Big Bang faster than light?

[Rasputin]

All right, so nothing is supposed to be able to travel faster than light, right?

Supposedly, when the Big Bang occurred, the universe expanded from a singularity (with zero radius) to a larger size several (thousand?, million?) light-years in diameter. All of this occurred in a fraction of a second. Explanations?

------------------
"I don't want to achieve immortality through my work... I want to achieve it through not dying."
-- Woody Allen

[Guy Propski]

Where did you hear that? Sure, the monoblock got a lot bigger in the first seconds, but I never heard anyone say light-years bigger.

[DrFidelius]

Last I heard (and I fully expect to be corrected by the real physicists on the board) the inflationary period ended with the Universe being about the size of a grapefruit. As if size were a valid concept in the early stages of the Universe.

[pluto]

IIRC, the inflation theory was proposed specifically to avoid problems with special relativity. The universe is too uniform, which meant the various parts had to be in contact with each other when they should have been relativistically separated. So physicists cooked up the inflation theory to allow the parts to mingle long enough to establish the proper uniformity and then inflate to create the proper size that we find today.

I'm probably talking through my hat about this next bit but the universe didn't just suddenly get larger -- it inflated. The distinction is that inflation wasn't an event that took place in space and time -- it was that the nature of space and time changed. Something like that. Next time I see Stephen Hawking I'll ask him again.

Relativistically,
pluto

------------------
If man was meant to fly faster than the speed of sound he would have been born with 50,000 pounds of thrust.

[DrFidelius]

I would LOVE to be a physicist! In my next life I will definately take those courses. Imagine, if your theories don't match observed reality YOU GET TO CHANGE REALITY! Superstrings, inflationary events, whatever you need to get your equations to balance YOU CAN CREATE! Beyond cool...

[manhattan]

Dr: Have you considered accountancy?

------------------
Livin' on Tums, Vitamin E and Rogaine

[pluto]

DrF -- Yeah, it gives you something to think about when someone tells you their world view is based on science, not on faith.


------------------
If man was meant to fly faster than the speed of sound he would have been born with 50,000 pounds of thrust.

[Rasputin]

I knew I had heard this somewhere, so I spent a little time surfing and found out where I heard it from.

In the early 1980s, Alan Guth, a professor at MIT, suggested a new epoch should be added, known as the inflationary epoch, lasting between 10^-35 and 10^-24 seconds after the beginning of the universe.
One characteristic of his inflationary epoch was as follows:
- An extremely small portion of the universe ballooned outward in all directions at speeds much greater than speed of light.

Here's a link to a page describing his book.
http://www.bkstore.com/mit/fac/guth.html

It seems to be widely accepted in the scientific community. It does in fact propose the universe expanded at speeds greater than the speed of light. I just couldn't find anything describing how this occurs. Anybody???

[DW3]

John Moffat theorizes the speed of light was faster at the beginning of the universe. And has slowed down to the speed it is today. Speed of Light May Not be Constant (http://www.spacer.com/spacecast/news/lightspeed-99a.html)

[mipsman]

The problem is that the universe is so smooth and regular. This homogeneity had to date back to the very early universe. Even when the universe was so much smaller, there is a problem that points far distant, even then, from each other somehow had to (excuse the anthropmorhisizing) "know" what each other's average temperature and density was. It was this equalization of temperature and density of the early universe that was somehow communicated at a speed faster than light.
However, I have a guess. First, dismiss the idea that the Big Bang was like some cartoon bomb exploding outward into a pre-existing void. Time and space and the other 6 or 7 dimensions were created/expanded/inflated from some quantum fluctuation into our friendly mipsman-loving universe that we know. But at some kind of boundary condition to the space time continuum (hate to say it but "the edge of the universe"), there is no requirement that any physical laws need hold especially the speed of light. So a point at one end of the universe need only communicate its temperature and density to the edge and the edge could instantly communicate and equalize those conditions to all points in contact with the edge. The smoothing process could cover the universe at faster than the speed of light. I thought of this based on a lab experiment I did at UCLA. They have a great cosmology lab. (Just kidding, it was an engineeering lab.)



