Fickle Physics

SicTimMitchell · Post by **SicTimMitchell** » Mon May 30, 2005 10:54 am

Embar,

Thanks for the points to ponder. I had never considered time being converted to energy nor matter. It does seem intuitively silly.

I started from two points: Zeno, who I feel was summarily dismissed a bit too quickly, and whose paradoxes I've been fascinated by since I was a kid (My dad fucked with me using them), and the fact that both light and gravity travel at C, which seems extraordinarily coincidental unless Einstein got that one right.

But Einstein never really explained why C was the "universal speed limit," and a bunch of folks have (unsuccessfully) tried to devise theoretical scenarios where something (usually information) exceeds C. (Example: You have a pair of scissors that are nearly shut, with the handle end at Earth and the pointy end any theoretical distance away. To give a signal, you snap the handle end shut.)

Also, if expansion theory is right, C was a variable relatively near the beginning of the big bang, and I can't account for that. (Then again, no one else can really account for expansion theory. So there.)

SicTimMitchell · Post by **SicTimMitchell** » Mon May 30, 2005 10:58 am

Oh, to be clear, Einstein did explain why C works as the universal speed limit, just not why C was the limit. If that makes sense.

Embar Angylwrath · Post by **Embar Angylwrath** » Mon May 30, 2005 12:49 pm

SicTimMitchell wrote: Also, if expansion theory is right, C was a variable relatively near the beginning of the big bang, and I can't account for that. (Then again, no one else can really account for expansion theory. So there.)

I think you'll find the explanation for that in quantum theory. Simply put, the nearer to a singularity you are, the less constants behave like constants. The BIg Bang was a singularity, so near the beginning of space-time, "C" would behave more like a variable and less like a constant.

Post by **Ddrak** » Mon May 30, 2005 1:24 pm

Einstein never really explained why C was the "universal speed limit,"

Sure he did. It comes from special relativity where to put it simply, the required energy to accelerate an object to c is infinite. If you're talking about information flow, then it's not explicitly stated that nothing can go faster than c, but it is stated that nothing involving gravitation or EM forces can. Relativity doesn't cover the strong nuclear force, and the weak nuclear force has been unified with EM, so relativity does cover it.

The scissors paradox isn't really a paradox at all. You are assuming that matter can transmit information faster than c, which is false. When you start closing the scissors at earth, a shock wave will travel down the scissors at sub-light speeds closing them. The tips will not start closing until well after the theoretical minimum time information can travel from one place to the other.

A far more interesting paradox involves length contraction between moving objects and what happens if you can toss a plank that's twice as long as a barn through the barn fast enough that it appears to fit in your frame of reference, then close the doors. To spoil it for you, the answer is the obvious one.

Dd

SicTimMitchell · Post by **SicTimMitchell** » Mon May 30, 2005 1:58 pm

Ddrak,

My understanding is that Einstein wasn't too keen on nuclear forces in general, since they totally fucked up his attempts at a unified theory. But anyway.

I know the scissors "paradox" is wrong, I used it as an example. Although my understanding is that at some point the blades themselves would reach C and be transformed into energy. (Again with the simplest solution.) A tougher one involves a super-laser on Earth pointed at one star and then flicked to another equidistant star -- but again it collapses if you really think about it for a moment. (Hint: how old is the light we see fom stars?)

Unless I'm way behind, Einsteinian physics still says there's NO way to communicate information faster than C, regardless of the method used. (I admit that the last full-length book I read on the subject was one of Rucker's, so I could be behind. But I've been trying to keep up with articles and such.)

Embar,

Yeah, I know. That's why I referenced it obliquely in my first post and explicitly later. It's interesting as hell, but it still sucks.

SicTimMitchell · Post by **SicTimMitchell** » Mon May 30, 2005 2:04 pm

Oh yeah.

To spoil it for you, the answer is the obvious one.

The George Costanza answer?

"It was the time space continuum! There was shrinkage! Everyone knows the barn shrinks when you dive into the continuum!!"

