Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

sgl_imaging_challenge_banner_dslr_mirrorlesss_winners.thumb.jpg.9deb4a8db27e7485a7bb99d98667c94e.jpg

nicks90

Slowing down light

Recommended Posts

If the speed of light is not constant as assumed, what does that do to the expanding universe theory ,which comes to that conclusion using the red shift of light?
 

Share this post


Link to post
Share on other sites

If the speed of light is not constant as assumed, what does that do to the expanding universe theory ,which comes to that conclusion using the red shift of light?

I think the speed of light is still constant - but they just slow it down by making it bounce around, which slows down the rate it passes through the material. It's similar to how the drift velocity of an electron through a circuit can be so slow when it moves at near the speed of light - because it is the net result of many bounces of said light. 

David

Share this post


Link to post
Share on other sites

Its only the speed of light in vacuum which is constant and defined. In all other cases it can have any value below this number.

P

  • Like 2

Share this post


Link to post
Share on other sites

Interesting read, that's all I am going to say for the moment, it would be more interesting if she could freeze or actually stop light travelling. One that would be something to talk about

Share this post


Link to post
Share on other sites

Yep the speed of light in vacuum, but in anything else it is less. In fact your telescopes and binoculars rely on this fact to bring light to a focus at your eye, refraction is caused when light goes from one medium (air) to another where it has a different speed (the glass of the objective or eye peice).

  • Like 1

Share this post


Link to post
Share on other sites

What about the speed of light, and of everything during the alleged cosmic inflation period. I've read it was greater, much greater by many magnitudes than 186,000 miles per second.

Share this post


Link to post
Share on other sites

What about the speed of light, and of everything during the alleged cosmic inflation period. I've read it was greater, much greater by many magnitudes than 186,000 miles per second.

indeed,

however there is still a lot of debate as to what form 'everything' took during this inflationary period - therefore there may not have been any 'light' or matter that we would recognise - and so it may not have broken any of our known laws of particle physics because it was completely different. 

:lipsrsealed:

Share this post


Link to post
Share on other sites

What about the speed of light, and of everything during the alleged cosmic inflation period. I've read it was greater, much greater by many magnitudes than 186,000 miles per second.

As far as we know, it stayed the same speed, its just space was stretched out "under its feet" very quickly. Inflation is partly brought about as a theory to stop us having to increase the speed of light, and still end up with the universe as it is.

Share this post


Link to post
Share on other sites

The problem i have allways had with the speed of light and the early universe is that "speed" is a function of distance and time  both of which where doing strange things.

Alan

Share this post


Link to post
Share on other sites

The constant © is the speed of light in a vacuum through space.  By the 'standard model'  the further you get away from us, the faster things are receding from us. This isn't because the objects are moving faster is just that the space is expanding faster.  As (as far as we know) there is no limit to the speed of space, the furthest away bits of the universe are expanding away from us faster than the speed of light and therefore the light from these areas will never reach us. Hence the concept of the 'observable universe'.

This gives a neat explanation of the concept.

http://www.einstein-online.info/elementary/cosmology/expansion

http://www.dnatube.com/video/29042/The-incredible-expanding-universe-explained

Inflation was the expansion of space, not the movement of energy or matter within space and hence would not have been bound by the speed of light

  • Like 2

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.