Hello BrowserUk,

As jdporter says, the expanding balloon analogy is not the best. The two I’ve seen are:

  1. baking raisin bread (see the animation in Metric_expansion_of_space)
  2. stretching rubber sheet (see http://www.felderbooks.com/papers/cosmo.html, section II)

— the point in each case being that while the “space” (bread dough, rubber sheet) expands, the entities in it (raisins, thumbtacks) do not:

In fact, not everything grows as the universe expands. In the example of the rubber sheet, the distance between thumbtacks keeps increasing but the thumbtacks themselves remain the same size. Similarly, while distant galaxies are pulled away from each other by the expansion, smaller objects like meter sticks, people, and the galaxies themselves are held together by forces that prevent them from expanding. So we expect that billions of years from now galaxies will still be roughly the same size they are today, but the distances between them will on average be much larger.

A minor point:

And if you accept the indivisibility of space & time; that they are aspects of the same thing as General Relativity suggests, ...

I believe that the concept of spacetime is actually a corollary of Special Relativity. If anyone is interested, I can recommend the book Simply Einstein: Relativity Demystified (2003) by Richard Wolfson as an excellent introduction for the layman (like me). It has a section which explains in detail the rationale for viewing space and time as aspects of a unified spacetime in the light of Special Relativity.

BTW, the “taster” paper you cite up-thread seems to say only that the speed of light may not be constant over time. Why do you assume that this implies it is increasing?

Athanasius <°(((>< contra mundum Iustus alius egestas vitae, eros Piratica,

In reply to Re^5: [OT] A prediction. by Athanasius
in thread [OT] A prediction. by BrowserUk

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.