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billions of light years is a bit further than mt rushmore. and 5 and i cant answer the last one its too hard as well.
What's so hard about the last one? You and a friend are standing together, side by side, looking at Mt Rushmore. Your friend is looking at it using a telescope. You're looking at it just with your eyes. Does your friend or Mt Rushmore suddenly change position so they (not you) are much closer? If that's true, then your friend would no longer be next to you, but would be off in the distance closer to Mt Rushmore, or Mt Rushmore would suddenly change position and be closer to both of you. Ever see anything happen like that?
So why does it look larger and closer to your friend? A telescope magnifies the view and can see more details because the telescope, in part, can collect more light (photons) and your unaided eye can. The object isn't any closer to either of you. It's that the telescope assists your eye by collection more light. All that light provides information that tells us what we're seeing.
Let's say you wear glasses. With your glasses on, you can see things more clearly. If you take your glasses off, then your view isn't so clear. Are you physically any closer to what you're looking at? No, because whether you're wearing your glasses or not, the distance is exactly the same. The only difference is that things are out of focus without your glasses. In other words, your eyes are messed up. Glasses help bring out more detail. The same amount of light enters your eye regardless of whether you're wearing your glasses or not. The reason you can't see as well without the glasses is because of a problem with your eyes. The same amount of light (photons) may enter your eye, but because the eye is messed up, the optic nerve inside the eye is not able to collect or register all the light clearly. So the object appears out of focus. Sure, if you move closer to an object, it can make your view more clear. But what if you can't get closer? That's where the use of glasses can help. And that's also the same reason why a telescope can help you see extremely distant objects.
Some things in space are so far that even if you look through the largest telescopes in existence, you still won't see them. That's because our own can't collect enough light at one time. Astronomers seldom look through telescopes anymore. Computerized cameras are used. Instead of capturing light in an instant, such as what happens with our unaided vision, the cameras are left open to collect more light and imprint the time-lapsed image. The longer they're left open, the more light they collect, meaning that very faint objects, so faint that we can't directly see them but we can see the end result images provided by the equipment.
Another thing to think about is that light isn't the same all the time. That's because the color spectrum of light is extremely varied. This is called the spectrum, like a rainbow. However, our eyes can only see a very tiny part of the light spectum. If we want to observe light at the extreme ends of the spectum, ultra-violet or infrared, which are invisible to us, then the only way we can detect it is with very sensitive and powerful equipment. For example, you can't see x-rays (that's light too) with your eyes, but we have equipment that is able to capture the x-rays on film. We can't look inside of our own bodies, but we have MRI scanners that can let doctors have a look at what there is without having to cut you open. We're all made of atoms, but we can't see any of those atoms. However, we have incredibly powerful microscopes that can capture the image of some atoms. The LHC is sort of like a gigantic microscope that can look at the activity of tiny subatomic particles, even as small as quarks.
So, how can we see something millions of light years away? Now you know.
What's so hard about the last one? You and a friend are standing together, side by side, looking at Mt Rushmore. Your friend is looking at it using a telescope. You're looking at it just with your eyes. Does your friend or Mt Rushmore suddenly change position so they (not you) are much closer? If that's true, then your friend would no longer be next to you, but would be off in the distance closer to Mt Rushmore, or Mt Rushmore would suddenly change position and be closer to both of you. Ever see anything happen like that?
So why does it look larger and closer to your friend? A telescope magnifies the view and can see more details because the telescope, in part, can collect more light (photons) and your unaided eye can. The object isn't any closer to either of you. It's that the telescope assists your eye by collection more light. All that light provides information that tells us what we're seeing.
Let's say you wear glasses. With your glasses on, you can see things more clearly. If you take your glasses off, then your view isn't so clear. Are you physically any closer to what you're looking at? No, because whether you're wearing your glasses or not, the distance is exactly the same. The only difference is that things are out of focus without your glasses. In other words, your eyes are messed up. Glasses help bring out more detail. The same amount of light enters your eye regardless of whether you're wearing your glasses or not. The reason you can't see as well without the glasses is because of a problem with your eyes. The same amount of light (photons) may enter your eye, but because the eye is messed up, the optic nerve inside the eye is not able to collect or register all the light clearly. So the object appears out of focus. Sure, if you move closer to an object, it can make your view more clear. But what if you can't get closer? That's where the use of glasses can help. And that's also the same reason why a telescope can help you see extremely distant objects.
Some things in space are so far that even if you look through the largest telescopes in existence, you still won't see them. That's because our own can't collect enough light at one time. Astronomers seldom look through telescopes anymore. Computerized cameras are used. Instead of capturing light in an instant, such as what happens with our unaided vision, the cameras are left open to collect more light and imprint the time-lapsed image. The longer they're left open, the more light they collect, meaning that very faint objects, so faint that we can't directly see them but we can see the end result images provided by the equipment.
Another thing to think about is that light isn't the same all the time. That's because the color spectrum of light is extremely varied. This is called the spectrum, like a rainbow. However, our eyes can only see a very tiny part of the light spectum. If we want to observe light at the extreme ends of the spectum, ultra-violet or infrared, which are invisible to us, then the only way we can detect it is with very sensitive and powerful equipment. For example, you can't see x-rays (that's light too) with your eyes, but we have equipment that is able to capture the x-rays on film. We can't look inside of our own bodies, but we have MRI scanners that can let doctors have a look at what there is without having to cut you open. We're all made of atoms, but we can't see any of those atoms. However, we have incredibly powerful microscopes that can capture the image of some atoms. The LHC is sort of like a gigantic microscope that can look at the activity of tiny subatomic particles, even as small as quarks.
So, how can we see something millions of light years away? Now you know.
what tool is used to measure the distance how does it do so?
what tool is used to measure the distance how does it do so?
For astronomy, the use of measuring tapes is certainly out of the question. It depends on what's being measured. Much involves estimations that are based on established standards that have been agreed on.
Here are a few links and a couple of videos for you (homework) that may help out a bit.
For astronomy, the use of measuring tapes is certainly out of the question. It depends on what's being measured. Much involves estimations that are based on established standards that have been agreed on.
Here are a few links and a couple of videos for you (homework) that may help out a bit.
That's a non-sequitur. The Hubble constant is 74 km/s/Mpc, but you aren't makin it clear how that has anything to do with parallax. Certainly parallax is required to measure Hubble's constant but the reverse is not true.
So X, back to you and your friend standing on the railroad tracks problem.
Who gets hit by the train first?
Well my friend was hit by a star's image flying to earth yesterday, and was crushed, so I am unable to answer your question.
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