Kerr Watch

Number of days writer Richard Kerr has failed to inform his Science readers of the confirmation of nanodiamonds at the YDB: 3 years, 8 months, and 26 days

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The Cosmic Tusk Newsletter

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Now Showing: Tusk TV

It occurred to me that there was no dedicated link on the Tusk to my (poorly produced) videos concerning the YDB hypothesis (mostly from conferences), and other YouTube content regarding our subject, such as full length TV shows, academic lectures, and nutty and not so nutty videos from the public.

So, for your viewing enjoyment, I am providing a permanent link to the YouTube playlist: “Tusk TV” over to your right.

UPDATE: Wow. I just came across the entire NOVA episode Last Extinction on YouTube. It has suffered a dead link for more than a year on the PBS website (hmmm). But here it is now – getting thousands of hits.

I have also figured out the playlist features and was able to make this video the permanent lead of the channel. Sweet. What a rich, wonderful television program this is. Enjoy:

36 comments to Now Showing: Tusk TV

  • chicken little

    Anyone see anything wrong with someone looking for proof of cosmic events with Fires storms in the white ice between the dark ice. dang now ! first Greenland was Green and part of the Mediterranean or there would not have been any Elephants on it or washed off of it into what is now coast off of what is now called Norway and the Netherlands and such .. when this event happened there was elephants living there , Elephants do not live on ICE that is science Fiction and myths created by Disneyland and the militant religion of
    “science”tism .. this crap you all call science is just more militant anti- theist FANTASY! I sure am sorry because know I am dashing all of your Hopium!

    you all need to lay off whatever it is you been smoking, because seems you all are getting just way to much of it if you believe this stuff you call science because your faith is just Hopium // Proof of Hopium that you are going to find radioactive space ashes in the white ice between the dark ICE … just ignorant Hopium stuff…. smokin Hopium that you can peddle this crap science to mankind and Hopium that they are buying this junk as a ‘truth’ !
    The militant Anti-theist” SCIENCE” is smokin Hopium and has told us lies for ages now.. hopium is written in our childrens books as truth and desperate militant hopium pumps that garbage to our children .. and that Hopium has not had the balls to tell us what happened in recorded eye witnessed history of just about 2000 years ago , nor abt 2800 can they tell us because they didn’t tell what happened 2000 years ago , nor abt 3200 because they didn’t tell us what happened just 2800 and 2000 years ago , and( as they rape Noahs site as we speak) of abt 4300 years ago because they didn’t have the balls to answer or even ask the the questions much less answer what happened 2000,2800,3200 years ago !! so they have not earned the right to tell me or mine what happened yesterday much less what happened 6000 years ago !

  • C. Little,
    Interesting post but a bit discontinuous. What is your hopium inspiration? Seems like it may be fouling your key lard a bit.
    TH

  • Nah!

    It ain’t inspiration Tom. She’s just gone off her meds again.

  • Turns out even small volcanos can loft aersols into the stratusphere, not previously though possible. Looking at the vertical loft angle of ice from the NASA gun range video (Tusk TV)makes me think that the stratusphere could have been lousy with suspended ice after an ice sheet impact…

    http://www.spacedaily.com/reports/Satellite_research_reveals_smaller_volcanoes_could_cool_climate_999.html

  • Hi folks

    Yes, it is true, it has long been known that volcanoes can reduce the temperature of the planet. Now imagine billions of cometary fragments exploding over the planet that can cause on global temperature. It is not common, but it happened. Perhaps with a millennial frequency. This can be a problem. Insist only on the ice sheet impact is pure naivete. The craters are everywhere, but there is no awareness of this fact.

    regards
    pierson

  • I think you’re right Pierson. And I agree there are many small craters associated with the YD events; so many that much of the impact community are totally incredulous, and will propose all sorts of off the wall scenarios for their formation rather than acknowledge that maybe, just maybe, they might be exactly what they appear to be.

    I guess the idea of a cluster impact event with hundreds, or thousands of small fragments hitting this world of ours within minutes, or seconds of each other is too extreme for some folks to confront. But so far my own humble catalogue of craters numbers about 700 in the Southwest that average about 100 meters wide, and which are visually a perfect match for craters of the same size on mars, complete with raised rims, and proximal ejecta curtains. But I also think it’s naive to assume the planetary scarring of the impact storms of the Pleistocene/Holocene transition consists only of craters.

    A lot of the places I’m studying do not consist of craters. Instead they have more in common with the Libyan Desert Glass, or the impact glass at the Dakhleh Oasis in Egypt. Neither of those events produced a crater. And like them, I’m finding a lot of ablative melt with no evidence of shock metamorphism.

  • Regarding impacts and the various characters they play in this YDB feature…

    It would seem that Earth was pelted w/ all sizes of impactors over the relatively recent past (as in YDLB), many making it close enough to the ground to fireball into the surface, much of the smaller stuff not making it that far down at all but still delivering PLENTY of heat over a large surface in a VERY SHORT TIME (plenty of fires from irradiative transfer when the sky suddenly heats to several thousand degrees over several thousands, or tens, or hundreds of thousands of square miles, all within moments), and a few chunks even hitting the surface in various places, such as ice sheet.

    An ice sheet impact by siliceous (SP?) bolide is a pretty good model for the formative process of the Carolina Bays imprint, now initially dated to that point in history (via OSL, Bunch et. al., 2012), laid down in one event over many vastly different aged geological formations, and never completely explained by contemporary (Uniformitarian) Geology. In fact the CB imprint is Uniformly Problematic. Very clean sand. Pure Quartz. No terrigenous detritus. Monolithically uniform grain size. Covering 7% of the continental U.S. (approx.) Hundreds of cubic kilometers of sand. Looks strangely like it was formed in a vacuum if you know what I mean. As in re-entry of the ejecta plume. Just as real as hellfire scarred South West. Just as deadly.

    You make the call.

