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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

#141

Post by dragonwriter »

speedgoose wrote: post #140
colordrops wrote: post #96

Earlier quoted context omitted.

Trump is saying that military intelligence indicates that it's a bomb: https://m.youtube.com/watch?v=tPvH-CqH7Q8 Edit: why am I being downvoted. I am not agreeing with him or saying he is right. Just stating what was said. It seems noteworthy that the president of the US commented on it regardless of accuracy or trustworthiness.

Unverified and likely false information (fake news) is downvoted. If you question the accuracy of the information it's better, still not good, but you didn't before your edit.

> On the flip side, perhaps knowing that you are off the hook for paying for the expense of many children would increase the desire to reproduce?

Prosperity, and strong social safety nets in particular, have been shown to lead to decreased propensity to reproduce. The less one relies on family for old age, disability, unemployment, etc., support, the smaller families people have.

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

#143

Post by est31 »

nerdponx wrote: post #120
peteretep wrote: post #99

Earlier quoted context omitted.

> help directly You could do much worse than donating to the Red Cross and selecting “Disaster Relief”, and if you want to take an action, call your representatives and let them know how important you’d find a robust USAID response. Neither are sexy options, but both will have an effect https://www.redcross.org/donate/D072002.html

Does MSF have operations in Lebanon?

Yes, in fact most international aid organizations have major operations in Lebanon, because there is a large population of Syrian refugees, currently about a Million. Per capita, Lebanon takes in the most refugees from the war, at about 1 refugee per 4 ordinary inhabitants. It would be comparable to the US taking in 80 million refugees. Extremely impressive hospitality. They should absolutely be helped now that it's their turn to need it.

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

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

#144

Post by Someone »

fuzzfactor wrote: post #124
nodesocket wrote: post #17

Earlier quoted context omitted.

It's hard to imagine, but that would mean this explosion was nearly 3.5x larger than 2015 Tianjin[1] which was 800 tonnes of ammonium nitrate (336 tons TNT equivalent). The video[2] from Tianjin looked way bigger and apocalyptic, but perhaps just because of the the fireball. [1] https://en.wikipedia.org/wiki/2015_Tianjin_explosions [2] https://www.youtube.com/watch?v=ONsmJAyFAAw

2000 tonnes is a lot. Two ships loading ammonium nitrate, the Grandcamp and the High Flyer, detonated in Texas City back in 1947. https://en.wikipedia.org/wiki/Texas_City_disaster It says there was a 15 ft wave out into the Gulf of Mexico that lasted for almost 100 miles. And Texas City is not actually on the Gulf Coast, it is on Galveston Bay about a half hour away from the Gulf shore. And there is only a relatively…

I would think that narrow channel prevented spreading of the energy of the wave, making it easier to get large waves in the Gulf of Mexico.

Think of blowing out through a straw. The airflow at the end of the straw is a lot stronger than when the straw wouldn’t be there.

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

#145

Post by bigiain »

nradov wrote: post #88
chmod775 wrote: post #83

Earlier quoted context omitted.

Some chemist acquaintances of mine suggested the same from just looking at the footage immediately after. Along with some scary explanations of what fast shockwaves like that do to human blood vessels. I was convinced this stuff should be outlawed for most uses pretty fast. https://en.wikipedia.org/wiki/Ammonium_nitrate_disasters Though on the other hand, the number of incidents and deaths aren't that high considerin…

Ammonium nitrate is essential as a fertilizer. There are no cost effective alternatives so we'll have to just accept the risk.

A media report here in .au today told me only 1% of the ammonium nitrate sold here is for fertiliser, and 99% is used to make explosives for mining.

(I can't find the article I read, but my guess is that writer got those numbers from here: https://www.worksafe.qld.gov.au/injury-prevention-safety/haz... )

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

#146

Post by 5m17h »

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…

The Tianjin explosion has been in the impression that many Chinese people have forgotten

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

#147

Post by varjag »

codebolt wrote: post #122
gonzo41 wrote: post #111

Earlier quoted context omitted.

The natural heat was the killer. IF twitter was right the fire started from sparks from a welding on a door. The AN must have already been decomposing in the heat and under weight just waiting. I wonder how often this storage facility was at a critical point like this. Like how many hot days. How often before this. It makes you think about all the other risks sitting out there just waiting for a small spark.

There was also fireworks going of just before the blast. Storing 2750 tons of AN next to a fireworks cache seems cartoonishly stupid. https://twitter.com/ConflictsW/status/1290681902781861888?s=...

If prior to the explosion you were told that all dangerous cargo is stored in dangerous cargo area of the port, would you've thought it is stupid?

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

#148

Post by WalterBright »

rmm wrote: post #73
WalterBright wrote: post #52

Earlier quoted context omitted.

My fluid mechanics prof told the class that a scientist in the 1940's published the yield of the Hiroshima bomb. Since this was top secret, he got investigated. But he showed how the yield could be calculated from the film of the explosion - how fast the blast radius expanded. So I imagine the yield of the Beirut explosion could be calculated the same way from the video.

Paper in question. http://sites.science.oregonstate.edu/~restrepo/MTH481/Classn... From videos: R=450m t=1.5s rho=1.2kg/m3 E=9.84E12 kg.m2/s2 or 9.84E19 erg Equiv TNT = 2.5kTonnes -TNT Equiv AN = 5400 Tonnes So double what current media is saying. edit:formatting.

You da man! Thank you.

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

#149

Post by read_if_gay_ »

bigiain wrote: post #145
nradov wrote: post #88

Earlier quoted context omitted.

Ammonium nitrate is essential as a fertilizer. There are no cost effective alternatives so we'll have to just accept the risk.

A media report here in .au today told me only 1% of the ammonium nitrate sold here is for fertiliser, and 99% is used to make explosives for mining. (I can't find the article I read, but my guess is that writer got those numbers from here: https://www.worksafe.qld.gov.au/injury-prevention-safety/haz... )

But Australia probably has a pretty strong mining and relatively weak farming industry compared to most other nations.

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

#150

Post by lordgrenville »

mhh__ wrote: post #80
kleton wrote: post #63

Earlier quoted context omitted.

Feynman told that story about Fermi.

Imagine being so good that Feynman tells stories about you (rather than himself). Fermi also put Dyson down gently once "A successful theory must have either a strong physical intuition or a rigorous mathematical basis: you have neither"

Fermi was an inveterate experimentalist, always trying to measure and test things. Hence the idea of the Fermi estimate.

There's a good piece about him here: https://www.lrb.co.uk/the-paper/v40/n10/steven-shapin/think-...

>Fermi saw the Trinity Test as an opportunity for one of his famous exercises of rational estimation, a Fermi problem. First, he offered to take wagers from other scientists on whether the bomb would ignite the atmosphere, destroying New Mexico or even the entire world. Then, the evening before, he carefully prepared an experiment to estimate the bomb’s explosive yield:

> "About forty seconds after the explosion the air blast reached me, I tried to estimate its strength by dropping from about six feet small pieces of paper before, during and after the passage of the blast wave. Since, at the time, there was no wind, I could observe very distinctly and actually measure the displacement of the pieces of paper that were in the process of falling while the blast was passing. The shift was about 2.5 metres, which, at the time, I estimated to correspond to a blast that would be produced by ten thousand tons of TNT."

> "He was so profoundly and totally absorbed in his bits of paper," his wife recorded, "that he was not aware of the tremendous noise." The answer later calculated by the instrumentation specialists was 18 kilotons, but Fermi’s answer was arrived at on the spot – and it was correct within an order of magnitude.

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