are the stars in the sky partially an illusion since we measure distances in millions of light years?

Question

are the stars in the sky partially an illusion,since we measure distances in light years,how can we be sure,this immages are really there,when it takes so much time for the light to travel to our eyes

Answer 1

It is not an illusion but if that light has traveled many light years it is not there any more. They do not appear to move very much because of the tremendous distances but every thing is moving.

Answer 2

Well, going by your logic, how can you be sure everything you see is not an illusion either? Since everything you see is in fact either light, or reflected light. The light from the stars in the sky (i.e. the stars you see) is no different from the light from our sun - the only difference is the light from our sun only takes about 8 minutes to arrive, where as the light from the stars takes between 4 and 15 billion years to reach us. Every object you see with your eyes is either emitting light (stars, sun, light-globe etc) or has light reflecting off it. If there were no light producing sources, we would see nothing.

Illusions do exist - but they involve your mind playing tricks on you. Stars in the sky are most definately not an illusion.

Answer 3

i've got in my opinion seen the Andromeda galaxy with purely touch lenses. that's not the farthest merchandise every person has seen. M33 is slightly farther. M81 and m51 are plenty farther. there is a minimum of one quasar it somewhat is two.5 billion gentle years away at around twelfth importance. it somewhat is interior the variety of a decrease back backyard telescope with purely your eyeball. With pictures, the telescope may well be plenty, plenty smaller, considering you're able to do time exposures. the attention accumulates gentle over a era of a pair of million/fifteenth of a 2d. that's slightly longer if the attention is dark tailored (used to the dark). that's not the area to the item that concerns. that's the brightness. Telescopes help with the brightness via amassing gentle from a greater physically powerful section. So the diameter of the massive end of the telescope is the bit that concerns. Magnification isn't as a great number of an help. the reason that some quasars at over 2 billion gentle years away are brighter as seen from Earth than fairly some the celebs interior the galaxy is that quasars are plenty, plenty brighter from the initiating. it could additionally be observed that stars selection from a pair of million/10,000th as astonishing because of the fact the sunlight to approximately one hundred,000 cases brighter. So fairly some the astonishing stars you will discover at night are not those that are extraordinarily close to via. Deneb is probable 3,000 gentle years away, even with the undeniable fact that curiously purely slightly dimmer than Sirius, at eleven gentle years.

Answer 4

The answer is that the images we see may not really be there. The light that we see may be several years old or several hundred or more years old. So, the light that you see from a star may have left that star in the Middle Ages. The light you see could be from a star that doesn't exist anymore, too!

Answer 5

We don't KNOW that the stars are still there for precisely the reason you give. We can only count on the constancy of the stars in the sky, because that is all that the laws of this physical universe will let us see.

Answer 6

You have to realize that many of the current Messier objects might not currently exist. For example, looking at the Hercules cluster is like looking 20000+ years into the past. Much like M57 whos ring was blown out thousands of years ago as well.

However they did exist at one time, therefore they are not illusions.

Vince

Answer 7

Some of them will have gone by now.

Keep thinking along this track and if you've got the brains you will independently come up with the theory of relativity (seriously its where Einstein started thinking about space and light).

Answer 8

You are correct in so far as if they all the stars went pop now then it would be nearly 4 years before we found out.

Answer 9

You are right, we can't be sure that the image we see is still in existance.