Talk:Explosion

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Can anyone write a stub here? What is an explosion?

gunpowder

I've been hopping from one article to another this morning trying to track down the difference between propellants and explosives. Maybe I'm wrong on the previous couple edits. —Preceding unsigned comment added by 71.63.88.111 (talk) 07:09, 6 September 2008 (UTC)

 We need a Definition here of the difference: By a Chemist's, an Expert's' definition: An explosive detonates at a velocity of 3,000 feet per second or more. It is usually one substance, it Detoates at an exponential rate. It usualy requires a detonator; most won't simply explode with a "fuse".
  A propellant; black powder, smokeless gunpowder, flash powder, etc, are often two or more separate substances that deflagrate, that is, burn quickly. They are designed to go off when lit.  Their velocity is usually subsonic, about 600-900 fps.
 A test: If gunpowder is laid out on some concrete and is set off, it goes Poof, impressive, but, the concrete is still there. The explosive force takes the path of least resistance; it goes upward.
 If some high explosive, say, RDX, is detonated on a slab of concrete, it will explode at 25,000 feet per second. The supersonic shock wave reflects the explosive  force downwards, and there is a hole blown in the concrete.70.162.46.94 (talk) 14:05, 25 August 2011 (UTC)

another kind of explosion

this term is used formally, and sometimes measurably, as a nonlinear increase in sets or populations--74.236.193.55 02:08, 17 November 2006 (UTC)

Big Bang not an explosion

It is incorrect to call the Big Bang an explosion. While often portrayed as such in popular accounts, this is deeply misleading, since there was nothing that exploded, nor was there anything to explode into; the Big Bang is simply the initial singularity of spacetime and/or the hot initial state of the universe, depending on your terminology. While associated with heat and an expansion, it is not an explosion in the conventional sense, and hence should be removed from the list of explosions. 142.3.164.195 23:55, 5 June 2006 (UTC)

The Big Bang is not an explosion it is an expansion because it has not/will not stop.

suspended particulate explosions

I'm no expert, but seems there should at least be mention of the explosive potential of fine dust when diffused in air--in the U.S. west, grain elevator explosions are an all-too-common phenomenon.

--nizo --68.55.122.146 13:12, 7 Jul 2004 (UTC)

Texas City

The Texas City Disaster of April 16, 1947 ... found elsewhere in Wikipedia ... surely is one of the major explosions of a chemical nature.

shoemaker-levy 9

shoemaker-levy 9 shouldn't be here, because it didn't explode. it was pulled apart by jupiters gravity and then collided with the upper atmosphere. It doesn't qualify as an explosion, so i'm removing it. Dallas 09:56, 1 August 2006 (UTC)

I'm not sure that I agree with you there. The fragments of Comet Shoemaker-Levy 9 hitting the atmosphere of Jupiter, were probably the largest explosions directly observed by man (have we directly observed any stellar novas yet?). As the article mentions, the largest fragment colliding with Jupiters atmosphere was estimated to have caused an energy release of 6,000,000 megatons of TNT or about 750 times the world's nuclear arsenal. It was a conversion of kinetic energy into heat, rather than a conversion from chemical energy or nuclear energy, but that doesn't make it any less of an explosion. It still resulted in a rapid heating of gasses in Jupiter's atmosphere, with fireball plumes reaching 3,000 km high. Each collision would have been quite similar to the Tunguska event, but _much_ larger. -- Solipsist 12:51, 10 October 2006 (UTC)

non-disaster, non-nuclear

How about a section for really big non-nuclear, deliberate explosions like Minor Scale? That's not the largest ever by a long way. The US military once stacked up enough TNT in the Nevada desert to equal the power of the Fat Man or Little Boy bomb. It was either in the 1960's or early 1970's. I saw it on a documentary on TV a few years ago. Many men were examining a dormant volcanoe when it exploded and killed them. This shows that dormant volcanoes can still be active, so take precation. They found a body with many bullet wound type things but they had been rocks that punctured his skin and went into his heart. One guy was missing his head. Nasty.

