Why is it when we look at stars it's like looking into the past?

Answer 1

Yes you are. The stars light takes time to reach the Earth. So, if the star changed and emitted some kind of light, we would only see it later. Therefore, looking at a star can result to looking back in time.

Answer 2

The stars you see at night are light years away. That means that the light from them has taken years for to reach us. Therefore we see that star as it was years ago. Contrary to the previous answer, the stars are not dead. Most of the stars that we can see without a telescope are within a few hundred light years of us, so we see them as they were a few hundred years ago at most. The closest is just over 4 light years away, so we see it as it was about 4 years ago. Most stars last billions of years.

Answer 3

Because the speed of light is finite (around 186,000 miles per second) and the stars are so distant, it takes a long time for the light to reach the telescope from the stars - at least 4.2 years. Many objects are millions of light years distant, meaning that what we see in the sky is from the distant past.

Answer 4

It takes a while for light to reach us. For example, the star Toliman is at a distance of a little over 4 light-years; the light that we see now was emitted over 4 years ago. The light that we see from the galaxy M31 (one of the nearest galaxies! - a member of the Local Group) took about 3 million years to reach us; so if we see a supernova explosion in M31, that supernova happened 3 million years ago.

Answer 5

This is because light travels around 186,000 miles per second. when you see the light being shined from the stars, as stars are balls of fire (light), you are actually seeing the light that the particular star shined at some time ago.

As well, the light being shined from the star closest to Earth is from 4 years ago, longer for all of the other stars. Some stars shine the light from 100's or 1000's of years ago.

Trippy stuff that we can look into the past...even if it is just light.

Answer 6

The idea is that the light of the stars takes several years to reach us. There are at least three galaxies that can be seen with the unaided eye; the Magellanic Clouds are at a distance of about 180,000 light-years - it took their light 180,000 years to reach us. In the case of the Andromeda Galaxy - still visible with the unaided eye! - it took the light something like 2.5 million years to reach us. Powerful telescopes can see light from galaxies that is much, much farther away - up to a few billion light years. In this case, we see light that was emitted when the Universe had a fraction of its current age.

Answer 7

Because the star's light takes time to reach Earth. So, if the star's light suddenly changed, we would not see it until the time taken for ligh to travel from the star to Earth. The light is showing what happened in the past, or back in time.

Answer 8

The idea is that the light of the stars takes several years to reach us. There are at least three galaxies that can be seen with the unaided eye; the Magellanic Clouds are at a distance of about 180,000 light-years - it took their light 180,000 years to reach us. In the case of the Andromeda Galaxy - still visible with the unaided eye! - it took the light something like 2.5 million years to reach us. Powerful telescopes can see light from galaxies that is much, much farther away - up to a few billion light years. In this case, we see light that was emitted when the Universe had a fraction of its current age.

The idea is that the light of the stars takes several years to reach us. There are at least three galaxies that can be seen with the unaided eye; the Magellanic Clouds are at a distance of about 180,000 light-years - it took their light 180,000 years to reach us. In the case of the Andromeda Galaxy - still visible with the unaided eye! - it took the light something like 2.5 million years to reach us. Powerful telescopes can see light from galaxies that is much, much farther away - up to a few billion light years. In this case, we see light that was emitted when the Universe had a fraction of its current age.

The idea is that the light of the stars takes several years to reach us. There are at least three galaxies that can be seen with the unaided eye; the Magellanic Clouds are at a distance of about 180,000 light-years - it took their light 180,000 years to reach us. In the case of the Andromeda Galaxy - still visible with the unaided eye! - it took the light something like 2.5 million years to reach us. Powerful telescopes can see light from galaxies that is much, much farther away - up to a few billion light years. In this case, we see light that was emitted when the Universe had a fraction of its current age.

The idea is that the light of the stars takes several years to reach us. There are at least three galaxies that can be seen with the unaided eye; the Magellanic Clouds are at a distance of about 180,000 light-years - it took their light 180,000 years to reach us. In the case of the Andromeda Galaxy - still visible with the unaided eye! - it took the light something like 2.5 million years to reach us. Powerful telescopes can see light from galaxies that is much, much farther away - up to a few billion light years. In this case, we see light that was emitted when the Universe had a fraction of its current age.

Answer 9

Light travels at a speed of 186,262 miles per second, and nothing we know of can go faster. Because light has a speed limit, we see things as they happen in the past. This is because in order for our eyes to see, the light from an object must reach us, and it can only do so at the speed of light--therefore, everything we see has already happened before we see it. In the case of a person standing across the room, this time delay is so small that it might as well be negligible. In the case of stars, which are much further away, we see them as they appeared in the past. The Sun is about 93,000,000 miles from the Earth, so when we look at it (don't stare!) we are seeing what the sun looked like about 8 minutes ago.

The further an object is out in space, the more this effect is pronounced. Looking at AB Centauri we are seeing those stars as they appeared just over 4.3 years ago. The light from Sirius is about 8.6 years old. In fact, because space is so big and light is so fast, we often use the 'Light Year' as a unit of measure. In this way, we say that Sirius is 8.6 light years from Earth.

Let's go much further--the Andromeda Galaxy is thought to be about 2.5 MILLION light years from Earth. The light that is arriving here from there started out right around the beginning of the Pleistocene era here on Earth.

A thought experiment: If a person could be instantaneously transported to the Andromeda Galaxy, and if a telescope powerful enough existed, that person could then see the Earth as it was 2.5 million years ago.

Old Answer:

Because the stars are millions of light years away so when they burn out say they were 100 light years away you would still see them for 100 years after they burn out

thomas einstien yes i am related to albert einsien he was my great grandad

So how's-come you still can't spell the family name ???

Everytghing we see is in the past! If you are sitting 3 metres away from your frind you are seeing them as they were 10 nonoseconds ago,NOT in "real time"

Answer 10

Because it takes years for light to travel from distance stars

Lets say we looked at Alpha Centauri the closest star to our sun its 4 light years a way which means the light we see today was generated 4 years ago from the star