    Anyway, looks like plenty of GeoSpace to go around for everyone, from high altitude air burst, to low altitude air burst, to impact. You can take your pick in this carnival. Plenty of Ablative Air Burst scarring. Plenty of black mat. Plenty of nano diamonds and other ET impact markers (not in every site, but plenty of stuff on multiple continents), and plenty of Uniformly Problematic sand.

    Regarding Tusk TV:

    In Part 3/3 Catastrophe, Planetary Geologist and Professor Peter Schultz fires a 3mm BB at about 5 km/sec and a 30 degree approach angle above horizontal into a fine sand target surface. (I believe that gun only goes in increments of 15 or 30 degrees, and the approach angle flash looks like 30) The first shot is into naked sand and forms a nice crater, w/ good close up slomo at 7 min 05 sec. Crater looks to be 5” or so inches in diameter and between 1 and 1.5 inches deep, dimensions rough guessed based on Dr. Schultz’s hand in the image w/ the crater at 7 min 25 sec.

    In this first shot, more ejecta is seen going down range than up range in the 7:05 close up.

    http://www.youtube.com/watch?v=tv3jxaZVjFM

    The second shot is w/ the same target and a sheet of ice laid atop the sand. At 7 min 58 sec there is an edge-on shot of the ice during target prep for shot two. Looks like around 1/2” to 3/4” thick, again just an estimate. This is 4 to 6 times the diameter of the BB projectile. The piece of ice, maybe 1 by 2 feet at the most, is blown into pieces by shot #2, shown after impact at 8 min 44 sec, with a smaller crater visible amidst the broken ice.

    There is good close up slow motion of shot #2 at 9 min 28 seconds.

    The ice shot has some pronounced difference in ejecta patterns vs. the shot into naked sand, including:

    A steam plume launching immediately after impact, before the ice fragments gain upward momentum, and;

    When the ice fragments do come up after the steam plume, they come up from the impact zone at a much steeper angle than the sand did with no ice, in fact very nearly vertical, and;

    The ice seems to gain much more velocity away from the impact site than the sand did, as seen when their flight is measured against the scale of target disc (sand bowl), and;

    The ice fragments start out as vapor, then smaller bits then medium sized bits, all following the well understood mechanism of the hottest (initial) push giving the greatest degree of pulverization, then finally large chunks toward the end of the process, some easily 10s of times bigger than the impactor, and;

    Toward the end of the ejection process, when the biggest chunks are taking flight, it looks like more mass moves down range than any other direction. Up to this point however, the ice all goes generally up, nearly vertically, for the whole process, and;

    Even some of the larger chunks fly way out of the close up frame at the end of the ejection process, and;

    Finally, the crater seems smaller, although still visible, and Dr. Schultz dismisses it as much smaller.

    I want one of those nifty test rigs. I wonder if one could be built to make miniature hyper velocity fireballs for ablative scarring scale tests…

    TH

  • Hi folks

    Well Dennis, you know, I was very “traditional” in my research, investigating only those structures more “obvious”. But certainly the meteoritc phenomenon has proved much more complex than previously imagined. I hope that academic arrogance gets rid of the past and move forward in the search. From what I’ve seen this attitude is not unique to academia in Brazil. I keep paying my research with my own resources or with the help of those few who understand me. Without arrogance and only provocative, bite by bite we will devour them all. I’m still excited. We are doing our part!

    regards
    pierson

  • Hey Tom,

    I don’t know about a hyper velocity rig that can achieve 4 or 5 km per sec. Like the HVGR at Ames can. But supersonic, and subsonic impacts are easy enough to model with a high powered rifle. You’d be amazed at the crater you can get from a match grade 50 caliber rifle that’s mounted on a high scaffold, and aimed at the ground.

    And small scale hyperthermal airbursts can be simulated with a plasma torch like the ones that are used in steel fabrication shops, and that’s rigged to a very high pressure pulse system. I know it’s possible to blow a 3 inch hole in 5 inch thick steel armor plate that way. But whether or not the results are scalable, and applicable to normal terrestrial materials, and atmospheric conditions is a question for the big kids to answer.

  • By the way, if you look closer at that ice sheet impact simulation you’ll realize it is a valid model of a hypervelocity airburst. Because the hypervelocity pellet vaporizes the instant it hits the atmosphere of the impact chamber, and well before it gets to the target. So that what you see hit the ice in the slow mo video clip is pure incandescent, hypersonic vapor. It is no longer a solid object at the time of impact.

    Scaled up to a half kilometer wide bolide, the depth of the Earth’s atmosphere is roughly equivalent to the distance from the muzzle of the gun, to the target surface in that video clip.

  • There was another period of multiple large impacts within a relatively short period of time (a few million years) in the mid to late Eocene (38 – 35 MY ago). It also saw substantial global cooling and a small extinction event. The paper linked below mentions a theoretical comet shower at the time.

    Unlike the YD, this is not yet thought to be a comet storm as it has several substantial crater structures associated. Cheers -

    http://www.somosbacteriasyvirus.com/cooling.pdf

  • I’m not sure how much ice was around back then, I’m guessing little or none. Plus they are really big impacts with a well defined proxy spike and well known strewn fields. Yet if something not quite that big hit on the ice there, then evidence would have been flushed down the drain, as it were, but still should have left an impact proxy record that should be reproducible by all concerned.

    If not, that’s a problem, too. A psychology problem, perhaps. I hope this gets some kind of quasi-definitive resolution soon. I’m tired of the wild goose.

  • Dennis,

    You and I need to get together and shoot stuff. 50 caliber sounds like fun, especially if I don’t have to hold it…
    I would like to try a target of ice over (thinner) water over rock, as well as just rock and just (thick) ice for comparison, at 5 or 10 degree increments from 30 degrees down to 5 degrees, not necessarily every target at every angle.
    I agree that ablation is going on in the Ames gun range, but how much is the question. Because of the extreme luminosity of the approach and the contrast within the scene, there is no way to tell from the video if it is more than just a fireball (fireBB) that makes contact. The steam plume that erupts nearly vertically seems to come up far faster than any of the particulate ejecta.

    Also, I wonder what selection of bullet mass may be available for .50 cal as another variable to play around with.

