Implosion vs. Explosion

RedvGreen

RedvGreen

RedvGreen

Soldato
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I was asked this yesterday (as I have a reasonable grasp of physics), but I was a bit stumped at trying to justify that an implosion can be dangerous, even equally to an explosion.

The case in point was concerning strip light bulbs.

My understanding is that an explosion is a release of energy - topically, this would throw glass shards and filament everywhere, irrespective of the gas and other material present in the bulb.

However, with an implosion, the idea is that the material is sucked inwards, however as this happens on the full area/length, this actually still throws material everything, just not directly outward - more chaotically as it will rebound off each other.

Is this a correct way of considering the situation, or is it actually the actual release of energy/pressure in such a situation?

So instead of being hit by a wave of energy pushing you away, you are instead impacted by a wave of energy pulling you in?
 
I drew this helpful diagram for you:
Jia3OPg.png


Implosion still makes a mess and goes everywhere.
 
Yea, implosion isn't like sci fi where **** is sucked into a mysterious hole. It's a mass of energy scattered in all directions.

I'm trying to think of an explosive that will give an example, but I can only think of one for Explosion which is C4 which is VERY directional and easy to control in terms of direction.
 
agnes said:
Yea, implosion isn't like sci fi where **** is sucked into a mysterious hole. It's a mass of energy scattered in all directions.
Click to expand...

Doesn't something going supernova mean that it collapses in on itself until it builds up so much energy it explodes? Isn't that what some types of nuclear weapons do as well, which is what makes them so powerful?
 
A nuke would be the easiest analogy.

Other than gun type nukes an implosion starts the process of an explosion.

Implosions will more than likely lead to an explosion depending on the material. An implosian in a metal case probably wouldnt expel enough energy to turn the metal into shrapnel a glass tube would as glass is relatively weak.

Ever cracked a CRT?
 
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the implosion in a nuke is the crushing of the fissile material to reach "critical mass" giving it enough gusto to start the nuclear bit of the explosion.

but thats caused by conventional explosives in a sealed vessel. although thats just the early trigger types, there's probably something slightly more sophisticated available now.

after a massive blast such as a nuke there is a sort of implosion, as air rushes back in to fill the gap created, this is what causes the "mushroom cloud"
 
As far as I know there are two basic methods to achieve nuclear critical mass in missiles and bombs, both of which are designed to increase the density of the material to provoke a chain reaction -
1) used a gun type idea where a lump of fissile material is fired into another, larger lump, the resultant impact causes critical mass to be reached and the nuclear chain reaction to occur.
2) the 'implosion method' used a spherical shaped charge surrounding a ball of fissile material. When ignited the conventional shaped charge creates a pressure wave that condenses the fissile material until the nuclear reaction happens.

These where the basic early type designs.

Roughly speaking, I guess an implosion is simply an expression of a difference in pressure between inside (lower) and outside (higher) on a structure that can no longer resist that differential.
 
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Wouldn't the results depend on the force of the implosion and the properties of the surrounding material?

An extremely forceful implosion might generate an inward force large enough to suck someone in, but that's not going to happen with a standard size flourescent light tube. With that, you'll get force (and shattered shards of the tube) outwards. But not enough to be a problem - if you're hit by a shard it would probably be due to gravity because the tube was above your head.

I managed to break a CRT in a fairly catastrophic way when I was a kid. I'd heard that they could explode (incorrectly, since they implode, but I didn't know that at the time) so when I found an old TV dumped in a small long-disused quarry shortly afterwards my first thought wasn't the message that the warning was intended to convey. It was "Wow, EXPLOSION!" because I was a kid. So I put it screen upwards and dropped rocks on it from about the edge a couple of dozen feet up. Sure seemed like an explosion to me - loud noise and bits of glass flung out forcefully.
 
Nuclear warhead designs use an explosion form "traditional" explosive material surrounding the nuclear material to create enough pressure within the nuclear material to start the fission process. This is what was used in the earlier bomb designs such as those dropped in Hiroshima and Nagasaki. Thermonuclear weapons, such as the Tsar "H" Bomb, then use the exhaust from the fission process to superheat a secondary nuclear material into a fusion reaction. So it's not an implosion, it's compression.
 
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