Jump to content

File:Tolman surface brightness test.png

Page contents not supported in other languages.
This is a file from the Wikimedia Commons
From Wikipedia, the free encyclopedia

Tolman_surface_brightness_test.png (549 × 401 pixels, file size: 40 KB, MIME type: image/png)

Summary

Description
English: According to the tired light hypothesis, given a simple (static and flat) universe, the photons per second received from an object drops proportional to the square of its distance and the apparent area of the object also drops proportional to the square of the distance, so the photons received per surface area per unit time would be constant, independent of the distance, even though the surface brightness is reduced because of tired light reddening. In an expanding universe, however, there are two effects that change this relation. First, the rate at which photons are received is reduced because each photon has to travel a little farther than the one before. Second, the energy of each photon observed is reduced by the redshift. At the same time, distant objects appear larger than they really are because the photons observed were emitted at a time when the object was closer. Adding these effects together, the surface brightness in a simple expanding universe (flat geometry and uniform expansion over the range of redshifts observed) should decrease with the fourth power of (1+z).
Date
Source Own work
Author Stigmatella aurantiaca

Licensing

I, the copyright holder of this work, hereby publish it under the following license:
w:en:Creative Commons
attribution share alike
This file is licensed under the Creative Commons Attribution-Share Alike 4.0 International license.
You are free:
  • to share – to copy, distribute and transmit the work
  • to remix – to adapt the work
Under the following conditions:
  • attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
  • share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.

Captions

Add a one-line explanation of what this file represents

Items portrayed in this file

depicts

26 October 2017

File history

Click on a date/time to view the file as it appeared at that time.

Date/TimeThumbnailDimensionsUserComment
current06:16, 26 October 2017Thumbnail for version as of 06:16, 26 October 2017549 × 401 (40 KB)Stigmatella aurantiacaUser created page with UploadWizard

The following page uses this file:

Global file usage

The following other wikis use this file:

Metadata