    TimH

  • My approach to this problem recently is trying to explain the patterning of the Canadian shield in this area, since I have come to the conclusion that flooding or outflow is required to initiate the Younger Dryas. I’ve spoken to Carlson about this, and the general consensus is that the shield is tremendously resistant to glacial ice sheet movement, by observation of the deep soft Lake Superior basin. There are glacial moraines in the area which are superficial and hardly noticeable, but the only thing that can explain the linear grooving and other strange anomalies is catastrophic runnoff perhaps directed by ice sheet geometry, which is distinct from the glacial moraines entirely and much more dramatic. So the only way I can explain these features is by catastrophic runoff or discharge (outburst flooding) around a static ice sheet geometry. If that geometry happens to be linear at any given time (over the last two million years or so) then the resulting features are linear, and if that geometry is circular, the flood would only enhance that. The legacy features are then propagated from one glacial advance to the next.

  • to TLE
    “the conclusion that flooding or outflow is required to initiate the Younger Dryas” and possibly multiple flooding/outflow events spread out over time to account for 1400 yrs of the Younger Dryas. This has been making me wonder about multiple impact or ‘impact storm’ events, not necessarily all on the ice sheet of course since that is less likely, but the multiple event model is good for adding heat to create multiple flood/outflow events. plenty of heat can be delivered by ejecta, not even requiring secondary impacts but delivering substantial energy through IR transfer from the reentry heating over large areas in short times.

    Also, if the ice sheet, much weaker than the rock it sits on, gets hit by one impact and absorbs most of that energy (not allowing much cratering or surface scarring beneath the ice), the sheet itself would likely shatter and displace significantly, perhaps even monolithically at distances farther from the impact where there is less fracturing but still plenty of unidirectional push. The entire southern edge of the ice sheet for an east-west distance of hundreds of miles could have moved all at once to the south. This is not likely for a static sheet of ice as it would crush under the compressive load required to move it against the friction of its own weight – but- imagine the scenario where lots vertical energy is dumped into the mix and there are (vertical) ground waves in both the ice and the rock underneath, along with possible hydrothermal blast jets lifting large portions of the ice sheet, then its easy to imagine lots of ice moving horizontally with lots of energy, which then causes its own signatures of motion and friction underneath.

    Lastly, a regionally fractured ice sheet would melt much faster due to orders of magnitude more exposed surface area, perhaps in a few hundred years instead of several thousand years otherwise required for warming climate trend to melt an unbroken ice sheet.

    Thomas “Tim” Harris

  • Tim, I load my own ammo. Also, I’ve got a fair to middlin’ milling machine, and lathe. So the only limits on what I can make a bullet out of, or how hot the round is loaded, are related to the structural integrity of the bullet, and whether it can withstand the breech shock when the round is fired.

    A very long barrel would allow one to achieve much higher muzzle velocities with lower breech shock. But when you start talking about a long enough custom barrel to really make a difference, the cost goes through the roof because the tech to make such a barrel is something you’ll only find in a world class machine shop, or gun smith. And their work does not come cheap.

    I often find myself daydreaming of something like a 20 foot long, 7mm refrigerated barrel that can fire pellets of ice at hypervelocity speeds. But except for ice pellets, in their more than 50 years of operation almost every other kind of projectile has already been fired at the HVGR at Ames.

    When the choice is whether to spring for the cost of a few pay-walled papers, or the cost of a long barreled hypervelocity gun, why re-invent the wheel?

  • Dennis,

    Beautiful. I wonder about a segmented barrel with threaded attachments to lengthen on demand. The (one) problem is the ablation through atmosphere at higher muzzle velocities, so if not firing through a partial vacuum, there is diminishing return to achieving higher V muzzle to begin with. I love the idea of machining bullets of density to order, and pwoder load to order! Needs to be non-abrasive, whatever is used. Ice projectile is an attractive option but problematic to keep it in-tact through manufacture, load and fire sequence.

    I guess the low budget approach would be to use an existing gun/barrel, w/ projectile density and grain load tailored to achieve desired velocity. I’m guessing the limit would totally be survivability of the projectile within the barrel as you say. I wonder if a soapstone projectile could be used for relatively low density and relatively low barrel abrasion, as such material is easy to come by and easy to cut.

    One question is where such experiments could be carried out. A range w/ access to a large freezer would be ideal, or a sub-freezing range so we could cast our own ice outside and maintain ice bullets once made. Also required is some way to position the gun repeatably at known angles like the Ames gun, only in smaller increments and down to a more shallow angle.

    It would be very helpful to characterize the hydrothermal blast immediately upon projectile contact of target, but would require excessively high frame rate photography w/ extremely bright lighting. The idea is to catch the expansion shock of steam and determine how it varies w/ prodectile approach angle if possible, how it gets under the ice if at all, and how the initial shock propogates through the ice. Such cameras, and lighting can also be rented, all at a cost.

    There is also a technology of pressure sensitive film that records max pressure over an area, and could be placed under the ice to determine the pressure delivered from the ice layer to a solid layer underneath. This wouldn’t work for a water layer between the ice and the solid surface below however.

    For scaling factor(s) (dynamic similitude) we could get the Aims or other NASA guys to fill us in on their assumptions and go from there. I have a background in this from my Mechanics BS and can speak that language.

    TH

  • Pete Schultz and Ted Bunch have both done extensive work at the HVGR. And they have both published many many related papers.

    Since my own focus is on the identifying the planetary scarring of large ablative airbursts, I’m more interested in working up a apparatus that can duplicate the patterns of wind flow at the bottom of a large airburst vortex such as those in the supercomputer simulations Mark Boslough has done at Sandia labs, than of modeling the hypervelocity impacts and/or airbursts themselves.

    Duplicating only the surface interface of such a vortex, i.e. downwards, and outwards at the periphery, and inwards, and upwards, at the center, is a different mechanical problem from trying to duplicate a scale model of the entire airburst impact sequence; or of trying to model ballistic kinetic impact events.

