[NotStein]

I got this crazy idea this morning while going back & forth with RascalPuff about time & motion. It's known that time slows to a stop/ceases to exist at the speed of light. Inflation is also pretty well accepted, i.e. the universe expanded much faster than 'C' just after the Big Bang. Would time have raced backward during inflation? Does that mean that when the universe winds down to an end, that time might just be winding forward back to zero?

Isn't that a bizarre thought? The lifespan of the universe actually being zero time in length?

What're y'alls thought on on this (I already used the word bizarre!)?

[Graybeard]

Originally Posted by NotStein It's known that time slows to a stop/ceases to exist at the speed of light. Inflation is also pretty well accepted, i.e. the universe expanded much faster than 'C' just after the Big Bang. Would time have raced backward during inflation? Does that mean that when the universe winds down to an end, that time might just be winding forward back to zero?

Wow ... if time stops at the speed of light and this is 'known' then its not known to me. I would have thought that our measurement of time would register at the normal rate regardless of speed. An observers perception of our speed may differ accordingly. I don't visualise this as time stopping. I think that our measurement of time is just our perception of order/disorder?

Second point is that if you chart space/time on a X-Y graph then you end up with the speed of light at 45 degrees to both. This does not allow for any backwards/forwards or you would be exceeding the speed of light?? Once again a different observer may see things differently, but these are relative perceptions.

IMO only

cool bananas ... greg

[RascalPuff]

Originally Posted by Graybeard Wow ... if time stops at the speed of light and this is 'known' then its not known to me. I would have thought that our measurement of time would register at the normal rate regardless of speed. An observers perception of our speed may differ accordingly. I don't visualise this as time stopping. I think that our measurement of time is just our perception of order/disorder? Second point is that if you chart space/time on a X-Y graph then you end up with the speed of light at 45 degrees to both. This does not allow for any backwards/forwards or you would be exceeding the speed of light?? Once again a different observer may see things differently, but these are relative perceptions. IMO only cool bananas ... greg

Hey Greg and Jeff (NotStein):
I'm with you on this every parsec, lightyear, mile, kilometer, yard, foot, inch, millimeter, millisecond, nanosecond, picosecond and angstrom unit of the way.

We're bound to be equalling and exceeding the speed of light relative to other coordinates, and conversely. I think it's going on all the time - all kinds of lightspeeds everywherewhen.

Kewl Kukumbers,
-RP

[Graybeard]

Originally Posted by RascalPuff We're bound to be equalling and exceeding the speed of light relative to other coordinates, and conversely. I think it's going on all the time - all kinds of lightspeeds everywherewhen. Kewl Kukumbers, -RP

Thanks Rascal ... The expansion of space, while occurring everywhere, is placing distance between our cosmic horizon and the rest of the universe at faster than light speed. This means we can never reach outside the horizon. Current speculation is that our cosmic horizon is considered a grain of sand within our Universe.

But, in my understanding the expansion of space is not bound by relativity, and as such would not affect spacetime as acceleration does. Acceleration may warp spacetime but the expansion of space does not. My easiest way to understand this is to say that anything that came into being at less than light speed can never exceed it. But on this point I am not so clear.

cool bananas ... greg

[N0B0DY]

I think the implication holds for the very reason you give, Greg. That any massive particle travelling at subluminal velocities can't exceed "c," so light will always be measured at the same acceleration rate. To light itself, there would be no time, but only pertains to the observable universe.

Space is a part of the universe, though, and therefore would represent the true universal time. For space itself, there would be absolutely no concept of time insertable.

What do you propose is the speed of spatial expansion, btw?

[Graybeard]

Originally Posted by N0B0DY I think the implication holds for the very reason you give, Greg. That any massive particle travelling at subluminal velocities can't exceed "c," so light will always be measured at the same acceleration rate. To light itself, there would be no time, but only pertains to the observable universe. Space is a part of the universe, though, and therefore would represent the true universal time. For space itself, there would be absolutely no concept of time insertable. What do you propose is the speed of spatial expansion, btw?

Nob .... am not sure about the rate of expansion. If expansion exists everywhere, and I believe it does, but is overcome by gravity at the galaxy cluster level then the rate of expansion would climb an exponential curve according to the distance between the two referenced objects.

What I mean here is that if you stand 100metres from me and Lloyd stands another 100metres from you so that he is 200metres from me, then if all the intervening space is expanding or increasing Lloyd will disappear from my view at a much greater rate than you would.

As our cosmic horizon can only reach to the age of the Universe, anything outside our cosmic horizon must be expanding at many, many times light speed.

I am willing to listen to other explanations on this, this is just my own take on it.

As to why this is happening ... my own guess is that if they solve the 'dark energy' mystery many things will become much clearer than they are now.

cool bananas ... greg

[N0B0DY]

If only it were possible to have Lloyd disappear.

Fair enough lesson, Greg, but I was thinking more along the lines of beyond the infinitesimal scale. Or do you propose that scale applies to space as well?

