CharlesChandler wrote: I was thinking that any water would have boiled off in the flare. I don't actually think that the "clouds" were water, but I'm still not sure that the meteorite fragments tell the whole story. Are the fragments typically pitted, like volcanic pumice, revealing the absence of stuff that boiled off? If not, then the ice would have to have been separate from the chondritic matter. I "think" that recent evidence from comets (e.g., Tempel 1) shows a lot less ice than previously expected. Does this apply to asteroids and meteoroids too? (As you can see, there's a lot that I don't know.)
Yes, the hydroxyl signatures that probes register at comets are not "water", hence, the snowy icy comet idea is bunk and has been for a long time. But the establishment perpetuates the icy comet myth as if it's a foregone conclusion.
justcurious
Re: Feb 15 Meteorite(s) hit Russia - Analysis
Regarding the loud bang/shock, I believe it is caused by the same phenomena as thunder, simply the magnetic field releasing after electric discharge, and therefore releasing its pinch on the inionized air. This is a direct cause and effect and seems the most plausible to me. We can be sure that fireballs trails are plasma, amateur ham radio enthusiasts bounce their waves off fireball/meteor trails all the time. Since the tail has lots of thick smoke, we can assume ablamation and matter being pulled off the meteor as well.
Regarding the buildup of charge, it appears that the meteor started lighting up after crossing from the ionosphere into the lower denser layers of the atmosphere. The triboelectric (static electricity) charging effect makes sense since we know now that the meteor was mostly non-conducting or semi-conducting matter, only a small percentage was iron, so charges would stick to it (as when we rub a balloon in our hair). In my view there was some sort of energy buildup and release mechanism. I believe only electric energy can release such a mighty flash of light. We may call it a flare up rather than a flash, but if you look at other footage of fireballs, notably from satellites, it's clear that there are flashes, like the flashes in everyday cameras. The disposable cameras use a simple capacitor to build up charge, likewise an inductor can also build up charge in a magnetic field. If the meteor was full of semiconductor material similiar to what we use in electronics, I could see how the flash could be created. The flash is still a bit of a mystery to me.
Charles's theory of bow shocks and fluid dynamics does not make much sense to me. It's mixing apples and oranges. Boundary layers in fluid dynamics separate fluid/air of different velocities. If the air is moving around, how would it maintain a bow shock of identicaly charged air? Not a spherical meteor, but an irregularly shaped one that is tumbling. Not only that, but there are just too many assumptions and speculations in his theory, rolling meteor creating dynamo effect, electrons creeping in from the sides, its just over the top complex. Triboelectric is not crude, it's simple, this is good. If the answer is highly complex, it's probably the wrong answer. We know from plasma 101 that double layers form between plasmas of different properties/types, but between plasma and ordinary air? Not so sure about that. And there is nothing to indicate or suggest that an electric bow shock is created in the first place. But we do know of a thing called Debye sheath which is a layer between plasma and a solid due to, you guessed it, friction. The rail gun was an interesting addition to the discussion. What I found most interesting was that fire was created from a purely electrical phenomena.
viscount aero
Re: Feb 15 Meteorite(s) hit Russia - Analysis
I have some counterpoints as I did some brief looking around about the Earth's atmospheric profile at 12 miles altitude.
CharlesChandler wrote:
dahlenaz wrote: The flash point does not seem to be as high as stated above,,, clouds don't form at 12-15 miles up and the time between the flash and the first concussion seems to support a low level fragmentation maybe you meant 12-15,000 feet.
No, I meant 12~15 miles. The latest estimate of the altitude of the bolide when it broke up was 27 km, based on the locations of observers, and the apparent angle of the bolide from the horizon for each observer. This is consistent with other measurements. The meteorite fragments were found about 40 km from Chelyabinsk. The hypotenuse of that 27/40 triangle is 48.25 km, giving the line-of-sight distance. With the speed of sound at the relevant altitudes being roughly 300 m/s, the sonic boom would have arrived 2.68 minutes after the point of nearest approach. I read somewhere that it was 2 minutes 50 seconds, which is 2.83 minutes. So I think that the estimates are reasonably accurate. Now, 27 km above the surface is well into the stratosphere, where there is little-to-no water vapor. So I'm still of the opinion that the "clouds" were made of smoke from arc discharges onto the surface of the bolide.
