See far away objects in space in real time?

  • Thread starter Thread starter robertito
  • Start date Start date
  • Tags Tags
    Space Time
AI Thread Summary
The discussion centers on the challenge of observing distant objects in space in real time, emphasizing that telescopes reveal the past due to the finite speed of light. When viewing an object 1000 light years away, observers see it as it was 1000 years ago, raising questions about the implications for life and events on those planets. Participants explore the concept of time measurement, noting that the perception of time is relative to the observer's frame of reference. The conversation also touches on the impossibility of seeing light emitted after a certain time without violating the principles of special relativity. Ultimately, the complexities of time and light travel underscore the limitations of current astronomical observation methods.
robertito
Messages
11
Reaction score
2
Hi,

I was asking myself if there is, or might be a way to see far away objects in space in real time? What I mean is that when we look even through the most powerful telescope we always see the past of the object we are looking at, and this past will depend on the distance the object is away from us, right?
So, if a planet is 1000 light years away from us and we have a telescope powerful enough to see its surface like, let's say, in google maps we will see how this surface looked like 1000 years ago. Then, maybe we see life on a planet, a supernova exploded 500 years ago and killed everything and we will see this in 500 years only.
Or maybe we don't see anything but there is life and the problem is that light still didn't reach us.
Is it like this or am I completely wrong?
Thanks!
 
Astronomy news on Phys.org
Yes, the only way to see what happened 500 years ago would be for the light that was emitted 500 years ago to travel at twice the speed of light which - more or less by definition - is not possible :)

For a rigorous discussion, we should probably think about what "500 years ago" means... 500 years on whose clock? :)
 
Thanks for your answer, you clarified something important!
About the clock, I don't know, because that's also something I never understood :) I guess, my clock here on earth? But it's a mechanical device, and this is what confuses me even more! (in the same way that the ruler you leave in the drawer is not measuring anything...)
By the way, you made me remember that I have to make a question about time, but in another place of the forum ;)
 
Yes, because you are saying that "the light is coming from a start 500 light years away", the distance is measured in your frame of reference, the time is measured in your frame of reference. In other words, by a clock sitting stationary next to you.
 
If there is any way to see light of later times (=not light emitted 1000 years ago for clocks on earth) here on earth, this allows time travel or completely ruins special relativity (or both).
I guess, my clock here on earth? But it's a mechanical device, and this is what confuses me even more! (in the same way that the ruler you leave in the drawer is not measuring anything...)
Well, you can use any clock here on earth, including radioactive decays, the orbit of Earth around the sun and so on. You are not limited to a specific clock.
 
Is a homemade radio telescope realistic? There seems to be a confluence of multiple technologies that makes the situation better than when I was a wee lad: software-defined radio (SDR), the easy availability of satellite dishes, surveillance drives, and fast CPUs. Let's take a step back - it is trivial to see the sun in radio. An old analog TV, a set of "rabbit ears" antenna, and you're good to go. Point the antenna at the sun (i.e. the ears are perpendicular to it) and there is...
This thread is dedicated to the beauty and awesomeness of our Universe. If you feel like it, please share video clips and photos (or nice animations) of space and objects in space in this thread. Your posts, clips and photos may by all means include scientific information; that does not make it less beautiful to me (n.b. the posts must of course comply with the PF guidelines, i.e. regarding science, only mainstream science is allowed, fringe/pseudoscience is not allowed). n.b. I start this...
How does light maintain enough energy in the visible part of the spectrum for the naked eye to see in the night sky. Also, how did it start of in the visible frequency part of the spectrum. Was it, for example, photons being ejected at that frequency after high energy particle interaction. Or does the light become visible (spectrum) after hitting our atmosphere or space dust or something? EDIT: Actually I just thought. Maybe the EM starts off as very high energy (outside the visible...
Back
Top