Season 2018
Episodes • 2018

1. What Do Stars Sound Like?
14 minWe can now map the interiors of stars by “listening” to their harmonies as they vibrate with seismic waves.
▶ Watch Episode
2. Horizon Radiation
15 minLearn about Horizon radiation and why it's essential for us to understand as we continue our journey towards the Unruh Effect and Hawking Radiation.
▶ Watch Episode
3. The End of the Habitable Zone
15 minThe Sun is slowly burning through its fuel. Hydrogen is fused into helium in the Sun’s core, producing energy that keeps it shining, and keeping the Earth warm and hospitable to life. But that fuel WILL run out, after which the Sun will swell into a red giant and flash-fry the Earth. But in fact that frying – well, slow-roasting – will begin much earlier. See, the Sun is getting brighter even now. This has complex, and for the most part terrible implications for life. The end of the world will come sooner than you think.
▶ Watch Episode
4. Kronos: Devourer Of Worlds
10 minWhat happens when a star eats its planets? Find out on today’s Space Time Journal Club.
▶ Watch Episode
5. What is Energy?
15 minEnergy is the most powerful and useful concept in all of physics, but what exactly is it?
▶ Watch Episode

7. The Trebuchet Challenge
9 minDo you have what it takes to calculate the awesome power of the trebuchet?
▶ Watch Episode
8. Should Space be Privatized?
13 minWill the future of space exploration be guided by public or private entities? Which is better?
▶ Watch Episode
9. Hawking Radiation
13 minIt’s the most famous prediction of perhaps the most famous genius of our time ... Stephen Hawking's theory of Hawking Radiation
▶ Watch Episode
10. Scientists Have Detected the First Stars
10 minWhat do the first stars in the universe, dark matter, and superior siege engines have in common?
▶ Watch Episode
11. The Andromeda-Milky Way Collision
13 minThe Andromeda galaxy is heading straight toward our own Milky Way. The two galaxies will inevitably collide. Will that be the very last night sky our solar system witnesses?
▶ Watch Episode
12. The Unruh Effect
12 minWorried about black holes? Consider this: Every time you accelerate - you generate an event horizon behind you. The more you accelerate away from it the closer it gets. Don’t worry, it can never catch up to you, but the Unruh radiation it generates sure can.
▶ Watch Episode
13. Physics of Life
14 minOur universe is prone to increasing disorder and chaos. So how did it generate the extreme complexity we see in life? Actually, the laws of physics themselves may demand it.
▶ Watch Episode
14. Using Stars to See Gravitational Waves
13 minNow that gravitational waves are definitely a thing, it’s time to think about some of the crazy things we can figure out with them. In some cases we’re going to need a gravitational wave observatory - in fact, we've already built one.
▶ Watch Episode
15. Black Hole Swarms
12 minIt’s been conjectured that the center of the Milky Way is swarming with tens of thousands of black holes. And now we’ve actually seen them.
▶ Watch Episode
16. The Star at the End of Time
12 minIf we, or any conscious being is around to witness the very distant future our galaxy, what will they see? How long will life persist as the stars begin to die?
▶ Watch Episode
17. How Gaia Changed Astronomy Forever
11 minThe great advances in any science tend to come in sudden leaps. April 25th of 2018 marks the beginning of just such a leap for much of astronomy. In the early hours of the morning, the Gaia mission’s second data release dropped. Our understanding of our own galaxy will never be the same again.
▶ Watch Episode
18. Noether's Theorem and The Symmetries of Reality
14 minConservation laws are among the most important tools in physics. They feel as fundamental as you can get. And yet they’re wrong - or at least they’re only right sometimes. These laws are consequences of a much deeper, more fundamental principle: Noether’s theorem.
▶ Watch Episode
19. Why Quantum Information is Never Destroyed
14 minIf you have perfect knowledge of every single particle in the universe, can you use the laws of physics to rewind all the way back to the Big Bang? Is the entire history of the universe perfectly knowable? Or has information somehow lost along the way?
▶ Watch Episode
20. What Survives Inside A Black Hole?
15 minWe’ve established by now that black holes are weird. The result of absolute gravitational collapse of a massive body: a point of hypothetical infinite density surrounded by an event horizon. At that horizon time is frozen and the fabric of space itself cascades inwards at the speed of light. Nothing can travel faster than light, and so nothing can escape from below the event horizon- not matter, not light, not even information.
▶ Watch Episode
21. The Black Hole Information Paradox
16 minWe’ve established by now that black holes are weird. The result of absolute gravitational collapse of a massive body: a point of hypothetical infinite density surrounded by an event horizon. At that horizon time is frozen and the fabric of space itself cascades inwards at the speed of light. Nothing can travel faster than light, and so nothing can escape from below the event horizon- not matter, not light, not even information.
▶ Watch Episode
22. How Asteroid Mining Will Save Earth
12 minThe days of oil may be numbered, but there’s another natural resource that’s never been touched, Asteroids.
▶ Watch Episode
23. Will A New Neutrino Change The Standard Model?
14 minSince the discovery of the Higgs boson, physicists have searched and searched for any hint of new particles. That search has been fruitless. Until, perhaps, now. Today on Space Time Journal Club we’ll look at a paper that reports a compelling hint of a new particle outside the standard model: the sterile neutrino.
▶ Watch Episode
24. Quantum Invariance & The Origin of The Standard Model
14 minIn simple terms a gauge theory is one that has mathematical parameters, or “degrees of freedom” that can be changed without affecting the predictions of the theory.
▶ Watch Episode
25. The Misunderstood Nature of Entropy
13 minEntropy and the second law of thermodynamics has been credited with defining the arrow of time.
▶ Watch Episode
26. Reversing Entropy with Maxwell's Demon
15 minCan a demon defeat the 2nd Law of Thermodynamics?
▶ Watch Episode

