BECAUSE IT HAD TO TRAVEL SO FAR?????????
SO THE LIGHT THEY SEE FROM US IF THERE IS A "THEY" COULD BE BEFORE LIFE STARTED ON EARTH......CORRECT..............
2007-04-03 12:36:21 · 14 answers · asked by Anonymous in Science & Mathematics ➔ Astronomy & Space
The light from any star you can see with your eyes is just from a star within our own galaxy. Any star you see would be no further than, say, about 25,000 light years. Stars live much longer than that, so any star you see is pretty certain to still be there. The Pleiades star group is fairly new, it came into being around 60 million years ago, when the dinosaurs walked the Earth, and even so, with a good telescope, you can still see the wisps of the molecular cloud they were born in.
Same with galaxies. The Hubble can detect galaxies 12 billion light years out. They look different than "modern" galaxies closer to us since they are part of the early universe. They may be long gone but more likely have evolved into barred spiral galaxies like our own.
2007-04-03 12:46:13 · answer #1 · answered by Anonymous · 1⤊ 0⤋
Draw a sun in the middle of a piece of A4 paper. Off to the edge draw the nearest star (just a point for both will do). Now with the sun as centre, draw a nice circle with the nearest star on the edge of the circle.
That star will be about 4 inches or 10cm away from the sun.
On that scale, how big do you think the orbit of the furthest solar planet (Neptune) would be?
Actually about a thousandth of a millimetre or a 25 thousandth of an inch.
So, you see, even in the realm of the nearest stars, the whole of the Solar System is nothing, and of course the tiny fragment of that, the Earth, is a minute fraction of nothing.
That's amongst the local stars.
The local stars (the ones we see in the sky) are a tiny patch in one small portion of one arm of our galaxy. That portion of perhaps a million stars, is just a minute fraction of the galaxy.
the galaxy is just one of billions.
So, nobody is going to have the slightest inkling that there is an earth billions of light years away. The Solar System as a whole would be difficult to detect from the nearest star at 4 light years, let alone out there.
2007-04-03 21:09:24 · answer #2 · answered by nick s 6 · 0⤊ 0⤋
Toney:
Wow, you are asking a lot of questions tonight.
Yes the light from other stars has had to travel a long distance to reach us. The nearest star to us is 4 Light Years away. That means that the very closest star's light (other than our Sun, which is a star) had to travel for 4 years to get here.
If there is life out there observing the heavens from their place, they will not see us, here on Earth. What they will see is light from our Sun. It will blind them and prevent them from seeing the other planets which are circling around the Sun such as Venus, Earth, Mars, etc. The only chance they have of seeing or recognizing one of those planets is if one of the bigger ones blots out part of the Sun as that planet moves between the Sun and that distant star in the orbiting motion of the big planet. If they were very observant they might notice a change in the light pattern from the Sun when this happened.
2007-04-03 20:03:26 · answer #3 · answered by zahbudar 6 · 0⤊ 0⤋
Absolutely! The fact is we are so small the chance of them seeing us is minute. Have you seen the Earth from Jupiter? We look like a little spot. Look how Jupiter looks from Earth and it is so much larger. Frankly no one sees us if there is anyone out there. Maybe that's a good thing.
On the other hand radio waves keep traveling. Maybe they will hear us. But not for many millions of years. Imagine they will see Gilligan's Island and the Lucy show. How embarrassing a million years from now it might be. Then again we may be gone by then as a species.
2007-04-03 19:44:15 · answer #4 · answered by Anonymous · 0⤊ 0⤋
Yes, that is correct. However, life on Earth started about 3.7 billion years ago, so assuming the light was traveling approximately straight the aliens would have to be more than 3.7 billion light years away. At that distance it would probably be essentially impossible to pick out the Earth from the background array of stars, galaxies and interstellar gas.
Also, I think your caps lock key is broken.
2007-04-03 19:40:34 · answer #5 · answered by Anonymous · 1⤊ 0⤋
Yes. If anyone is out there from another star, they are seeing us as we were *at least* 4.3 years ago. (The nearest star is 4.3 light years away). And, the distances goes up to billions of light years away, so they could, in fact, be seeing the light of the sun BEFORE the Earth was formed.
2007-04-03 19:41:19 · answer #6 · answered by quantumclaustrophobe 7 · 1⤊ 0⤋
True. Also, if you created a mirror 30 million light years away from Earth and looked into it, you'd see Earth 60 million years ago, in theory.
It's quite fun to think of the possibilities.
2007-04-03 19:40:03 · answer #7 · answered by atmtarzy 2 · 3⤊ 0⤋
Absolutely if they are a few billion light years away. But remember the universe is only about 15 billion light years in size.
2007-04-03 19:42:45 · answer #8 · answered by David Dodeca 5 · 0⤊ 0⤋
All of the galaxies seen in the Hubble deep space series went out of existence billions of years ago.
If they were looking back far enough they would see the massive star that went super nova and eventually caused the solar system, that we live in, to coalesce.
2007-04-04 12:09:12 · answer #9 · answered by Billy Butthead 7 · 0⤊ 0⤋
Yes, Light from Vega takes 26 years to reach us. So when you are 26 you will be seeing the light from when you were born. Until you factor in Einstein's Special Relativity. The light actually gets here faster then we actually observe.
2007-04-03 19:46:56 · answer #10 · answered by gnatlord 4 · 1⤊ 0⤋