------------------

[ZenBeam]

The limit of the speed of light applies to matter/energy/particles/waves in the universe. In the inflationary theory, the universe itself expands. Think of the analogy of a pond, with waves travelling at a fixed speed. The pond itself suddenly gets larger, faster than the waves themselves travel. How? I don't know.

The problem with the uniformity of the universe is that when you look at very great distances in opposite directions, the universe is very uniform. The universe isn't old enough for light or anything to haev got from one side of the universe to the other, so there is no reason to expect such uniformity.

------------------
It is too clear, and so it is hard to see.

[jab1]

I have a related question: It's believed that the universe is expanding today because distant galaxies exhibit a severe red-shift, meaning they're flying away from us so fast, their light has been stretched out and they appear more red than they really are.

Has anyone detected a galaxy that is blue-shifted, coming toward us at high speed?

And if all galaxies suddenly become blue-shifted, does that mean the sky is falling?

------------------
Those who do not learn from the past are condemned to relive it. Georges Santayana

[Stephen]

Zen is on the right track. 'C' as a speed limit, applies to matter/information/etc. moving through the Universe. There is no rule saying the Universe itself cannot move faster.

------------------
Stephen
Stephen's Website (http://stephen.fathom.org)
Satellite Hunting 1.1.0 visible satellite pass prediction
shareware available for download at
Satellite Hunting (http://stephen.fathom.org/sathunt.html)

[jab1]

Energy moves at the speed of light. Why? It has no mass and it is the nature of energy to move at the speed of light.

Matter cannot move at or beyond the speed of light. Why? It has mass and infinite energy is needed to accelerate something massive to the speed of light.

Space has no mass. Therefore, it seems to me that space can "move" or "expand" at any speed it needs to to maintain the integrity of the universe. It could even stop or change direction instantaneously because it has no mass and therefore no inertia. And any matter occupying that space is simply carried along. Since that matter is moving with space and not through it. the laws of motion do not apply to the mass.

Am I even close to being right? Where's Undead Dude when you need him?

------------------
Those who do not learn from the past are condemned to relive it. Georges Santayana

[Konrad]

By the way, there's nothing stopping matter from going faster than light. It's just very unlikely. Light speed is an average, not an absolute.

When you're talking something as small as the unviverse was back then (according to theory) it would have been very easy for mass to go faster than the speed of light for a very short amount of time, for a very short distance. And 10E-34 is a very short amount of time.

[Glitch]

I would LOVE to be a physicist! In my next life I will definately take those courses. Imagine, if your theories don't match observed reality YOU GET TO CHANGE REALITY! Superstrings, inflationary events, whatever you need to get your equations to balance YOU CAN CREATE! Beyond cool...

Not only that but you get to cancel out a pi with a 3! Boy, the mathematicians hate it when cosmologists do that.

A bit of an inside joke but when I went to university our Astrophyics professor cancelled a pi with a 3 to which a math student exclaimed "You CANNOT do that!".

------------------
What more could you expect from somebody who lets people kick him to the head?

[NanoByte]

Well, back when they taught just the simple-minded part of physics to engineers, we used to figure that there was something called the Physics Supply Store out there somewhere, where you went to obtain things like ideal gases. That's probably where all those theory patches and whatever are procured also.

As an engineering student, I never got an account with that place, because I always kept running into reality on the bench, and it never let me use any of those rubber concepts used in cosmology. Cosmology's kind of neat, though, in how it masquerades as a science and yet seems just to flex with faith in the face of empirics, as it rambles along, ignoring falsifiability.

Ray

[pluto]

jab1 -- IIRC, there are blue shifted galaxies, but they have to be nearby (since red shift grows with distance). Galaxies move in relation to each other besides their motion due to the expansion of the universe and a few of them happen to be moving toward our galaxy.