28. Quantum Theory's Most Incredible Prediction
17 minLet’s talk about the best evidence we have that the theories of quantum physics truly represent the underlying workings of reality.
▶ Watch Episode
29. How Will the Universe End?
18 minWe live in an unusual age – the age when the stars still shine. We should count ourselves lucky – nearly all of future history will be dark. But events will still unfold in that long, cooling darkness, and civilizations may endure. So how will the universe and its far-future denizens spend eternity?
▶ Watch Episode
30. Is There Life on Mars?
14 minThere is no greater hero in our search for life on mars than a little robot named Opportunity.
▶ Watch Episode
31. The Black Hole Entropy Enigma
13 minBlack Holes should have no entropy, but they in fact hold most of the entropy in the universe. Let’s figure this out.
▶ Watch Episode
32. How Much Information is in the Universe?
17 minThere’s quite a bit of stuff in the universe, to put it mildly.
▶ Watch Episode
33. Quantum Gravity and the Hardest Problem in Physics
17 minBetween them, general relativity and quantum mechanics seem to describe all of observable reality.
▶ Watch Episode
34. How to Detect Extra Dimensions
16 minPhysics seems to be telling us that it’s possible to simulate the entire universe on a computer smaller than the universe.
▶ Watch Episode
35. Computing a Universe Simulation
16 minPhysics seems to be telling us that it’s possible to simulate the entire universe on a computer smaller than the universe.
▶ Watch Episode
36. What are the Strings in String Theory?
17 minWhy strings? What are they made of? How did physicists even come up with this bizarre idea? And what’s all this nonsense of extra dimensions?
▶ Watch Episode
37. Will We Ever Find Alien Life?
18 minThe silence of the galaxy and the resulting Fermi Paradox has perplexed us for nearly 50 years. But our most recent surveys of the Milky Way finally allow us to draw scientific conclusions about the depressingly persistent absence of aliens.
▶ Watch Episode
38. Are Virtual Particles A New Layer of Reality?
18 minLet me tell you a story about virtual particles. It may or may not be true.
▶ Watch Episode
39. Why String Theory is Right
17 minSome see string theory as the one great hope for a theory of everything – that it will unite quantum mechanics and gravity and so unify all of physics into one glorious theory.
▶ Watch Episode
40. Supersymmetric Particle Found?
17 minWith the large hadron collider running out of places to look for clues to a deeper theory of physics, we need a bigger particle accelerator. We have one - the galaxy.
▶ Watch Episode
41. 'Oumuamua Is Not Alien
18 minTo repeat the space time maxim: it’s never aliens … until it is. So let’s talk about ‘oumuamua.
▶ Watch Episode
42. Did Life on Earth Come from Space?
19 minHow did life on Earth get started? Did life on Earth originate on another planet? Either Mars, or in a distant solar system? Could Earth life have spread to have seeded life elsewhere? Let’s see what modern science has to say about the plausibility of panspermia.
▶ Watch Episode
43. Quantum Physics in a Mirror Universe
18 minWhen you look in mirror, and see what you think is a perfect reflection. You might be looking at universe whose laws are fundamentally different.
▶ Watch Episode
44. Why String Theory is Wrong
19 minThere’s this idea that beauty is a powerful guide to truth in the mathematics of physical theory. String theory is certainly beautiful in the eyes of many physicists. Beautiful enough to pursue even if it’s wrong?
▶ Watch Episode