The Universe, Take 2

[RainOfSteel]

Originally posted by princelian:
[...] the simplest analogy being that space is a big sheet of black cloth and planets and stars are balls on its surface. Whereever they are, space curves "downward," and draws other balls toward them if the curvature (the depression made by the ball) is big enough.

Yup, that's Einstein's general relativity combined with Newton's gravity.

Originally posted by princelian:
Hmm....using that analogy... as the universe expands and the galaxies get further and further apart, does the gravitational constant get smaller because space is under more and more tension?

I'm not positive about this one. My knee-jerk answer is that the gravitational constant is not changing. (My apologies if it turns out that I am incorrect.)

Originally posted by princelian:
And does this tension eventually force space to spring back inward (or rupture)?

Current thought is that the expansion of space will beat out gravity and win in the Big Goodbye where everything eventually runs down and goes black ("The universe will end with a wimper.").

 

[RainOfSteel]

Originally posted by sid6.7:
well i have heard that before that everything
will fall back to a center point(big bang spot?)

The Big Crunch/Big Expansion war seems to have come down on the Big Expansion.

Originally posted by princelian:
so that means even after the bang there was
still "something left" there thats still
exerting gravity of some sort on the whole shebang? right?

No. Exactly what happened before the big bang, and what would have happened in the "Big Crunch", no one knows.

As they say, "The math breaks down at that point and gives answers that make no sense."

However, there are those who posit, in all seriousness, that there was literally nothing prior to the Big Bang.

This is why the M-"theory" development of String-"theory" has a lot of pysicists interested. It actually has an explanation for what caused the Big Bang. (There's just no way currently to test/verify anything in these "theories".)

 

[aramis]

No need to put quotes on theories... They are theories. They fit the data, and have survived the "Best Fit to Data" test within constituencies of peer review. Just because the 4 most popular ones are all at odds, and require 9+dimensions... and outside their constituencies very few people have a real clue as to what the fuss is about...

It's all still conjecture, but it is conjecture that closely fits the data and produces many results that we know are possible by virtue of their existence.

If M-Theory is right, however, J-Space might be a parallel 'brane, one with a different speed for light.

To be honest, Michio whats-his-name almost makes it make sense... key word "almost"

 

[RainOfSteel]

Originally posted by Aramis:
No need to put quotes on theories...

They're called theories only in common usage. In the technical usage of the scientific method, they aren't. We just had a flamewar that resulted in a couple of bannings, so I was attempting to be . . . I don't know, careful.

 

[aramis]

Actually, they are... as far as the scientific method applies in non-experimental sciences (Astronomy, Sociology, History, certain branches of physics, Archaeology, Anthropology.)

Hypothesize, Predict, and see if the predictions say something you have data to prove isn't possible. They can't become laws; that requires proving some action theorized to be impossible doesn't occur.

Understanding this dichotomy of science is important (and underemphasized in current educations.)

 

[TheEngineer]

Just a sidenote:
This is perhaps a funny text, which shows a scientific dialog about "theories" and their value

http://arxiv.org/PS_cache/hep-th/pdf/0310/0310077.pdf

regards,

TE

 

[Plankowner]

I think one of the problems is in the terminology. There are theories and there are Theories.

The Theory of Relativity is not just an idea. It seems to really explain reality.

The String Theory seems to be a little fuzzier and, like the article that TheEngineer linked to above, doesn't do so well at predicting reality.

THEORY is the same word in both cases, but they really have very different meanings. There are VERY few people who doubt that the Theory of Relativity is wrong, so it should really be more than a Theory, but I don't think we have a word for that yet.

 

[RandyT0001]

The problem arises by the improper usage of the terminology. In the scientific method the word 'theory' has a specific meaning asociated with having been proved by experimentation. The Theory of Relativity is an example of this. Within the scientific method what has been popularly touted as "String 'Theory'" is the first stage, the hypothesis. There has been alot of work in the effort to formulize String hypothesis into something that can be verified by experimentation but this has been difficult.

What scientists (of all types, physicists, chemists, biologists, etc.) should do is use the proper terminology when presenting their ideas and hypotheses to the masses and not mislead them by using the word 'theory' (even though some definitions of 'theory' are somewhat similar in meaning to hypothesis) in a effort to popularize their pet idea.
IMO

 

[aramis]

Randy:

In the observational sciences, there is no "Experimental Proof" You hypothesize, rejection hypothesis, observe for rejection criteria, post for peer/oversight review, then publish.

Relativity is only partially proven. We can't test it to Natural law, because it is beyond our technological capability to approach light-speed.

Very little science anymore ever progresses to "Accepted Natural Law"

Fundamentally, Most of Astronomy, History, Sociology, Anthropology, Archaeology, Astrophysics, and a few others is non-experimental; by insisting upon an experimental subset, one precludes 90% of these sciences.

 

[TheEngineer]

Usually a theory is thought to be "proper" if no evidence is found, that she's not true. Its called "Falsifiability".
Thats a bit vice verse but done, because you can never can set up tests for all circumstances to prove the truth of a theory.
Anyway, if you find one point, where the theory does not work, its usually broken, at least for this topic.
It was a kind of enlightment in science history to step away from the believe in the absolute truth to the believe in the chance of truth

Refering to General Relativity, it has passed ALL falsification tests successfully so far.
Thats why it is considered to be a pretty good
theory. Though that does not mean, that there is an experiment someday, that reveals a weakness.
But until then, its status is "clean".

Just keep in mind one central aspect, which perhaps becomes visible in my last document link.
A theory should have content, which is actually useful to predict or describe some aspect of physics/nature. The way it works, the extensiveness etc. is a secondary aspect.

