Cosmology We understand the universe is expanding. But do we understand the physics of it? This prediction is about the future of cosmological principle; how space expansion can be thought of as redshifting light. We treat expanding space like motion. There is a space-stretch inbetween the galaxies that makes the universe as a whole larger. It is also seen as galaxies moving away from each other in space. And this is what we do with the "Doppler shift" or the redshift to light. We use "motion" redshift to calculate the distance of a galaxy. This is Hubble's law. But there is more to it. I believe that the space-stretch I talk about is equivalent to the motion of galaxies away from each other. The space-stretch inbetween the galaxies is identical to their actual motion through space. What I am proposing is that the space-stretch can be seen as resposible for the redshift to light. In other words stretching space also stretches out the light that is traversing intergalactic space. So the two phenomonon space stretching light and the Doppler shift to light due to motion appear to be equivalent. And in physics we can use the term "operational" to describe this fact. It can be explained in two ways. The redshift to light is thus an operational phenomenon. The space-stretch stretches light. And by the way the universal expansion is now known to be accelerating. In other words the rate of the stretch is getting faster. Mitch Raemsch |