Hi, new guy here. I once saw a graph on the development of the energy density of the universe, with the X axis measuring time (I believe it was in billion years or so) while the Y axis meansuring the density. There were three lines in that graph, energy density of empty space, energy density of (visible) matter and cosmo constant. And that graph showed somehow we exist pretty much at the time period when the two of them crosses (forgot which two but I believe it should be "visible matter line" and "cosmo constant line") So any of you ppl can be kindly enough to post that graph here? Or even draw me one? I thought I saw it on a magazine in a library but failed to locate it after pawing through almost 2 years' publication. Also, I'd like to know if there is a consensus on whether the zero-point energy can be utilized. Based on what I've read, most scientist deems the zero-point energy has little practical use. I'd be delighted to know that I was misinformed. None of the issue above was a part or related to homework of any kind, should mod find this topic inappropriate for any reason, this thread can be deleted. And BTW, sorry for my linguistic skills. I'm not a native speaker. Thanks in advance and have a nice day.