The precision of the definition

I'm no expert, but isn't an explosion a combustion that has accelerated into supersonic velocity? So something has to burn with a certain speed expressed in meters per second to be counted as an explosion? Then, there's no such thing as a "Gasoline explosion" (image text). Burning of gasoline should then, strictly speaking, not be counted as an explosion. --85.165.66.228 (talk) 07:55, 13 September 2008 (UTC)

It is not the rate of burning, which can depend on many local factors, but the rate of travel of the shock wave, that distinguishes between explosion and deflagration. Both are forms of rapid combustion. Combustion without a shock wave is merely combustion. Some materials will burn VERY fact but that does not make their buring necessarily an explosion or deflagration. Pzavon (talk) 21:11, 13 September 2008 (UTC)

What exactly occurs inside an internal combustion engine, anyhow? An explosion, a deflagration, or just plain burning? 204.52.215.107 (talk) 16:59, 22 January 2009 (UTC)

Deflagration article says that it's a deflagration, but it compares the term to "detonation", not "explosion", when talking about the sonic barrier - suggesting that "explosion" can include both detonations and deflagrations. 204.52.215.107 (talk) 17:02, 22 January 2009 (UTC)

and, of course, I wind up learning "just plain burning" can be taken to be a deflagration, too. 204.52.215.107 (talk) 17:03, 22 January 2009 (UTC)

Gasoline burns in an auto engine. If it explodes, it's called a "knock".70.162.46.94 (talk) 14:06, 25 August 2011 (UTC)

Explosion sound

I was hoping to find information on the sound of explosions on the page, but... no. Aside from what different real explosions sound like, a mention of how hollywood explosions usually don't sound real would probably be useful information.

There's probably a lot of attributes of explosions that aren't as sexy as the different materials that can explode but that should be in the article. —Preceding unsigned comment added by 91.153.238.155 (talk) 16:09, 5 May 2009 (UTC)

Kilotons and damage

Perhaps a small section can be added displaying how much damage several explosions (described in Ktons or released energy) can cause. E.g. how much released energy/ktons of explosives will damage a certain size of area (in m²); how much will incapacitate or even kill a man, how much will damage a house, a larger building, ... —Preceding unsigned comment added by 81.245.85.122 (talk) 12:12, 25 May 2009 (UTC)

Repeated vandalzation by 62.21.130.5.

This user needs to be reported.Adi4094 (talk) 09:01, 4 January 2010 (UTC)

Subsonic Shock Wave

From the intro to the article: "Subsonic shock waves are created by low explosives through the slower burning process known as deflagration."

This makes no sense. A shock wave, by its very nature, must travel at a supersonic speed. If it's subsonic then the temperature/density/pressure would be able to propagate through the medium faster than the shock, and the shock wouldn't exist at all. —Preceding unsigned comment added by 76.181.65.49 (talk) 02:49, 6 June 2010 (UTC)

No. Shock waves can travel as slow or fast as they want.The shock waves travelling thru the deflagration of the low explosive propellant travel In Air at at usually a subsonic velocity, by definition. They don't "speed up", they are the propagation velocity of the substance.

Now, if you are talking shock waves thru ground, or water,they often travel at 4-5x sound, as sound waves go faster thru denser mediums.70.162.46.94 (talk) 14:12, 25 August 2011 (UTC)

Additional movie suggestion

• YouTube video showing real gas tank explosion

I thought this might be an interesting video for this topic. I don't know if this kind of video is appropriate for wikipedia, so I post it here. The video shows all the mentioned elements of the explosion in the last part of the other youtube movie. It also shows the debris of the gas tank flying into the air as a result of the explosion. Do you think it's worth to link this video too? —Preceding unsigned comment added by 84.72.76.249 (talk) 00:59, 4 May 2011 (UTC)