OT -- Starlight Question

[Dutch]

I'm taking a natural science class on the weekends and we discussed the speed of light a bit and then I did an astrolab science project a couple of weekends ago (where you have to find Polaris and figure out where you are based on that).

Anyway, I explain to my son that some of the stars we see are millions of light years away.

After saying that, it has me wondering, if we are millions of light years away from a particular star, what do we see when we look at said star? Do we see it in it's current form or are we looking at what the star *used* to look like millions of years ago.

Just wondering.

[ice4277]

We are looking at what the star used to look like.

[Dutch]

That's pretty cool. So...if some amazingly advanced intelligent life had a telescope that could zoom in on Earth close enough to see people, and they were 516 light-years away (for instance) they would be looking at us in the year 1492 and might possibly catch Christopher Columbus land in the "New World"? Today? That's pretty interesting stuff. Maybe they'll record it and send us a tape of it. Probably take millions of years to get it here if they send it with free shipping though.

[clintl]

Originally Posted by Dutch

That's pretty cool. So...if some amazingly advanced intelligent life had a telescope that could zoom in on Earth close enough to see people, and they were 516 light-years away (for instance) they would be looking at us in the year 1492 and might possibly catch Christopher Columbus land in the "New World"? Today? That's pretty interesting stuff. Maybe they'll record it and send us a tape of it. Probably take millions of years to get it here if they send it with free shipping though.

Or 516 years if they sent it by radio.

[sterlingice]

It's an interesting concept. If we had ways to travel at higher than the speed of light (wormholes, etc) to pass a message along to do such a thing and if they had the technology to lok that closely (that's the impossible catch- I mean something thousands of miles across looks like a pinpoint so I think viewing individual events on said small point... well, you get the idea), it would make for a fun sci-fi story

SI

[Bad-example]

Originally Posted by clintl

Or 516 years if they sent it by radio.

And if radio waves travelled the speed of light.

[Bad-example]

And a quick bit of research shows I was completely wrong.

Radio waves are part of the Electromagnetic Spectrum. All waves of the electromagnetic spectrum travel at the same speed of 300,000 kms per second in space.

[Crim]

Originally Posted by Bad-example

And if radio waves travelled the speed of light.

Originally Posted by Bad-example

And a quick bit of research shows I was completely wrong.

That was funny, B-e. I read yer first post, had time to think "Hrrrrm?!?", then saw yer oopsmybad post and giggled.