Caveat -- this is one of those arcane "facts" stuck in my mind somewhere and I honestly can't remember whether it was stars or galaxies they were talking about. I know that is not a trivial point. There are certainly blue-shifted objects of some kind out there, but I'm not sure if even nearby galaxies aren't so far away that they're all red-shifted.

Glitch -- Three is a pretty good approximation of pi. My heat transfer professor used 5. And, in spite of NanoByte's complaining, that was one branch of engineering where precision wasn't required. Anything within an order of magnitude was considered quite an accomplishment.


------------------
If man was meant to fly faster than the speed of sound he would have been born with 5000 pounds of thrust.

[Cabbage]

3 as an approximation of pi?...5?!!?...As a mathematician, I must say...What's wrong with you people??!!!?? ;)

[Konrad]

Mathematicians, always whining. Hey! Listen up!

There is a finite chance that at any time pi = 3 or 5 for that matter.

And the limit of 2 + 3 = 6 as 3 approaches 4.

We can do it cause we're physicists. Quantum mechanics allows it. And besides, the theory seems to work so why quibble over some trivial .1415926535897932384626...

In QM things dissappear and reappear all the time on their own, electrons go backward in time whenever they feel like it and know the state of the rest of the universe AND WHEN WE'RE KNEE-DEEP IN QUARKS WE'RE NOT GONNA START WORRYING WHETHER THE MATHEMATICIANS LIKE US CANCELLING PI WITH A 3!

Uhhh... I just had 4 physics midterms in 8 days so don't mind me... but don't piss me off either or I'll integrate you from here to infinity like this (snaps fingers).

[Cabbage]

You're right, there is a finite chance that at any time pi = 3 or 5. Turns out that chance is zero, though.

BTW, I've never known 3 to approach 4... :)

[DrFidelius]

But 2+2=5 for sufficiently large values of 2.

[Rysdad]

Bah! Chicanery and balderdash, I say! Twos creeping up to be almost threes, pi deciding to be 5 sometimes, electrons having long distance conversations, space shifting universes, 10 to the minus bejesus...it's confounding!

I wish I could understand it. Serves me right for taking business and English courses in college...I never learned the neat stuff.

In the immortal words of Jethro Bodine, "Ought plus ought is ought. One plus ought is one..."

[dasmoocher]

I remember reading this years ago so I may have it wrong; but it was a proposed example of faster than light travel.

If the tip of the second hand on my watch sweeps around the dial faster than a point next to the center--that is, travels a greater distance in the same amount of time (Conservation of angular momentum? Where's a physics book when I need it), could the tip of a "almost infinitely long (light years in length)watch hand" be rotated faster than light?

No way to test this puppy, but in theory, if it was long enough, could the tip travel faster than light?

[rowrrbazzle]

no, it won't work. Nothing is 100 percent perfectly rigid, which is what the second hand would have to be for the scheme to work. The forces transmitting the movement of the hand from atom to atom are the electromagnetic forces between said atoms, all travelling at c.

[dasmoocher]

I don't know if I buy that.

1). The tip of a bullwhip moves much faster than the handle, IIRC, the "crack" is the sound of the tip breaking the sound barrier. Even if it's not, it's still an example that it doesn't need to be rigid, isn't it? Say a long enough bullwhip instead of a "second hand".

2). Even if the forces "transmitting the movement of the hand from atom to atom are the electromagnetic forces between said atoms, all travelling at c" is a correct statement; isn't this in the direction of the length (to hold the thing together) and not in the direction that the length is traveling?

I'm grasping here, but doesn't relativity deal with "frames of references"? The atoms of the second hand/bullwhip aren't moving faster than light with respect to each other, are they?

[AuraSeer]

Yes, they are.

Let's say you do construct a rigid stick one lightyear long, to test your theory. You hook one end up to a very strong motor, and press a button to make it sweep through one "tick".

The motor applies a force to your end of the stick, making the atoms there start moving. Well and good.

The atoms at your end are bonded to their neighbors. So when Atom 1 starts moving, it exterts an attraction on Atom 2, which also starts moving. Atom 2 exerts the same kind of attraction on Atom3, which attracts Atom 4, and so on down the length of this stick.

