Is there any real proof that distant objects we observe through telescopes are actually older? I understand the theory that it takes time for the light to travel to the earth and therefore the light we see may be millions of years old. However therein lies my objection. Is the light we see through our telescopes a magnification of the light reaching our telelscopes or do our telescopes allow us to view light "closer" to its source. An analogy: if you take a photo place it into your computer and zoom in on that photo, the photo becomes distorted. this happens because we are zooming in on the light as it appears in that photo, as the light was accepted at a certain distance from the lens. It is in effect stagnant at that moment in time and space. If however we zoom in with our camera that object can be brought into focus because we have brought our insturment closer to it. We are capturing its light closer to the object therefore closer in time. Thoughts?
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Welcome to the forum.
"Is the light we see through our telescopes a magnification of the light reaching our telelscopes or do our telescopes allow us to view light "closer" to its source."
A telescope provides optical magnification through bending of light rays. It does not allow us to view light from a position we do not occupy.
Wayne
"Is the light we see through our telescopes a magnification of the light reaching our telelscopes or do our telescopes allow us to view light "closer" to its source."
A telescope provides optical magnification through bending of light rays. It does not allow us to view light from a position we do not occupy.
Wayne
mvansome":xpynsdjt said:
Thoughts ... OK #1 is huh ? What did you mean by "if you take a photo place it into your computer and zoom in on that photo, the photo becomes distorted. this happens because we are zooming in on the light as it appears in that photo, as the light was accepted at a certain distance from the lens. It is in effect stagnant at that moment in time and space." I have to say that makes no sense to me. Are you disputing that light travels at some finite speed ? Are you disputing that the measured redshift is an indication of distance ?
#2 is ... your explanation for why a picture displayed on a computer becomes "distorted" (??) as you "zoom in" (assume you mean magnify) is wrong.
I have seen some similar arguments tbat seek to establish that objects being viewed are not
actually at the distances we think they are due to lensing effects, or that the timeline is not
what we think it is because lensing effects enable us to see things in time/space long before
the light has actually reached us.
Many of the people I have seen apply these sorts of arguments are seeking to reconcile
young earth beliefs with real world observatiions.
actually at the distances we think they are due to lensing effects, or that the timeline is not
what we think it is because lensing effects enable us to see things in time/space long before
the light has actually reached us.
Many of the people I have seen apply these sorts of arguments are seeking to reconcile
young earth beliefs with real world observatiions.
Magnifying an object does nothing to change the speed of light, which is fixed. A telescope can make if brighter (by collecting more photons) or bigger (by magnifying the image) but light still traves as 186,000 miles per second no matter how you view the object.
MeteorWayne":2h3hxrvy said:
The slippery slope I have seen this logic applied to is when one tries to say that magnification,
rather than simply making something look closer, has the effect of making the effective position
of the viewer *be* closer in the "space-time continuum", therefore making the trip that the light
takes at the speed of light shorter, and take less time. This can important to you if you are trying
to make astronomical data fit with a timeline on the order of 10,000 years.
Less than tangetially related semi-funny story alert:
I remember a web site that had joke ads for bionics. In th ad for a bionic eye, it made reference to
the eye's optical power to allow the observer to see things from perspectives that the user is
not actually located at. (Like looking up at a helicopter and seeing things from a perspective of
a camera right outside the chopper)
Wayne
Thanks for most of these replies. I do understand that the speed of light is a constant. Not debating that. Nor am I debating red shift used to judge distance or speed an object moves away from another object. I am debating the idea expressed in the recent headline "oldest object in universe discovered" and the assertion that by viewing this obect we are actually seeing into the past. I of course don't understand fully how telescopes "bend light rays" and optical magnification (drwayne, a bit more would be great), but really find it hard to accept that we are actually seeing things that have happened millions or billion of years ago through these advanced telescopes. I get the theory, it takes light x amount of time to travel x distance and therefore a solar flare, for example, would not be noticed as it happens on some distant sun by people on Earth but rather only after light had travelled here.
Theoretically then, if one placed a telescope 2500 light years away from the Earth and looked back on it, we would be able to see the pyramids being built. (assuming it was technically possible) I really doubt that. Please don't counter with arguments that reiderate established laws rather provide explanations.
Theoretically then, if one placed a telescope 2500 light years away from the Earth and looked back on it, we would be able to see the pyramids being built. (assuming it was technically possible) I really doubt that. Please don't counter with arguments that reiderate established laws rather provide explanations.
Your last paragraph has it correct. If you placed a telescope (unimaginably large of course) 2500 light years away the images of the pyramids being built would just be arriving there. Of course it would take another 2500 years to send that information back to us
For a close up view, when you look at the sun, you don't see it where it is now, you see it where it was 8 minutes ago.
If you look at Saturn tonight beneath Leo, you see it where it was an hour and 13 minutes ago, not where it is now.
You may doubt it, but is an immutable truth.
there's nothing to discuss really. The speed of light is fixed. It only travels at 186,000 miles per second. You may consider that "reiderate established laws rather provide explanations.
