Notices
Results 1 to 5 of 5

Thread: CMB in the past

  1. #1 CMB in the past 
    Forum Freshman
    Join Date
    Nov 2007
    Location
    San Diego, California
    Posts
    96
    Just had a thought about this that I haven't heard anything about before so I gotta ask. The CMB is the remenance of the surface of last scattering, but just after the universe became transparent this background radiation was all gamma rays. As the universe expanded, the radiation streatched into x-rays, and then UV. On its way to being microwaves, there would've been a period where it's peak went through the visible spectrum. Assuming there were creatures with eyeball like ours back then (I know, big assumption), what would they have seen? Would the sky (even night) just be blinding?


    Reply With Quote  
     

  2.  
     

  3. #2  
    Anti-Crank AlexG's Avatar
    Join Date
    Mar 2012
    Posts
    2,809
    I don't think it would be limited to the sky. The CMB does not just exist very far away, it exists right here as well. I believe the current estimate is that there are about 400 million CMB photons in each cubic meter. If this was in the visible spectrum, I'd guess we'd see everything in a faint, ever present glow.


    Reply With Quote  
     

  4. #3  
    Forum Freshman Schrodingersothercat's Avatar
    Join Date
    Oct 2011
    Location
    Now in Glendale AZ but formerly from Elkhorn WI, just outside Milwaukee.
    Posts
    37
    Would this transition from one state to the next be instantaneous in a given area? Meaning, would each transition from one state to the next happen in a specific region of the universe and then radiate out to the farther reaches of the universe so it would appear as a wave from a thearetical observer at the edge of our universe? Or would the whole universe reach each next state universe wide so, to that same observer, it would seem to change like a light switch being flipped? Plus how long would these different states last until the next state came into existance?
    Reply With Quote  
     

  5. #4  
    Quagma SpeedFreek's Avatar
    Join Date
    Jan 2011
    Location
    London, UK
    Posts
    2,787
    The CMB had a temperature of around 3000K when it was emitted, which puts it firmly in the visible spectrum when it was emitted. It was never gamma rays or x-rays, it started out at 3000K (visible light) and has cooled to 2.7K (microwaves).
    Reply With Quote  
     

  6. #5  
    Forum Freshman
    Join Date
    Jul 2012
    Posts
    6
    I don't know much on the subject but I would think so.The reason we can't see radiation is because it is beyond our spectrum of visible light. It could be a glow, or it actually might be a a flood of dots depending on what planet the hypothetical creature lives on, the sharpness of eyesight relative to our own, and the star type, velocity, orbit, axis tilt, and distance to stars which may effect the eye's ability to detect the neutrino particles blasting across the planet by trillions per second.
    Reply With Quote  
     

Similar Threads

  1. Time ( i.e. the past)
    By curious1 in forum Philosophy
    Replies: 43
    Last Post: March 21st, 2011, 12:50 PM
  2. Past Insurgencies
    By kojax in forum History
    Replies: 9
    Last Post: July 15th, 2009, 04:47 PM
  3. geological past
    By chloej in forum Earth Sciences
    Replies: 2
    Last Post: May 30th, 2009, 10:22 AM
  4. CMB, multiconnected space and isotropy.
    By Jean-Pierre Liégeois in forum Physics
    Replies: 8
    Last Post: April 4th, 2009, 08:29 PM
  5. Hard is in the past ?
    By GhostofMaxwell in forum General Discussion
    Replies: 0
    Last Post: August 27th, 2007, 07:19 PM
Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •