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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

#21
post #3

Similar in size to the Halifax explosion, then. https://en.wikipedia.org/wiki/Halifax_Explosion

Wow, and for comparison the viral 2015 Tianjin explosions in total released 28 tonnes of TNT of energy, or 100GJ.

https://en.wikipedia.org/wiki/2015_Tianjin_explosions notes "336 tons TNT equivalent."

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

#22

Wikipedia's page of the largest non-nuclear explosions [1] was already updated and states "It generated a shock-waves equivalent to 13 tonnes TNT". Not sure who made this estimation and how, but various photos on that page can give you an idea what a large explosion looks like. For example take a look at the Yamato explosion [2]. Yamato was a 70000 ton Japanese battleship; the large explosion was due to its magazines…

It has been updated to approx. one kiloton of TNT equivalent now.

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

#23
post #11

Al Jazeera is reporting that according to the president in Lebanon, it was almost three thousand tons of ammonium nitrate that blew up https://www.aljazeera.com/news/2020/08/huge-explosion-rocks-... .

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

Yeah, honestly, the Beirut explosion looked bigger/scarier to me, like how they show nuclear explosions in the movies. The Tianjin explosion was an enormous fireball but didn't seem to have the same magnitude of shockwave from the videos I've seen of it.

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

#24
post #9

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).

The underlying assumption in this analysis is that the constant is 1. Maybe I should have clarified that in the thread.. Thank you for pointing it out!

Okay looks like there is some justification for that assumption given by G.I. Taylor.

By the way with your data it looks like you get a better fit if you assume your first image is not at 50ms but rather 38 ms. A line fit between t and r^(5.2) gives a slope of 1.6 10^13. This gives 4 kt if you use the lower estimate of 1 kg/m^3 for the density of air.

I do worry you may have overestimated the distance slightly, as these numbers are frankly ridiculous, and with a power of 5 even small errors grow quickly.

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

#25

Earlier quoted context omitted.

What's with "Media"-blaming nowadays, it seems every Tom and Dick expects them to say/do in-depth analysis of everything Tom or Dick wants... At least the main media I read gets it, e.g.: https://www.theguardian.com/world/live/2020/aug/04/beirut-ex... On a slight positive side, at least this explosion will mean the rulers of that country can now ask for help without losing face/admitting their failures/corruption...

It's buried when I go to the Guardians homepage. Might be localised though. This is real news. I expect it to be easy to see. Not a doomscrolling meaningless repeat of the C19 countdown for the day.

Is it? A fireworks explosion in Lebanon is more important to me than whether Congress gets unemployment support fixed, or how my city is doing with the pandemic? Or whether a tropical storm is flooding NYC?

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

#26
Lebanon has its share of enemies, internal and external. All it would take is a mavic inspire drone to fly over and drop the initial explosive.

Trump said "it looks like a terrible attack" at his news conference. Which is probably what his intelligence officers/advisors speculated when they briefed him.

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

#27

Earlier quoted context omitted.

It's buried when I go to the Guardians homepage. Might be localised though. This is real news. I expect it to be easy to see. Not a doomscrolling meaningless repeat of the C19 countdown for the day.

See, again with the expectations. If every big event requires a link to in-depth analysis on the front page of a news site, they'd need to have a small font size and a 16K monitor... And you'd complain that it's not in the corner you looked.

If you think this shouldn't be the clear headline, then I guess we consider news to be different things.

I'll go back to reading next in my feed how George R R Martin is racist because he mispronounced someones name (Not an article in the Guardian, and the Guardian's coverage is exceptional for Beirut compared to others like CNN or Fox)

[edit] Does the media not care about the largest peacetime explosion in a capital city because they are Arabs? What exactly is bigger than this today?

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

#28
post #11

Al Jazeera is reporting that according to the president in Lebanon, it was almost three thousand tons of ammonium nitrate that blew up https://www.aljazeera.com/news/2020/08/huge-explosion-rocks-... .

I'd like to know why it initially sounds like fireworks

https://twitter.com/HeshmatAlavi/status/1290683991369097216 [camera operator probably would have died in the second blast]

Is that what set it off? Or is that what ammonium nitrate sounds like burning?

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

#29

Earlier quoted context omitted.

See, again with the expectations. If every big event requires a link to in-depth analysis on the front page of a news site, they'd need to have a small font size and a 16K monitor... And you'd complain that it's not in the corner you looked.

If you think this shouldn't be the clear headline, then I guess we consider news to be different things. I'll go back to reading next in my feed how George R R Martin is racist because he mispronounced someones name (Not an article in the Guardian, and the Guardian's coverage is exceptional for Beirut compared to others like CNN or Fox) [edit] Does the media not care about the largest peacetime explosion in a capital…

Reply to your edit: who's "media" here? The Guardian has it front and center and red (red means live news event). If your "media" falls below your expectations, then stop reading them. But stop saying all media is shit because you read shit news sites. IMO you're part of this problem of people saying all media is illegitimate because some of it is shit...

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

#30
post #4

The media doesn't seem to understand how big this is yet in short and long term damage and loss of life. I guess that doesn't matter? They are more for political bickering now? Running theory Ammonium Nitrate stored at port for many years - https://mobile.twitter.com/HachemYassin/status/1290702640930... [Edit] Skipping the loss of grain and produce in port and the actual port in a country on the brink during a pandem…

This story is on the front page of every major news site in the world right now.

They're not providing an "in-depth analysis" because there aren't yet sufficient facts to analyze. Even the authorities don't yet know what actually exploded, or what caused the explosion, or the number of dead, or the number of wounded, or the number of missing.

Get off your high horse.

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