    For working out the expected patterns of wind flow, and movements of the blast-effected surface materials, and the resulting planetary scarring once the dust settles, only the movements of the fluidized flows at the surface and up to about 200 meters above it need to be modeled.

    Instead of a hypervelocity gun, what’s needed is something that can move an awful lot of high velocity, hyperthermal air hot enough to melt silicate rock, in downwards directed flow patterns with an updraft at the center for periods of up to 20 seconds.

    Imagine a hyperthermal, high velocity, torch hot enough melt rock like butter under a blowtorch, and with a vacuum straw extending down through the middle of the fire to simulate the updraft in the middle of the impact plume.

  • What if…
    How about something like this acetylene/air cannon but in a more vertical orientation:

    http://www.youtube.com/watch?v=IyAyd4WnvhU

    and then instead of that long expansion nozzle, we used something to ‘focus’ the output into a more concentrated jet. I’m envisioning a longer combustion chamber and no diffuser, so what comes out is hotter and faster. Basically a supersonic impulse torch.

    Momentary flame thrower w/ attitude.

    I wouldn’t even worry about the updraft in the first pass of the design – just aim the gun vertically downward and let convection take care of the details, same as the natural case.

    Then select a target material that will ablate at something below the ‘muzzle’ temperature of the vortex cannon, and vary the muzzle-to-target distance for effect. Basically, all we’re looking for out of the muzzle is hot, supersonic and momentary. I’m guessing the vortex will happen automatically and so will the convective updraft after contact, same as the larger scale case. The system could then be tuned to for similitude to larger scale systems.

    The trick would be to record the result at some useful resolution of time and space for comparison of whatever variables. That fancy laser velocimetry system that they use in some cratering research would be extremely helpful for characterizing the ablative effluent in terms of velocity, direction, particle size, etc.

    The target surface could be saw dust, frozen water droplets (man made snow or hail), liquid water, or something more difficult to melt/vaporize like sand, pea gravel, metal chips or BBs, etc.

    I definitely want to see that footage!

    TH

  • PS

    It could also be that a projectile that completely ablates from the velocity of the shot could be used at the proper range to yield fireball only (no projectile remaining) at the target surface, so perhpas no special gun just special projectile for our friend Mr. .50 cal.

    Either way some high speed footage would reveal the shape of the basic shock wave which could be compared to the Boslough solutions to address scalability or lack thereof. The target surface scarring could also be compared to proposed full scale impact sites for a first guess at similitude if any exists.

    TH

  • maybe a cold (deeply frozen) wax bullet w/ a heavy load behind it. The wax would heat up and ablate relatively quickly, leaving little but heat, momentum, shock and a little wax vapor in the mix. Then just determine the range necessary for useful fireball impact. Dennis, can you chill your machining center to cut frozen stuff while it stays frozen?

    The Polly Doodle pix is really very funny!

    TH

    TH

  • OR,
    what about just loading Mr. .50 cal w/ plenty-o-powder and no projectile, just a paper cover on the cartridge, perhaps a few small chips of titanium or some tracer component for streamline visualization

    and plenty of high speed photography

    TH

  • Speaking or titanium fragments; some of the nastier military rounds for the .50 are frangible bullets made from titanium fragments. They’re designed for punching holes in masonry walls. So you get a half inch dia. entry hole, and on the back side of the wall you get an expanding cone of supersonic sparks of molten titanium. Behind an 18 inch thick stone wall ain’t a good place to hide from one of these things.

    Even shooting blanks, you still wouldn’t get the flow patterns at of an ablative airburst. So the result would give no clue what the planetary scarring from a five mile wide ablative airburst vortex should be expected to look like. For experimental purposes, the problem is one of sustaining the flow patterns of a toroidal vortex at the surface for 10 to 20 seconds. (Full scale, the rotation speeds are supersonic) So the .50 cal LRSR will never be able to simulate airburst phenomena. But it should be noted though that some of the ejecta and tektites from a very large ablative event would be accelerated to the kind of velocities a .50 cal can achieve. So if you were close enough to see one, and even if the IR pulse didn’t get you, you’d be toast.

    Bottom line: The .50 cal is a really cool, ultra macho gun that’s useful for high energy supersonic impact experiments. But it’s useless for studying, or predicting, the planetary scarring of ablative airburst phenomena.

  • Steve Garcia

    Dennis -

    I worked with ablative materials in R&D years ago. That doesn’t mean I am any kind of expert, but can ask halfway intelligent questions. With your ablative events, I have always understood the melting to come from radiant heat of the passing – and possible overhead explosions of the air burst. Not the flow, but just the melting. I see it as a two-stage process – 1.) melting, and 2.) explosive shock wave. The radiant heat arrives first, because it travels essentially at the speed of light. But radiance itself is not necessarily enough to cause flow of the type at your sites. And a blast wave/shock wave would be more likely to shatter, if the rock was not melted or semi-melted. I don’t see either one being capable of doing the flow, not by itself.

    Also, the heat transfer via air is impossible in the time scheme you are talking about. Air is not a good heat transfer medium. By the time the air stopped flowing/pushing downward and outward, very little heat would have transferred into the rock, and only to a very shallow depth.

  • Steve Garcia

    One could work backward from a best estimate of the depth of the melt on the peaks and slopes, determining how much total radiant energy (per square meter) and energy density would have been required. I am thinking the wavelengths would have to be at least in the microwave region to penetrate to any depth – especially in the few second(s) before the shock wave arrived. I am not a physicist, so I can’t do the calculations myself.

    But based on the resultant flow depth and area, the size of the air burst should be calculable within a fairly close range.

  • Dennis,

    Very respectfully I would suggest – don’t bet it would be useless till you try it. Cheap to try, and you never know…
    Vorticity in fluid can happen wherever there are potential fields (gravity, pressure, temp etc.) oriented perpendicular to one and other. I would lay odds that you will get that perpendicular potential situation to some extent, somewhere in the mix with some kind of combo of .50 cal load.

    True it may not be useful at all, but to give up before trying could be giving up a chance to use science funding (all be it possibly minimal) to shoot Mr. .50 cal into a sandbox in the name of science. A great tradegty!

