Dynamics behind rock explosions(??)

Okay, recall the 1908 Tunguska event. The most
likely scenario is a meteor or piece of a comet
about, say, 60 meters in diameter, entering the Earth's
atmosphere at high speed, then exploding with the force
of maybe 10 to 20 megatons before reaching the ground.
Now, I realize the tremendous heat build-up that must
have occured with this natural object as it streaked
through the air, but just *what* are the dynamics behind
this, i.e. just HOW does a rock (or chunk of ice) explode
with such temendous force?

I did a quick search on this before posting, but I'm too lazy
to keep at it. Does someone here know just what would cause
such an object to blow with such force? To say that it just
heats up and explodes is not good enough.

(BTW, imagine this happening just 50 years later, at the height
of the Cold War...)

--
Oracle

(OracleofBugtussle) wrote in
om:

Okay, recall the 1908 Tunguska event. The most
likely scenario is a meteor or piece of a comet
about, say, 60 meters in diameter, entering the Earth's
atmosphere at high speed, then exploding with the force
of maybe 10 to 20 megatons before reaching the ground.
Now, I realize the tremendous heat build-up that must
have occured with this natural object as it streaked
through the air, but just *what* are the dynamics behind
this, i.e. just HOW does a rock (or chunk of ice) explode
with such temendous force?

Sir Isaac Newton worked this out for you. Kinetic energy = 1/2 MV^2.
Do the math.

Llanzlan.

"Llanzlan Klazmon The 15th" replied to "OracleofBugtussle":

Okay, recall the 1908 Tunguska event. The most
likely scenario is a meteor or piece of a comet
about, say, 60 meters in diameter, entering the Earth's
atmosphere at high speed, then exploding with the force
of maybe 10 to 20 megatons before reaching the ground.
Now, I realize the tremendous heat build-up that must
have occured with this natural object as it streaked
through the air, but just *what* are the dynamics behind
this, i.e. just HOW does a rock (or chunk of ice) explode
with such temendous force?

Sir Isaac Newton worked this out for you. Kinetic energy = 1/2 MV^2.
Do the math.

That is not an answer to his question. Why does a rock explode
rather than disintegrate gradually, or dig a hole deep into the
Earth, or get really hot, or bounce, or something else? It's
like asking why a stick of dynamite explodes when hit by the
shock of a blasting cap, while a stick of wood containing the
same amount of chemical potential energy just gets nudged.

He obviously wants something more than just "a large amount of
energy goes into an object in a very short period of time", but
less than a detailed analysis of what happens to each molecule.
I do, too.

-- Jeff, in Minneapolis

..

Llanzlan Klazmon The 15th wrote in message . 37.6...

Sir Isaac Newton worked this out for you. Kinetic energy = 1/2 MV^2.
Do the math.

I was hoping for a lot more than this. Giving the simple kinetic
energy equation does nothing to explain how a rock or ice chunk
explodes in mid-air with 15 MT force.

--
Oracle

"OracleofBugtussle" wrote...
in message om...

Llanzlan Klazmon The 15th wrote...
in message . 37.6...

Sir Isaac Newton worked this out for you. Kinetic energy = 1/2 MV^2.
Do the math.

I was hoping for a lot more than this. Giving the simple kinetic
energy equation does nothing to explain how a rock or ice chunk
explodes in mid-air with 15 MT force.

--
Oracle

Well, let's think about it, Oracle...

What if the shockwave caused by entry into the atmosphere
was all that hit the ground? And by the time the physical mass
of the object got near the surface, it had disintegrated to just
about nothing. No explosion, just the tremendous shockwave,
that apparently had a null area near its center, hits the ground
with enough force to level a forest.

Another possibility...

If there was still sufficient mass to leave a crater, then could
the shockwave have bounced/reflected back after hitting the
surface? Perhaps this was enough energy to blow the mass
of the object to smithereens? and to leave no crater?

Or...

Shot apart by alien artillery? g

happy days and...
starry starry nights!

--
"Oh give me please the Universe keys
That unlock all those mysteries!"
You pay your fees, you find some keys,
That keeps you always groping.

"Oh give me please the Happiness keys
That ease the pain of biting fleas!"
Today you seize you need no keys,
That door is always open.

Paine Ellsworth

"Painius" wrote in message ...

Well, let's think about it, Oracle...

What if the shockwave caused by entry into the atmosphere
was all that hit the ground? And by the time the physical mass
of the object got near the surface, it had disintegrated to just
about nothing. No explosion, just the tremendous shockwave,
that apparently had a null area near its center, hits the ground
with enough force to level a forest.


Another possibility...

If there was still sufficient mass to leave a crater, then could
the shockwave have bounced/reflected back after hitting the
surface? Perhaps this was enough energy to blow the mass
of the object to smithereens? and to leave no crater?

Or...

Shot apart by alien artillery? g

You apparently have little or no knowledge of this event. This is
just more idle BS. I'm surprised at the quality (or lack thereof)
of responses here. I was discussing this subject with a friend, and
neither one of us can come up with ideas on how this mid-air explosion
(of high thermonuclear weapon yield) could have come about.