 

[Icosahedron]

Originally posted by Archhealer:
i thought part of the mythos of the J-Drive was that it didn't actually achieve FTL travel; nothing travelled faster than light, or even all that fast, in J-space. It was more like a prolonged teleportation. So, in theory, perhaps the FTL rules aren't being broken at all (Of course, that brings into question what laws of physics ARE being broken; J-Travel just seems too good to be true).

It achieves FTL travel in the sense that you can reach a destination more quickly than light can - by taking a shortcut through Jump Space. So no, FTL rules are not being broken. As people have explained to death elsewhere, the laws of physics are never broken, they are simply corrected in the light of experience. Of course it's too good to be true - that's what puts the F in SF.

Ravs: I agree, the J-drive, along with a lot of other stuff, is left unexplained IMTU. Saves getting bogged down in petty arguments and explanations when you could be playing.

Princelian: IYTU you can handwave anything, that's what makes the game popular.

I am a hard science person, I am wincing, but you can do what you like in YTU, It can border on science-fantasy if that's what you want.

More pondering than we have here has already been done by the scientific community over the past few decades. You could Google this stuff for months. Watch your sources, though.


Sid: I am everywhere!
Thought, in terms of electrical impulses in neurones, is limited to light-speed, but AFAWK it doesn't travel outside of a single human head. Maybe it depends on your definition of thought, but please don't let's get hooked on definitions again. Hardcore science has nothing to say about telepathy.

 

[aramis]

Icosahedron: Nerve signals travel WELL below C. They can readily measure travel times of nerve signals (I know, I've had 3 EMG's... OUCH!!!).

Also, while the laws of physics are never broken, they are also unknown, except by approximation.... (IIRC, heisenberg.)

 

[princelian]

Sorry I made you wince, there, Icosahedron.

I'm actually going to shoot for more of a hard science feel than my earlier post implied. What I meant about MTU was rhetorical, not that I was actually going to use that as the in-campaign "hard facts" on how the universe works.

 

[Icosahedron]

Originally posted by Aramis:
Icosahedron: Nerve signals travel WELL below C. They can readily measure travel times of nerve signals (I know, I've had 3 EMG's... OUCH!!!).

Also, while the laws of physics are never broken, they are also unknown, except by approximation.... (IIRC, heisenberg.)

Yes, nerve signals (and horses!) are limited to the speed of light as the original question asked.
You're right, they nowhere near achieve it.

Hmm. The laws of physics are not completely known, but as a certain friend of ours correctly stated, the approximations are generally very close. In many cases, much closer than we can actually make use of.
Heisenberg was talking about a specific case there, and even so his findings only modified existing theories, in certain circumstances. If you want to find out more, I can recommend Heisenberg's own book on the Uncertainty Principle (I forget it's title) it's pretty cool.

 

[RainOfSteel]

Originally posted by Icosahedron:
[...] Yes, nerve signals (and horses!) are limited to the speed of light as the original question asked.

Just FYI on how I read that.

Super car X is limited to 200 MPH.

Horse Y is limited to 50 MPH.

Both of these statements indicate to me that these classes of nouns are capable of going the listed speeds.

"Nerve signals are limited to the speed of light," reads exactly the same way to me, it appears to be an assertion that nerve signals can move at the speed of light.

I agree with several others who have piped in, Nerve signals are limited to a mircoscopic fraction of the speed of light. They do not propagate at the speed of electicity through a wire, they propagate at the speed of millions of independent electrochemical transactions, each one building up more and more time used the farther and farther the signal travels.

Originally posted by Icosahedron:
You're right, they nowhere near achieve it.

I apologize that I do not see this qualifying addendum as meshing with the previous statement, although it certainly appears to me that you also agree with what the others said.

 

[Icosahedron]

"Nerve signals are limited to the speed of light," reads exactly the same way to me, it appears to be an assertion that nerve signals can move at the speed of light.

I agree with several others who have piped in, Nerve signals are limited to a mircoscopic fraction of the speed of light. They do not propagate at the speed of electicity through a wire, they propagate at the speed of millions of independent electrochemical transactions, each one building up more and more time used the farther and farther the signal travels.

I apologize that I do not see this qualifying addendum as meshing with the previous statement, although it certainly appears to me that you also agree with what the others said.

Yes, we all seem to be in general agreement. I apologise if my choice of words caused some confusion. The original question asked whether thought could travel faster than light. That was what my reply referred to.
Not wishing to offend, but I am not interested in discussing semantics any further - only gaming and science.

 

[mike wightman]

Interesting article in today's Sunday Times:

http://www.timesonline.co.uk/article/0,,2087-2320877,00.html

 

[RainOfSteel]

Originally posted by Sigg Oddra:
Interesting article in today's Sunday Times:

http://www.timesonline.co.uk/article/0,,2087-2320877,00.html

I found the article to be scattershot in concept, weaving its way between a scientific controversy spat between physicists, to wildly inaccurate descriptions of physics (probably as a result of abysmal editing).

"Rather than challenge the idea that time and space began with the Big Bang, he suggested the new universe had suddenly expanded trillions of times in a millionth of a second. That idea, called inflation, did such a good mathematical job of explaining the shape of the universe that it was adopted far and wide."

Balderdash!

Inflation isn't the idea that our new universe suddenly expanded trillions of times in a millionth of a second . . . it's that it expanded at huge velocities in a tiny fraction on an instant, and those are two totally different statements.

This goes straight to my general gripe about journalism in general, lately. The writing and editing quality seems to keep spiraling down.

 

[TheEngineer]

Guess the author feels more comfortable with bio-chemistry than theoretical astrophysics

Anyway the article stresses the existence of a kind of new "frontier" in astrophysics...

TE

 

[aramis]

Agreed, Chris, Journalism is sucking and spewing forth a lot more ill wind than in times past. Some other board I'm on was commenting upon that.