    That being said, you may have done something like this already so I’ll shut up already!

    Other low cost ideas in this type of experimentation include spreading flash paper or a fine dusting of gunpowder over a target surface to determine what portion of that surface is exposed to flash point temperature during whatever experiment such as a fireball above that surface, etc. or using low melt wax in chip, pellet or solid form to determine the extent of thermal deposition to target surface.

    Blah blah blah

    TH

  • Example

    Fire a blank load vertically downward at a very smooth sheet of low melt wax, with a witness fence at some distance around the wax target.

    After the shot, examine the target and witness fense with a magnifying glass or microscope to determine direction of ablative scoring an deposition patterns on those surfaces. On a very small scale you may find that score marks near target center face inward. If not, try again with different load or at different range depending on the degree of target destruction.

    A fat load of slow burning powder may help make the process more easy to visualize (the fun part!).

    This could be repeated for oblique approach angles.

    TH

  • Also,

    I agree in principal w/ Steve G about needing both IR as well as conductive heat transfer, but think about the elongated shape of some of the Northern Mexico scars.

    The elongated shape seems to be due either to (a) oblique impact or (b) by the surface-attached fire column being shoved sideways by other adjacent bursts. The first case actually seems unlikely since some scars in the same cluster are nearly round (much less elongated), implying that the group of bolides came in parallel and are not likely to change direction significantly at the last moment (although we know convection can turn them upward if they do approach obliquely). But we assume an essentially coincident event so parallel approach trajectories.

    So for the latter case, an attached fire column being shoved sideways by adjacent burst, causing horizontal translation during the attached ablative phase, this implied that temperature effects are dominant in the scarring process since the shock effect is largely at the leading edge of the fireball.

    This actually makes sense if the central ridges are raised by deep thermal heating of the subsurface to lift them, vs. shock rebound which would only be dominant at the beginning of the strike. Dr. Boslough implied strong thermal coupling with the surface, so there you go.

    If the fire column acts as a thermal lasing cavity into higher wavelengths for its period of existence, it would deliver heat and expand the solid volume beneath, but any water in the subsurface would flash to steam and really push hard on all material around it, a process unconstrained vertically at the surface boundary, causing very rapid elevation of that surface.

    Just some more thoughts.

    TH

  • Steve,

    1.)Have you ever actually studied the Boslough’s simulations in detail?

    2.)Have you ever used a cutting torch?

  • Steve Garcia

    Dennis -

    I am well aware of oxyacetylene cutting ‘torch’/flame. It is actually – like my scenario – a two-step process. The flame is used to melt, and then the high-velocity blast of oxygen blows the still molten slag out of the gap that has been cut.

    So you actually make my argument for me.

    Boslough has not covered enough possible scenarios, at least not as is available online that I’ve seen. All I’ve ever seen online is one basically vertical model scenario. Using the word ‘studied’ is an ambiguous phrasing. I have not looked into it to the degree you do, nor with the exact POV you carry into it. There are other POVs.

    I look at it primarily as a question of what happened in the first few seconds in the Michigan/Great Lakes area to loft apparently water/ice/quartz ejecta toward the CBs, both to the east and west. I want to know what order of events transpired and what the ice did when heated to plasma. Did it act like volcanic gases do, but on a much more sudden and increased scale? Boslough doesn’t even begin to address such questions. As far as I know he doesn’t look at the substrate as anything non-homogeneous. My mental efforts are mostly in the CB direction, trying to glean new info that reflects on what might have happened in the Great Lakes and then the CBs. As time has gone by these last few years and months it seems the CBs and YDB are drawing closer together in time, much like the Solutreans and Clovis have.

  • Heck Steve,

    In the first place, no one has even made the case yet that the LIS was hit at all beyond imaginative speculation, and suspicion. So demanding that a physicist do the work to provide numerical models of what happens when an ice sheet gets hit is a bit premature. But the impact physicist who’s done the most work on the physics of ice sheet impacts is Pete Schultz, at Brown U. not Mark Boslough. And instead of using a supercomputer to do numerical models, he did a few hundred hypervelocity shots at the HVGR at NASA Ames Research Center; a couple of which can be viewed online.

    Most of what Pete’s done on the subject remains unpublished at this time. But he’s a pretty decent sort who appreciates interest in his work, and doesn’t mind answering intelligent questions when asked. You might want to try getting in contact with him.

    You’re welcome to your very own point of view. But it would help if you were to actually express it in a lucid, and coherent way. Perhaps you could even be so kind as to cite some literature, or physics, to support it. But since by your own admission you haven’t studied any of the literature, or physics, described in any of those sims, and have only seen one of them, in fact, you fail to even state an argument; much less have one "made" for you.

    The important thing to keep in mind when considering a cutting torch for comparison is that the hot gasses are barely hot enough to melt steel. And the velocity of the stream that ablates the melted steel out of the cut is only a little bit more than a stiff breeze. So comparing it to the hyper thermal temps, and supersonic winds of a miles wide  airburst vortex is like comparing a mouse breaking wind to a hurricane. But if that all it take to ablate steel, then it’s fair to assume that supersonic winds hotter than the surface of the sun are going to leave a mark by moving a hell of a lot of material.

    You are welcome to imagine for yourself what the results might be once the dust settles.

    The are a couple of videos of Pet’s work right herew on the Tusk. And for a little more of the Sims from Sandia labs, one could begin with the PBS video titled Modeling a Comet Airburst There are a few more of them on Sandia’s Website that show different angles.

    Most of the literature that’s applicable to those sims is freely published without restrictions.  I’ll be happy to provide links to the ones I have on request. And for the math-heads out there who’re into the really wonky math behind them, Mark’s not stingy with the actual numbers, and math they were based on. All you need do is contact him, and ask.

  • Steve Garcia

    Dennis -

    You are the one who brought up oxyacetylene torches – which is what a ‘burning torch’ is. I was just telling you that it was ALSO a two-stage process, since you brought it up as some kind of argument against my radiance-heating-then-blow-off ablation concept. I wasn’t trying to equate the temps or velocities, just the principle.

