Frontiers of Science – Dark Energy
Ambience – cosmic background radiation
Contained within this hiss is the energy signature of the Big Bang, the cataclysmic explosion which marked the creation of the universe. This energy, which permeates the universe, is called cosmic background radiation and it’s revealed to scientists the existence of an invisible form of matter – dark matter, and an equally mysterious form of dark energy. I’m Jim Metzner and this is the Pulse of the Planet.
Pillonen: The observations for the existence of dark energy and of dark matter are all based on looking at cosmic microwave background radiation.
Leo Pillonen is chairman of the physics department at Virginia Tech.
Pillonen: So, this is light that’s coming at us from the earliest days of the universe when light moved freely through the universe and headed towards Earth, where we eventually can observe it. That light has been affected by all the stuff that it’s gone through in the intervening billions of years. The universe has been expanding. And so, through the way that the light has interacted through the expansion of the universe, we have some idea of the presence of this dark energy. And then, as the light is scattered from one galaxy to another as it’s heading towards us, you can see the presence of the dark matter.
Well, we might be surrounded by invisible dark matter and energy, but scientists haven’t found a way yet to interact with it.
Pillonen: Once we start to see a little bit of the properties of dark matter, we may find that it has just as rich a structure as ordinary matter does. Dark matter, since it can travel great distances, may be a way for us to communicate with distant, distant galaxies.
If we could harness it in some way, could dark energy be used as a power source, because it’s abundant and it’s always around us? What we would have to do is find that mechanism by which dark energy couples to ordinary matter. So far, we haven’t found that. We’re looking for it, but we haven’t found it yet.
Pulse of the Planet is made possible in part by the National Science Foundation. I’m Jim Metzner.