Also, why would gravity overcome expansion when it is the cause of expansion according to Kirchoff's law? I would think that the denser the matter, the greater the expansion would be, no?

[Graybeard]

Originally Posted by N0B0DY Also, why would gravity overcome expansion when it is the cause of expansion according to Kirchoff's law? I would think that the denser the matter, the greater the expansion would be, no?

I don't understand the reference to Kirchoff's Law. I had to learn it as an apprentice electrician many years ago and to me it is forever associated with the current balance in a circuit.


Hmmmm ... Nob, please be aware that I don't really know what I'm talking about from here on.

Lets accept that the gravitational force consists of Mass, Energy and Pressure as described by Einsteins General Relativity. The greatest contributor of course is Mass.

Mass is always positive. Energy I'm not so sure about, but Pressure can be positive or negative. Now where ever Mass is present in large quantities then 'positive' gravity dominates. We know by the blue-shift that all the galaxies in the local cluster, known as the local group, are hurtling towards each other. Why, because Mass, in the form of stars, is the dominant contributor to gravity inside the local group.

But, out in space Mass is no longer the dominant contributor to gravity. Space consists of energy and pressure and virtual 'Rascal' particles but very little Mass. If the dominant contributor is now pressure, and that pressure is positive then gravity will be attractive. But if the pressure is negative then gravity will be repulsive.

You can quickly see from this that Gravity can be both attractive and Repulsive. Within a galaxy, group of galaxies, or cluster of groups attractive gravity rules, drawing them closer and closer together.

But outside that region, space is being created by repulsive gravity between that cluster and the next. Why is the pressure negative? I'm not sure but Einstein had to have a negative Cosmological Constant to develop a stationary state (static) Universe which he then abandoned. So an expanding Universe would also have to have a negative cosmological constant. Possibly Lloyd or Dave might know this?

The effect of positive gravity can be seen in the blue-shift of galaxies. The effect of negative gravity can be seen in the red-shift.

As I explained in the previous post, when referring to the 100m distance between me, you and Lloyd, negative pressure is cumulative because it is acting everywhere at once so that the further apart two objects are the greater their rate of separation.

This also is confirmed in the red-shift, the greater the distance, the greater the red-shift. There are three methods of determining the recession between galaxies, red-shift is only one of them. Importantly all three agree on the recession of distant galaxies and all three are independant of each other.

This means as the Universe gets older we (the milky-way kids) are going to huddle closer and closer together as we become more and more isolated until eventually the only stars in our sky will be the stars of the milky-way. (And Andromeda of course, which will have carved through the milky-way like a circular saw blade by then).

Don't take this as gospel

cool bananas ... greg

[N0B0DY]

I never do, Greg, but it is a superb explanation.

I'm thinking of abandoning the attractive factor altogether, focusing more on that shadow gravity effect that Rascal had posted a while back - everything pushing, no such thing as a pull, or the pull is really opposing pushes.

The other thing is how we can be sure that the mass of the galaxies are actually coming together and not only the radiation of decaying galaxies - if acceleration of energy would result in the same observed gravitational effect as the acceleration of mass?

[NotStein]

Originally Posted by Graybeard Wow ... if time stops at the speed of light and this is 'known' then its not known to me. I would have thought that our measurement of time would register at the normal rate regardless of speed. An observers perception of our speed may differ accordingly. I don't visualise this as time stopping. I think that our measurement of time is just our perception of order/disorder? Second point is that if you chart space/time on a X-Y graph then you end up with the speed of light at 45 degrees to both. This does not allow for any backwards/forwards or you would be exceeding the speed of light?? Once again a different observer may see things differently, but these are relative perceptions. IMO only cool bananas ... greg

Good point, postulate crushed. I don't think time stops/runs backwards for the object travelling at/above 'C' (from his own reference frame), but I think it's been proven (orbiting clocks, etc.) that time would appear to stop/r.b. from the reference frame of a 'stationary' observer. Looking at yourself in your own reference frame, time stays constant regardless of your velocity measured from another reference point.
As far as exceeding 'C' and allowing forward/backward movement through time, however, haven't scientists recently been able to actually kick particles forward in time (they exit the apparatus before entering)? I could have swore I read this in a major publication, but haven't had success Googling it.
Two points we might explore further from the great feedback 'yall have posted:
1) You state in your 2nd post "Current speculation is that our cosmic horizon is considered a grain of sand within our Universe." If so, doesn't this account for the "missing matter" in the Universe? Won't most matter in the Universe reside beyond our event horizon? If so, couldn't the ratio of the amount of matter we can see vs. the amount their 'should be' tell us just how much of the universe resides beyond our event horizon?
2) N0b0by asks in his post "What do you propose is the speed of spatial expansion, btw?" I think it could be calculated using:
a) the total amount of energy falling into black holes (recycles into 'space'?)
b) the 'density' of the 'vitual particle sea' we call space (the max. amount of energy/area before particles 'pop' out of it)
c) the total area of the universe at the time of the calculation (calculated from #1 above maybe?)