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- I'll guess that something about hot lava prevents some kind of radioactive decay from occurring, but I can't imagine how.
That's because it doesn't influence the decay rates. The age of stones is measured by effects of decaying nuclei or other forms of radiation on them, from within (Uranium-Lead or other forms of isotope ratio dating) and without ((thermo)luminescence). Once the rock is formed, it stops releasing (some) products of decay or replenishing less stable isotopes, which is not unlike removing a living organism from C14 cycle after it dies.
EDIT: Do keep in mind that the above explanation is somewhat idealised. Also, wikipedia has a nice overview of chronological dating methods if you are interested.
My opponent didn't show up, probably because of all this influenza going around. Shame, I was looking forward to this match. We played six years ago, shortly before I burned out for a few years, and I remember that game as having one of the most inventive endgames I got to experience first-hand. Anyway, for better or worse, I'm 3/3 and taking the lead.
Exam season will start soon, but about a third of my courses already handed out our 'take home' problem sets. I'm oscillating between panicked "where do I even start?!" and "I got this" about every other hour, so it's business as usual. This just doesn't end. Seven semesters in and nothing about it feels routine.
I'm almost ready to delude myself into thinking that the hardest parts of my theses are behind me and all that's left is smoothing out the rough edges.
Thanks for the explanation. I'll probably ask questions in a separate post.
- What if we chose a dipole moment for 'Oumuamua consistent with a superconducting medium, just to be conservative?
I guess it would magnify the effect but make a measurable change to the tumbling motion? That is unless your probe has some inertia dampeners next to its tachyon coils. ;)
For an idealised case with weaker magnetic fields (i.e. not strong enough to forcibly change the superconductor's nature to one of the mixed states/phases), it would also be solely and universally repelled from the incoming solar wind and said magnetic field, so there's your acceleration source.
- As an example, if Mars were to have something hit it, and a chunk was to break off, it would be a magnetized chunk, albeit extremely weak compared to superconducting moment. The Martian mantle cooled below the Curie temperature like a billion years ago and the local orientation of the global magnetic field was frozen in.
Wouldn't ejecta from such impact become at least largely demagnetised by a combination of shock and temperature? Especially seeing how it would be cooling in the interplanetary space. I know that Martian meteorites are slightly magnetic, but I'm not sure (and can't seem to find conclusive papers/sources) if what we measured on Earth is mostly the original, unchanged field.
Cool! If you (or anyone else) would like to play a correspondence game (1 move per week or so), then feel free to hit me up on Lichess. I'm always open for taking back moves, discussing potential situations and offer hints/instruction as we play.
According to this article, the strongly magnetized object hypothesis is unlikely to be the only source of anomalous acceleration. To quote:
- If ‘Oumuamua had a strong magnetic field, then interaction with solar wind could affect its motion. Assuming a dipole field, a plasma-fluid model and typical solar wind speed and proton number density, we find the resulting acceleration for an object of the nominal size of ‘Oumuamua to be only 2 × 10^(-11) m/s², too small by a factor of about 10^5, even if we adopt the high magnetization and density of asteroid (9969) Braille.
(Changed some of the typography to make it more readable.)
I'm somewhat interested in the odds of an interstellar object not having a neutral magnetic field. Intuitively, lack of net charge or magnetization should be the norm but I'm far out of my depth here.
Also: consider yourself prompted.
This week's chess match concluded with a very rare victory for me: opponent timeout. Usually, I was the one wasting too much time during tournaments and needed to scramble something halfway decent during the last few precious minutes. It was a very close situation up until the very end. Were the game allowed to continue, I'm not sure if I'd pull it off.
Both of the theses progress at a respectable pace. My physics adviser told me he'd be happy to take me as his PhD student and there's a grant placement with my name on it if I so choose. I'm still a bit uncertain about all of it, though. On the one hand, I have my merits. On the other hand, almost everyone from this department over the age of 40 knew or worked with my father at some point. It's not like 'legacies' are without precedent, but it's been in the back of my head all this time. There are still a few months to decide, but I'm wondering if it wouldn't be for the better if I switched to a different university for the doctoral programme.
But, overall, the hot streak continues!
I set my windows station as a dual-boot of Win 7 and 10 a few months ago. In my case, it's mostly for testing stuff, learning C#/F# on their proper platform (yes, I know about Mono) and getting some hands-on experience with those systems. The overall experience is neither appalling nor amazing. Both were thoroughly decrapped, and IMO I did my best to prevent suspicious network activity. There are no long-term plans for this box, but at the moment I have no reason to repurpose or wipe it clean.
I'd guesstimate that 90% of my work continues to be done on Linux or FreeBSD, so there's that.
EDIT: I'll likely preserve the Windows 7 partition, maybe a VM copy as well, after the final updates. At worst it's going to be a waste of space, at best I'll find some cool use for it, for a loose definition of cool that is.
- Won the first match of the chess tournament.
- So far I aced every single one of the bullshit "Christmas break doesn't imply free time" assignments.
- After two months of walking in circles, I had such a lucky streak of minor findings that my maths thesis finally goes somewhere.
- My first paper got a green light from peer review, so I guess it's getting published.
As far as the start of the new year is concerned, this one is looking bitchin'. Top one of the decade for me.