NASA astronauts Nichole Ayers, Jonny Kim and Anne McClain marked Independence Day with a few heartfelt words for their compatriots here on Earth.
For generations, humans have gazed at the stars and wondered about the ultimate fate of the Universe. Will it expand forever into the cold emptiness, or meet a more dramatic end? A new study published by physicists from Cornell University, Shanghai Jiao Tong University, and other institutions suggests we may finally have an answer, and it's surprisingly specific.

