Interesting Items...

The margin "proof" could have encapsulated the main steps of the modern formal proof leaving out a lot of the tricky detail that needed work to reach the rigour that is needed these days. The various fields employed in the formal proof are effectively different expressions of the same mathematical structures but which can make it easier to visualise and express the various detailed steps needed.
 
FFS. Send him back to Slovakia, and ban him from re-entry to the UK for life. It's so simple. Why can't anyone grasp it?
 
Someone guilty of manslaughter bleating about his social life. What about the poor person he killed? He should have been tried in an adult court. A (long) sentence followed by prpr's suggestion seems right to me.
 
A (long) sentence followed by prpr's suggestion
Why should we pay for that? At least a tag is cheaper.

I think all articles of that nature (whether newspaper or social media) should be compelled to carry a snowflake warning.
 
I've been reading in a recent Scientific American about using atoms in a Bose-Einstein Condensate and a hexagonal interference pattern of laser beams to simulate electrons in graphene, in a way which behaves analogously and is large/slow enough to be observed.

So far, so meh (he says, nonchalantly).

What really staggered me was that to form the BEC, the rubidium atoms (IIRC) in question have to be cooled to 100nK!!! That would freeze the brass monkeys well and truly.

I was explaining this to a friend (most of whom normally glaze over, or just say "yes" at strategic intervals), but all he could say was "what's a nanokelvin?".
 
I've been reading in a recent Scientific American about using atoms in a Bose-Einstein Condensate ...

What really staggered me was that to form the BEC, the rubidium atoms (IIRC) in question have to be cooled to 100nK!!! That would freeze the brass monkeys well and truly.

I was explaining this to a friend (most of whom normally glaze over, or just say "yes" at strategic intervals), but all he could say was "what's a nanokelvin?".

When I worked at Rutherford Appleton Laboratory a colleague was doing similar things with a laser to cool helium to very cold temperatures. It was part of working towards quantum cryptography capability for satellite communication IIRC.
 
Because it's that time of year, I was wondering today how long it takes to go from 24h light to 24h dark at the poles. Turns out it's about 7 weeks, and today is the last day of 24h light at the north. 2 weeks of civil twilight, then 2 more of nautical, then 3 weeks of astronomical. Coming out of it is about the same, as you might expect, obvs. the other way round.
 
It must be very strange seeing the Sun graze the horizon for a whole circuit.

I presume the "last day of light" is this far past the equinox because of the angular diameter of the solar disc, plus atmospheric refraction.
 
It must be very strange seeing the Sun graze the horizon for a whole circuit.
It must be very weird all year. It effectively helixes up to the top then helixes down to the bottom and so on, ad infinitum. No daily up and down at all like we are used to.
 
It must be very weird all year. It effectively helixes up to the top then helixes down to the bottom and so on, ad infinitum. No daily up and down at all like we are used to.
As nobody lives there, is it a case like a tree falling in the forest?

Just putting it out ... :)
 
I was gonna say spiral (as lots of people do), but that implies a changing radius.
Draw a line from top to bottom on a cylindrical packet of biscuits whilst rotating it (on the long axis). That's what I call a helix. Is that not what anyone else calls it?
 
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