Throwing Einstein for a Loop

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Because the speed of light is finite, you can see only a limited slice of the universe. Your position in space-time is unique, so your slice is slightly different from everyone else's. Although there is no external observer who has access to all the information out there, we can still construct a meaningful portrait of the universe based on the partial information we each receive. It's a beautiful thought: we each have our own universe. But there's a lot of overlap. "We mostly see the same thing," Markopoulou Kalamara explains, and that is why we see a smooth universe despite a quantized space-time. "I actually think theoretical physics is very much like art," concludes Markopoulou Kalamara, the daughter of two sculptors. "Putting these things together is like taking clay and making something out of nothing, and it should work from every side. I like the creative part, but I also like that you can check.

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Is this esoteric physics or poetry?

Fotini Markopoulou Kalamara: No disrespect meant, but doesn't this sound like something tasty at an Italian restaurant?

[ November 18, 2002: Message edited by: JimmyBrogan ]

Its like this. The universe is 14 billion years old we're told. This means that there can be nothing further away than this and since few galaxies move at the speed of light, most things should be a lot closer. The farther away things are the faster and closer to the speed of light they will be. The math is daunting but there must be some way to determine what this effect will have on what we can see.

For example

There are two wagons one has a guy in it shining a light at another guy. If he accelerates by some fantastic means to the speed of light and turns on his flashlight it seems to me that the light will never reach the 2nd wagon. Moreover, even at 90% percent of the speed of light the photons will be travelling toward the 2nd wagon at 1/10 of the speed of light and away from wagon 1 at 9/10 of the speed of light and the observor in the second wagon will never see any of that light. (Ed. note on reflection this is not I think correct.) Only at less than 50% of the speed of light will the observor ever be able to see wagon A's light. (Ed.Note nor this)

This means in a 14 billion year old universe (if this is a firm number) we can only see objects that are 7 billion light years away. (Ed. Note not because of the above phenomenon but because it would have taken a star 7 billion years to get to that place and a nother 7 billion for the light to get back) Or another way of looking at it that the oldest objects we should be able to see should be only 7 billion years old.

I calculate this because to get to places beyond 7 billion light years away they would have to have been travelling at speeds greater than 50% of the speed of light and if they maintained this velocity then no light could have ever reached good old planet earth.

(Ed Note: The amended idea is still that for anything further away then 7 billion light years, if that object had to move to that position through time space, there would be insufficient time for us to receive the light back.)

On the otherhand a galaxy speeding through space would need considerable time to slow down to the point where it would cross that threshold where light could make it back to earth.

Additionally no galaxies or celestial objects travel anywhere near the speed of light. So the question for me is how did they get there to begin with if the speed of light is the barrier that nothing in the Universe can supercede?

Any takers?

(P.S. I asked Ivan Seminuk, Discovery's astronomer, about this. He did respond but did not really explain how we can see things to far away. How did they get there and how did the light get back to us? It is a mystery to me. The media seems to take it all for granted )
too far out...

Editing for major revamps in my little theory.

[ November 20, 2002: Message edited by: Boinker ]

a)spinning at 1000 mph

b)orbiting the sun at 66,000 mph

c)travelling along with the sun and the rest of the solar system around the center of the galaxy at over 500,000 mph

d)our galaxy and its neighbors, the so-called Local Group, are moving at 1,350,000 mph in the direction of the constellation Hydra.

e)everything in the universe is moving along with the expansion of space itself

Are you hangin' on to something?

Because of e) I would guess the answer to your question is no, they would not arrive at the same time.

[ November 20, 2002: Message edited by: JimmyBrogan ]

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The earth is moving in many different ways.
a)spinning at 1000 mph

b)orbiting the sun at 66,000 mph

c)travelling along with the sun and the rest of the solar system around the center of the galaxy at over 500,000 mph

d)our galaxy and its neighbors, the so-called Local Group, are moving at 1,350,000 mph in the direction of the constellation Hydra.

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OK lets assume that by some good fortune we get them all lined up and that it takes light roughly 1/6th of second to travel around the planet under static conditions, say 167 milliseconds. Now adding up 1,350,000 + 500,000 + 66,000 + 1000 = 1,916,000 mph/3600 = 53.2mps (miles per second)or .00029 of the speed of light. That is, the beam fired in the opposite direction arrives .047 milliseconds later by my calculations (and they are probably wrong as to quantum but correct in principle)

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e)everything in the universe is moving along with the expansion of space itself

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How fast is space expanding?

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Are you hangin' on to something?

Because of e) I would guess the answer to your question is no, they would not arrive at the same time.

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Whew! I'm gettin' dizzy just thinking about it!

[ November 20, 2002: Message edited by: Boinker ]

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How fast is space expanding?

