Split time

[herme3]

Jdurg said in another thread, “I've always found it interesting how when we look up at the stars at night, we're actually looking back in time (Since if a start is hundreds of thousands of light years away, it takes the light hundreds of thousands of years to reach us). For all we know, many of the stars we are looking at may have gone 'BOOM' a long time ago. I always found that to be neat.”

 

I understand that this happens because it takes that long for the light to reach us. However, doesn't this split time itself? Time is change. If the light that we are seeing hasn't changed to the present time yet, aren't we seeing another time? Therefore, isn't time itself is split throughout the universe? I mean isn't the light that has been reflected from Earth a year ago somewhere else in the universe, but still from last year?

[JaKiri]

You're confusing 'time' with 'things'.

 

I have a book from 1943, it doesn't mean it's 1943 where the book is.

[TimeTraveler]

If the light that we are seeing hasn't changed to the present time yet, aren't we seeing another time?

 

Well, yes you are seeing another time, relative to you (the observer) I think we have seen all the way back to about 14 billion years with hubble. But yes, when you look at a star in the sky you are seeing it how it was in the past.

 

Not really sure I understand the rest of your question. Split time? What ever do you mean?

[herme3]

You're confusing 'time' with 'things'.

 

I have a book from 1943' date=' it doesn't mean it's 1943 where the book is.[/quote']

 

Yes, but the book is just matter that exists with us. It is part of our time, because we can change it. If I wanted to get a pen and write in a book, the book would change in our time. The stars we see are in the past. If we could somehow change the stars, we won't change what is seen on Earth until way into the future.

 

By split time, I mean that there is a different time from each part of the universe in a different part of the universe. Lets say that there is a planet that is many light years away with an advanced alien civilization living there. To them, the Earth may be in the time of the dinosaurs. To us, that planet may be an ancient civilization with no technology. However, the aliens may be a very advanced civilization. We just wouldn't know because their time is split from our time.

[psi20]

Suppose people built a telescope so enormously powerful, just imagine with me, that it can actually see extrasolar planets that are in our a billion-light year radius.

 

Say a billion years ago, alien civilizations went to war with each other on a small planet we call PeZe.

 

This planet happens to be a billion-light years away. You point the telescope at it. Will you see the aliens going to war with each other?

[jdurg]

Suppose people built a telescope so enormously powerful' date=' just imagine with me, that it can actually see extrasolar planets that are in our a billion-light year radius.

 

Say a billion years ago, alien civilizations went to war with each other on a small planet we call PeZe.

 

This planet happens to be a billion-light years away. You point the telescope at it. Will you see the aliens going to war with each other?[/quote']

 

Theoretically speaking, if the telescope was powerful enough, yes. You'd see it because the light traveling from the planet would take a billion years to reach us, so you'd see an image that took place a billion years ago. Think of it as 'extreme lag'.

[herme3]

I'm thinking this is more than just an "image". Isn't it everything of a different time? If we had an extremely powerful microphone that can take out all background noise, wouldn't we hear all the sound many years after we see the light? Sound travels slower than light, but if we did receive it, it would also be from a long time ago.

[Douglas]

Suppose people built a telescope so enormously powerful' date=' just imagine with me, that it can actually see extrasolar planets that are in our a billion-light year radius.

 

Say a billion years ago, alien civilizations went to war with each other on a small planet we call PeZe.

 

This planet happens to be a billion-light years away. You point the telescope at it. Will you see the aliens going to war with each other?[/quote']

If you took a photograph of this war, I guess you could say it's a "real time" photo, taken a billion years ago.

[jdurg]

I'm thinking this is more than just an "image". Isn't it everything of a different time? If we had an extremely powerful microphone that can take out all background noise, wouldn't we hear all the sound many years after we see the light? Sound travels slower than light, but if we did receive it, it would also be from a long time ago.

 

 

Very true. But remember one thing, sound requires matter in order to transfer. Outer space is completely silent because there is no matter out there to transfer the sound waves. Light does not require matter as a transmission medium so it is able to traverse the long distances. (Now if you're talking about radio waves, then yeah, it could travel that distance because I believe radiowaves travel as an electromagnetic pulse which is turned back into sound with the help of a receiver).

[psi20]

Suppose you set up 2 of those super-telescopes very far away from each other. You see the PeZe war happening and record it on the calendar as the PeZe war. Then a couple months later, the other telescope sees it and records it on the calendar as the PeZe war.

 

How does the expansion of the universe change this? Should the expansion be slower than the speed of light? If it was faster, how would that change the scenario?

[MOTP]

Supposing we did receive a radio broadcast from a planet 1 billion light years away. We would be thrilled that there is other life in the universe. Unfortunetly, Their entire race could have easily been wiped out in 1 billion years.

 

It's a form of time pollution. You gain things from 1000 years ago, 1 million, 1 billion, and so on.

[alt_f13]

I hope your brains don't explode when you find out gravity also acts on a lag.

[TrueHeart]

"Split time" is an understandable and okay conceptualiztion of relativity, in reaction to the fact that there is no universal time standard; and to the fact that all causations are constrained to propagate no quicker than lightspeed. Here's a quote from my web treatise (Addendum 3):

You may hear tell that the stars and galaxies we see, because of their great distances and because of the finite speed of light, are really only after-images of what they once were. But relativistically speaking, no! what you see is what you get. We are viewing the distant stars as they are now, because now is the only time that's real for us, as gauged by causality. If a distant star blows up and its offshoot radiations eventually affect the Earth, then we are 'under attack' at the moment of their impact, the moment of causation... nothing else is relevant to physics. In a situation such as that, the X-rays and whatnot are attacking us while we see the star explode. So causality pretty much defines what is real now, and any 'deeper' analysis is at best a derivative and at worst a concoction.

[MadScientist]

By split time, I mean that there is a different time from each part of the universe in a different part of the universe. Lets say that there is a planet that is many light years away with an advanced alien civilization living there. To them, the Earth may be in the time of the dinosaurs. To us, that planet may be an ancient civilization with no technology. However, the aliens may be a very advanced civilization. We just wouldn't know because their time is split from our time.

 

 

Let's do a hypothetical experiment.

We'll synchronise our watches, I'll go and stand on the Sun and at 9pm we'll both throw a ball into the air. After throwing your ball you look through a telescope and wait 8 minutes to see me throwing my ball into the air. We both threw our balls into the air at 9pm though.

 

Time is split though but for different reasons than you've used, time dilation.

The faster something moves through space the slower it moves through time, so a planet or solar system that's travelling really slowly and was born at the same time as ours will have aged more than ours.

At least that's the way I think things work, maybe one of the more knowledgable members could elaborate...