" reiderat(ing) (sic) established laws rather provid(ing) explanations, but the speed of light is well known, well measured, and even though you have trouble acceptingit, it is true.
The key part is "established laws" which means it is absolutely true.
For a close up view, when you look at the sun, you don't see it where it is now, you see it where it was 8 minutes ago.
If you look at Saturn tonight beneath Leo, you see it where it was an hour and 13 minutes ago, not where it is now.
You may doubt it, but is an immutable truth.
there's nothing to discuss really. The speed of light is fixed. It only travels at 186,000 miles per second. You may consider that "reiderate established laws rather provide explanations.
" reiderat(ing) (sic) established laws rather provid(ing) explanations, but the speed of light is well known, well measured, and even though you have trouble acceptingit, it is true.
The key part is "established laws" which means it is absolutely true.
mvansome":1js1iqir said:
If you get the theory that it takes light a certain amount of time to travel, you have all the information you need.
Yes, theoretically, if you position a telescope 2500 light years away from Earth and look back at it, you will be seeing light that left the Earth 2500 years before. But you would not be able to see the pyramids built, nor would you be able to see anything that happened on Earth before you left, because it would take at least 2500 years to get that telescope 2500 light-years away from Earth.
The light from the oldest object in the universe was emitted by that object around 13 billion years ago, so when we look at that light as it reaches Earth, 13 billion years later, the image we see is of the object as it was when the light was emitted, 13 billion years ago.
When you look at the Moon with your eyes, you are seeing it as it was over a second ago. When you look at the sun you are seeing it as it was over 8 minutes ago and as you look at a distant galaxy you are seeing it as it was billions of years ago. The telescope is irrelevant here, it is the light-travel time between emission and detection.
mvansome":3episzym said:
If you could instantly travel 2500 ly (actually it is closer to 4000 ly), then what you are saying is exactly correct, you could in fact see the pyramids being built (if it were possible to magnify to the level which it is not).
Look at it this way, when someone 300 meters away hits a hammer on a bell you will hear it about 1 second later. I'm sure you have seen this where you see an action and later the sound arrives. Lightning and thunder is another example. Well assume that you have a microphone with an amplifier. The sound can be made louder with the amplifier, or magnified. You are in no way closer to the sound you have only magnified the sound. Telescopes magnify light waves, which is analogous to an amplifier magnifying sound waves.
Edited to add: Take a look at this. This url explains in simple terms how a telescope works.
"Theoretically then, if one placed a telescope 2500 light years away from the Earth and looked back on it, we would be able to see the pyramids being built."
Not exactly. You see, to build it (or to visit it), we would need to travel to that position, and the trip there would be limited by the speed of light - so to get 2500 LY from Earth would take at least 2500 years. So we could not use this
method to see our own past. The best we could do would be to see our trip.
Wayne
Not exactly. You see, to build it (or to visit it), we would need to travel to that position, and the trip there would be limited by the speed of light - so to get 2500 LY from Earth would take at least 2500 years. So we could not use this
method to see our own past. The best we could do would be to see our trip.
Wayne
There are some interesting animations here:
http://en.wikipedia.org/wiki/Lens_(optics)
(This is one of those times where being with someone with a blackboard would be useful)
http://en.wikipedia.org/wiki/Lens_(optics)
(This is one of those times where being with someone with a blackboard would be useful)
MeteorWayne":epwx09v7 said:Good paradox, otherwayne
Said much better/clearer than I did!
Thanks for your reply,
I'm glad that you brought up microphones (this I have experience with) because if you use a directional microphone (shotgun mic) focused on that bell, the sound is not delayed even when you have not physically moved the microphone closer. The action and the sound happen closer in time, if not simultaneously. You are not magnifying the sound as it arrives at the mic, you are focusing the microphone to pic up the sound at a closer distance. Maybe telescopes/light behave differently but am still not convinced.
Sorry, didn't see the other posts. Not debating whether it would be possible to do something like sending a telescope that far, but theoretically, this should be possible?
I'm glad that you brought up microphones (this I have experience with) because if you use a directional microphone (shotgun mic) focused on that bell, the sound is not delayed even when you have not physically moved the microphone closer. The action and the sound happen closer in time, if not simultaneously. You are not magnifying the sound as it arrives at the mic, you are focusing the microphone to pic up the sound at a closer distance. Maybe telescopes/light behave differently but am still not convinced.
Sorry, didn't see the other posts. Not debating whether it would be possible to do something like sending a telescope that far, but theoretically, this should be possible?
Sorry, you've got that wrong again. Apparently your "experience" has failed to educate you. Even with a directional microphone, the sound still takes the same amount of time to get to you, about 5 seconds per mile. A directional mike and amp does not get the sound to you quicker, it just makes it louder. That's why you can find out how far a lightning strike is from you. 5 secnds per mile between the flash (which travels at 186,000 miles per second) and the sound (which travels at 5 seconds per mile). So if the sound comes 15 seconds after the flash, the lightning strike was 3 miles away.
