![]() Radiation - in this case, in the form of photons - is generically a massless particle that moves at the speed of light. Could Dark Energy be that radiation? -Jordan Brooke Which is to say, I can't even imagine how to do it under those circumstances, given the physics that I currently know.Ĭould Dark Energy be the final stage of light? I learned in High School (provided my memory serves me right) that as light travels and expands it moves further along the spectrum and that the universe is filled with Cosmic Microwave Background Radiation. If dark energy isn't a particle, however - and since it doesn't appear to interact, clump or cluster the way other particles do - our prospects are much more pessimistic. If it is, then all it will take is a powerful enough collider to create that particle, and a way to distinguish that missing energy from things like neutrinos. That depends on whether dark energy is related to a particle or not. Is there any plausible experimental handle on dark energy? Any reasonable way, either on the ground, or at least on Solar-system scales, to directly interact with whatever it is? -Michael Kelsey Is there a known (or suspected by a theory) connection between dark energy and fundemental particles? -Erol Can Akbaba In your opinion, what length of timeframes and advances in technology do you relatively think it’ll take to understand dark energy beyond just observing its effect on the expantion of the universe? -James G. Image credit: Lynette Cook / Science Photo Library. They may be fun (for some) toys to play with, but there is so far no evidence to indicate that dark energy requires any more complexity than the simplest explanation: the cosmological constant. A large class of the models we can imagine ( parametrized by a scalar field, if you care for that detail) are known as quintessence. ![]() But it could be something more complicated: dark energy could be time dependent, it could have the pressure not satisfy the above equation exactly, it could behave in any way other than this that you can imagine. The simplest model that fits the data is to have dark energy be what Einstein called a cosmological constant, where the pressure is equal to the negative of the energy density times the speed-of-light squared, and that's still 100% consistent with the best data we have today from all sources. When physicists say "dark energy," we mean that we observe a uniform accelerated expansion to the Universe, and in physical cosmology the thing that causes that is a uniform energy density with a sufficiently negative pressure. Let's back up a little bit and explain "dark energy" first. not a handwave or ether redux) can you give us some idea of what it is? -anatman In my present state of knowledge, the word might as well be “magic”. I’ve never seen any explanation of what that would be. In articles about the nature of dark energy, I frequently see “quintessence” mentioned as one possibility. Image credit: NASA / Chandra X-ray observatory.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |