I don't know if this guy is right or wrong about this. But how can the speed of light work going away, but not coming back, when both speeds and distances are equal?
The Speed Of Light ??
- Thread starter billt460
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There is no difference between traveling away from earth and returning again. In both cases time dilation occurs with the time for the traveler running slower both on the way out and on the way back again. Traveling on the way back doesn't cancel out the time dilation on the way out.
Yes he's right. The time dilation that appears to shrink the distance only works for the traveler. If the andromeda galaxy is 2 million years away, that's how long the ship would take to get there as seen from earth. But for those aboard it would seem like a minute.
If that's not clear to you think of the journey as it has been done with the crew in stasis or hypersleep. They won't have aged.
How so? Speed is speed, and distance is distance. If you're traveling at the speed of light, and it takes light 2 million years to reach Andromeda, that's 2 million years regardless of how you figure it.
Why would it seem less for the traveler? No matter how you cut it, 2 million years is 2 million years. The light now reaching us from there left 2 million years ago.
So if we left now it's the same 2 million years back.
The Special Theory of Relativity explains it. Time slows down if you're traveling close to the speed of light.
The effect is measurable even at speeds much lower than that.
I’ve always been fascinated with this subject and I remember reading that the internal clocks of satellites (traveling at speeds of well above 10,000 mph in orbit) need compensation to deal with the relative difference with clocks back on earth.
if you hitched a ride on that light, it would arrive instantly from your perspective
Speed of light doesn't work this way. Effects of relativity apply. You'll have to do some reading on General Relativity for this one.
Yes, distance is distance.
But time is not time. Space, and time, can be distorted.
We see this effect in GPS satellites - even at their slow (relative to the speed of light) speeds, time passes more slowly for them, and the GPS constellation has to compensate for relativistic time dilation happening to the clocks in those satellites.
Time dilation happens with velocity - so, near the speed of light, time does, inarguably, slow down.
It slows down a tiny bit at 18,000 miles an hour.
So, you can bet it slows down when getting up near 669,000,000 miles an hour (speed of light).
So after I arrived and looked back through a telescope at Earth, I would see it as it was 2 million years ago?
No, you'd see it as it was as you left., but that was 2 million years ago
I guess I need to start driving faster.
yep, the faster you drive, the more time you have.
Time is relative to velocity, it slows down noticeably as you approach some fraction of the speed of light. This is how it is almost always explained; time slows at very high velocities. What they omit to say because it's not measurable (and even if it was it would still be irrelevant) is that time also slows down when you walk across a room. Special Relativity doesn't stop working at low velocities, it's just that we don't notice it and can't measure it.
That's a tricky question. Yes, the earth is 2 million years older but it takes the light 2 million years to reflect back in your telescope. These questions always stumped me when I studied physics in college.
It's very hard to wrap your head around this kind of stuff.
What about speed relative to Earth? We're all flying through the Solar System at 60,000 MPH relative to everything else, as we orbit around the Sun.
Eskimos living near the pole aren't moving as fast as the people who live in Singapore near the Equator. They're moving almost 1,000 MPH as Earth rotates on its axis once daily.
Eskimos living near the pole aren't moving as fast as the people who live in Singapore near the Equator. They're moving almost 1,000 MPH as Earth rotates on its axis once daily.
And it is also important to point out that this is always in reference to some outside observer. For the traveler's and the observer's clocks, a second is still a second, and year is still a year to them You're both aging in your own reference frame. It all traces back to the fact that the speed of light is a constant in both frames.
Yep. For you only a little bit of time would pass. But in fact, it took 2 million years to get there as viewed by an observer at rest.
Not quite enough difference between the Pole and Singapore to measure.
Remember, you’re comparing to C - which is, roughly 669,000,000 miles an hour. That’s 669 MILLION - so, a thousand or so either way? Not enough.
But 18,000? The difference between an orbiting satellite and a person on the ground?
Yep, measurable difference.