I'm going to have to disagree with the premise that there is a lack of sufficient moisture at 12-15 miles altitude. That region is the upper troposphere of the Earth which holds most of the moisture in the entire atmosphere, particularly if the meteor's fiery train appeared within 12 miles altitude (which is highly likely). Most of the weather occurs at this region. Water plays a vital role in Earth's weather--which directly involves electrical phenomena. The vapor trail was probably mostly water, with some smoke, too. Both can exist at the same time
dahlenaz wrote: Upon fragmentation the dynamics change violently but the twin trails seem to indicate that forward momentum was not altered greatly by the blast. [...] The cloud which is spread along the fragmentation region takes on a life of its own, which may misrepresent the behavior of the fragments. A lot was happening in those few seconds of fragmentation and continued well after the fragments departed. This raises the requirements for the explanation of this event beyond that of a solid body at extreme altitude.
...
dahlenaz wrote: Indeed, that's why I'm not really thinking that the bolide "exploded" per se--rather, it could have simply broken up. The flares were from charge recombination and molecular reformation, entirely within the nitrogen and oxygen in the stratosphere. The charge separation caused by a bolide can persist for tens of minutes in the atmosphere, so a flare that persisted for a second or two is not surprising. And clearly, the flare wasn't moving. So this was the stationary air recombining.
Yes it broke apart as it hit the air at such extreme velocity and it also exploded. In my opinion, there was a massive aerial explosion. It destroyed man-made dwellings for miles. There was billowing fire visible, an incendiary explosion. It was akin to a bomb blast.
viscount aero wrote: NASA themselves uses that reference to describe meteor entry and charge separation.
CharlesChandler wrote: I know. Meteorologists say that thunderstorm electrification is triboelectricity, from hail falling through the air! But that just ain't right... Anyway, I agree with your main point that friction causes ionization.
I agree with most of what you say, namely about the charge separation profile of the bow shock, with the meteor becoming the + body and the - electrons stripping away, etc... but static electricity isn't across-the-board an incorrect premise. It's exactly as you seem to describe: charge separation due to friction. Your premise includes friction and can only exist with friction.
dahlenaz wrote: If the meteor cloud was as high as proposed then there must have been extra moisture provided by the meteor itself upon breakup, where else would it come from?
Consider that that region is the troposphere, the region with most of the aerial moisture. This is the region where large anvil-head cloud structures take form. This is a volatile region.
CharlesChandler wrote: The meteorite fragments have been classified as chondrites, which typically contain silicon, aluminum, iron, nickel, etc. But maybe the meteoroids are actually just dirty snowballs, and the chondrite material is the dirt, and where nothing is left of the snowball except (in some cases) a cloud. I dunno... Spectral analysis on the cloud would have told the whole story, if anybody had bothered doing it, instead of running around fixing broken windows in the middle of the winter.
From earlier, comets/asteroids/meteors are not icy, snowy, dirty icy balls. They're rocks. In my layperson's summation, by just looking at the footage, there was an aerial explosion. Something ignited or detonated in multiple and quick bursts. It sent a shock wave, a concussion, for miles and destroyed buildings. There were giant billows of fire in the sky. That's an explosion. The railgun experiment is, for me, more of a paralleling model than any other explanation thus far. This doesn't exclude charge separation and/or electrical phenomena but directly involves and includes it. The railgun experiment takes place because of charge separation, not without it. In my opinion there need not be a "pure" EU explanation that excludes all other phenomena that did possibly take place
viscount aero
Re: Feb 15 Meteorite(s) hit Russia - Analysis
justcurious wrote: Triboelectric is not crude, it's simple, this is good. If the answer is highly complex, it's probably the wrong answer.
Occam would agree
viscount aero
Re: Feb 15 Meteorite(s) hit Russia - Analysis
In my opinion, the level of the vapor/smoke train more than likely appeared at the boundary layer of the upper troposphere, the tropopause. This could be between 4 to 12 miles high depending on location:
justcurious wrote: Boundary layers in fluid dynamics separate fluid/air of different velocities. If the air is moving around, how would it maintain a bow shock of identically charged air?
The charge is constantly being refreshed by the incoming atoms. This phenomenon only occurs at high mach numbers, because the hydrostatic pressure plus the Coulomb force (oops, I did it again! ) would disperse the matter.
justcurious wrote: Not a spherical meteor, but an irregularly shaped one that is tumbling.