    Your statement that, “The velocity of the stream that ablates the melted steel out of the cut,” is incorrect. The blow-off is not ablation. See the definition below.

    You posit a supersonic super-hot wind, and I would argue that the heat transfer is inadequate, since the heat has to penetrate by brownian motion convection in a solid. 99.999999% of the heat energy never would penetrate the solid, but would be simply carried forward with the wind. There is no way that heat transfer could happen in the minuscule time allotted. Example: A convection oven is much faster than a conventional oven at heating food, but it is nowhere near as fast as a microwave oven at penetrating deep into the matter. The supersonic wind of your model would certainly transfer some heat into the cerros, but the wind would have come and gone before the rock had begun to melt more than a handful of millimeters deep. The supersonic blast wave lasts how many seconds? One? Two? Ten? Not enough for the heat to penetrate enough for the flows to occur. The wind would be gone before the rock had melted. IF it melted. Scorched? Yeah, and that is what ablation is about, really – scorch and then erode/impact the fractured material away.

    ABLATION science definition (from Yourdictionary.com)

    The wearing away or destruction of the outer or forward surface of an object, such as a meteorite or a spacecraft, as it moves very rapidly through the atmosphere. The friction of the air striking the object heats and often melts or burns its outer layers. Spacecraft and missiles are often equipped with heat shields designed to wear away by ablation in order to prevent heat from building up in structurally important parts.

    Ablation is a process that is basically like peeling away, layer by layer. In spacecraft that carries the heat energy away and is why it is used in space, since the vacuum of space doesn’t allow the convecting of heat away. It happens in spacecraft because of the frictional heat, but even then it is a relatively slow process that takes scores of seconds, even minutes, to peel away an inch or two. As such, though it is appears to be what you see in your sites, it is not the right perception or assignation of the term. The flow – and I agree that what you see is flow – cannot be done by ablation. The supersonic wind is too short-lived to move solid rock or to melt the rock as the wind goes by so that the rest of the wind can push it downslope.

    In short, it is not ablation.

    The heat penetrates deeply into the rocks. Ablation is essentially a surface process, and only goes deeper after the surface layer has been removed. Thus it is a progressive process. In an air blast there is no time for any progression to occur.

    …I’ve seen Pete Schultz’s video several times. I don’t see it as expository about what kind of mixing goes on between the impactor, the ice, and the substrate. His velocities are also considerably too low (by a factor of 5 or so, if I recall the numbers) to really teach us anything. Unless his impacts are creating plasmas, they are like a pop gun versus your 50-calibre bullets, even low mass 50-cal ones. He is on the right track, but he doesn’t have the equipment.

    From the Boslough models it is obvious that on an ice sheet the temps are going to dissociate water beyond steam. Once that happens the process is similar to a volcanogenic pulverization of the rock, but at magnitudes higher temps and magnitudes more abrupt.

    Also, an air burst is not enough to melt the rock, not if it is of the size of Tunguska, which is our only real-world model. Tunguska basically set trees on fire, and blew them down, but that is a far cry short of melting rock and pushing it downlsope. At the same time, I DO agree with you that a bigger one WOULD likely be adequate. Boslough’s work points in that direction, for sure. At the same time, no one is sure how friable a comet fragment has to be to air burst before impacting. What size will air burst but also be big enough for the burst to melt the surface rock?

    And one more thing: This argues against it being an air burst… An airpburst would not melt hilltops and not the surrounding ground surface. The radiation (or blast, if you prefer) would carry the few tens of meters further down. We should SEE melting there, too. But we don’t. How do you explain this?

    It may not withstand all arguments, but it seems to be more like an incandescent coma and trail that has its lower boundary literally pass lower than the summits of the melted hills. The burning/melting is direct and/or close radiation. I don’t have that worked out yet, but the air burst model won’t work on your SW ‘ablated’ hill sites. One thing is that if the tail passes low on the hill, the duration of heating is much longer. But then we have to assign the flow to gravitational forces. I am not sure that would work out. But an air burst can’t tell all its explosive materials and its radiation to only go so low and no lower.

    …If you have Peter Schultz’s email address, I’d love to run these things by him.

  • Steve said:

    “Ablation is a process that is basically like peeling away, layer by layer. In spacecraft that carries the heat energy away and is why it is used in space, since the vacuum of space doesn’t allow the convecting of heat away. It happens in spacecraft because of the frictional heat, but even then it is a relatively slow process that takes scores of seconds, even minutes, to peel away an inch or two. As such, though it is appears to be what you see in your sites, it is not the right perception or assignation of the term. The flow – and I agree that what you see is flow – cannot be done by ablation. The supersonic wind is too short-lived to move solid rock or to melt the rock as the wind goes by so that the rest of the wind can push it downslope.

    In short, it is not ablation.”

    Too short lived? Supersonic winds in contact with the surface for upwards of 20 seconds per airburst doesn’t sound like “short lived” to me. And we are talking about a cluster of them.

    “The heat penetrates deeply into the rocks. Ablation is essentially a surface process, and only goes deeper after the surface layer has been removed. Thus it is a progressive process. In an air blast there is no time for any progression to occur.”

    Says who? And who says rocks would be the only blast-effected materials? What about loose soils that don’t even need to get melted to move?

    “…I’ve seen Pete Schultz’s video several times. I don’t see it as expository about what kind of mixing goes on between the impactor, the ice, and the substrate. His velocities are also considerably too low (by a factor of 5 or so, if I recall the numbers) to really teach us anything.

    Unless his impacts are creating plasmas, they are like a pop gun versus your 50-calibre bullets, even low mass 50-cal ones. He is on the right track, but he doesn’t have the equipment.”

    Beyond your own assumptive reasoning, what science can you cite that shows an impact must create ionized plasmas in the surface materials? In fact even in the most energetic of impact events ionized plasmas only exist at high altitude. And at that, only in the super heated atmosphere the bolide is passing through.

    An impact event the size of the one that created Barringer Crater would not even produce ionized plasmas in either the bolide, or the surface materials. No ionized plasma, just incandescent vapor.

