*breaking news* Boston Marathon explosions
- Thread starter Azza
- Start date
Associate
Wish I didn't go to Live leak now
Associate
Indeed, but directly near to (i.e. shortest distance)?
Probably meaningless, but any clues are helpful.
Associate
With the way the glass is on the street it almost looks like the bomb was inside the building?!?!
If the bomb was outside surely the glass would have been blown inwards??!?!
Truly horrific stuff , RIP
Doesn't work like that, the bomb sends shock waves faster then the outwards force wave, shockwaves will cause the glass to shatter first causing the glass to be blown towards the source
Ahh o.k, cheers for clearing that up.
Yeah I don't recommend anyone goes liveleek unless you have the stomach for seriously gruesome images
Soldato
Have they said whether it was the first blast of the second which was deadly? Or both?
This reminds me why I do, actually, like you.
You made me smile and laugh when I was a bit depressed thinking about the actualities of the apparent - and rather indiscriminate - death of an innocent 8 year old child.
/ ![[TW]Sponge](/styles/overclockers/avatars/6.png){kind=avatar}
Soldato
I should think there were crowds of people around both of the explosions, so strong possibility both were deadly.
Associate
I'm not at all sure about this statement, I am no expert in the dynamics of explosions however I am currently studying Physics at university so I know a bit. You seem to be implying that there will be an inwards force causing the glass fragments to be pulled towards the detonated explosive - I am struggling to determine what exactly that inwards force is* if there is one; either I'm tired, or you're statement is incorrect.
Sure, the supersonic exothermic front will produce a shockwave - however, the shockwave essentially is the "outwards force" you are speaking of, is it not?
* Of course, there may be some inwards force due to oxygen being propelled very briefly towards the source but that would not cause the glass to be drawn towards the source I don't think.
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Associate
Went to ******** for updates, regrettably.
It's so messed up when innocents get cut down like this.
I made the same mistake... curiosity got the better of me and now I doubt I will be able to sleep. I could never be in the emergency services. The things those guys must see....
Awful act.
Associate
There is negative pressure (suction) immediately behind the initial overpressure blast wave, which in confined spaces can suck smaller airborne fragments back into the centre of the explosion, some of which is then pushed upwards by convection caused by the heat of the blast. There will also be reflection of the shock wave as it bounces off nearby surfaces. It all happens rather quickly.
Most of the time though the initial shock wave pushes stuff outwards and this is kept moving outwards by suction as the wave travels away from source.
The Omagh bomb looked similar and it was outside some buildings too.
Source: designed some blast-resistant structures in the past. Interesting document here: http://www.google.co.uk/url?sa=t&rc...GmK8qM1qDyJ6yk_Aqdga9cQ&bvm=bv.45175338,d.d2k
Also here:
http://www.scribd.com/doc/33468937/...the-Effects-of-Accidental-Explosions-USA-1990
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I think the whole thing would depend on how the building front flexed with the shockwave. I don't think the glass exploding out from building neccesarily tells us where the blast came from.
The picture of the guy with his legs blown off, both lying on the ground with blood every where and the bones of his legs sticking out where his legs have been severed from above the knee and then the other 2 of him being transported by a hero in a cowboy hat and 2 others are pictures that need to be seen, but I doubt they can be posted on a family forum such as this.
Obviously that would only occur in an open space as I'm struggling to believe an explosion inside a building would cause the windows/glass to blow inwards!!
I'm 99% sure the glass would be blown outwards if a bomb was detonated inside a building!
I'm 99% sure the glass would be blown outwards if a bomb was detonated inside a building!
The issue I have is that the pictures of him have been posted unpixelated in places.... seriously not cool. Any number of worried families will be trying to get information about this incident and for a relative of his to find out whats happened to him that way isn't really on. He and others might still die from their injuries.
Associate
Obviously the blast wave is travelling faster than the speed of sound, so immediately following the blast any fragments will still be in mid air as the reflected shockwave (high pressure gas front) pings of all the nearby surfaces, affecting their position. Combine this with the suction effect following a high pressure front screaming past along with heat convection and you'll find that it is pretty difficult to predict the final resting place of small fragments.
Very true, too late for that though, and since they are out there, people should see the true face of violence.