Post by **Ddrak** » Mon May 30, 2005 6:50 pm

Einsteinian physics still says there's NO way to communicate information faster than C, regardless of the method used

As far as I'm aware that's still the case. I only included the qualification because there may yet be undiscovered stuff outside of Einsteinian physics. Hell, as far as I'm aware we don't even know if gravity is quantized yet.

And Einstein didn't like a lot of stuff - quantum theory, nuclear forces, all sorts of stuff. I believe his quote is "God does not play dice".

Dd

SicTimMitchell · Post by **SicTimMitchell** » Mon May 30, 2005 7:55 pm

All this just reminded me of my favorite silly "faster than the speed of light" conundrum, because there are no theoretical elements required to pose it:

When you're in your car doing 60 mph, and you flick on your headlights, don't the beams travel at C+60mph?

Fobbon Lazyfoot · Post by **Fobbon Lazyfoot** » Tue May 31, 2005 12:01 am

Translation - I'm too stupid to understand this shit, so I'll make inane comments instead.

Translation - I don't agree with you, therefore you must be stupid.

Get real dude. One dosen't have to simultaneously agree with the theory as they comprehend it.

Excuse me for preferring a more solid foundation before I buy into something. My mistake.

Embar Angylwrath · Post by **Embar Angylwrath** » Tue May 31, 2005 12:37 am

Ok genius...

Explain string theory to us. Make sure you tell us, in layman's terms, why open and closed string theory have different type's of manifestations, and why closed string theory is so important to prediciting the existance of the gravitron.

While you're at it, please explain to me why bosonic string theory limits the dimensions of space-time to 26... and no fair telling me its because the equations won't support the required number of unphysical states. That, I aleady know.

I'd also like to know why you are having troulbe with the most fundamental aspect of string theory.. that the mass of quantum particles is dependent on the spin of the string.

And finally, can you please explain why the T duality and S duality interact with one another, and please touch on why type I superstring theory is S-dual to heterotic SO(32) superstring theory.

You see, the point I'm trying to make is that no one on this board, understands string theory. You saying that you know enough about it to actually have an informed comment is as ludicrous as Beeker getting Harlowe to suck his schlong (or schlort... but that's another type of string theory).

Post by **Ddrak** » Tue May 31, 2005 2:50 am

When you're in your car doing 60 mph, and you flick on your headlights, don't the beams travel at C+60mph?

Not sure if you are wanting me to take you seriously or not, because I'm sure you know the answer.

No. The beams travel at C. As measured from *both* the car and the earth. And that's the basis of special relativity. :)

I pride myself for knowing a decent amount of physics (about 3rd year university level - and not as much as Arathena) but string theory I leave to my PhD friends back in Australia. That's hellishly complex stuff.

Dd

SicTimMitchell · Post by **SicTimMitchell** » Tue May 31, 2005 6:48 am

Embar,

Tee hee. You had me at "gravitron."

SicTimMitchell · Post by **SicTimMitchell** » Tue May 31, 2005 7:06 am

P.S.,

I highly recommend Nova's "The Elegant Universe" to anyone who's interested in theoretical physics. I think I raved about this show here when it first aired.

It explains stuff from Newtonian physics to string theory in two easy-to-swallow, layman-friendly hours that got my kid interested in hyperspheres and multiple universes to the point where we were sharing Sci-Am articles on them and she already had the basic knowledge to understand what they were writing about.

(It was so cool when my daughter was trying to figure out how a solid hypersphere could rotate along the surface of its axis and equator at the same time on her own, and Sci-Am came out with the er, multiple-torus topology for the multiverse and a light bulb appeared over her head when she realized a hypersphere was torus-like.)

It's obviously not going to give you a complete understanding, but it's an incredibly easy-to-swallow and solid foundation to explore more from.

Anyone remember that cartoon from grade school that explained Einsteinian physics with the two spacemen? Or Donald Duck in Mathmagic land? Like that, only a bit more in-depth.

