1. “The Death of a Universe” -- Terrific talk this evening by Dr. Katie Mack (@AstroKatie) at @yorkuniversity. Here are a few highlights. This of course is the CMB, the faint microwave “echo” of the big bang. (cont’d) #physics #astronomy #cosmology (@YorkUScience) 
@AstroKatie @yorkuniversity @YorkUScience 2. The big bang happened ~13.8 billion years ago. So what lies ahead? Could the universe collapse in a big crunch? Maybe – but as Prof. Mack explained, it's more likely that it will keep expanding. In fact, the universe is currently not only expanding but also accelerating...
@AstroKatie @yorkuniversity @YorkUScience 3. We seem to live in a universe with a non-zero cosmological constant. Right now, the CC appears small – but in the far future, the CC could come to dominate. That won’t end well! At best, in that scenario, we’re going to freeze to death in the dark...
@AstroKatie @yorkuniversity @YorkUScience 4. But there’s a lot that we don’t know about the dark energy that’s pushing galaxies apart from one another. There’s a hypothetical kind of DE called “phantom dark energy” which increases over time... <gulp>
@AstroKatie @yorkuniversity @YorkUScience 5. In that case, the universe gets torn apart in something called the “big rip,” in which galaxies and then planets and then matter itself gets shredded into nothingness. Yikes! @astrokatie showed a timetable for this cheery scenario:
@AstroKatie @yorkuniversity @YorkUScience 6. I’m skipping lots here – @AstroKatie also described another intriguing doomsday scenario known as the “vacuum decay” (aka "decay of the false vacuum"). But the good news is that we’re probably ok for about the next 120 billion years. (Yay!)
@AstroKatie @yorkuniversity @YorkUScience 7. The universe pie (mmm, pie!) -- Main thing to remember: We still need to figure out what dark matter and dark energy actually are. The answers may well take us beyond the Standard Model of particle physics, and thus shed new light on the universe’s ultimate fate.
@AstroKatie @yorkuniversity @YorkUScience 8. Meanwhile, I'm looking forward to reading Katie’s book, which will be out soon; here’s a link: astrokatie.com/book Let's be good to each other between now and the ultimate demise of the universe. Cheers!
