41–50 of 142 posts
With all the high speed trains in Europe, I'm wondering why we don't see more security around them. It seems a much easier target than airplanes.
There is, in Spain you have mandatory luggage control before boarding high speed trains. I think it was implemented following this massive terrorist attack in 2004: https://en.wikipedia.org/wiki/2004_Madrid_train_bombings
Earlier quoted context omitted.
That's more because of the ozone layer. While it's not good to use halon in a semi contained space like an airplane, it is incredibly effective at killing fire. It really sucks the heat out of it. Thus in most cases the fire is killed quickly and not much toxins are produced. This is important too because fire itself produces a lot of lethal toxins too, most people in a fire don't burn to death but get poisoned by th…
> It really sucks the heat out of it. One of the problems with halon, and the write-up mentions this, is that it is super effective at starving the fire of oxygen, but has zero effect on the heat of the fuel that was burning. So the fire goes out, but if oxygen is reintroduced before the fuel has a chance to cool sufficiently, it reignites - and now not only are you back where you started, but you have all the toxic…
That's not actually quite how it works. But yes, the end result is the same. I'll copy-paste my comment from the Medium:
That's NOT how halon works! It's a common misconception, but it's incorrect. In fact, halon doesn't react with pretty much anything, it's very chemically stable. You can mix halon with pure oxygen and it'll just sit there, doing nothing.
This stability is exactly why it works so well. You need only a few _percent_ of halon by volume to stop the fires, not even close to consuming even a fraction of the 21% of oxygen.
Normal oxygen consists of two atoms bonded together (thus "O2"). And fire is spread by oxygen radicals, lone oxygen atoms that have an unpaired electron, eager to make bonds. In a fire, an oxygen radical reacts with a molecule of fuel, and this reaction produces enough energy to create at least one more oxygen radical, sustaining the chain reaction.
But halon has these chlorine and bromine atoms, they are bound tightly to carbon, but not as tightly as oxygen would be. So oxygen radicals have enough energy to displace them and bind to the central carbon atom. But the resulting energy release is not enough to create _more_ radicals, so the chain reaction is stopped.
Moreover, the chlorine radical can then snap back onto another carbon atom (from the fuel source), releasing a bit of energy, but not enough to create a new oxygen radical. And the cycle can repeat again.
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given how long and heavy trains are, and how fast they can go, and the fact that rails aren't straight, sure you can. https://spectrumlocalnews.com/tx/south-texas-el-paso/news/20... a train crashed into the chamber of commerce building in Pecos Tx 5 days ago.
…yes, but you can’t do this with a train https://en.wikipedia.org/wiki/September_11_attacks
https://en.m.wikipedia.org/wiki/List_of_terrorist_incidents_...
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…yes, but you can’t do this with a train https://en.wikipedia.org/wiki/September_11_attacks
But you can do all of these: https://en.m.wikipedia.org/wiki/List_of_terrorist_incidents_...
A rather well-written piece. My takeaway is that the French investigators are pros and the Egyptians are hacks. And that safety culture matters. One must not bend the facts to draw a desired conclusion. One must review the data without bias, or else recuse oneself.
> My takeaway is that the French investigators are pros and the Egyptians are hacks Describing them as "hacks" is weird. In most dictatorships, the concern is usually "What does the country's leadership want the official story to be" rather than "What actually happened". Take this quote from the article for example > "In my opinion, the problem with the report is that it appears to treat the findings of the Triple Co…
A rather well-written piece. My takeaway is that the French investigators are pros and the Egyptians are hacks. And that safety culture matters. One must not bend the facts to draw a desired conclusion. One must review the data without bias, or else recuse oneself.
There are essentially two ways to solve a mystery:
A) Consider the evidence and draw a conclusion from them.
B) Consider the conclusion and draw the evidences for it.
Neither is the correct methodology, especially when politics, power dynamics, and social justice are involved.
A rather well-written piece. My takeaway is that the French investigators are pros and the Egyptians are hacks. And that safety culture matters. One must not bend the facts to draw a desired conclusion. One must review the data without bias, or else recuse oneself.
>One must not bend the facts to draw a desired conclusion. One must review the data without bias, or else recuse oneself. There are essentially two ways to solve a mystery: A) Consider the evidence and draw a conclusion from them. B) Consider the conclusion and draw the evidences for it. Neither is the correct methodology, especially when politics, power dynamics, and social justice are involved.
Earlier quoted context omitted.
>One must not bend the facts to draw a desired conclusion. One must review the data without bias, or else recuse oneself. There are essentially two ways to solve a mystery: A) Consider the evidence and draw a conclusion from them. B) Consider the conclusion and draw the evidences for it. Neither is the correct methodology, especially when politics, power dynamics, and social justice are involved.
With all due respect, (B) is logically unsound in my mind. You may have meant considering the hypotheses, and then using available data and only available data to rule in or rule out certain scenarios. In my mind, based on decades of studying engineering defects and failures, starting with a conclusion is not a way to solve a mystery at all. Rather, it is only a way to convince oneself of a falsehood. To give an exam…
That's because you're concerned about finding out what happened. Not everyone thinks like that, namely some (many) are concerned about creating what happened.
Earlier quoted context omitted.
With all due respect, (B) is logically unsound in my mind. You may have meant considering the hypotheses, and then using available data and only available data to rule in or rule out certain scenarios. In my mind, based on decades of studying engineering defects and failures, starting with a conclusion is not a way to solve a mystery at all. Rather, it is only a way to convince oneself of a falsehood. To give an exam…
>With all due respect, (B) is logically unsound in my mind. That's because you're concerned about finding out what happened. Not everyone thinks like that, namely some (many) are concerned about creating what happened.
Earlier quoted context omitted.
>With all due respect, (B) is logically unsound in my mind. That's because you're concerned about finding out what happened. Not everyone thinks like that, namely some (many) are concerned about creating what happened.
Very interesting. Thank you for making the distinction explicit and for helping me to understand the other mindset. You are totally right, in that my mindset is closer to a forensics mindset in such instances, trying to get as close as possible to the "truth", so as to avoid future similar defects and improve system reliability. I do agree that some people prefer to manufacture truth. Any advice on how to get along w…