273 karma · joined March 4, 2015
A lot of people complain about DM being fuzzy, and that’s exactly why: we only have indirect evidence. So what everyone wants is a direct measurement of DM, for example a particle signal if DM is a WIMP.
And to your last point: that’s exactly it, the thought of an unknowable thing in the universe is terrifying, frankly. And this has nothing to do with wanting to be right, whatever DM is, I just want to know, even if it’s fancy MOND without defects somehow, or MACHOs.
The gravitational discrepancies we have already, but without an explanation or observation, they’re not very satisfactory.
Until there’s an actual convincing alternative, that indeed is not as apparent as you make it out to be, that would be pretty terrible for a lot of physics.
Also: what makes you say a linear collider would be a better investment?
We use it in ATLAS to deploy both tagged releases and nightly builds. These can be about 100GB in size each.
The releases are used for production jobs across the worldwide grid, while the nightlies are used as development targets for individual developers.
It doesn't make sense to me however that the economics are ostensibly so different between e.g. Germany and France, where in the latter basically even small shops don't care. Either it's something to do with taxes like you said, or German shop's margins are razor thin.
This seems to indeed have started to rapidly change with covid.
That is not correct. Yes, alpha radiation doesn’t penetrate skin, but is dangerous if you ingest it. That’s one of the reasons people have abandoned underground long-term storage sites: they all eventually have water break ins and the worry is that the waste will contaminate fresh water supplies.
I find it fascinating that on HN anecdata that conforms with the vaccine being dangerous is totally accepted, but anecdata about people getting very sick from COVID are either considered lies or statistical outliers.
This is effectively a measure to maximize the output we can get from the machine, so to maximize the return in investment.
There’s a lot of debate in the field what should happen next. FCC is one possibility, but I’m personally sceptical (even though I work at CERN myself).
It seems to me there’s a clear need for a Higgs-factory as a follow up to LHC, but that doesn’t have to be a ring collider, a electron positron linear collider could fulfill this purpose as well.
He effectively had to limp his bike home because he was stuck in the gear he had riding uphill. Took him half a day or so rather than an hour.
I’m certainly not a Luddite but this doesn’t seem to be a worthwhile trade off for me.
Basically you observe that stuff stays the same if you move around (not true on earth, but like, in space, generally speaking). The physics is invariant under translation. That’s what we call a symmetry.
Now Emmy Noether came up with a relationship and formulae that connects each such fundamental symmetry with a conserved quantity. For translation the quantity turns out to be momentum. Conservation of momentum is one of the most fundamental building blocks of classical mechanics. And we can derive that it is in fact conserved from something as simple as a symmetry.
And it doesn’t stop there: next in line: invariance under rotation: angular momentum conservation, which is equally important as momentum conservation. If angular momentum wasn’t conserved, our universe would look entirely different.
Ages later people figured out that this symmetry business goes way deeper than initially thought. These U(1), SU(2) and SU(3) from the posted link are notation for other, less intuitive, symmetries. Here they don’t apply to space itself anymore but to quantum fields. With that and Noethers theorem (and some admittedly kind of involved maths) you can derive theories describing all electromagnetic and nuclear interactions.
So basically, these symmetries are effectively at the heart of the world (and physics) and I think that’s amazing.
We can measure the mass differences between the neutrinos pretty well through these oscillation experiments, but this also doesn’t tell us which the mass hierarchy. It could be bottom up or the other way round.
In principle, one neutrino could be massless and the mass differences we’ve measured so far would still be correct.
Aside from this, pretty much anything is on the table. Neutrinos being their own anti particles? Maybe. Fourth generation of neutrinos? Could be.
MMS (and in all likelihood RCS) is a complete non-starter for this market.
It's not surprising >90% of people in Germany use WhatsApp (+ other messengers)