Is Time Travel (going backwards) Possible?

[Umbran]

Actually, the weak nuclear force interacts (roughly) equally with protons and neutrons, so that won't work.

I know. I was thinking more about the effect on cross section from the density and size of nuclei, and thinking back to my lectures on how materials for the various neutrino detectors were chosen - the only issue being how long ago those lectures were

The collisions are shockingly low energy, actually. The earth's orbital speed is only about 1/1000 the speed of light, which is similar to what we believe is a typical DM speed in the galaxy.

Ah, yes, that'd do it.

I'd recalled some reading a while back that suggested that what we'd likely see in detectors was the DM equivalent of a high-velocity star, that has come out of an interaction with a bunch more energy than the run-of-the-mill particle. The piece included some cogent thoughts on the velocity distribution, and justification for thinking that such particles would be common enough to detect, and more likely to be seen due to the higher energy.

 

[Bullgrit]

Reading these extreme scientific conversations is fascinating to me. But as a non-scientist, I can only understand [parts of] it in a vague sort of way. It's sort of like back in the 80s trying to watch porn on a scrambled cable channel.

Bullgrit

 

[Dannyalcatraz]

It's sort of like back in the 80s trying to watch porn on a scrambled cable channel.

That had an entirely different kind of dark matter, though.

 

[Umbran]

It's sort of like back in the 80s trying to watch porn on a scrambled cable channel.

I believe this is the first time I have seen physics-geekery compared to porn.

Anyone here watch the American version of "Whose Line Is it Anyway"? They had a game called, "If you know what I mean...," where the players attempt to put together a dialogue using improvised innuendo and euphemisms.

"Well, he got himself stuck in a closed timelike curve, if you know what I mean..."

 

[freyar]

Reading these extreme scientific conversations is fascinating to me. But as a non-scientist, I can only understand [parts of] it in a vague sort of way. It's sort of like back in the 80s trying to watch porn on a scrambled cable channel.

Bullgrit

Yeah, I'm not entirely sure how we got on this subject myself. It's also very difficult to know how to explain things here, since I like to make things understandable for as many people as possible while at the same time having a discussion on sometimes pretty technical issues with other science folks on the boards.

 

[Aaron L]

Oh I think you're doing fine. I get easily lost in the math of physics (genuinely having Attention Deficit Disorder tends to screw with ones advanced mathematical abilities, regardless of how intelligent one is otherwise ), but when it's talked about the way you and Umbran have been I find it fairly straightforward to follow. And utterly fascinating. Please, keep going.

 

[the Jester]

Oh I think you're doing fine.... I find it fairly straightforward to follow. And utterly fascinating. Please, keep going.

All of this!

 

[Someone]

I believe this is the first time I have seen physics-geekery compared to porn.

Anyone here watch the American version of "Whose Line Is it Anyway"? They had a game called, "If you know what I mean...," where the players attempt to put together a dialogue using improvised innuendo and euphemisms.

"Well, he got himself stuck in a closed timelike curve, if you know what I mean..."

The Cyberiad has a tale of an artificial poet that composes a poem about love in mathematical language (it makes more sense in context). It's absolutely hilarious.

Edit: I even found the quote:

Come, let us hasten to a higher plane
Where dyads tread the fairy fields of Venn,
Their indices bedecked from one to n
Commingled in an endless Markov chain!

I'll grant thee random access to my heart,
Thou'lt tell me all the constants of thy love;
And so we two shall all love's lemmas prove,
And in our bound partition never part.

Cancel me not — for what then shall remain?
Abscissas some mantissas, modules, modes,
A root or two, a torus and a node:
The inverse of my verse, a null domain.

 

[Nellisir]

Perhaps very pertinent? http://www.sciencedaily.com/releases/2012/11/121119094627.htm

 

[Dannyalcatraz]

They say they are only certain to a 1 in 10 tredecillion (1043) or 14-sigma level of certainty, but they're getting their info from BaBar. Why trust any elephant that much? Especially a FICTIONAL one?