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dH/dt and ds/dt. Both are changing with respect to time, but because the Hubble constant is itself changing, so is the expansion of the universe.

[ November 20, 2002: Message edited by: DrConway ]

From the article about the deliciously named Fotini Markopoulou Kalamara:

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Because the speed of light is finite, you can see only a limited slice of the universe. Your position in space-time is unique, so your slice is slightly different from everyone else's.

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This means that vast amounts of the universe are already "over the horizon", forever so far away their light will never reach us. Interestingly, if the new discovery that the universe isn't just flying apart but is flying apart faster and faster every second proves true, virtually the whole universe will be over the horizon in a few 10's of millions of years.

Now I know that doesn't answer the conundrum but I'm sure it is all tied up with that expansion of the universe thing. The best estimate of the rate of expansion, known as the Hubble Constant, is constantly in flux.

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dH/dt and ds/dt. Both are changing with respect to time, but because the Hubble constant is itself changing, so is the expansion of the universe.

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Sorry this doesn't help much since my Calculus stops after 1st year University ehgineering courses. But this represents a description for accceleration and I believe is some sort of derivative I think. What is the signifigance of dH?, Does the H = the Hubble constant?

I'll be back after I look it up.

I still think Einstein's universe has some "big" problems. The way I Look at it can only be 28 billion light years in diameter. of which we can only see 7 billion years into.

(I'm back)

OK here is what other sites say:

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The Hubble Constant can be stated as a simple mathematical expression, Ho = v/d, where v is the galaxy's radial outward velocity (in other words, motion along our line-of-sight), d is the galaxy's distance from earth, and Ho is the current value of the Hubble Constant.

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The value of the Hubble Constant initially obtained by Edwin Hubble was around 500 km/s/Mpc, and has since been radically revised because initial assumptions about stars yielded underestimated distances. For the past three decades, there have been two major lines of investigation into the Hubble Constant. One team, associated with Allan Sandage of the Carnegie Institutions, has derived a value for Ho around 50 km/s/Mpc. The other team, associated with Gerard DeVaucouleurs of the University of Texas, has obtained values that indicate Ho to be around 100 km/s/Mpc. A long-term, key program for HST is to refine the value of the Hubble Constant.

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Still a small amount compared to the speed of light(@~300,000 km/s).

More later

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In other words, for each megaparsec of distance, the velocity of a distant object appears to increase by some value. (A megaparsec is 3.26 million light-years.) For example, if the Hubble Constant was determined to be 50 km/s/Mpc, a galaxy at 10 Mpc, would have a redshift corresponding to a radial velocity of 500 km/s.

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OK now we are getting somewhere. 14 billion divided by 3.26 million = 4640.67 times the Hubble Constant of say 100 = 464,067 mps. ANK!!
Too fast! Light can only travel at 186,000 mps.

So turn it around. Assume that the age of the Universe is correct 14 billion and divide this by a megaparsec and again by the speed of light and you get a hubble constant of 46.4kmps/mps.

Now I understand why Dr C is using acceleration notation. Isn't this fun!

And it seems logical that the furthest galaxies would be travelling the fastest in order to get that far, but they could,t have gotten there riding on the wave of the universe's expansion. It's just too slow.

(So this is explained somewhat by assuming that things travelling at the edge of the Universe are moving near the speed of light. The question is is are they really accelerating or is their velocity constant given their position? In other words assume they have a quantum frame of reference since the very fabric of spacetime is growing. ? So still... )

How did they get there?

[ November 21, 2002: Message edited by: Boinker ]

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This means that vast amounts of the universe are already "over the horizon", forever so far away their light will never reach us. Interestingly, if the new discovery that the universe isn't just flying apart but is flying apart faster and faster every second proves true, virtually the whole universe will be over the horizon in a few 10's of millions of years.

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This seems true as stated in the SA article:

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By tracing this evolution, Markopoulou Kalamara can explain the structure of spacetime. In particular, she argues that the abstract loops can produce one of the most distinctive features of Einstein's theory-- light cones, regions of spacetime within which light, or anything else, can reach a particular event. Light cones ensure that cause precedes effect. We can understand this concept by gazing upward and knowing that there are countless stars we cannot see because not enough time has passed since the birth of the universe for their light to shine our way; they are beyond our light cone.

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Kalamara is a University of Waterloo professor (my Alma Mater) - go U of W!

(Sorry about that)

Now does anyone know if this new theory being described has a correlative ib reality? Omnes,the author of Quantum Reality, basically says that although quantum physical laws determine everything they are laws derived from formal rules of logic and mathematics, derived from a level of existence where the two are one in the same.

What is a "cone of light"? Any tolerant quantum physicists out there willing to inject some actuality into these things, i.e. give a better explanation? This kind of science all sounds very mystical at times.

[ November 23, 2002: Message edited by: Boinker ]