Kevin's Watch

Posted: **Fri Nov 11, 2011 5:25 pm**

Vraith wrote:Is that part of one of the string-versions and the extra dimensions they need, or an entirely separate theory?

*shrug* I have no idea. It is probably one of the string theories, which as far as I can tell are just subsets of M Theory, which some people absolutely despise.

Gravity is weird, though. Think about it--with all the fuss that people were making over superluminal particles a few weeks ago when we already have a real-world example of superluminal phenomena--if the Sun moved (somehow) then the Earth would move instantly, not 8 minutes later. Gravity is faster than light.

Posted: **Fri Nov 11, 2011 5:52 pm**

That violates special relativity. Gravity in theory and as demonstrated in practice (though I think the experimental observations from obects in space are still somewhat shaky) travels at the same speed as light. The earth wouldn't notice the lack of the sun's gravitation for 8 minutes.

Posted: **Fri Nov 11, 2011 6:00 pm**

That is what is truly aggravating here--I have seen cosmologists and physicists state both as true. Of course, no one has yet discovered any particle responsible for "carrying" gravity.

Posted: **Mon Nov 14, 2011 11:50 am**

Vraith wrote: Talking on the fairly recent, and very surprising, discovery that not only is the universe expanding, which we knew...it is accelerating in expansion. So one approach to the reason for this is that "empty" space has some kind of material reality. And [this is a quick, not precise paraphrase, with many things left out you should watch it] because space is getting "larger," "more of it" it is pushing outward harder, against gravity, which is trying to pull things in. And space is winning.

Guess this is going to scupper the 'expanding/contracting over and over' model of the universe then (or is that one already long dead with the advent of string driven multi-dimensional multiverses with a sprinkling of dark matter to season).

(re above - wasn't the LHC on the verge of nailing down the fabled 'Higgs boson' at the time of last communication - or was that the point at which the machine went tits up and the boffins had to retreat back under ground to thier circular lair smarting and licking their wounds

)

Posted: **Mon Nov 14, 2011 4:16 pm**

peter wrote:
Vraith wrote: Talking on the fairly recent, and very surprising, discovery that not only is the universe expanding, which we knew...it is accelerating in expansion. So one approach to the reason for this is that "empty" space has some kind of material reality. And [this is a quick, not precise paraphrase, with many things left out you should watch it] because space is getting "larger," "more of it" it is pushing outward harder, against gravity, which is trying to pull things in. And space is winning.
Guess this is going to scupper the 'expanding/contracting over and over' model of the universe then (or is that one already long dead with the advent of string driven multi-dimensional multiverses with a sprinkling of dark matter to season).

(re above - wasn't the LHC on the verge of nailing down the fabled 'Higgs boson' at the time of last communication - or was that the point at which the machine went tits up and the boffins had to retreat back under ground to thier circular lair smarting and licking their wounds )

I would seem to scupper that...but eventually it will tear apart even on the atomic/quantum scale...and I don't think anyone knows what happens then. In a way it sounds to me like an anti-black hole...infinite negative density, whatever that might be...but how does that work if the "space" is material in some way?

anyway...the LHC is working fine last I knew. They hadn't found Higgs, but had eliminated many possibles for it. Now they've changed experiments for a while, working on quarks and gluons with heavy stuff colliding to look at the big beginnings. Going back to Higgs stuff sometime in 2012.

Posted: **Tue Nov 15, 2011 4:50 am**

Vraith wrote:
Hashi Lebwohl wrote:Some cosmologists hypothesize that gravity is a "spill-over" force that leaks into this dimension from one of the higher dimensions we cannot perceive. This would explain why gravity has infinite operational distance yet is the weakest force--even small magnets can overcome gravity.
Is that part of one of the string-versions and the extra dimensions they need, or an entirely separate theory?

Yes, it's either part of usual string-theory or M-theory. IIRC, they think there's not enough matter in the universe to account for all the gravity, so it must be coming from somewhere else.

--A

Posted: **Tue Nov 15, 2011 5:12 am**

omg

geeks are so hot!

ps...i LOVE this thread guys!

Posted: **Tue Nov 15, 2011 3:58 pm**

Avatar wrote: Yes, it's either part of usual string-theory or M-theory. IIRC, they think there's not enough matter in the universe to account for all the gravity, so it must be coming from somewhere else.