This attractive force is electromagnetism, which propagates at the speed of light. It should be obvious that the "wavefront" of movement-- the spot in which the atoms are just feeling the motive force-- propagates at the same speed.

If your stick were short, this effect could be ignored. But we're talking about an object one lightyear long. The wave of movement cannot move faster than c, so when you push on your end of the stick, the other end doesn't hear about it until a year later.

In short, the stick doesn't act rigid. Instead of sweeping it instantaneously through a degree of arc, you've only served to bend it in the middle, and the end is never forced to exceed C.

(Does this make sense? I can't tell, it's 5 AM and I haven't slept yet.)

------------------
Laugh hard; it's a long way to the bank.

[DrMatrix]

AuraSeer,
Your explanation was good. I would add that a co-ordinate system could have points that move "faster than light", but since rigid rods cannot exist, no material is moving at faster than light locally.

------------------
Virtually yours,

J Matrix

[jab1]

There is nothing to prevent a circle or a globe (or any other geometric form) to increase its size faster than the speed of light. If a circle expands at the speed of light, its diameter will increase at twice the speed of light; its circumference will increase at pi times the speed of light; and its area will increase at pi times the radius squared times the speed of light. But as long as the radius increases no faster than the speed of light, no law of physics has been violated.

Here's the exciting part: This has been observed in nature. A few years ago, National Geographichad an article on lightning that revealed that modern videography and photography had captured on tape and film forms of lightning totally different from the familiar jagged line. One looks like a fountain of light. Another of these newly-discovered forms was a ring that expanded outward at nearly the speed of light. These other forms of lightning had been seen by pilots and some scientists were skeptical of the lightning's existence until only recently.

---------------------------------------------

One should remember something when cosmologists describe the universe as expanding: They're not necessarily saying that it's blowing up like a balloon. They're saying that new space is being created, and that it's in creation all around us, not just at the so-called "edge" of the universe. Or so one theory of many states.

(We are not stationary, we are in motion just as those red-shifted galaxies are. It's that we are each flying away from the other. Think of two cars driving away from each other, each going at 60 MPH. Their velocity of separation would thus be 120 MPH. And any visible red-shift would be identical to that observed if one car was stationary and the other was driving away at 120 MPH. It's all relative, you see. :) )

Don't bother looking for that new space; we can't sense it directly. But we can, of course, observe those galaxies flying away.
The creation of new space seem to be the theory that best fits the observations.

Where is that space coming from? No one really knows for sure. (I need to bone up on those theories.)

------------------
Those who do not learn from the past are condemned to relive it. Georges Santayana

[Konrad]

Cabbage sez:
You're right, there is a finite chance that at any time pi = 3 or 5. Turns out that chance is zero, though.

Zero is not finite.

[ravenous]

Zero isn't infinite either. I always understood finite to mean "not infinite", i.e. bounded.

[dasmoocher]

In theory, what if you started with "short watch hand", got it rotating, and then began extending it? Add subunits to either end like a microtubule in a cell (using Borg technology, no doubt). Since it's already rotating, would it still bend? Could you get the tip going fast enough this way?

[DrMatrix]

Nice try dasmoocher, but the watch hand would still bend. The speed of light is still the speed limit for material objects and signals.

------------------
Virtually yours,

J Matrix

[Fyodor]

"Faster than the speed of light" is a pretty sophisticated topic and there have been some damned good posts in this thread. Let me humbly submit a concept I picked up somewhere in my reading (I hope it wasn't in a Straight Dope book):
If you have something expanding from a singularity think of it as a yeasty dough with raisins in it. As it expands in all directions it must make room and be pushed by more material from the source. As the doughball gets bigger the raisins on the outer edge are moving a lot faster than the raisins near the source. When the doughball gets really huge, as in light years across, the raisins at the outer edge are really moving. Theoretically there is no limit on their speed. They must move to accommodate the expansion even if it means moving faster than the speed of light.

