had it dead nuts? If so, I would posit that everything you worked on was at an engineering level.
I would like to ask a question. Approximately when was the mexico impact supposed to have happened? I’m new to this concept of impacts and it’s intrigueing.
Steve G said —
>If the both the asteroid belt and the Moon were pelted by that population of projectiles, then
>so was the Earth.
>
>Duh.
>
>Oh, excuse me, GOD protects the Earth. God and the Uniformitarians who say (…altogether now,
>class…) “It can’t happen here!”
It is more like God erases the evidence of craters — air and water don’t form long lived craters and they both keep the ones on land from lasting through geologic time — while delusion and tenure protects the Uniformitarians from reality…and lets them persecute those who say “The Emperor has no cloths” out of academia.
Jim Coyle:
Delighted to get you started — 65 million years ago, end-Cretacious.
And so was Mumbai-Seychelles, a much larger event, 500 km crater
off Mumbai. See under “Shiva” in Wikipedia. The Uniformitarians do
not want to hear about it, so they label it “controversial.”
Thanks, Herman. A bloger, Big Al, Mnetioned seeing bay type structure while on a flight from Minneapolis to Denver. He thought they were over western Nebraska. These bays were aligned SE- NW not the alignment for a Saginaw impact bay. I first thought possibbly it might be from a Yellowstone volcanic blast but I don’t think vulcanism would produce that sort of impressions. The age you give is most likely too old for that to be the causation. So back to the drawing board. Have to keep looking Seatle to the Gulf coast. SDomeone must have lost an asteroid somewhere in that area. Jim
Jim Coyle,
maybe you meant more recent event, 12.9 K BP at Lake Cuitzeo in central Mexico (20N,101W), YDR impact related. Details in article by Israde-Alcántara et al:
http://www.pnas.org/cgi/doi/10.1073/pnas.1110614109
Also, ashfall dated to 10 M BP, in NE Nebraska killed rhinos, “Ashfall Fossil Beds,” Wikipedia. Caused by explosion of Yellowstone hotspot in SW Idaho at Bruneau-Yarbidge caldera. The hotspot from 16 M BP impact, Modoc Plateau, NE California, “Chalk Mountain,” see 40.994,-121.809 on Google terrain map for central uplift. Also origin of Columbia River Basalt Plateau, LIP, Large Igneous Province. But pro geologists do not recognize impact volcanism, responsible for the numerous LIPs. For this, need impact through thin oceanic crust penetrate into mantle. Modoc Plateau was coastal.
“BTW, I haven’t been able to find out the infrasound data used to make determinations about its kt.”
“Anybody?…”
No s**t, Sherlock.
BTW, the number is 540 KT, at ca. 22 kilometers altitude. More precise numbers will be publihsed in the future.
Next, a quick comment about all the BS here about uniformatarianism versus catastrophism. That is not the problem. It is impact hazard estimates, and specifically those regarding cometary impact.
Finally, a note about climate models and responding to any AGW hazard. If you look at the per capita CO2 numbers, if China and India industrialize the same way the US has and put out the same per capita CO2, we’re baked.
But there are places to discuss those models adn workable responses. That being the case, the Tusk should not duplicate them, IMO.
Hi TH
“How does one expect a complete plasma spawned by an irregularly shaped and disintegrating meteor to retain a directional momentum into a denser gas or solid over tens of kilometers, when minus those intense magnetic and gravitational forces, it can expand elsewhere?”
Yeah.
B.’s model also ignores what is known about the Tunguska meteoroid and its entry path.
For that matter, B. is trying to with away the Chelyabinsk point explosion.
While his interest in this field is laudable, it is clear to me that B. is trying to play way out of his league.
In asm uch as typing away on the internet daily whould not be confused with meningful work, I hope you will forgive me, but I have some things that needed to be done yesterday.
Mr Burchard; I did some checking into the Lake Cuitzeo impact and it just might be the cause for the Bay structures in Western Nebraaska. I wasn’t able to locate any info on the entry trajectory of the object. If the entry was from a generally E-W or vice versa the butterfly ejecta pattern would fit and the time frame seems right. Thanks for your time in answering my ?s Jim C
See–
Glenn Reynold’s latest on asteroid defense and the lack of same from NASA.
http://www.usatoday.com/story/opinion/2013/04/08/killer-asteroids-nasa-column/2061419/
E.P. Grondine and Steve Garcia are going to have some real fun with this Science Daily article and the “SCEIENCE” article it is trying to quote —
http://www.sciencedaily.com/releases/2013/04/130425144654.htm
NASA Probe Observes Meteors Colliding With Saturn’s Rings
Apr. 25, 2013 — NASA’s Cassini spacecraft has provided the first direct evidence of small meteoroids breaking into streams of rubble and crashing into Saturn’s rings
These observations make Saturn’s rings the only location besides Earth, the moon and Jupiter where scientists and amateur astronomers have been able to observe impacts as they occur. Studying the impact rate of meteoroids from outside the Saturnian system helps scientists understand how different planet systems in our solar system formed.
The solar system is full of small, speeding objects. These objects frequently pummel planetary bodies. The meteoroids at Saturn are estimated to range from about one-half inch to several yards (1 centimeter to several meters) in size. It took scientists years to distinguish tracks left by nine meteoroids in 2005, 2009 and 2012.
Details of the observations appear in a paper in the Thursday, April 25 edition of Science.
Results from Cassini have already shown Saturn’s rings act as very effective detectors of many kinds of surrounding phenomena, including the interior structure of the planet and the orbits of its moons. For example, a subtle but extensive corrugation that ripples 12,000 miles (19,000 kilometers) across the innermost rings tells of a very large meteoroid impact in 1983.
“These new results imply the current-day impact rates for small particles at Saturn are about the same as those at Earth — two very different neighborhoods in our solar system — and this is exciting to see,” said Linda Spilker, Cassini project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “It took Saturn’s rings acting like a giant meteoroid detector — 100 times the surface area of the Earth — and Cassini’s long-term tour of the Saturn system to address this question.”
>Snip 1/2 of the article<
Journal Reference:
Matthew S. Tiscareno, Colin J. Mitchell, Carl D. Murray, Daiana Di Nino, Matthew M. Hedman, Jürgen Schmidt, Joseph A. Burns, Jeffrey N. Cuzzi, Carolyn C. Porco, Kevin Beurle, and Michael W. Evans. Observations of Ejecta Clouds Produced by Impacts onto Saturn’s Rings. Science, 2013; 340 (6131): 460-464 DOI: 10.1126/science.1233524
That Saturn has the same impact rates as Earth, despite the orbital and mass differences, will be good grounds for a lot of impact rate threat re-evaluation.
What is needed is a grand accretion model for our solar system, and that will require a whole lot more data and analysis.
I intend to confine my efforts to what I can now do, small aspects of Earth’s recent impact history, and leave this big issue for others to work on.