    “From the Boslough models it is obvious that on an ice sheet the temps are going to dissociate water beyond steam. Once that happens the process is similar to a volcanogenic pulverization of the rock, but at magnitudes higher temps and magnitudes more abrupt.”

    Incandescent oxygen, and hydrogen, do not fit the definition of a plasma.

    “Also, an air burst is not enough to melt the rock, not if it is of the size of Tunguska, which is our only real-world model. Tunguska basically set trees on fire, and blew them down, but that is a far cry short of melting rock and pushing it downlsope. At the same time, I DO agree with you that a bigger one WOULD likely be adequate. Boslough’s work points in that direction, for sure. At the same time, no one is sure how friable a comet fragment has to be to air burst before impacting. What size will air burst but also be big enough for the burst to melt the surface rock?”

    That threshold is dependent upon object density, and velocity. But the vertical simulation you’ve seen is based on a 120 meter stony object. And it most certainly is hot enough to melt rock.

    “And one more thing: This argues against it being an air burst… An airburst would not melt hilltops and not the surrounding ground surface.”

    Says who? Where are the hilltops melted without effecting the surrounding surface? And who says the surrounding surface wasn’t effected?

    “The radiation (or blast, if you prefer) would carry the few tens of meters further down. We should SEE melting there, too. But we don’t. How do you explain this?”

    Where?

    Who says we don’t? But without a specific location or article in my blog to refer, and answer to, you’re making a straw-man argument. In fact, since you invalidate all of the experimental work that has been done based on nothing more than your own unsupported assumptive reasoning, and without citing a single specific location, or valid reference to support those assumptions, this whole thing is an elaborate straw man argument.

    “It may not withstand all arguments, but it seems to be more like an incandescent coma and trail that has its lower boundary literally pass lower than the summits of the melted hills.”

    Beyond your own fertile imagination, perhaps you would be so kind as to cite some real experiments or science that describes such an “incandescent coma and trail”

    “The burning/melting is direct and/or close radiation. I don’t have that worked out yet,”

    Since you fail to provide any kind of lucid, coherent, description, or cite any real experimental science or literature to support that description, it’s pretty clear you haven’t really got anything “worked out” at all.

    “but the air burst model won’t work on your SW ‘ablated’ hill sites.”

    Oh yes it does.

    One thing is that if the tail passes low on the hill, the duration of heating is much longer.

    What tail?

    But then we have to assign the flow to gravitational forces.

    What flow? Location please.

    “I am not sure that would work out. But an air burst can’t tell all its explosive materials and its radiation to only go so low and no lower.”

    What are you talking about? Who ever said it did? And where?

  • Steve Garcia

    Dennis -

    Odd, you didn’t even address the ‘ablation being wrong’ point, which I thought you’d fight tooth and nail.

    “Supersonic winds in contact with the surface for upwards of 20 seconds per airburst “

    Where do you get the 20 seconds from? That is a really LONG blast wave. Is the air entrained?

    “And who says rocks would be the only blast-effected materials? What about loose soils that don’t even need to get melted to move?”

    ANY impact is going to move loose surface soils. That is not an issue. It is the rocks melting – and then flowing – that is the tough part.

    “Beyond your own assumptive reasoning, what science can you cite that shows an impact must create ionized plasmas in the surface materials?”

    You keep harping at me about citing papers, but you rarely do it yourself, Dennis.

    At no point did I say an impact MUST create ionizing plasmas. Perhaps ‘plasma’ is the wrong word, though. Maybe I should talk about the disassociated oxygen and hydrogen.

    “Incandescent oxygen, and hydrogen, do not fit the definition of a plasma.”

    After my sheit experience with Wiki a few months ago I don’t often use it anymore (and don’t miss it much), but let’s see what it has to say in its intro to plasmas [emphasis added]:

    In physics and chemistry, plasma is a state of matter similar to gas in which a certain portion of the particles are ionized. Heating a gas may ionize its molecules or atoms (reduce or increase the number of electrons in them), thus turning it into a plasma, which contains charged particles: positive ions and negative electrons or ions.[1] Ionization can be induced by other means, such as strong electromagnetic field applied with a laser or microwave generator, and is accompanied by the dissociation of molecular bonds, if present.[2]

    This refutes your claim about ‘incandescent’ oxygen and hydrogen. Incandescant is your word, not mine, anyway. Michael Davias is the one who told me that water beyond steam is a plasma, and I take him at his word. It sounds right. If you’ve got more on it, cite it.

    It also refutes your claim that water heated to the point of disassociation is not a plasma.

    “That threshold is dependent upon object density, and velocity.”

    You left out angle of incidence, which is a big deal; the longer the impactor is in the atmosphere, the more heat buildup and the more likely it will explode. Incoming velocity is usually assumed to be a fairly consistent figure at about 30 km/sec (19 mps) – the speed of most objects in the solar system. From what I recall of reading on this, it is the density which matters, and that is tied directly to friability. Looser agglomerations break up more readily, and they are also the least dense. My point was exactly in line with your rebuttal: The more dense incomers are going to break up lower in the atmosphere (in general), and at some point they actually impact. Napier had numbers on this, based on reasonable assumptions.

    “But the vertical simulation you’ve seen is based on a 120 meter stony object. And it most certainly is hot enough to melt rock.” A

    120m stony object will impact the ground or at a low enough angle to NOT impact will almost certainly not air burst. I cannot imagine one that big – about 150% the length of San Francisco Bay – at a low enough angle to not impact, would explode in the atmosphere. By and large comets are not taken to be ‘stony objects.’ If some are, I haven’t heard about it. I am talking about air bursts, and ones that are not coming straight down.

    I found this brief discussion by meteor chasers specifically about the threshold between air bursts and ground impactors: http://www7.pair.com/arthur/meteor/archive/archive4/Feb98/temp/msg00155.html :

    > That being said I want to toss out a figure I read recently.
    > Stone rocks from space less that 200 meters (about 600 feet) will always
    > cause an air burst and never impact the ground.

