When we look at the stars are we looking into the past?

Question

and what if some of those stars don't exist anymore?

Answer 1

Possibly. The recent reports of probable past life existence of life on Mars certainly seems to indicate that.

Answer 2

Yep.  The farther away a star is, the farther into the past you're looking.  Specifically, every light-year in distance corresponds to 1 year in the past (generally speaking).  The sun is about 8.5 light-minutes away, so even looking at the sun is looking into the past a little bit.  It kind of makes you have to rethink the term "real time", because light travels roughly 1 foot per nanosecond, so looking across the room is actually looking several nanoseconds into the past.  Amazing, huh?  The closest star other than the sun is 4 light-years away.  The farthest stars are about 40 billion light-years away, but less than 14 billion light-years old.  This is because of inflation (talking about space, not the economy :)).  The light we see from the farthest galaxies is 13-14 billion light-years old, but the universe has inflated much over that time, so we know that now they are much farther away than that.  Since stars don't live that long, it's safe to say pretty much none of those stars are there anymore (at least in the farthest galaxies), but new ones have formed to take their place.  Within our own galaxy, 100,000 light-years across, it's safe to say that pretty much all the stars are still there.

Answer 3

=S me no entender bien tu pregunta jeje xD

entiendo lo ke dice pero no lo ke kiere decir :S

Cuando miramos a las estrellas que están buscando en el pasado?

y ¿qué ocurre si algunas de esas estrellas no existen ya?

no estoy en lo mejor de entenderte sorry jeje

Answer 4

Good question.

I think everyone's heard of light years, it's the time it takes for light to travel 1 year.

Light takes 8 seconds to go from our sun to earth. So, if the sun blew up we wouldn't know for 8 seconds.  We also wouldn't miss the suns gravity for 8 seconds.

We are looking billions of years into the past, at stars that may not exist anymore, depending how far away they are from us.

Answer 5

When you look at anything you are seeing it as it existed in the past.

  Even a person in the same room with you,you are seeing them as they existed hundreds of millionths of a second in the past.

  When you see them you know they are there but before you see them maybe they don't exist.

  It's an extreme from a star light years away

Answer 6

You are seeing your hand in the past.

It takes time for the light to travel from any object to your eyes (and then to your brain). It takes light about 8 minutes to get here from the sun. it takes longer from jupiter ( which is bright in the night sky) .

Since it takes time for the light to get here, the light is from a time in the past. Something 100 light years away, it took light 100 years to get here. You see what it looked like 100 years ago. It could have blown up last year and we wouldn't know for 99 more years.

You can find the Andromeda Galaxy in the sky. The light from the far side is 250,000 years older than light from the near side. This means you don't actually see what it really looks like, though it really doesn't matter. It is about 2,900,000 light years away.

Answer 7

If the star blew up you would still see it as normal until the light from the explosion got here.

Answer 8

Dear Friend:

This is the hardest Question I have ever answerd in Yahoo Answers. This Question is really Deep.

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I would say yes.

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When we look at stars we are truly looking into our past but not only our past but the History that got us here ( as a human beeing )

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When i look at the stars i always want to choose one of the stars and i do not know which one is the living star and then i look into the past, that what got me here and why am i confused.....

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Every day is a Gift, That is why we call it Present.

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Good Luck

little john

Answer 9

You see a thing as it was when the light coming from that thing started on its journey to your eye. If the trip takes a long time, then you see the thing as it was a while ago: then you look into the past. You can compare this to an instant picture of yourself that you immediately put in a letter to a friend. Your letter is delivered to your friend a few days later, so when he takes out your picture and looks at it, he sees what you looked like a few days ago. The delay in the arrival of light is therefore not a special characteristic of light, but shows up for any kind of transmission of information. Because light travels very much faster than mail, the travel time of light is not noticeable in your day-to-day life.

So, you see any thing as it was a while ago. This holds for a very distant star, but also for a nearby planet or for a tree next to your house. The travel time of light is very short if the thing is nearby, and is very long if the thing is very far away. The travel time of the light indicates how far you look into the past if you look at the thing.