How did you determine that it was not spherical? Objects tumbling are quickly rounded down because the friction acts on the high points more quickly.
justcurious wrote: Not only that, but there are just too many assumptions and speculations in his theory, rolling meteor creating dynamo effect, electrons creeping in from the sides, its just over the top complex. Triboelectric is not crude, it's simple, this is good. If the answer is highly complex, it's probably the wrong answer.
The 3 metrics for a construct under consideration are scope, accuracy, and simplicity (not necessarily in that order). Sometimes we might sacrifice accuracy to get simplicity. But that doesn't make it the "correct" answer — that just makes it the economical one. Yet sometimes it's a false economy.
My attitude is that we already have quick-n-dirty answers, courtesy of the mainstream. Yet they've been at it for a while now, and you'll find in the history of science that whenever people cling to a paradigm for the convenience of it, as new information comes in, they tend to bastardize the existing framework, rather than considering any new ideas. After a while, the quick-n-dirty construct that was built and maintained purely for convenience is no longer so convenient. In fact, the mainstream constructs are abstract, and extremely complex. Every so often, people have to make new investigations, to find out what's really going on.
For example, the Ptolemaic model of the solar system started out simple enough. But as telescopes got better, they found that they had to make some fine adjustments. This continued until the math was staggering. By the time Copernicus came along, they had done all that they could do, and they still couldn't get the formulas to return exact solutions. Whatever they did to fix one problem just made something else worse. To Copernicus, this meant that there was a fundamental flaw. So he re-conceived the whole thing, and now we have a much more accurate model. The math was arguably more complex, because it required translating Earth-based observations into a heliocentric coordinate system. But this was necessary in order to make the next step.
So was the Ptolemaic system actually the "correct" answer, because it didn't require coordinate transforms, and ultimately calculus, to accurately predict the motions of celestial bodies? Now you're really comparing apples to oranges. The hacks that it would have taken to assimilate modern data into the Ptolemaic system would have made it far, far more complicated.
So as a rule, I go for accuracy. Those bothersome anomalies that aren't worth additional complexity right now actually represent fundamental flaws in the existing frameworks. In the end, the most accurate model doesn't need hacks and abstractions to keep pace with new data.
justcurious wrote: There is nothing to indicate or suggest that an electric bow shock is created in the first place.
All of the tests with supersonic blunt objects (such as spheres) produces detached bow shocks.
Since fluid dynamics has no explanation for this, it can only be evidence of electromagnetism. And since the Chelyabinsk meteoroid was hypersonic, it would have produced a detached bow shock.
justcurious wrote: But we do know of a thing called Debye sheath which is a layer between plasma and a solid due to, you guessed it, friction.
Debye sheaths form due to the difference in velocity between electrons and atomic nuclei at any given temperature, because of the difference in mass.
justcurious wrote: The rail gun was an interesting addition to the discussion. What I found most interesting was that fire was created from a purely electrical phenomena.
The difference between a rail gun and a bolide is in the prime mover. In a rail gun, a bunch of capacitors are discharged into the chamber, creating a Coulomb explosion (i.e., expansion of positive ions due to the electrostatic repulsion of like charges). Coming out of the barrel, we see "flames" — this is charge and molecular recombination, just like the oxidation of atomic hydrogen or carbon. In a bolide, it's the other way around. The momentum of the bolide separates charges, due to friction, which recombine when they get the chance, sometimes near the fireball itself, and sometimes in the coma, as we saw at Chelyabinsk.
viscount aero wrote: I'm going to have to disagree with the premise that there is a lack of sufficient moisture at 12-15 miles altitude. That region is the upper troposphere of the Earth which holds most of the moisture in the entire atmosphere, particularly if the meteor's fiery train appeared within 12 miles altitude (which is highly likely).
Actually, most of the moisture is near the surface of the Earth. The amount of water vapor that the air can hold varies directly with the temperature, which decreases with altitude. The following table shows the grams of water vapor per kg of air. -40 °C is the temperature of the tropopause, which during the winter would be less than 15 km above the surface, at least in Chelyabinsk.