    I’m a bit surprised by this statement. Although there could be several reasons
    why meteoroids progressively fragment in the atmosphere (fissures, inclusions,
    shape, gas bubbles, etc.) it is difficult to fully model the fragmentation
    process. Other factors must be taken into account, such as entry velocity and
    angle, but I would have thought that some meteoroids of less than 200m across
    would survive.

    First off, note that the initial statement is about stone rocks. Whether the threshold is 200m or 150m or 300m, your 120m is on the low end and would almost certainly air burst. But, for comparison, most of the fragments of SL/9 would not have – IF they were stony, which they were almost certainly not. A 120m NON-stony, low-angle, low-density object airbursting is another story, and that is what I am talking about. If it bursts the downward radiation and blast would hit flat ground as well as hill summits. Where is the evidence that the flat ground melted, too? If it melted (vitrified) that should be fairly obvious.

    “Who says we don’t? But without a specific location or article in my blog to refer, and answer to, you’re making a straw-man argument.”

    Dennis, they are YOUR sites. It is not a straw man at all. You should be knowledgeable about what is there – and from other than GE images. I am still unclear whether you’ve been on the ground there. You shouldn’t be pointing me at your articles and making me prove what is in them or what is on the ground or not; you should know what is onsite yourself. The onus is on you, not me. IS the ground melted? If so, it means one thing. If not, it means something else. I am saying I don’t think the flat ground is melted. If you’ve been there tell us yes or no.

    In your defense, even a high-altitude GE image of the WIDE area gives the impression of something having made that area unsuitable for most flora. Something odd is there. It begs looking into, and maybe I am wrong about the melting not being also on the flat ground. I am going from what I’ve seen in your GE images that appears to show the summits having been somewhat fluidized and then having flowed downhill – past the bottom of the hill, no less, which suggests to me that the viscosity was relatively low. What info do you have about this flat area being melted or not? I am asking you – you are the expert.

    “In fact, since you invalidate all of the experimental work that has been done based on nothing more than your own unsupported assumptive reasoning”

    I am not invalidating anything, and specifically “all of the experimental work that has been done”. First of all, your own hypothesis on these has never had ANY experimental work done on these sites. And I am merely asking how it can be that ONLY the summits were melted. If you know, say so and put it to rest. If you don’t, don’t go talking about experiments on your sites and your hypothesis, because you haven’t done any experiments.

    “Beyond your own fertile imagination, perhaps you would be so kind as to cite some real experiments or science that describes such an ‘incandescent coma and trail’”

    Re a tail, see following. Re coma, see any video of a meteor going across the sky.

    “What tail?”

    Even meteors have tails on entering the atmosphere. Even double tails sometimes: http://www.meteorobs.org/bagnall/tail.htm

    Do comets also have tails within the atmosphere? Tunguska was reported to have been seen with a tail. Do I have the primary source material? No. But I’ve been reading on it since the very early 1970s, and, no, I don’t keep a footnote in my head of everything I’ve read on it over 40+ years.

    “What flow? Location please.”

    In your ‘ablated’ hills hypothesis you show GE images of hilltops that you argue show flow downhill. You may call it blast-pushed, but I call it flow. ALL flow is either from higher pressure to lower pressure, or it is from gravity – higher potential to lower. No flow can EVER happen without one of those, not that I know of. So either it is gravitational flow (which I don’t think it is) or it is from a pressure wave/blast. But if it moved downhill, it was a flow. Now, the Scottish vitrified forts (which I have repeatedly pointed out to you with no feedback whatsoever) don’t seem to show the flow as much, but have the same bald look AND were melted by heat in the thousands of degrees C. The latter is a given in every account I’ve ever read – it had to be a heat high enough to melt rocks. Sound familiar? Though there is slumping (which is flow, too), it seems to be much less than on your hills.

    I am only posing this coma-and-tail as a possible explanation, Dennis. Impactors DO have tails. And the tails are incandescent, meaning they not only radiate EM energy but also contain heat energy. I am positing a hypothetical tailed object at a VERY low angle but that penetrates deep into the atmosphere, low enough to skim hill summits. It seems to fit the evidence – but only if I am correct about the flat ground not being melted. I am not certain of what transpired – but it is evident that it was NOT radiant heating of the summits, nor an air burst. Either would have melted the flat ground essentially as much as the hill summits. My premise is built on that assessment of what I see in your images from GE.

    And yes, the assessment came out of my head. New hypotheses DO come out of people’s heads. it is common to then run those ideas past others, which is what I am doing here. Pick it apart. Prove me wrong. I don’t mind you being tough on me, but ad hoc accusations of straw men and pulling stuff out of my butt doesn’t move anything forward.

    Note this: I see nothing in any point you made that shoots down the idea in the slightest. If you can, go ahead. All you’ve done is tell me I am thinking instead of running high-energy high-velocity experiments on multi-million-dollar equipment and supercomputers. Duh. I am living off Social Security, so I have the feeling that those are not going to be within my budget. The one falsifying piece of evidence would be if the ground is melted. Is it or isn’t it? If it is melted, then I am wrong. And if I am shoot me.

  • Yes Steve,

    The ground at the central uplifts of the cryptoexplosion structures I am studying shows significant evidence of surface melting, radial outwards flowing aprons of non-volcanogenic pyroclastic breccias etc. As well as a host of shock metamorphic features such as shattercones. Many of them have all the geomorphology you would expect to see in an impact structure. But without any trace of a crater rim.

    As for shooting you, since you are clearly suffering from a case of the Dunning Kruger effect, and have nowheres near the comprehension of impact physics, or the actuall physics of airburst phenomena you are convinced you do, I am more apt to simply ignor you, and continue trusting the mentorship and friendship of real scientists.

    But you know what? You can keep your self assumed expertise. Pick it apart?Nah, since you are incapble of producing a lucid, and coherent explanation of your hypothesis, or backing it up with real supportive science, while invalidating my own work based on nothing more that your own subjective opinions, and without citing a single specific location to compare to a geologic map, or something I’ve actually about that place, I won’t be wasting my time.

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