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sliceadjust
04-23-2007, 10:18 AM
Okay what do you guys think. Someone sent this to me and thinks its real. I have my doubts:

http://www.dailymotion.com/us/cluster/tech/featured/video/x1rcd4_100tonnesexplosifdesert

bloontz
04-23-2007, 10:20 AM
As in a real explosion? Not!

sliceadjust
04-23-2007, 10:30 AM
I agree but chatting with a friend who swears its a real explosion. My guess is it was done in Maya.

mattclary
04-23-2007, 11:28 AM
Why specifically do you think it is not real?

sliceadjust
04-23-2007, 11:34 AM
The shockwave looks strange and the sounds.

mattclary
04-23-2007, 11:41 AM
The shockwave looks strange and the sounds.

If you watch old footage of bombings in Vietnam, you often see that shockwave. It's inclusion is one thing that indicates realism to me. It caused by water vapor condensing due to compression. The timing of that shockwave where it visibly compresses the water vapor to where it travels over the sand, to where it reaches the camera is too good to be faked IMO. If you were going to create an explosion via CG, you would probably build a better soundtrack than that too, wouldn't you? Once again, probably real because it's not what you expect and not what you see (or rather, hear, in movies).

StereoMike
04-23-2007, 11:46 AM
What 100 tons should that be? 100 tons ammunition?
The sound is odd, and the shockwave looks strange, but in the video they ignite something left, than right, and then in the middle. So the air gets really confused where to go, I guess. Could be something like a condensation trail, just disguised as shockwave.
And if it's ammunition or something, then the sound makes sense.

mike

warrenwc
04-23-2007, 12:20 PM
Looks good to ME.
Seems to be ordinance disposal (secondary ricochets).
If a program can do it that well, I WANT IT!

cresshead
04-23-2007, 01:16 PM
looks bang on to me!

SplineGod
04-23-2007, 01:42 PM
I also agree that the shockwave looks consistent with other footage Ive seen. The weird initial shockwave I believe is actually water vapor condensing.

Avebeno
04-23-2007, 02:49 PM
The audio sounds good at the beginning, like a striog wind on a cheap, unfiltered microphone... The breakup in the video looks consistient with the breakup you'd see on DV video.

What's with the sound of bullets flying?

Qslugs
04-23-2007, 07:40 PM
The only odd part I found was the time between the guy leaving the frame and the actual explosion. It seems there is a slight jump in there. However, I assume they just cut a bit of the more boring portions out.

Does it seem as if the background is static during the explosion?

Mark The Great
04-23-2007, 07:49 PM
The only odd part I found was the time between the guy leaving the frame and the actual explosion. It seems there is a slight jump in there. However, I assume they just cut a bit of the more boring portions out.

Does it seem as if the background is static during the explosion?


They probably cut it because the guy had to get away from the actual scene of the explosion. That dust looks (and sounds) like it could take off a layer of skin...

jameswillmott
04-23-2007, 08:18 PM
If its a fake, it was done by a true master.

shrox
04-23-2007, 08:36 PM
It's real.

shrox
04-23-2007, 08:40 PM
Report all bugs to [email protected] Every time you don't report a bug, God kills a kitten. Do it for the kittens.

God doesn't kill the kittens, he just hides them, them ushers them to safety in the Kitty Underground Railroad. It is run by the Kitters, and branch of the Quakers. They help the kittens intergrate into their new surroundings and find meaningful jobs.

jasonwestmas
04-23-2007, 08:41 PM
I've never seen anything as real as that.

voriax
04-23-2007, 10:17 PM
Definately real. You're misled into thinking it's fake because you've seen too many fake movie explosions. This is how a real explosion looks. The strange cloud that appears momentarily is a result of the huge concussive force of the detonation.
The shockwave passing over the ground is also what happens when you have a real explosion. Causes large amounts of dust to rise from the ground. That sort of thing gets left out of movies because they're inconvenient :P

There's a video online of a fuel refinery or storage facility exploding, with the video being shot from a high and far away vantage point. You can see a massive shockwave spreading out as the building explodes. Also look for a high-speed video of a car exploding. You can actually see the air ripple from the shockwave. It's cool :D

It's like watching footage of old nuclear tests.. they look somewhat unreal because even though we see "nuclear bombs" going off in movies, they rarely capture the reality of what happens when a bomb that powerful goes off.

voriax
04-23-2007, 10:22 PM
Well, here's the car video I was talking about...

http://www.dailymotion.com/relevance/search/slow%2Bmotion/video/x124xm_car-explosion-in-slow-motion

And here's the fuel storage place exploding..

http://www.youtube.com/watch?v=kUPIDVMl8XM

jameswillmott
04-23-2007, 11:04 PM
For a great explosion try getting hold of the Mythbusters episode where they blow up the concrete mixer with high explosive.

Here it is on YouTube...

http://www.youtube.com/watch?v=IWN5VGJjctI

StereoMike
04-24-2007, 01:41 AM
Biggest. Explosion. Ever.

http://www.youtube.com/watch?v=FfoQsZa8F1c

prospector
04-24-2007, 02:18 AM
bee-ut-eee-ful

jameswillmott
04-24-2007, 04:43 AM
Tsar Bomba!!! That's a scary mutha... I'm glad they only made one.

*Pete*
04-24-2007, 06:48 AM
What 100 tons should that be? 100 tons ammunition?



I believe i read about US army blowing up huge quantities of ammunition in Iraq (not the "shock and awe" thingy)...old Iraqi military supplies i quess.