As a consequence of the low temps, the water vapor condenses. While the vapor is lighter than air, condensation is heavier than air, and thus it falls. Practically none of it ever makes it up into the stratosphere, since in the tropopause, there is a temperature inversion, and surface-based updrafts lose all of their positive buoyancy when the temperature starts rising again. So while the top of the stratosphere might be room temperature, capable of holding 20 grams of water vapor per kilogram of air, there's nothing to hoist the ice crystals up there, so that they could evaporate.
How much water vapor would it take to make a trail? I dunno. How bright would the re-oxidation be? I dunno. But the far more abundant molecular nitrogen and oxygen will do the same thing (i.e., get split by high temperatures, and then reform into molecules when they get the chance). So why look for the burning needle in the haystack, when the entire haystack is on fire?
viscount aero
Re: Feb 15 Meteorite(s) hit Russia - Analysis
CharlesChandler wrote:
viscount aero wrote: I'm going to have to disagree with the premise that there is a lack of sufficient moisture at 12-15 miles altitude. That region is the upper troposphere of the Earth which holds most of the moisture in the entire atmosphere, particularly if the meteor's fiery train appeared within 12 miles altitude (which is highly likely).
Actually, most of the moisture is near the surface of the Earth. The amount of water vapor that the air can hold varies directly with the temperature, which decreases with altitude. The following table shows the grams of water vapor per kg of air. -40 °C is the temperature of the tropopause, which during the winter would be less than 15 km above the surface, at least in Chelyabinsk.
As a consequence of the low temps, the water vapor condenses. While the vapor is lighter than air, condensation is heavier than air, and thus it falls. Practically none of it ever makes it up into the stratosphere, since in the tropopause, there is a temperature inversion, and surface-based updrafts lose all of their positive buoyancy when the temperature starts rising again. So while the top of the stratosphere might be room temperature, capable of holding 20 grams of water vapor per kilogram of air, there's nothing to hoist the ice crystals up there, so that they could evaporate.
I should have clarified and said the troposphere and not the upper troposphere. The troposphere begins literally at the surface of the Earth. Wherever the vapor/smoke trail was created was within the troposphere. The boundary of the upper troposphere with the stratosphere is the tropopause. Therefore, the troposphere contains most of the moisture in the entire atmosphere and is where most of the weather occurs. That is where the vapor trail was. How high? Between 0 and 14 miles. I will maintain that it was primarily a moisture plume.
CharlesChandler wrote: How much water vapor would it take to make a trail? I dunno. How bright would the re-oxidation be? I dunno. But the far more abundant molecular nitrogen and oxygen will do the same thing (i.e., get split by high temperatures, and then reform into molecules when they get the chance). So why look for the burning needle in the haystack, when the entire haystack is on fire?
I don't think we really disagree inasmuch as we are coming from different backgrounds and points of view. I'm agreeing that the entire haystack is on fire. I totally agree that molecules were split, electrons were stripped away, charge separation occurred, the whole nine yards. Perhaps we don't fully agree on which molecules were split apart. If there was enough moisture then electrolysis could have happened and the explosion was hydrogen. But perhaps there wasn't enough moisture at that location and temperature.
Maybe take me through it again, your premise behind the concussion (and thus the explosion). I've lost track of some things that each member has said as a lot has been said. Do you agree or disagree that there was an explosion?
justcurious
Re: Feb 15 Meteorite(s) hit Russia - Analysis
CharlesChandler wrote:
justcurious wrote: Charles's theory of bow shocks and fluid dynamics does not make much sense to me. It's mixing apples and oranges.
My impression was of an attempt to explain electric phenomena through a mechanistic lense.
CharlesChandler wrote:
justcurious wrote: Boundary layers in fluid dynamics separate fluid/air of different velocities. If the air is moving around, how would it maintain a bow shock of identically charged air?
The charge is constantly being refreshed by the incoming atoms. This phenomenon only occurs at high mach numbers, because the hydrostatic pressure plus the Coulomb force (oops, I did it again! ) would disperse the matter.
Has this been verified? Or is it a hypothesis? I'm referring specifically to the electric part, that a double-layer is formed in front of an incoming fireball meteor.
The picture you provided from the wikipedia bowshock entry does not mention electricity, only that it is a projectile from a gun in a wind tunnel.
CharlesChandler wrote:
justcurious wrote: Not a spherical meteor, but an irregularly shaped one that is tumbling.
How did you determine that it was not spherical? Objects tumbling are quickly rounded down because the friction acts on the high points more quickly.
I never saw a recovered meteor that fell to Earth, which was spherical. I would be curious to see some pictures of these spherical meteors, or any evidence of this claim. Is this just another assumption, or is it a well known and accepted fact?
CharlesChandler wrote:
justcurious wrote: There is nothing to indicate or suggest that an electric bow shock is created in the first place.
All of the tests with supersonic blunt objects (such as spheres) produces detached bow shocks.
Since fluid dynamics has no explanation for this, it can only be evidence of electromagnetism. And since the Chelyabinsk meteoroid was hypersonic, it would have produced a detached bow shock.
Really? Fluid dynamics doesn't explain this? I could have sworn I saw bowshocks in front of boats at the beach last summer. Isn't that what bullets do (ie the picture you provided)? And at supersonic speeds, they produce a cone instead (which would actually be behind the meteor not in front).
CharlesChandler wrote:
justcurious wrote: But we do know of a thing called Debye sheath which is a layer between plasma and a solid due to, you guessed it, friction.
Debye sheaths form due to the difference in velocity between electrons and atomic nuclei at any given temperature, because of the difference in mass.
To me, that is a form of friction. It's also the only plausible way I see of some sort of charged layer forming around the meteor. But I must admit, the bowshock idea is an interesting hypothesis.
CharlesChandler wrote:
justcurious wrote: The rail gun was an interesting addition to the discussion. What I found most interesting was that fire was created from a purely electrical phenomena.
The difference between a rail gun and a bolide is in the prime mover. In a rail gun, a bunch of capacitors are discharged into the chamber, creating a Coulomb explosion (i.e., expansion of positive ions due to the electrostatic repulsion of like charges). Coming out of the barrel, we see "flames" — this is charge and molecular recombination, just like the oxidation of atomic hydrogen or carbon. In a bolide, it's the other way around. The momentum of the bolide separates charges, due to friction, which recombine when they get the chance, sometimes near the fireball itself, and sometimes in the coma, as we saw at Chelyabinsk.
I don't know about all that recombination stuff, but I'm almost certain that you are completely wrong about how railguns work and the underlying physical principles. Wikipedia has a good entry on it. It's based on standard simple electrical engineering formulas every undergrad student has to learn. mainly, the Bio-Savart law and Lorentz Force. The electric current is not discharged into a chamber, it is run through the rails and through the projectile. The proper arrangement of the current and magnetic field results in a force exerted on the projectile. I believe they may sometimes use plasma arcs and here I'm assuming, in order to reduce the friction yet maintain electrical contact between the rails and the projectile. Your mechanistic lenses are really strong, you carry a lot of baggage, seriously!
Maol
Re: Feb 15 Meteorite(s) hit Russia - Analysis
Apart from and in addition to the sonic shockwaves, if it was a carbonaceous chondrite the heat would have vaporized and disassociated the carbon and H2O resulting in a large fuel-air bomb.
CharlesChandler
Re: Feb 15 Meteorite(s) hit Russia - Analysis
viscount aero wrote: Maybe take me through it again, your premise behind the concussion (and thus the explosion). I've lost track of some things that each member has said as a lot has been said. Do you agree or disagree that there was an explosion?
I'm not really sure, actually. There was a sustained release of energy, and then there were some flare-ups, when the energy release peaked. And then we can see in the trail that at a very specific point, it appears that the mass of the bolide was drastically reduced.
I couldn't tell from the videos whether the booms were from different events, or echos off of other buildings in the vicinity. Has anybody tried to match up the sound from the one video with the flare-ups in the others? Anyway, I think that the sounds were sonic booms. And I think that the light was from electrostatic discharges. The model that I'm using doesn't specifically address anything that would cause an explosion.
justcurious wrote: My impression was of an attempt to explain electric phenomena through a mechanistic lens.
Do you mean to say "mechanical"? Mechanistic means fully physical, as opposed to abstract. But "impressions" are not nearly so useful as specific statements concerning whether or not the construct accurately explains the phenomenon.
CharlesChandler wrote: The charge is constantly being refreshed by the incoming atoms.
justcurious wrote: Has this been verified? Or is it a hypothesis? I'm referring specifically to the electric part, that a double-layer is formed in front of an incoming fireball meteor.
