John Cuthber

What do you mean by by "metal paint "?

Good catch; 30 years or so would do. It hardly matters.

A couple of years worth of decay for enriched uranium would get it a couple of parts in 700,000,000,000 towards "like that". I wasn't kidding about the ice age.

Well, you are right about "it doesn't matter". You may find this shocking, but before they make bombs out of it they have to remove practically all of those impurities and they only return on a timescale comparable with the decay rate of uranium- billions of years to get back to equilibrium, so... As long as the terrorists are not using enriched uranium produced- say during the last ice age- the fact that uranium is, itself, a very effective screen would solve most of their problem on the alpha , beta and gamma score. It's the neutrons that are a bit of a giveaway. And it still doesn't matter. Nobody is going to point a detector at the container until it is unloaded. If it's "booked" for through travel to, say, Canada, but goes off in the US nobody will ever know what ship it was on, never mind what container. This is why it's really important to keep weapons grade uranium and plutonium well guarded. Fortunately, for the most part, the people responsible for making the decisions do understand that weapons grade uranium is a pretty near pure alpha emitter and you can't rely on Geiger counters at the port.

If N Korea can't sensibly get caught out- there's always a plausible denial involving them being framed by a 3rd party- then the question of "how much is enough" takes on a different significance. And it's easy to get it out- just stick it in a shipping container. An answer might be " no money at all- but we will buy stuff in the West that is banned and then ship it to you". Still feeling safe?

The uranium and plutonium used in nukes are alpha emitters. you could use a cardboard box as shielding if you only wanted to fool a Geiger. It would do something towards shielding the spontaneous neutrons too. A tank of water would be better. But why bother. Stick it in a shipping container in N Korea. Maybe change ships somewhere unsophisticated. Send it to a large pot city in the USA + blow it. It doesn't eve need to be labelled for delivery in the US- it could go off in transit. There's no way they would find enough of the harbour (never mind the ship) to work out exactly what happened. It never goes near a radiation detector until it's unloaded- and you don't need to unload it to "deliver" it. There's no sensible way to prove it was the Koreans (even if the terrorist decide to say it was). How would you go about proving that it wasn't a "false flag" attack set up by the US itself? (perhaps as a pretext for war with N Korea)

It seems likely that he meant what he said; given the material, he could make a nuke. If all he wanted was what's usually referred to as a "dirty bomb" he wouldn't need a workshop and he wouldn't expect to be significantly contaminated.

The other 99 ideas are wrong.

Surges when you first turn the supply on are common- it takes a finite time for the bits of metal to move and throttle the supply. In principle, you should always turn the regulator "off" before connecting the supply (I'm not sure anyone actually does this unless it's critical). Surges during the day for no reason seem to me to be saying it's time to replace the regulator. Adding some sort of buffer volume may reduce the magnitude of the surge, especially if it is preceded by a flow restriction of some sort.

Which bits of this would be beyond the ability of a well funded terrorist or criminal gang? https://en.wikipedia.org/wiki/Gun-type_fission_weapon I can see how it's hard to get hold of the uranium (that's why enriched uranium is usually carefully guarded), but the rest seems simple.

They are also not flammable. Propane, butane and dimethyl ether meet most of your stated requirements but you should realise that this is a potentially very dangerous game to play.

It seems that 9/11 has made people forget that many, perhaps most, terrorists are "home grown" and don't need to ship internationally.

As opposed to a non vocabulary word?

Yes it does, that's more or less the definition of "drawback" isn't it? And it promotes things that are a huge advantage. It's just that sometimes the same trait can fall into either category depending on external circumstances, Well, it does. A big brain, for example, is a huge advantage- unless you don't need one for your lifestyle- in which case it's just a huge waste of calories. It's often an advantage for a useful trait to become widespread, but not universal, because of the value of diversity. For example the sickle cell trait is only useful sometimes but not at others. Can you explain the circumstances where a trait like, for example, mind-reading, would be a bad thing? (especially give that it would intrinsically provide a warning of such a circumstance.)

There's a summary here

The 184.9 nm light is, at best, poorly transmitted by air. The oxygen absorbs it. At least some bacteria (and other microorganisms) generate coloured materials to act as a "sunshade". These will generally be harder to kill Also, if the bacteria are in, for example, mud, they are pretty safe.

Are you aware of this? https://en.wikipedia.org/wiki/Solar_water_disinfection

I'm not sure if it's Trump being a good salesman or the media bigging him up and running down the opposition. If all the newspapers and TV say you are great then you are going to do well even if you are as bad as Trump is known to be.

I suspect that more alcoholics die from DTs than from dreams. We won't ever know.

Actually, its alcohol withdrawal that kills them. it's because they're alcoholics. without alcohol

Yes, we can choose to represent the whole Library by the character "#" Unfortunately, the system for expanding that character back to the original books will be longer than the books were and thus not useful.

As far as I can tell, the "sea" on Titan is largely methane and that's probably not dense enough to swim in either. And it would be cold. It would still be an interesting place for a holiday.

He lied about London before https://www.independent.co.uk/news/uk/politics/donald-trump-uk-should-thank-him-london-radicalised-police-scared-no-go-a6767606.html

John is a very common name for blokes my age. Cuthbert is a comic character I was likened to at school (my mum was a teacher so... sort of) Initially I dropped the T because the software wouldn't let me have more than 12 characters. I think I could change it, but I don't want to get muddled with anyone whose real surname is Cuthber and real first name is John.

I suspect that you will get hydrogen, rather than silicon.