I'm no Einstein but I can visualize this.

[DrMatrix]

The raisins in dough analogy, while it is a good analogy, can only be taken so far. There is no dough expanding--space itself is expanding. And since it (space) is not material it can expand "faster than light". The other problem with this image is it makes it seem the big bang was a localized phenom that flung mass-energy out into an existing universe. The bang was the entire universe (all space and all matter) expanding from the point that was the entire universe.
You have the same problem with the spots on a baloon analogy. The spots are the only physical things. The baloon surface does not exist as a physical thing.

------------------
Virtually yours,

J Matrix

[pluto]

DrMatrix -- something just clicked. Do you have a daugher named Iva?


------------------
"Vandelay!! Say Vandelay!!"

[Konrad]

ravenous: Doh!

But it's still not zero.

[DrMatrix]

pluto So you've heard of me. Martin Gardner's reports of me are slightly exaggerated.

Konrad Zero is finite.

[Konrad]

Dr. Matrix: Lies, lies, lies, spam and lies. But still, my point is that at that scale anything's possible.

[Claymore J]

Unfortunately, the universe has not been refined to a limited number of mathematical models yet. So it must be based on chaos. Due to this, there is a 50% chance that Pi will equal nothing and infinity simultaneously and 50% chance that it won't.

Whatever happens everything is 50% chance - it either happens or it doesn't.

The universe could not have expanded at the speed of light because it would not experience time. Despite time being created by humans, it is still theoretically a recordable unit. If it did not experience time, it could not decelerate as all physicists know:

Change in acceleration is equal to change in velocity over time.

If time = 0 or infinity,
the change in acceleration would also equal 0 or infinity. Because 1/0 = 0 or infinity.

If the Big Bang occurred at the speed of light it would continue to do so, therefore due to relativity everything in the Universe would also have to travel at the speed of light. Will that do?

I am an A-Level Physics student at Reigate college UK. I am 17 and spend too much money on drugs. I also spend too much time thinking about things.

E-ME at m_sworn@hotmail.com cos i can't get to this site on the college sever for some reason.

Remember:

If the human brain was simple enough to understand, we would be too simple to understand it.
-----------------------------------------

[TheRugrat]

I may just be a neophyte here, but everyone seems to be applying rules of the universe to something that actually occured OUTSIDE the universe. We are scratching at what the rules are within the universe, who knows how everyhting works outside of it. Take the example of a large body of liquid suspended in zero gravity. Within that sphere of liquid, even though there is no gravity, the laws of friction will still apply which means objects within it will move slower. Outside that sphere of liquid, no such restriction applies. I know it oversimplifies, but I'd like to know what you think

------------------
If at first you don't succeed, use a sldgehammer.

[DrMatrix]

Konrad says
Dr. Matrix: Lies, lies, lies, spam and lies.

Well..? I can't argue with that...

But getting back to the Original Post. The universe can expand faster than light. Stars far enough from us are moving away at faster than the speed of light, but they are not moving faster than light locally to them.

------------------
Virtually yours,

I J Matrix

[dasmoocher]

For my own edification, is the reason that the speed of light is the "universal speed limit" is that it would take an infinite force to accelerate a mass to c? I got Newton's F=ma in the two semesters of physics I needed to graduate. I vaguely remember a "relativistic" version of this equation. Something like force= blah blah in the numerator, but c-velocity in the denominator. c-c would give an infinite number and, therefore an infinite force would be required to accelerate a mass to c. Am I remembering this correctly? Since you can't have an infinite force, you can't have a velocity of c. Also, as I understand it, mass approaches infinity as v approaches c (I think that's right).

Like I said, where's a damn physics book when you need it. ;-) Clarification from the physics phynatics would be appreciated.

[Konrad]

Dr. Matrix: Yeah, but when you're talking about the universe at the size of 10E-34 metres it doesn't really matter either way whether or not it could classicly move faster than light. Just by the uncertainty principle you'll have lots of the universe going faster than light and jumping around randomly. Unless of course Planck's constant was different back then.