It's the same thing with telescopes. It doesn't get the light to you any faster, it just makes it brighter and bigger.
It's the same thing with telescopes. It doesn't get the light to you any faster, it just makes it brighter and bigger.
"Not debating whether it would be possible to do something like sending a telescope that far, but theoretically, this should be possible?"
We weren't debating that either. Merely pointing out that the only way you are going to see 2500 years into
the your own past with that telescope is to move from here, instantaneously to there, which is impossible.
Wayne
We weren't debating that either. Merely pointing out that the only way you are going to see 2500 years into
the your own past with that telescope is to move from here, instantaneously to there, which is impossible.
Wayne
"You are not magnifying the sound as it arrives at the mic, you are focusing the microphone to pic up the sound at a closer distance."
As I stated earlier, a sensor, a telescope, a microphone etc. does NOT allow one to observe from a position
at which you do not currently reside. It does not move your effective range to the source closer. You are simply
processing the light (or sound) to improve your reception of it.
Wayne
As I stated earlier, a sensor, a telescope, a microphone etc. does NOT allow one to observe from a position
at which you do not currently reside. It does not move your effective range to the source closer. You are simply
processing the light (or sound) to improve your reception of it.
Wayne
mvansome":dzdonhe5 said:
The others have described what happens in the above case so I won't elaborate on that part. I do wonder what experience you've have that makes you think the above way. The distant lightning flash is a good example. Have your aimed your directional mike at a distant storm ? If all you've experienced is the sound from a close source the difference in arrival times (between the light and the sound) may not be readily apparent. I'm scratching my head trying to think of a more everyday experience that you can use to judge it for yourself. Know anyone who has access to commercial grade fireworks ? :|
heres one simple point that a telescope does not make our viewing distance closer: The light has to reach the telescope here, before it even does anything to it!
The way telescope works is that the light hitting the surface of the mirror (most modern research telescopes use a mirror) and scatter off in another direction. By controling the shape of the mirror you can direct where that light scatters to.
Now, an image size is dependent upon the angle the incoming photons make with your eye.
Imagine this setup, you are looking at a ball. The ball is the top point of a triangle, and your eye is actually the entire base (from one edge of your pupil to another). The light coming from the ball spreads out in sphereical pattern, but your eye catches a small section of that, making it wedge shaped (well, a cone really). The parts we care about are the outermost parts of this wedge, which will form the legs of the triangle.
If you move the ball away from you, the triangle gets skinnier (as the size of the base, your eye, is fixed), and the angle between the two legs of the triangle (centered on the ball's top vertex point) gets smaller. Thus the ball appears to be smaller.
Now a telescope messes with the light coming from that ball. It's curved mirror bends the path of the light, allowing that apparent angle to change making the object appear larger (or even smaller). That's it, that's all it does.
If it did bring us closer...then by using different telescopes, of different sizes, curvatures, and all other sorts of specifications, we should be getting different distance values to each star, depending on the telescope we use. Unless you are suggesting that all telescopes, of every design, always make us the same distance to the object in question.
The way telescope works is that the light hitting the surface of the mirror (most modern research telescopes use a mirror) and scatter off in another direction. By controling the shape of the mirror you can direct where that light scatters to.
Now, an image size is dependent upon the angle the incoming photons make with your eye.
Imagine this setup, you are looking at a ball. The ball is the top point of a triangle, and your eye is actually the entire base (from one edge of your pupil to another). The light coming from the ball spreads out in sphereical pattern, but your eye catches a small section of that, making it wedge shaped (well, a cone really). The parts we care about are the outermost parts of this wedge, which will form the legs of the triangle.
If you move the ball away from you, the triangle gets skinnier (as the size of the base, your eye, is fixed), and the angle between the two legs of the triangle (centered on the ball's top vertex point) gets smaller. Thus the ball appears to be smaller.
Now a telescope messes with the light coming from that ball. It's curved mirror bends the path of the light, allowing that apparent angle to change making the object appear larger (or even smaller). That's it, that's all it does.
If it did bring us closer...then by using different telescopes, of different sizes, curvatures, and all other sorts of specifications, we should be getting different distance values to each star, depending on the telescope we use. Unless you are suggesting that all telescopes, of every design, always make us the same distance to the object in question.
OK, lets try this. Have you ever seen any of those television shows where they show a huge explosion and you can see the shock wave moving out from the explosion? Here is a youtube video. Notice the shock wave? That is a pressure wave that is moving at the speed of sound. Sounds are simply pressure waves also. The sound and the shock wave arrive at the same time becasue they are both simply pressure waves. So according to your experience a directional mic can almost instantly transport that presure wave (sound) to your location before the shock wave makes it to you? How in the world can a microphone 'grab' that pressure wave and bring it to your location instantly (or even any speed faster than the shock wave)? I hope you see that this is clearly impossible.
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