Ember
04-24-2007, 08:21 AM
I've seen explosions of military grade explosives with my very own eyes and I tell you that the shockwave is authentic. The firestorm is a bit strange if there is no napalm or stuff like that with the explosion. The hollywood explosions with huge firestorms are just fake, such thing happens only when there's something to actually burn (like napalm).

But yeah, it's real. Trust me.

:edit: Oh and by the way, REAL explosions are loud, short BANGS, not huge bass rumbling like in movies.

tfrank
04-24-2007, 10:58 AM
It sure looks real, but there seems to be one thing missing. Based on several videos that my son took in Iraq destroying various explosive devices, I don't see very much "fall out". The amount varied depending on the ground type the explosion took place in...but for 100 tons of stuff, there should be a heck of a lot of earth coming back...well to earth. The firestorm could be due to diesel fuel that is sometimes added to help insure a "complete burn".

sliceadjust
04-24-2007, 11:08 AM
One thing is for sure is I am clueless about the nature of explosions. Not sure what I should expect when seeing a real one. I did find out that the popping is just left over ordinance going off. Hey you live and learn.

Ember
04-24-2007, 11:11 AM
It sure looks real, but there seems to be one thing missing. Based on several videos that my son took in Iraq destroying various explosive devices, I don't see very much "fall out". The amount varied depending on the ground type the explosion took place in...but for 100 tons of stuff, there should be a heck of a lot of earth coming back...well to earth. The firestorm could be due to diesel fuel that is sometimes added to help insure a "complete burn".

Yes and no. That explosion was obviously a surface blast, thus it wouldn't throw up dirt into air too much. Also, the explosion is pretty far away, the time the blastwave takes to reach the camera proves that (and who in his right mind would be anywhere close to that thing when it goes off anyway?). Thus all the ground material reaching the camera would be pretty scattered at that distance. And I think it wouldn't had reached camera level anyway during that clip - an explosion like that will throw stuff literally kilometres into all directions.

I remember when a finnish "telamiina" exploded while I was serving in military. There was this old portable radiator beside it when it blew up (9,3kg of military grade TNT). Half of that radiator disintegrated, the other half was found twisted and scarred about 300m away. The blast wave from that explosion on top of a snow field was pretty cool to look at by the way, very similar what you see in the video with sand.

In the video the blast wave takes about a second to reach the camera, maybe a bit less. Military grade TNT has explosion speed of over 6500 m/s. Of course that explosion consists of a lot of different explosives, so I'm guessing an average speed of maybe 3000 - 4000 m/s which would give us about 3 km distance to the actual blastpoint.

I do agree about the diesel thing though :)

creach
04-24-2007, 12:45 PM
Military grade TNT has explosion speed of over 6500 m/s. Of course that explosion consists of a lot of different explosives, so I'm guessing an average speed of maybe 3000 - 4000 m/s which would give us about 3 km distance to the actual blastpoint.

Alright then. We have worked out the physics of the explosion.

That means the zing sounds are debris picked up by the shockwave and hurtling past the microphone, because they make themselves apparent at approximately 5 seconds after detonation. That's roughly 1900 feet/second - bullet speed for some ammo. Even at 20 seconds, you can still hear some stuff flying past the mic, and that's 450 feet/second - bullet speed - SLOW bullets - but bullets nonetheless.

And that *is* what they sound like. When I was younger I spent a fair amount of time on a military range at BOTH ends of the range. At the target end you sat in concrete trenches and used a long pointer (8 foot 2X4 with a cardboard arrowhead) to point to the hits the shooter made on the target.

Cool.
Dan

ghostlight
04-24-2007, 02:13 PM
Real.

Jarno
04-24-2007, 08:58 PM
Military grade TNT has explosion speed of over 6500 m/s.

That's the speed at which the explosion propagates through the explosive itself. Explosives don't change the basic properties of air (ignoring funky things happening if there is a signficant thermal pulse like with a nuclear bomb). The shockwave through the air is still around the speed of sound in air. So the blastpoint would be more like 300m away. The speed of sound through earth is in the thousands of metres per second. That'll be the initial rumble heard.

---JvdL---

Andyjaggy
04-25-2007, 07:32 AM
I didn't realize we had so many experts on blowing stuff up on here :) Your all a bunch of pyros. Very interesting though :)

regularfry
04-26-2007, 12:58 PM
That's the speed at which the explosion propagates through the explosive itself. Explosives don't change the basic properties of air (ignoring funky things happening if there is a signficant thermal pulse like with a nuclear bomb). The shockwave through the air is still around the speed of sound in air. So the blastpoint would be more like 300m away. The speed of sound through earth is in the thousands of metres per second. That'll be the initial rumble heard.

---JvdL---

Yes. There is a way for an explosive shockwave to travel faster than the speed of sound, but it takes some funky atmospheric effects to set up right, if I'm remembering my A-level physics correctly. Also, you'd hear it as a sudden crack, not a rumble.

Solitons are fun :-)

tfrank
04-26-2007, 01:12 PM
I didn't realize we had so many experts on blowing stuff up on here :) Your all a bunch of pyros. Very interesting though :)
You have to love this forum!:)

Bog
04-29-2007, 04:10 AM
I didn't realize we had so many experts on blowing stuff up on here :) Your all a bunch of pyros. Very interesting though :)

Dunno, 'bout you mush, but I got into this game to build airplanes and spaceships, then blow 'em up :D

So, er, now I'm some kind of specialst on 3D book re-creations. Ah, well. Best laid plans, and all that... :thumbsup: