Posted by Alan Baltes on Sunday, January 7, 2007 at 6:52:53 PM
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If time travel into the past will ever be reality, then why aren't our distant descendants coming back in time to visit us? Or are they?
A fact:
When we gaze at a faint star in the night, we are actually looking back in time. Just imagine that we could look into a telescope and see a planet with intelligent life on it orbiting that star. If that planet is 5000 light years away (light travels at 185,000 miles per second), then what we see in the telescope took place 5,000 years ago.
Just a thought.
I'm still trying to get a grip on Einstein's theory that as matter approaches the speed of light, it begins to travel forward in time. I do understand his theories that matter can not exceed the speed of light, and that travel backwards in time is not possible.
Re: Time Travel Comment by mommyoftwoboys on Monday, January 8, 2007 at 2:01:33 PM
Interesting that you posted this topic. My husband were just talking about Einstein's equation for relativity last weekend. Of course, most of us know the equation, but what does it really mean. My husband is a complete genius when it comes to math and scientific matters (me, not so much). He tried explaining it to me - I think I got some of it, but still don't understand how Einstein was able to come up with "relativity." Just goes to show you how brilliant Einstein was.
I would love to learn more about this subject and on Einstein. So if you have any good sites to go to that explain these matters in layman's terms, please feel free to list them. Thanks!
Melissa
By the way, you might have already read Stephen Hawking's newest A Briefer History of Time but I am listening to it on CD. I believe there is a chapter on time travel. I haven't gotten there yet, but thought you might be interested.
Re: Time Travel Comment by Alan on Thursday, January 11, 2007 at 10:39:45 PM
While traveling back in time is not yet considered possible, VIEWING back in time is technically possible. Follow this line of reasoning:
Let's say you went through a wormhole and went exactly 2000 light years away from Earth in an instant. Then you took a huge telescope and pointed it back at Earth -- and the telescope is so good that you can actually see detail on the planet. Well he light hasn't reached you yet, so in theory, you are viewing the Earth as it was 2000 years ago.
Re: Time Travel Comment by Jen Filmtopia on Tuesday, February 27, 2007 at 2:27:44 PM
My brother explained time travel theory to me as:
"Imagine a circle and you at one point, now imagine you could travel round the circle so fast that you arrived before you left."
It blows my mind every time I think of it. Although weirdly it seems to make perfect sense to me.
I can't actually get my head round if the size of the circle makes a difference; the longer the circle, the faster you need to go and the farther back in time?
I love Alan's telescope idea - but no-one on earth would see it unless you beamed back the signal through the wormhole? History channel - LIVE! ;D
Re: Time Travel Comment by Jen Filmtopia on Tuesday, February 27, 2007 at 4:18:42 PM
I wondered - if there was such a thing as mind projection (bit like remote viewing?) and we could train our minds to project through time, could we mentally time travel?? - I how fast can brainwaves travel?? Are they faster than light? or is esp undetectable in current science? I wonder if that's what psychics can do, but it's not quite developed into mind projection yet?? Ooh I feel like an idea of a sci-fi movie brewing... must have Christopher Walken, Gary Busey and Alan Baltes in it.... ::imagination runs away into cosmic freefall::
Re: Time Travel Comment by Draevyn on Friday, March 23, 2007 at 11:15:16 AM
I'm still trying to get a grip on Einstein's theory that as matter approaches the speed of light, it begins to travel forward in time. I do understand his theories that matter can not exceed the speed of light, and that travel backwards in time is not possible.
This may help, the faster you go, the slower time goes for you. On Earth the difference between someone who always walks to work versus someone who always drives fast would be so small it would be barely noticeable over a lifetime.
Now, person 1 is traveling to work at the speed of light (he works on alpha centauri) while person 2 stays home.
Since person 1 is going so fast, time is moving very slowly for him.
When person 1 returns from work, 25 years have passed for him because time is going slower. (imagine the overtime check)
50 years have passed for person 2, because time is going much faster for him.
So.. from person 2's perspective, person 1 has traveled into the future.
Re: Time Travel Comment by quantumpork on Friday, March 23, 2007 at 11:56:19 AM
Close but no cigar. The time always remains constant for the stationary observer and also for the traveling person. Where the discrepancy originates is from the stationary observer measuring time of the traveler from his stationary time line or vise-versa.
If we could travel 100 psol the trip would last about 8.8 years for the traveler and 52.8 years for the stationary observer. (see equation)
Read: Relativity and the Absolute - Is Spacetime an Einsteinian Abstraction or a Physical Entity? It is chapter #3 of "The Fabric of the Cosmos - Space, Time, and the Texture of Reality (Brian Greene 2004)
Re: Time Travel Comment by Draevyn on Friday, March 23, 2007 at 12:07:09 PM
Lol.. We actually said the same thing. Time would, in fact, be slower for person 1, but not from his perspective, it would be slower from person 2's perspective.
I tried to keep it simple to help answer the question:D
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