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Order of magnitude estimate of Beirut explosion at 3 kilotons of TNT

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Re: Order of magnitude estimate of Beirut explosion at 3 kilotons of TNT

#211

Post by lma21 »

mekster wrote: post #199
lma21 wrote: post #174

I have family and friends living in Lebanon. The explosion destroyed the windows of most homes in Beirut. Apartments of my family, friends, and colleagues have been shattered. Even the ones living dozens of kilometers away from Beirut. It's horrible, what pure incompetence can do to a people already living in poverty and under the covid-stress. I hope something good comes out of this...

What good do you expect out of this mess? Like, some other location fixed their storage strategy to avoid same fate?

Change the whole governmental bodies. Build a new constitution. Hold new elections. Create a government that acts and builds, not one that talks and promises. Something that can lift this poor, small, desperate country out of its misery. I'm hoping for such changes...

Re: Order of magnitude estimate of Beirut explosion at 3 kilotons of TNT

#212

Post by est31 »

agumonkey wrote: post #161

What are the pollution consequences of this (if any) ?

Dust pollution has turned out to be quite significant in the 9/11 aftermath, causing cancer in thousands of people.

> As of August 2013, medical authorities concluded that 1,140 people who worked, lived, or studied in Lower Manhattan at the time of the attack have been diagnosed with cancer as a result of "exposure to toxins at Ground Zero". It has been reported that over 1,400 9/11 rescue workers who responded to the scene in the days and months after the attacks have since died.

https://en.wikipedia.org/wiki/Casualties_of_the_September_11...

The pictures of Beirut seemed quite dusty, reminiscent of the 9/11 pictures.

Beirut 2020: https://streamable.com/22e152

NYC 2001: https://i.imgur.com/jfLUAiK.jpeg

Re: Order of magnitude estimate of Beirut explosion at 3 kilotons of TNT

#213

Post by zimpenfish »

sillysaurusx wrote: post #76

@quantian1 correctly determined that this was an ammonium nitrate blast by analyzing the footage: https://twitter.com/quantian1/status/1290695231910875136 CHEMISTRY FACT: Explosives have characteristic "detonation velocities" at which shockwaves expand. Smartphone video records at 30 FPS, so the adjacent frames here suggest the front expands at ~100 m/(1/30 sec), or 3,000 m/sec. Consistent with ammonium nitrate, not…

Dr Moudhy Al-Rashid has a thread of ways you can help.

https://twitter.com/Moudhy/status/1290969922672173057

Re: Order of magnitude estimate of Beirut explosion at 3 kilotons of TNT

#214

Post by vishnugupta »

nitred wrote: post #186
supernova87a wrote: post #109

The amount of material must have been ridiculous to store in such a place. The blast is staggering in size, almost like the Tianjin explosion a few years ago. Collected videos: Angle #1 https://streamable.com/xmmoa7 Angle #2 https://streamable.com/nscx9m Angle #3 https://streamable.com/zbjj5f Angle #4 https://streamable.com/saoafz Angle #5 https://streamable.com/4ga1vb Angle #6 https://streamable.com/lmivb2 Angle #7…

In Angle #6, did that crack in the roof occur in real time due to the explosion or does it just seem that way due to low resolution of the camera? If that crack was due to the explosion, then I'm concerned for much of the infrastructure which is within a 3 KM radius around the explosion.

It does seem to be real time. I noticed the delay as well in angle #7. The shock wave hits the car and the driver a good 3-4 seconds after the blast.

Re: Order of magnitude estimate of Beirut explosion at 3 kilotons of TNT

#215

Post by worldpeacenow »

Ammonium nitrate is 1.35 less potent than TNT. So this was just over 2,000 tons of TNT blast. The first nuclear bomb ever dropped was 15,000 tons of TNT of force. So this was 13.3% of the force of what Hiroshima experienced. About 70,000 people died from Hiroshima. So 13.3% of Hiroshima force is still devastating. It's probably not going to be nearly as bad as 13.3% of 70,000 deaths because Hiroshima was more densely packed and there wasn't the electromagnetic pulse wave that vaporizes people and long lingering radiation associated with a nuclear bomb. ... Still what happened in Beirut is immensely devastating.

Re: Order of magnitude estimate of Beirut explosion at 3 kilotons of TNT

#216

Post by moksly »

mekster wrote: post #197
moksly wrote: post #108

Earlier quoted context omitted.

Why is Trump used as a source on HN? I don’t think I’ve ever seen that man say something that was useful or true. I’m not American, mind you, so I’m certainly biased because he’s mainly in our media when he does something stupid, but everything I have ever heard him say about Europe has been so far from the truth that it’s hard to take his word on anything.

> I don’t think I’ve ever seen that man say something that was useful or true. Bashing a foreign president is easy but why don't you keep it to the facts? No, I'm not an American either.

Well, turned out it wasn’t a bomb. So the anecdotal record holds.

Re: Order of magnitude estimate of Beirut explosion at 3 kilotons of TNT

#217

Post by ashtonkem »

TooSmugToFail wrote: post #175
ashtonkem wrote: post #137

Earlier quoted context omitted.

You could tell it wasn’t a military explosive by the noise. Military explosives tend to be of the high speed type, and tend to make a sharper snap. This looked and sounded more like what you’d see in mining, which is pretty close since ANFO (made with ammonium nitrate) is indeed a mining explosive.

But what about the regular shape of the blast? Looking at the videos of Tianjin disaster, there are multiple large explosions, each with a massive fireball, highly irregular, fiery projectiles flying everywhere etc. The massive blast in Beirut was a singular event, with no preceding or subsequent blasts of similar magnitude. As if the ignition of the material was very efficient.

What you’re describing is the difference between a detonation and deflagration. Explosions are usually extremely regular in shape unless if obstructed in some way due to the way shock waves propagate in open air.

And the Beirut explosion wasn’t just one detonation. There were two explosions, with a large fire and small detonations prior to the largest detonation. In all of the videos you can see a huge plume of smoke before the final detonation, as well as fire and smaller explosions if the video was close enough.

Re: Order of magnitude estimate of Beirut explosion at 3 kilotons of TNT

#218

Post by mzs »

kgm wrote: post #44

I am seeing other analyses that put the size of the explosion at about one tenth of this size. The analysis in this Twitter thread correlates the observed degree of damage with the distance from the explosion. It comes up with an estimated 240 tons TNT-equivalent, though naturally this comes with a considerable margin of error. https://twitter.com/GeorgeWHerbert/status/129071971954515968... This Twitter thread is mak…

an expert's thread from this morning: https://twitter.com/johnismay/status/1290858204788924416

Re: Order of magnitude estimate of Beirut explosion at 3 kilotons of TNT

#219

Post by hanche »

tigerlily wrote: post #102
selimthegrim wrote: post #53

Earlier quoted context omitted.

It was G.I. Taylor.

Using the Buckingham Pi theorem.

And data from smaller explosions of known magnitude, in order to determine the dimensionless constant that cannot be determined from Buckingham’s theorem alone.

Re: Order of magnitude estimate of Beirut explosion at 3 kilotons of TNT

#220

Post by hanche »

contravariant wrote: post #6

Unless I'm missing something they forgot to account for the fact that dimensional analysis will only give you a result up to a constant. This should be somewhat obvious as otherwise you'd get a different result with different units (and no SI units won't save you here, those just work for several common equations in physics not ones you came up with yourself).

You should be able to determine the constant experimentally by running controlled experiments. Preferably with smaller amounts of explosives.

(It’s been too long since I read Taylor’s paper. I thought he had relied upon such experimental data, but it appears I misremembered.)

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