Evaluating distance of far objects in space

  • Thread starter Thread starter philhar
  • Start date Start date
  • Tags Tags
    Space
philhar
Messages
4
Reaction score
0
This is question that has been on my mind for quite some time.

As technology advances, telescopes are more and more powerful. This means that we can see further and further out.
So if I look at an object (ie. a galaxy) with a powerful telescope don't I "intercept" the light earlier than I would with a less powerful telescope? By that I mean in a snapshot, don't I see a portion of the light emitted by the object viewed before it gets to Earth?
Leading to another question (if the above is coorect): does this skew the estimation of the distance at which the object viewed lies?
Or am I missing something (of which I have little doubt!) In writing this I am asking myself see the light before it gets to Earth where your telescope is situated? Hum!
 
Space news on Phys.org
philhar said:
This is question that has been on my mind for quite some time.

As technology advances, telescopes are more and more powerful. This means that we can see further and further out.
Yes, for a variety of reasons...

philhar said:
So if I look at an object (ie. a galaxy) with a powerful telescope don't I "intercept" the light earlier than I would with a less powerful telescope? By that I mean in a snapshot, don't I see a portion of the light emitted by the object viewed before it gets to Earth?
No. The reason why you can see things further out with better telescopes is a combination of a few factors:

1. Better resolution. Objects far away are typically smaller, and therefore harder to resolve.
2. Better light collecting. Objects far away are typically very dim, so it may be difficult to separate them from the background.
3. New wavelengths. Objects far away are redshifted, and so may not appear in optical wavelengths at all. Telescopes that look at the infrared and longer wavelengths are needed for the furthest objects.
 
philhar said:
This is question that has been on my mind for quite some time.

As technology advances, telescopes are more and more powerful. This means that we can see further and further out.
So if I look at an object (ie. a galaxy) with a powerful telescope don't I "intercept" the light earlier than I would with a less powerful telescope? By that I mean in a snapshot, don't I see a portion of the light emitted by the object viewed before it gets to Earth?
Leading to another question (if the above is coorect): does this skew the estimation of the distance at which the object viewed lies?
Or am I missing something (of which I have little doubt!) In writing this I am asking myself see the light before it gets to Earth where your telescope is situated? Hum!

telescopes catch the lights here on earth. that means view of the object must arrive Earth so we can detect it by our telescopes. this rule applies for all telescopes regardless of their power.
 
Thank you for your answers!
 
https://en.wikipedia.org/wiki/Recombination_(cosmology) Was a matter density right after the decoupling low enough to consider the vacuum as the actual vacuum, and not the medium through which the light propagates with the speed lower than ##({\epsilon_0\mu_0})^{-1/2}##? I'm asking this in context of the calculation of the observable universe radius, where the time integral of the inverse of the scale factor is multiplied by the constant speed of light ##c##.
The formal paper is here. The Rutgers University news has published a story about an image being closely examined at their New Brunswick campus. Here is an excerpt: Computer modeling of the gravitational lens by Keeton and Eid showed that the four visible foreground galaxies causing the gravitational bending couldn’t explain the details of the five-image pattern. Only with the addition of a large, invisible mass, in this case, a dark matter halo, could the model match the observations...
Hi, I’m pretty new to cosmology and I’m trying to get my head around the Big Bang and the potential infinite extent of the universe as a whole. There’s lots of misleading info out there but this forum and a few others have helped me and I just wanted to check I have the right idea. The Big Bang was the creation of space and time. At this instant t=0 space was infinite in size but the scale factor was zero. I’m picturing it (hopefully correctly) like an excel spreadsheet with infinite...
Back
Top