Is it true that when you travel in space you can see the past on earth?

Question

my cousin took astrology in highschool and her teacher sid that when you travel through space the farther you are away from earth the world looks younger like you can see dinosaurs or something

Answer 1

Not quite true. I think the message got garbled in translation.

A person a 100 light years away from Earth RIGHT NOW would see the Earth as it was 100 years ago. A person a 1000 light years away would see the Earth as it was 1000 years ago.

If you traveled through space, you'd have to take into account that the travel would take some time. If you traveled to a planet 100 light years away at half the speed of light, you'd reach the planet in 200 years. When you looked at the Earth, you'd see Earth as it looked 100 years before you arrived, which would be 100 years after you left.

Yes, you're looking at the Earth as it existed in the past, but that's not the same as travelling back in time.

Answer 2

It's astronomy, not astrology. Haven't seen a high school yet that teaches it and if any did someone would need to go up to that teacher, slap them on the wrist and say "NO!".

Now, about the topic. You would not be able to see Earth's past. Right now, man has only gone as far as the moon, which isn't far enough for this supposed theory to work. But, let's say it did work. To see dinosaurs, you would need to travel more than 65 million light years away to be able to them. At that distance, at best you would be able to see our galaxy, and only our galaxy. You wouldn't be able to pick out our sun, let alone Earth. You would be too far away.

Okay, let's say you want to watch the landing on the moon with your own eyes. Well, you would need to travel 38 light years away. At that distance you could pick out our sun. But without a very powerful telescope attached too the craft you are flying, you wouldn't be able to see the Earth, the moon would likely be lost in the glow, and you definitely wouldn't see such small details. Heck, we couldn't watch it with a telescope here on Earth.

It is a bad theory based on the facts around the speed of light and science fiction stories. If....I said IF it could happen, you would have to be much farther away and while you could see a younger Earth, you definitely would not see details about what's happening on the surface.

Answer 3

Short answer - no.

It IS true that when we view very distant objects we see them as they were in the distant past. For instance, a quasar that is 8 billion light-years away appears to us as it was 8 billion years ago. But moving away from the Earth does not cause this to happen. If you traveled 10 light years from Earth, then looked back, you would see the Earth as it appeared ten years ago from our point of view. But since FTL travel is (as far as we know) impossible, you can't get ahead of the light that left the Earth in the past.

Answer 4

first: your cousin took ASTRONOMY, not that other stuff with the crystal balls and incense.

second: i hope the teacher was doing a 'thought experiment' saying something like... "If we could travel faster than light and zipped out to 1000 light years from Earth and pointed a VERY BIG telescope back at the Earth, we would see our planet as it was 1000 years ago."

Otherwise... even if you could travel AT the speed of light (and you can't) if you traveled 1000 light years from Earth you would see the Earth as it was when you left. Not earlier.

Answer 5

There was a theory about travelling in space faster than the speed of light that basically said something along those lines. But it was based on the fact that you were travelling faster than light and would therefore get ahead of light from the past. But it has never been proven as we can not travel that fast... yet.

time is time and moves at the same constant speed. So ask teacher where they got their facts from.

Answer 6

You mean 'astronomy', right? Astrology is the defunct Ptolemic nonsense that is in the papers...

One can't see dinosaurs from the void in space...but I have heard it said that when one looks up at the stars, the light you see coming from them started from the time of the dinosaurs, and is only reaching us now. "You are looking into a vast time machine", as Richard Dawkins put it.

That been said, have you seen how big Mars is up there?

Answer 7

As you approach the speed of light, time slows down. Since you can only see visible light, if you were able to instantaneously move yourself to a few billion light-years away, you could see the earth as it looks a few billion years ago, since the light THERE would be billions of years old.

But this is not possible so you could not.

Answer 8

If you could travel faster than the speed of light and had a powerful enough telescope then yes it would be true! The light we see from stars is old, some of them no longer exist! Unfortunately we can't travel faster than light and there isn't a telescope that powerful...LOL

Answer 9

I would be VERY concerned about any schol ofering astrology as a subject.

Answer 10

Nope, that was a joke. You can only see PAST the earth...