Arathena · Post by **Arathena** » Tue May 31, 2005 7:37 am

Ddrak wrote: I pride myself for knowing a decent amount of physics (about 3rd year university level - and not as much as Arathena) but string theory I leave to my PhD friends back in Australia. That's hellishly complex stuff.

Don't expect any words of wisdom from me on this one - It's out of my specialty, and I know enough to know how much I /don't/ know. That said, this could be a potentially interesting development. Knowing that the major constants are influenced by semi-local conditions means a search for the conditions that control those contants. Knowledge of the conditions means engineerability, which means localized control over "universal" constants.

BTW, I believe both nuclear forces have been mathematically resolved to unify with the EM force, and, iirc, the expected carrier particle has been detected under the correct conditions in a particle acclerator. It's also calculated that the energy of the Big Bang was such that the strong force decoupled from the electro-weak force at roughly 10^-26 seconds after the start.

As another interesting note, while c(0), the propagation speed of an electro-magnetic wave in the absence of the influence of anything else is a traditional constant(Your familiar 2.998 x 10^6 m/s), c itself is a localized material of transmission dependant variable. It's how things like lenses work. Who else wants a lens for focusing gravity?

Post by **Ddrak** » Tue May 31, 2005 9:17 am

c itself is a localized material of transmission dependant variable

I know strictly speaking this is from absorption and retransmission of photons but it always made me wonder what you would see if you were in a submarine travelling at something beyond the speed of light in water...

Dd

Klast Brell · Post by **Klast Brell** » Tue May 31, 2005 9:46 am

Strictly speaking you would see your instrument panel infront of you showing the state of your force field, photon torpedos, and wave motion gun. You would also see your alien science officer on your left,and a hot alien space babe on your right. Strangely the submarine would have no bathroom

Arathena · Post by **Arathena** » Tue May 31, 2005 10:13 am

Ddrak wrote:
c itself is a localized material of transmission dependant variable
I know strictly speaking this is from absorption and retransmission of photons but it always made me wonder what you would see if you were in a submarine travelling at something beyond the speed of light in water...

Dd

Besides Klast's fantasy for green chicks, you see on that instrument panel an absolutely ferocious storm of high energy photons that you're blazing through much like the sonic boom cone of a supersonic aeroplane - You shed energy, and momentum by twanging the accumulated EM field of the local medium, until such time as your velocity is beneath local c. This 'luminal boom' is called Cerenkov radiation, and it's the source of the pretty blue-green glow in a reactor pile. Electrons are ejected from the pile at extreme fractions of c(0), much higher than c, and shed energy down to c through radiation.

Post by **Ddrak** » Tue May 31, 2005 10:15 am

Dammit. I've been wondering that for a long time and never made the connection to Cerenkov Radiation. Clearly I suck because it's so friggen obvious.

Dd

JamiesanTGrauerwolf · Tue May 31, 2005 11:02 am

/makes a whooshing sound whilst waving his hand over his head.

Zyllen · Post by **Zyllen** » Tue May 31, 2005 11:05 am

Embar Angylwrath wrote:Ok genius...

Explain string theory to us. Make sure you tell us, in layman's terms, why open and closed string theory have different type's of manifestations, and why closed string theory is so important to prediciting the existance of the gravitron.

While you're at it, please explain to me why bosonic string theory limits the dimensions of space-time to 26... and no fair telling me its because the equations won't support the required number of unphysical states. That, I aleady know.

I'd also like to know why you are having troulbe with the most fundamental aspect of string theory.. that the mass of quantum particles is dependent on the spin of the string.

And finally, can you please explain why the T duality and S duality interact with one another, and please touch on why type I superstring theory is S-dual to heterotic SO(32) superstring theory.

You see, the point I'm trying to make is that no one on this board, understands string theory. You saying that you know enough about it to actually have an informed comment is as ludicrous as Beeker getting Harlowe to suck his schlong (or schlort... but that's another type of string theory).

The whole time I was reading this post, I felt like Charlie Brown listening to one of his teachers talking.