See: Beech, M.; Foschini, L., 1999: A space charge model for electrophonic bursters. Astronomy and Astrophysics, 345: L27-L31
When a meteoroid enters the Earth's atmosphere it moves at hypersonic speeds, that is with Mach number greater than 5. Hence, behind the bow shock the effect of ionization becomes very important (for a brief description of hypersonic flow around a meteoroid (see Foschini, 1999a and references therein). Other effects, such as ablation, contribute to enhance the presence of charged particles in the fluid around the meteoroid (for review see Ceplecha et al., 1998). Moreover, the presence in meteoroids of alkaline and alkaline–earth metals, which easily ionize, results in the rapid formation of a plasma sheet around the meteoroid body (see Foschini, 1999b).
There are other papers on the same topic, but that one is a good place to start.
justcurious wrote: I never saw a recovered meteor that fell to Earth, which was spherical. I would be curious to see some pictures of these spherical meteors, or any evidence of this claim. Is this just another assumption, or is it a well known and accepted fact?
It's an assumption, but I think that it's reasonable to think that it's rounded, if not perfectly spherical. What hits the Earth after the break-up of the bolide isn't necessarily indicative of the original shape. I don't see any reason why a bolide (of any shape) would break up into spherical pieces, or that if it did, it would prove that the bolide had to be spherical. So I'm just saying that the bolide is probably tumbling, and just like a pebble in a stream, friction will round it down.
CharlesChandler wrote: All of the tests with supersonic blunt objects (such as spheres) produces detached bow shocks. Since fluid dynamics has no explanation for this, it can only be evidence of electromagnetism.
From: Kim, H. D.; Setoguchi, T., 2007: Shock Induced Boundary Layer Separation. 8th International Symposium on Experimental and Computational Aerothermodynamics of Internal Flows, Lyon, France
Shock wave/boundary layer interaction (SBLI) appears usual in transonic or supersonic flows, and involving almost all kinds of fluid dynamic phenomena. Of many aspects of SBLI phenomena, Shock-Induced Separation (SIS) is the most important as it has deterministic influence on the overall flow characteristics. Though there have been many works on SBLI to investigate SIS, a clear and concrete idea of the onset of SIS is still lacking.
I'll take their word for it. Note that the production of waves is not the hard part to understand. It's the detached shock front. Did you happen to notice any waves preceding the motorboats by several meters?
CharlesChandler wrote: Debye sheaths form due to the difference in velocity between electrons and atomic nuclei at any given temperature, because of the difference in mass.
justcurious wrote: To me, that is a form of friction.
Is electricity a form of friction?
justcurious wrote: I'm almost certain that you are completely wrong about how railguns work and the underlying physical principles. [...] The electric current is not discharged into a chamber, it is run through the rails and through the projectile.
There are a couple different designs. Here's the brief description of one of them:
Wikipedia wrote: A plasma armature is formed by an arc of ionised gas that is used to push a solid, non-conducting payload in a similar manner to the propellant gas pressure in a conventional gun.
The "ionized gas that is used to push a solid..." would explain the fireball coming out of the barrel. Lorentz forces do not. NB: when reading about military technology, try to use a little common sense! They don't always lay everything out in practical terms. Usually the truth is in there somewhere, but you might have to dig for it.
justcurious wrote: Your mechanistic lenses are really strong...
Again, do you mean mechanistic, or mechanical?
justcurious wrote: you carry a lot of baggage, seriously!
That's uselessly vague. If you care to make a statement, get up the nerve and speak your mind.
viscount aero
Re: Feb 15 Meteorite(s) hit Russia - Analysis
Maol wrote: Apart from and in addition to the sonic shockwaves, if it was a carbonaceous chondrite the heat would have vaporized and disassociated the carbon and H2O resulting in a large fuel-air bomb.
And H2O dissociates into two ions, a hydroxyl ion OH- and a hydrogen ion (proton) H+. This is the alleged electrolysis that I have been talking about. The friction would beget a triboelectric environment. The dissociated carbon, which is flammable, would have become CO2 (and perhaps the vapour trail contained CO2).
http://www.psrd.hawaii.edu/PSRDglossary.html Carbonaceous chondrites contain water-bearing minerals and carbon compounds including a variety of organic molecules such as amino acids. Carbonaceous chondrites are the most primitive meteorites--primitive in a chemical way. For example, the CI group of carbonaceous chondrites are closest in composition to the photosphere (visible surface) of the Sun.
viscount aero
Re: Feb 15 Meteorite(s) hit Russia - Analysis
CharlesChandler wrote:
viscount aero wrote: Maybe take me through it again, your premise behind the concussion (and thus the explosion). I've lost track of some things that each member has said as a lot has been said. Do you agree or disagree that there was an explosion?
