Hubble Constant Refined to an Error of Less than 5%
Researchers at Johns Hopkins University have refined the measurement of the universe's present expansion rate to a precision where the error is smaller than 5 percent. The new value for the expansion rate, known as the Hubble constant — named after Edwin Hubble who first measured the expansion of the universe nearly a century ago — is 74.2 kilometers per second per megaparsec with an error margin of ±3.6.
Comments:
So much is being written about Dark Energy..... I need help with a few questions....<br><br>Is space expanding, or are objects in space being pushed away from each other by dark energy? If they are being pushed away from each other, why are objects farther from us being pushed harder or faster? (and why no center point?) If space is expanding without pushing objects, is all of space expanding including the objects, i.e. atoms, planets, galaxies? If not, do objects in space experience the "feel" of the acceleration, other than by observing the redshift of another object? If not, is the expansion simply a relativistic illusion for something else happening? Is everything being stretched, or are objects being repelled? Dark energy - repulsion or stretch? Is the effect of expansion uniform throughout space, or does it vary in pockets, directions, as it appears to vary over time? Someone please elaborate.....<br><br>Thank you,<br><br>Rick A
<blockquote class="blockquote"><div class="italic"><i>Rick Auerbach said:</i><br><br>So much is being written about Dark Energy..... I need help with a few questions....<br><br>Is space expanding, or are objects in space being pushed away from each other by dark energy? If they are being pushed away from each other, why are objects farther from us being pushed harder or faster? (and why no center point?) If space is expanding without pushing objects, is all of space expanding including the objects, i.e. atoms, planets, galaxies? If not, do objects in space experience the "feel" of the acceleration, other than by observing the redshift of another object? If not, is the expansion simply a relativistic illusion for something else happening? Is everything being stretched, or are objects being repelled? Dark energy - repulsion or stretch? Is the effect of expansion uniform throughout space, or does it vary in pockets, directions, as it appears to vary over time? Someone please elaborate.....<br><br>Thank you,<br><br>Rick A </div></blockquote><br>Space is expanding. No, me, you, stars, planets are being carried along. Local gravitational effects trump the Hubble flow. Thus, M31 is approaching us. <br><br>
Rick<br>Measurements indicate that space is flat across very large distances (the angles of a really big triangles always add up to pi radians), I think that means the effect is uniform.<br><br>Professor Suskind at Stanford University has an interesting lecture on the topic here<br><br>http://www.youtube.com/watch?v=Jm0sT3t-rb0&feature=PlayList&p=5F9D6DB4231291BE&index=7<br><br>
Myself and many others would like to know what precedes the expansion.<br><br>What's outside the "universe". When the universe shrinks during the "big crunch", does something stretch back with it?<br><br><br>That's what I want to know.
