“The more clearly we can focus our attention on the wonders and realities of the universe about us, the less taste we shall have for destruction.” -Rachel Carson
The idea that the spatial fabric of the Universe itself is expanding, and that’s what’s behind the observed relationship between redshift and distance has long been controversial, and also long-misunderstood. After all, if more distant objects appear to recede more quickly, couldn’t there be a different explanation, like an explosion that flung many things outward? As it turns out, this isn’t a mere difference in interpretation, there are observations we can make that tell us the answer!
It isn’t simply that galaxies are moving away from us that causes a redshift, but rather that the space between ourselves and the galaxy redshifts the light on its journey from that distant point to our eyes. Image credit: Larry McNish of RASC Calgary Center.
The Universe is not expanding ‘into’ anything, despite what your intuition might tell you. The Hubble ‘constant’ isn’t actually a constant, but is rather decreasing as time goes on. The Universe looks like it’s going to expand forever, but even that scientific conclusion is subject to revision depending on what ...