I dunno, but it seems like there's a lot of theorizing going on about something we know very little about. Was c different, was h different, how many dimension etc, etc...

Either way, all I'm saying is that even if you don't assume space can move faster than light because it's not 'real' you can still have an expansion faster than light. In fact, at that scale, you almost certainly will have lots of things going faster than light.

[jab1]

647, you're right, the mass of an object increases as it approaches the speed of light. It also gets smaller. If an object did reach the speed of light, it would be infinitely massive and infinitely small. It would disappear from our universe. It would be a black hole, though a black hole is normally formed by the collapse of a super-massive star. Once its radius drops below a certain limit,(Schwartzchild radius?) its gravitational force becomes so strong (strength of gravity depends upon both radius and density), escape velocity is greater than the speed of light. No light can escape, it's black and everything falls down into it.

------------------
Those who do not learn from the past are condemned to relive it. Georges Santayana

[DrMatrix]

jab1 said
If an object did reach the speed of light, it would be infinitely massive and infinitely small.

Except that GR says it cannot. So I don't see how you can talk about what happens at the speed of light. You can only approach c, you cannot reach it.

[dasmoocher]

I'd still like to know if I got the c speed limit right, but as a physics layman, what's the deal with relativity and quatuum mechanics both being experimentally correct but mutually exclusive (or something like that)? Not my area of expertise, but I'm under the impression that they (GR and QM) conflict with each other (at least with regard to experimental data).

[Claymore J]

Quasars have beenmeasured to travel at 94% speed of light. This recording was taken approx. 16.8 billion years ago. We know this because it is 16.8 billion light years away, and if originally travelling at velocity just a fraction off of the speed of light, it would still decelerate. So if quasars define the furthest reach of the visible universe, we can safely assume that the universe as we know it is 16,800,000,000,000 x Speed of light (km) long.

However, if the age of the universe minus 16.8 billion years is the time taken for a quasar to decelerate from practically the speed of light to 94% the speed of light then we could also assume that its rate of negative acceleration is constant due to the lack of friction, and possibly even the state of zero mass assumed by quasars. So, if the universe were expanding at the speed of light it would reach zero density instantaneously. If this occurred there would be approximately 7EXP-3600 kgs of matter to every cubic metre of the universe. At this point the stars would be under compression caused by the shift in viable expanse caused by their vast energy. Every star would become a black hole, and would eventually turn the remaining universe into a large gravity well - a physical impossibility, as energy can neither be created and destroyed unless this situation occurs.

So in conclusion, if the universe were expanding at the speed of light, the gravity and inertia caused by the infinitely undefinable energy needed would make it impossible for light to exist within the possible form of the universe, if it has a form.

To discuss check topic asking what shape is the universe - - Claymore J

[DrMatrix]

Earlier DW3 said that some bright spark named John Movvat theorized that the speed of light has changed since the Big Bang. The speed of light is constant by definition.

The second is defined by be the time it takes for an atom of some particular element (I forget which one) to vibrate 1.79 bazilion times. The speed of light is defined as one light sec per sec. A light second is defined as the distance light travels in one sec. A meter is defined as some fraction of a light second.

The speed of light cannot change. It is a matter of definition.

------------------
Virtually yours,

I J Matrix

[DrMatrix]

Konrad
Would you mind if I used "Lies, lies, lies, spam and lies." in my .sig.
I promise to give you credit. ;)

[Konrad]

DrMatrix: Sure thing, but only cause you have a cool name like DrMatrix.

[torq]

Stars far enough from us are moving away at faster than the speed of light, but they are not moving faster than light locally to them.

Relativity says you can't simply add "we're moving away from object X at the speed of light" to "they're moving away from object X at the speed of light in the opposite direction" and get "they're moving away from us at twice the speed of light." To X, this is apparently true, but to us (and them) we're receding from each other at the speed of light.

If you meant something else, do you have a citation for it and could you clarify?

