As we approach the end of Crash Course Astronomy, it’s time now to acknowledge that our Universe’s days are numbered. Stars will die out after a few trillion years, protons will decay and matter will dissolve after a thousand trillion trillion trillion years, black holes will evaporate after 10^92 years, and then all will be dark. But there is still hope that a new Universe will be born from it.

Crash Course Astronomy Poster:

Hawking Radiation Mechanism resources:

Table of Contents
The Universe’s Days Are Numbered 0:32
Stars Eventually Die Out 3:02
Protons Eventually Decay 5:04
Bye-Bye Black Holes After 10^92 Years 7:49
With Death Comes Life 12:04

PBS Digital Studios:

Follow Phil on Twitter:

Want to find Crash Course elsewhere on the internet?
Facebook –
Twitter –
Tumblr –
Support CrashCourse on Patreon:

Hubble ACS SWEEPS Field [credit: NASA, ESA, W. Clarkson (Indiana University and UCLA), and K. Sahu (STScI)]
Flare [credit: NASA’s Goddard Space Flight Center/S. Wiessinger]
Hubble Views Stellar Genesis in the Southern Pinwheel [credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)]
White Dwarf [credit: NASA, ESA, H. Bond (STScI) and M. Barstow (University of Leicester)]
Neutron Star Illustrated [credit: NASA, Casey Reed – Penn State University]
Black Holes: Monsters in Space [credit: NASA/JPL-Caltech]
Binary Neutron Star Video [credit: NASA]
Giant Elliptical Galaxy NGC 1316 in Fornax Cluster [credit: ESO]
Proton Aurora [credit: NASA/Goddard Space Flight Center Conceptual Image Lab]
A Race Round a Black Hole [credit: NASA/Dana Berry, SkyWorks Digital]
The Big Bang [credit: NASA]
Hubble Ultra Deep Field 2014 [credit: NASA, ESA, H. Teplitz and M. Rafelski (IPAC/Caltech), A. Koekemoer (STScI), R. Windhorst (Arizona State University), and Z. Levay (STScI)]
Galaxy [credit: Subaru Telescope (NAOJ), Hubble Space Telescope, Robert Gendler]
One star, many stars (M13) [credit: Rogelio Bernal Andreo]
Earth [credit: NASA’s Earth Observatory]
Explosion video [credit: Shutterstock / Richard Finch]


Xem thêm bài viết: link danh muc

39 thoughts on “Deep Time: Crash Course Astronomy #45

  1. Why do I get the feeling that science just now discovers concepts that religion and spirituality have know about for thousands of years? They are talking about similar concepts using different words.

  2. Sir I want to say that most of your videos are been watched by Indians so it's will become more comfortable to us if you add hindi subtitles on all your videos

  3. reboot now
    Failed to write reboot param to /run/systemd/reboot-param: Permission denied

    if universe wont to reboot and got this error please use sudo instead

  4. I ask you a question on another video you did that you answered for me here. Apparently there's a lot more hydrogen still in the universe than I imagined. So I guess new stars will be still lighting up for a while.

  5. If we're going to the end of the universe, I got a tip from Douglas Adams there's a great restaurant there! I guess you've probably got to wait for an eternity to get a reservation though..

  6. We just need to gather large quantities of matter before this point and use it to 'go digital' or to alchemise our own star material for stellar use. Tranhumanism ftw.

  7. the universe dies out.. ok so how did it start, where did all the energy come from. We get a huge amount of energy that just dies out.. What if the energy that started this universe is still fueling it.

  8. This just goes to show that Douglas Adams was correct in "The Hitchhiker's Guide to the Galaxy" when Ford Prefect says that "Time is an illusion. Lunchtime doubly so."

  9. Issac Arthur points out planets or other non luminous bodies of heavy metal will even long after the last black holes are gone slowly fuse elements lighter than iron into iron, and elements heavier than iron will slowly decay into it. Many will recognize this as the last element "normal" stars can fuze together before the implosion of a super red giant and subsequent super nova. This doesn't become possible until far into the future because the universe as a whole needs to be even colder than all background radiation, essentially, everywhere. When either process — decay into iron or fusion into iron — happens a tinny tiny amount of energy is released. This possible 6th stage after the black hole epoch could, just maybe, persist until about 10 to the power of Epstein didn't kill himself.

  10. I don't understand how all of this should be depressing. Seriously. Like, we'll all be dead anyways 🤷 Since the universe "started" (with the big bang), it obviously will also end. It's logic and not sad at all. Something else will happen ✌️ don't worry people ❤️ we literally ARE the universe. Our molecules were contained in stars and who knows what else that travelled in space before they smashed here. It was all contained in the Big Bang. When we die we do not disappear, we just de-assemble and turn into something else. Stop thinking we're gods, we're part of a miracle, and we do not own it. All you can do is enjoy life and earth while you're here in this form. Nihilistic optimism is the right way for looking at this subject, in my personal opinion.

  11. Wonderful video! But it still begs the question – how did the Big Bang happen in the first place and why can't it happen again? Why can't stars form again? Hydrogen didn't exist at the time of Big Bang, it was just all energy. Then I am guessing subatomic particles fused together to form the first H atoms, which then coalesced to form stars. Why can't the same thing happen again?

  12. Does anyone else find it creepy that we may be the only creatures in the universe? I don't know why, it just creeps me out. If there are other creatures, dontyou think they would of ound us by now? And what about all those dimension, alternate universes, blackholes etc? AAHHH ITS SO COOL/CREEPY!! I said creepy tooo much lol

  13. sometimes thinking about space stresses me out (but then I remember I'll be dead and eating chips and salsa with Jesus in heaven) …*so I click another episode, because life is short, and spending it watching these videos aint a bad deal to me* 🙂

  14. So end or beginning of universe is nothingness or it will begin again by single light hmm 'the cosmic horror' we cannot imagine Amazing video explains the most complex topic like Beginning and end of everything in simple manner

  15. Wait the big bang was a time where the universe is so small it explodes right?So when the black matter shrinks down to the smallest thing won't another big bang happen?I mean it can't get any smaller right?It can only get bigger.Right?

  16. Very interesting! It doesn't worry me at all. None of us will be here to see it. There's only a tiny chance that we won't be extinct in even a million years, and it could be much sooner. If we do, We'll be evolved into a much different species of beings. And they may not even remain intelligent. It's whatever genetic drift and the environment guides us toward.

  17. But but, has time been at the same rate throughout the 13.7b so far? Does time run at different rates at different parts of the universe?

  18. Great content. Keep up the good work. This guy is straight up donk.

    Edit – This guy is like a straight up donktor. Dont ever stop!

Leave a Reply

Your email address will not be published. Required fields are marked *