But FYI, there was a book written in about '78 that, I think, covered
and promoted the idea that the explosion was caused by the nuclear
engines on an extraterrestrial spacecraft that was in trouble high
in the Earth's atmosphere that morning. I didn't read the whole
book, and it's been a long time, but I believe they speculated that
the craft was deliberately steered to that sparse area so as not
to have much of an effect on life here, etc. The name of the book
is _The Fire Came By_.

--
Oracle

"OracleofBugtussle" wrote...
in message om...

"Painius" wrote in message...
...

Well, let's think about it, Oracle...

What if the shockwave caused by entry into the atmosphere
was all that hit the ground? And by the time the physical mass
of the object got near the surface, it had disintegrated to just
about nothing. No explosion, just the tremendous shockwave,
that apparently had a null area near its center, hits the ground
with enough force to level a forest.

Another possibility...

If there was still sufficient mass to leave a crater, then could
the shockwave have bounced/reflected back after hitting the
surface? Perhaps this was enough energy to blow the mass
of the object to smithereens? and to leave no crater?

Or...

Shot apart by alien artillery? g

You apparently have little or no knowledge of this event. This is
just more idle BS. I'm surprised at the quality (or lack thereof)
of responses here.

What i lack in knowledge of this event, you certainly make
up for with your lack of diplomacy and tact!

You remind me of me! g

I was discussing this subject with a friend, and
neither one of us can come up with ideas on how this mid-air explosion
(of high thermonuclear weapon yield) could have come about.

But FYI, there was a book written in about '78 that, I think, covered
and promoted the idea that the explosion was caused by the nuclear
engines on an extraterrestrial spacecraft that was in trouble high
in the Earth's atmosphere that morning. I didn't read the whole
book, and it's been a long time, but I believe they speculated that
the craft was deliberately steered to that sparse area so as not
to have much of an effect on life here, etc. The name of the book
is _The Fire Came By_.

--
Oracle

I like my speculations SO much better.

Why don't you thrall me with your acumen, Oracle? Tell me
what you think is wrong with my reflections?

happy days and...
starry starry nights!

--
Sometimes OH! my mind grips a thought so unkind
That it twists me to heights of contortion...
I'm often so glad that my mom and my dad
Didn't follow along with abortion!

Paine Ellsworth

(OracleofBugtussle) wrote in
om:

Okay, recall the 1908 Tunguska event. The most
likely scenario is a meteor or piece of a comet
about, say, 60 meters in diameter, entering the Earth's
atmosphere at high speed, then exploding with the force
of maybe 10 to 20 megatons before reaching the ground.
Now, I realize the tremendous heat build-up that must
have occured with this natural object as it streaked
through the air, but just *what* are the dynamics behind
this, i.e. just HOW does a rock (or chunk of ice) explode
with such temendous force?

I was under the impression that the rock itself doesn't get that hot, but
the air in front of it builds up a HUGE shock wave. When that hits the
earth, it has nowhere to go so it blows the falling object up with the
crater. Meteors themselves are very cold inside from what I've heard.

On Tue, 09 Dec 2003 04:53:26 GMT, Doug Cunningly
wrote:

(OracleofBugtussle) wrote in
. com:

Okay, recall the 1908 Tunguska event. The most
likely scenario is a meteor or piece of a comet
about, say, 60 meters in diameter, entering the Earth's
atmosphere at high speed, then exploding with the force
of maybe 10 to 20 megatons before reaching the ground.
Now, I realize the tremendous heat build-up that must
have occured with this natural object as it streaked
through the air, but just *what* are the dynamics behind
this, i.e. just HOW does a rock (or chunk of ice) explode
with such temendous force?

I was under the impression that the rock itself doesn't get that hot, but
the air in front of it builds up a HUGE shock wave. When that hits the
earth, it has nowhere to go so it blows the falling object up with the
crater. Meteors themselves are very cold inside from what I've heard.


LK the XVth summed it up. yep, you do get a huge shockwave, but a
comet/asteroid travelling at a multiple number of miles per second
hits the atmosphere like it were a solid incompressible wall. it
dumps just about all its velocity into kinetic energy - shockwave,
light, heat, sound, etc.
if you have a realistic idea of its mass, its speed and know the
conversion factor between joules and kT or Mt, voila, there's your
answer.

Doug Cunningly wrote in message link.net...

I was under the impression that the rock itself doesn't get that hot, but
the air in front of it builds up a HUGE shock wave.

I'm sure there is a huge shock wave in front, but the rock DOES get
very hot...white hot.

When that hits the
earth, it has nowhere to go so it blows the falling object up with the
crater.

Well, there was no crater at Tunguska, as the explosion took place
thousands of feet above ground. In fact, the area under the explosion
had trees standing, while the area all around had the forest flattened,
which is typical with a high-energy airburst.

--
Oracle