It's not possible for material objects to move faster than (or as fast as, though you could in theory get arbitrarily close) the speed of light in a vacuum, which is the c in the relativity equations.

However, it's definitely possible for material objects to move faster than the speed of light in a medium, such as water. I've seen this; it's what produces that odd blue glow around the core of a pool-type reactor.

And immaterial objects can move more quickly than c. The usual example involves some kind of huge scissors-like structure in which the point where the upper blade crosses the lower blade moves faster than c when the blades are closed... this is okay, because it's an imaginary geometrical construct and not an actual object (the scissor blades themselves, being material objects, are limited to c).

[moriah]

More pop explanation:

Don't forget that space is a geometrical construct of matter and energy. Matter and energy creates space. There is no law (yet) which says space can't be created in three dimensions at a velocity faster than light.

And expansion (or contraction) of the universe is related to gravity, so, it might be gravity which is not the universal constant it seems to be.

And to throw out a whimsical WAG with absolutely no science or mathematics to back me up: If all those early big-bangish particles were moving at near c speeds, then they had a very high relativistic mass which may be the cause for the ftl creation of space.

Peace.

[torq]

Hubble's law V = H*r gives the velocity V of an object at a distance of r. If we set V>c, then we find that at distances greater than c/H the velocity would be greater than c.

What you've basically said is "If we assume that V can be greater than c, then we can find the conditions under which V is greater than c," and I agree with that. My question was whether it would be valid to make that assumption in the first place.

[DrMatrix]

torq
I was trying to find the distance where V was greater than c.
If you want to go the other direction: What would the recession velocity be for objects whose distance is greater than c/H? Phrased this way I am not assuming V>c. I am only assuming there is no upper limit on distance.

[jab1]

DrMatrix, pointing out that an object would become infinitely small and infinitely massive at c implies that said object cannot achieve c. I simply didn't think that needed to be said. I hope no one thinks it's possible to reach infinity.

------------------
Those who do not learn from the past are condemned to relive it. Georges Santayana

[Claymore J]

Another theory is that the universe is encased in dark matter expanding at the speed of light. The edge of the universe is a layer of photons forming a layer of pure energy expanding a fraction off of the speed of light, as it is not as far away as the 'Dark Matter'. This would also explain why it was expanding but I don't have time to go into that.

If the edge of the universe were not travelling at quite the speed of light it would also be decelerating. Suggesting that Black Holes and White Holes are areas that are travelling at the same speed as the dark matter and have not decelerated, so they have stretched with the dark casing and have intercepted the photon barrier.
Thus explaining why they cannot be seen.

[DrMatrix]

torq said:If you meant something else, do you have a citation for it and could you clarify?

You mean I gotta support my statements?

Hubble's law V = H*r gives the velocity V of an object at a distance of r. If we set V>c, then we find that at distances greater than c/H the velocity would be greater than c. Of course at r = c/H there would be some sort of event horizon preventing us from receiving any information about what's beyond.

[DrMatrix]

AuraSeer Now, now. If you look back at Claymore J's posts you will find:Change in acceleration is equal to change in velocity over time.
This makes perfect sense to me. The rest of his statments sure have me puzzled though.

------------------
Virtually yours,

DrMatrix

[AuraSeer]

Claymore J, are you gonna keep posting like you have been, or do you plan to start making sense?

[DrMatrix]

torq I was wondering wheither there is some Lorentz-type correction.
Thank you.
I used the term event horizon because an event horizon is something such that nothing can cross from the other side to "us" without exceeding the speed of light. I admit this is a unique event horizon but I think it fits the definition.
Of course if I am wrong about Hubble implying FTL then there might not be such an event horizon.



------------------
Virtually yours,

DrMatrix

[DrMatrix]

But seriously folks,
Earlier I made the assertion that by Hubble's law objects whose distance is greater than c/H would have recession velocity greater than that of light. I also figure there would be an event horizon at a distance of c/H making such objects undetectable (except for their mass, charge, and angular momentum). I think the only two assumptions I am making are the universe is infinite (or has diameter at least 2c/H) and that Hubble's law applies at all distances.

