JavaScript is required to use Bungie.net

Forums

originally posted in: Ask me anything about Astronomy
4/5/2016 6:01:50 PM
11
If space is infinite, how far away is the edge?
English

Posting in language:

 

Play nice. Take a minute to review our Code of Conduct before submitting your post. Cancel Edit Create Fireteam Post

  • It's constantly expanding. No edge and no beginning. It's just there lol

    Posting in language:

     

    Play nice. Take a minute to review our Code of Conduct before submitting your post. Cancel Edit Create Fireteam Post

  • Well, if it's expanding, then it must have an edge, doesn't it? It's an edge that's expanding. So at this moment, what's the radius of the edge?

    Posting in language:

     

    Play nice. Take a minute to review our Code of Conduct before submitting your post. Cancel Edit Create Fireteam Post

  • There is no edge.

    Posting in language:

     

    Play nice. Take a minute to review our Code of Conduct before submitting your post. Cancel Edit Create Fireteam Post

  • And they also used to say the earth is flat

    Posting in language:

     

    Play nice. Take a minute to review our Code of Conduct before submitting your post. Cancel Edit Create Fireteam Post

  • Yes, they use to say the universe had an edge as well, but if the evidence so obviously points to a spherical Earth, and the evidence so obviously points to an infinite universe, we usually follow what the evidence says.

    Posting in language:

     

    Play nice. Take a minute to review our Code of Conduct before submitting your post. Cancel Edit Create Fireteam Post

  • So, you're saying the evidence once pointed to the universe having an edge, but now it doesn't? Seems you can't trust the evidence :)

    Posting in language:

     

    Play nice. Take a minute to review our Code of Conduct before submitting your post. Cancel Edit Create Fireteam Post

  • No, it was speculated, like flat Earth was speculated, until evidence came to be.

    Posting in language:

     

    Play nice. Take a minute to review our Code of Conduct before submitting your post. Cancel Edit Create Fireteam Post

  • Oh I see. So what was the evidence that proved its got no edge, then?

    Posting in language:

     

    Play nice. Take a minute to review our Code of Conduct before submitting your post. Cancel Edit Create Fireteam Post

  • Edited by The Cellar Door: 4/7/2016 10:29:40 PM
    The cosmic microwave background (CMB). The "no edge" proposal was speculated as a result of the cosmic microwave background being mapped in 1964 because of how isotropic the data was, which spawned the flatness problem, which states that this isotropic nature geometrically implies a flat universe. This is an issue because it implies that information must have traveled faster than light, resulting in a fine-tuning explanation, which we [i]do not[/i] want. Just as Flat Earth theories and geocentricism require many unnatural "work arounds" to resolve contradictory observations. There are several other issues surrounding the isotropic nature of the CMB, one of which deals with the supposed abundance of theoretical particles that we've never found evidence of, and would contradict the process by which our fundamental forces would form. Studying this in 1980, Alan Guth proposed an inflation era by which the universe expanded exponentially fast from initial conditions, which resolved all of these issues. What this implied is that the initial conditions of the universe had to be infinite, uniform vacuum energy in correspondence to the laws of thermodynamics. What this implies is that said energy is still infinite, therefor the universe is infinite. This was fine and dandy, but the land-based telescope that mapped the CMB in 1964 had to have alot of noise in order to work around our atmosphere, and so while all the data supported this, we couldn't be conclusive. Well, with the power of space observatories, COBE (1989), WMAP (2003), Planck (2013), we have conclusive evidence. Each of these allowed for progressively more accurate data, the WMAP being accurate enough showed us that changes in the temperature were small enough to be caused by quantum fluctuations, of which Planck affirmed with extreme accuracy. The evidence provided is clean cut and conclusive.

    Posting in language:

     

    Play nice. Take a minute to review our Code of Conduct before submitting your post. Cancel Edit Create Fireteam Post

  • It doesn't have an edge due to Olbers' paradox

    Posting in language:

     

    Play nice. Take a minute to review our Code of Conduct before submitting your post. Cancel Edit Create Fireteam Post

  • Good ole Olber! Haha, I wouldn't trust anything that mad old drunk says!

    Posting in language:

     

    Play nice. Take a minute to review our Code of Conduct before submitting your post. Cancel Edit Create Fireteam Post

You are not allowed to view this content.
;
preload icon
preload icon
preload icon