--A

Yep...synchronicity...they mentioned it leaking just after I asked it, either on an episode of the "Fabric of Cosmos" show, or the show right after it...I think it was leaking from other dimensions required by string, but technically still part of this universe or somesuch...I was distracted and missed part.

Posted: **Tue Nov 15, 2011 4:06 pm**

Avatar wrote:
Vraith wrote:IIRC, they think there's not enough matter in the universe to account for all the gravity, so it must be coming from somewhere else.
Didn't the so called 'dark matter' stack up as a candidate for explaining this exess of gravity then? (or was dark natter just hypothesized to account for all this G but never actually established as existing in reality.)

Posted: **Tue Nov 15, 2011 4:43 pm**

Yeah, dark matter is still the proposed solution for the mass of galaxies being much higher than it should be, but because it doesn't interact it's very difficult to prove. Similarly "dark energy" is proposed to explain the accelaration of the universe's expansion.

Posted: **Tue Nov 15, 2011 5:27 pm**

Murrin wrote:Yeah, dark matter is still the proposed solution for the mass of galaxies being much higher than it should be, but because it doesn't interact it's very difficult to prove. Similarly "dark energy" is proposed to explain the accelaration of the universe's expansion.

Ya. And then there's "quintessence"...a particular kind of dark energy [heh...that's right, we don't even know what dark energy is and we're naming different flavors]
The thing about it: we might not be doomed to have everything ripped apart. Because quintessence can flip. It was attractive force for 5billion years, then flipped to repulsive which it is now, but it could change back again according to some scenarios. It's like that dork you're following on the highway who can't control consistent pressure on the gas pedal, and won't use cruise control. I'd hate to be the universe behind this one, especially in heavy multi-verse traffic.

Posted: **Tue Nov 15, 2011 5:55 pm**

Like the earth's magnetic poles flip?

Posted: **Tue Nov 15, 2011 6:18 pm**

Fist and Faith wrote:Like the earth's magnetic poles flip?

Nah...it's more like how Mitt Romney flips by calculating the actual vs. potential voters that he will attract/repel on an issue.

Seriously, though: apparently whether it is attractive or repulsive is related to the difference between kinetic and potential energy in the universe.

Seems to me [pure spec] the pole change is just spinning a ball, this flip is like the ball collapsing cuz the air inside started sucking in.

EDITED To add:
I assumed that dark matter and dark energy had some kind of close relationship with each other like normal matter and energy do...I just found out that is not necessarily so, they may or may not have any connection at all, no one has a clue, they're both called dark just cuz we don't know much [if anything] about them.

Posted: **Wed Nov 16, 2011 5:18 am**

Ah, the joys of physics.

--A

Posted: **Wed Nov 16, 2011 6:17 am**

totally amazing how you guys just talked around that post.

Posted: **Wed Nov 16, 2011 6:31 am**

Geeks huh?

--A

Posted: **Wed Nov 16, 2011 4:15 pm**

lucimay wrote:totally amazing how you guys just talked around that post.

didn't have anything to say. It was so obviously and purely true, the only appropriate reaction was to gaze silently in adoration and awe.

Posted: **Wed Nov 16, 2011 8:20 pm**

Vraith wrote:
lucimay wrote:totally amazing how you guys just talked around that post.
didn't have anything to say. It was so obviously and purely true, the only appropriate reaction was to gaze silently in adoration and awe.

personally i think it looks like Schrödinger is smokin a doobie!! which would totally explain the cat thought experiment. heh.

Posted: **Thu Nov 17, 2011 4:29 am**

Hahahaha, not to mention the grin.

--A

Posted: **Thu Nov 17, 2011 4:28 pm**

What was the point of that cat thing - was it that the cat was neither alive or dead in the box, but in some indeterminate intermediate state and it was only the act of opening the box that forces the universe to choose which of the two (ie live or dead) it will adopt. If I'm right about this, what are we supposed to learn from this. Is this the way the world works on the macro level. (ie behind the closed door is my boss in an intermediate state between having sex with the secretary and dictating a letter, and it is only my opening the door that forces one or the other state into reality) or does it only relate to the quantum level. Or (most likely) have I got it all wrong.

Kevin's Watch

Uncertain about uncertainty - and Zeno isn't helping!