Am I justified here or am I off base?

Thank you.

[torq]

I don't think Hubble's Law applies at all distances, at least not in the form you stated it. I would expect that something analogous to the Lorentz transformation would need to be applied in some way in order for it to be strictly true. However, I'm not an astrophysicist, so I could very well be wrong.

It's interesting you use the term "event horizon", though. I recall reading many years ago, when black holes first began being mentioned in popular culture, that as black holes became more massive they also became less dense. The article I was reading said that the observable universe had an average density which was a sizable percentage (roughly 10% IIRC) of the expected density for a black hole of the same size.

[John W. Kennedy]

The fallacy in the scissors-blade thing was pointed out decades ago. The actual limit is the speed of sound in the material the blades are made of.

------------------
John W. Kennedy
"Compact is becoming contract; man only earns and pays."
-- Charles Williams

[John W. Kennedy]

The second is defined by be the time it takes for an atom of some particular element (I forget which one) to vibrate 1.79 bazilion times. The speed of light is defined as one light sec per sec. A light second is defined as the distance light travels in one sec. A meter is defined as some fraction of a light second.


From the National (USA) Institute of Standards and Technology



[quote]
The meter is the length of the path travelled by light in vacuum during a time interval of 1/299 792 458 of a second.


Note, however, that this definition assumes the idea that the speed of light is invariant. If this were to be overturned, a new definition would be found.

------------------
John W. Kennedy
"Compact is becoming contract; man only earns and pays."
-- Charles Williams

[rubes]

Does anyone have a timeline of these events?
Big Bang
Milky Way Forms
Our Sun
Our Solar System
Earth
Moon
Life on Earth

Slightly off topic, but I have been digging for info on this for an animation I want to create.

email me directly if you do:

rubes@citilink.com

thanks

[DrMatrix]

John W. Kennedy saidThe fallacy in the scissors-blade thing was pointed out decades ago.If we position two rulers at a small enough angle and move them so that they approach each other, their point of intersection can be made to move as rapidly as we desire by decreasing the angle. The speed can reach infinity by making the angle zero. I would be interested in knowing how this involves a fallacy.Note, however, that this definition assumes the idea that the speed of light is invariant. If this were to be overturned, a new definition would be found. Well, yes...
One of the assumptions of GR is that the speed of light (in a vacuum) is constant for all observers. The current definitions of our units of time and distance are based on this assumption. If this were to be overturned, more than just the definition of the meter would have to be reexamined. All of relativity would be affected.

------------------
Virtually yours,

DrMatrix

[John W. Kennedy]

If we position two rulers at a small enough angle and move them so that they approach each other, their point of intersection can be made to move as rapidly as we desire by decreasing the angle. The speed can reach infinity by making the angle zero. I would be interested in knowing how this involves a fallacy.


You're making the unstated assumption that your two rulers are infinitely rigid. If infinitely rigid objects existed, you could transmit information faster than light much more easily just by pushing and pulling a long rod.

------------------
John W. Kennedy
"Compact is becoming contract; man only earns and pays."
-- Charles Williams

[jab1]

I think my head is spinning faster than light. Linda Blair's got nothin' on me!

------------------
Fighting my own ignorance since 1957.

[DrMatrix]

Imagine a stationary ruler and a second parallel and approaching the first. When they meet the point of contact moves with infinite speed.
If a second observer moves along the ruler fast enough for special relativity to be taken into account the points of contact will still have space-like separation and therefore be moving faster than light. The aparent direction of this movement will be in the opposite direction to the direction of the second observer's motion. I would note that even though the point of contact moves faster than light, this cannot be used to transmit information faster than light.

------------------
Virtually yours,

DrMatrix

[John W. Kennedy]

If you assume one stationary ruler and one ruler that "was always spinning", then, yes, you might get the point of "contact" moving faster than light, at which point, of course, there is no transfer of information.


------------------
John W. Kennedy
"Compact is becoming contract; man only earns and pays."
-- Charles Williams