I'm not really sure, actually. There was a sustained release of energy, and then there were some flare-ups, when the energy release peaked. And then we can see in the trail that at a very specific point, it appears that the mass of the bolide was drastically reduced.
I couldn't tell from the videos whether the booms were from different events, or echos off of other buildings in the vicinity. Has anybody tried to match up the sound from the one video with the flare-ups in the others? Anyway, I think that the sounds were sonic booms. And I think that the light was from electrostatic discharges. The model that I'm using doesn't specifically address anything that would cause an explosion.
Ok thanks for restating your position. I had an inkling you were not of the belief there was an explosion. As for me I cannot see how one would surmise from observation that there was not an explosion. There was aerial fire which denotes ignition. You don't see this? How would billowing aerial fire come into existence otherwise?
D_Archer
Re: Feb 15 Meteorite(s) hit Russia - Analysis
Charles wrote:
So I'm just saying that the bolide is probably tumbling, and just like a pebble in a stream, friction will round it down.
This is complete nonsense, any meteorite pieces ever found are in no way spherical or rounded down. There is no tumbling either, the rock stays the course and any phenomena is strictly electrical, it is the plasmasphere that is round not the bolide.
Regards, Daniel
dahlenaz
Re: Feb 15 Meteorite(s) hit Russia - Analysis
Here is a link to other Meteosat-9 Images and a place to ask questions. d...z
viscount aero wrote: As for me I cannot see how one would surmise from observation that there was not an explosion. There was aerial fire which denotes ignition. You don't see this? How would billowing aerial fire come into existence otherwise?
A fire doesn't guarantee that there was an explosion. Anyway, I did read somewhere today that there were 3 booms. Perhaps these corresponded with the 3 brightest flare-ups. I'm thinking that these were electrostatic discharges. So perhaps they weren't sonic booms, but just the "thunder" from the discharges? Or 1 of them was a sonic boom, and the other 2 were thunder? Regardless, there was a substantial amount of sustained energy release, which produced a steady trail of smoke, and which continued to flare after the bolide was gone. Explosions don't act like that. So it's starting to look like we have a mixed bag of phenomena, and a variety of mechanisms at work.
D_Archer wrote: Any meteorite pieces ever found are in no way spherical or rounded down.
Actually, this isn't an important point. The solenoidal magnetic fields would be produced by any rolling or tumbling object, if it was charged. Magnetic fields are generated by moving charged particles, not the shape of the object containing them. And the detached bow shock is not shape-dependent either — it just has to have a relatively blunt face. Properly designed jets don't produce detached bow shocks at high mach numbers. I don't know how well-designed they have to be, but I don't think that space rocks get the benefit of design review.
D_Archer wrote: There is no tumbling either.
No, we can safely assume that it's going to tumble. When did you ever see anything falling through the air that wasn't tumbling, unless of course it was an airplane with dedicated control surfaces to prevent it?
D_Archer wrote: The rock stays the course and any phenomena is strictly electrical.
You're welcome to present a complete model if you want...
The latest estimate of the altitude of the bolide when it broke up was 27 km, based on the locations of observers, and the apparent angle of the bolide from the horizon for each observer. This is consistent with other measurements. The meteorite fragments were found about 40 km from Chelyabinsk. The hypotenuse of that 27/40 triangle is 48.25 km, giving the line-of-sight distance. With the speed of sound at the relevant altitudes being roughly 300 m/s, the sonic boom would have arrived 2.68 minutes after the point of nearest approach. I read somewhere that it was 2 minutes 50 seconds, which is 2.83 minutes. So I think that the estimates are reasonably accurate. Now, 27 km above the surface is well into the stratosphere, where there is little-to-no water vapor. So I'm still of the opinion that the "clouds" were made of smoke from arc discharges onto the surface of the bolide.
dahlenaz wrote:Meteorologists say that thunderstorm electrification is triboelectricity, from hail falling through the air!
But that just ain't right...
