S2018 E1 • What Do Stars Sound Like?

We can now map the interiors of stars by “listening” to their harmonies as they vibrate with seismic waves.

Première diffusion : 10 janvier 2018

S2018 E2 • Horizon Radiation

Learn about Horizon radiation and why it's essential for us to understand as we continue our journey towards the Unruh Effect and Hawking Radiation.

Première diffusion : 17 janvier 2018

S2018 E3 • The End of the Habitable Zone

The 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.

Première diffusion : 24 janvier 2018

S2018 E4 • Kronos: Devourer Of Worlds

What happens when a star eats its planets? Find out on today’s Space Time Journal Club.

Première diffusion : 31 janvier 2018

S2018 E5 • What is Energy?

Energy is the most powerful and useful concept in all of physics, but what exactly is it?

Première diffusion : 14 février 2018

S2018 E6 • The Death of the Sun

What exactly will happen when the sun dies?

Première diffusion : 21 février 2018

S2018 E7 • The Trebuchet Challenge

Do you have what it takes to calculate the awesome power of the trebuchet?

Première diffusion : 28 février 2018

S2018 E8 • Should Space be Privatized?

Will the future of space exploration be guided by public or private entities? Which is better?

Première diffusion : 7 mars 2018

S2018 E9 • Hawking Radiation

It’s the most famous prediction of perhaps the most famous genius of our time ... Stephen Hawking's theory of Hawking Radiation

Première diffusion : 15 mars 2018

S2018 E10 • Scientists Have Detected the First Stars

What do the first stars in the universe, dark matter, and superior siege engines have in common?

Première diffusion : 21 mars 2018

S2018 E11 • The Andromeda-Milky Way Collision

The 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?

Première diffusion : 28 mars 2018

S2018 E12 • The Unruh Effect

Worried 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.

Première diffusion : 4 avril 2018

S2018 E13 • Physics of Life

Our 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.

Première diffusion : 11 avril 2018

S2018 E14 • Using Stars to See Gravitational Waves

Now 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.

Première diffusion : 18 avril 2018

S2018 E15 • Black Hole Swarms

It’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.

Première diffusion : 25 avril 2018

S2018 E16 • The Star at the End of Time

If 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?

Première diffusion : 2 mai 2018

S2018 E17 • How Gaia Changed Astronomy Forever

The 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.

Première diffusion : 9 mai 2018

S2018 E18 • Noether's Theorem and The Symmetries of Reality

Conservation 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.

Première diffusion : 16 mai 2018

S2018 E19 • Why Quantum Information is Never Destroyed

If 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?

Première diffusion : 23 mai 2018

S2018 E20 • What Survives Inside A Black Hole?

We’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.

Première diffusion : 13 juin 2018

S2018 E21 • The Black Hole Information Paradox

We’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.

Première diffusion : 20 juin 2018

S2018 E22 • How Asteroid Mining Will Save Earth

The days of oil may be numbered, but there’s another natural resource that’s never been touched, Asteroids.

Première diffusion : 27 juin 2018

S2018 E23 • Will A New Neutrino Change The Standard Model?

Since 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.

Première diffusion : 4 juillet 2018

S2018 E24 • Quantum Invariance & The Origin of The Standard Model

In 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.

Première diffusion : 11 juillet 2018

S2018 E25 • The Misunderstood Nature of Entropy

Entropy and the second law of thermodynamics has been credited with defining the arrow of time.

Première diffusion : 18 juillet 2018

S2018 E26 • Reversing Entropy with Maxwell's Demon

Can a demon defeat the 2nd Law of Thermodynamics?

Première diffusion : 25 juillet 2018

S2018 E27 • How Close To The Sun Can Humanity Get?

Première diffusion : 1 août 2018

S2018 E28 • Quantum Theory's Most Incredible Prediction

Let’s talk about the best evidence we have that the theories of quantum physics truly represent the underlying workings of reality.

Première diffusion : 15 août 2018

S2018 E29 • How Will the Universe End?

We 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?

Première diffusion : 23 août 2018

S2018 E30 • Is There Life on Mars?

There is no greater hero in our search for life on mars than a little robot named Opportunity.

Première diffusion : 30 août 2018

S2018 E31 • The Black Hole Entropy Enigma

Black Holes should have no entropy, but they in fact hold most of the entropy in the universe. Let’s figure this out.

Première diffusion : 5 septembre 2018

S2018 E32 • How Much Information is in the Universe?

There’s quite a bit of stuff in the universe, to put it mildly.

Première diffusion : 12 septembre 2018

S2018 E33 • Quantum Gravity and the Hardest Problem in Physics

Between them, general relativity and quantum mechanics seem to describe all of observable reality.

Première diffusion : 20 septembre 2018

S2018 E34 • How to Detect Extra Dimensions

Physics seems to be telling us that it’s possible to simulate the entire universe on a computer smaller than the universe.

Première diffusion : 3 octobre 2018

S2018 E35 • Computing a Universe Simulation

Physics seems to be telling us that it’s possible to simulate the entire universe on a computer smaller than the universe.

Première diffusion : 10 octobre 2018

S2018 E36 • What are the Strings in String Theory?

Why 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?

Première diffusion : 18 octobre 2018

S2018 E37 • Will We Ever Find Alien Life?

The 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.

Première diffusion : 25 octobre 2018

S2018 E38 • Are Virtual Particles A New Layer of Reality?

Let me tell you a story about virtual particles. It may or may not be true.

Première diffusion : 31 octobre 2018

S2018 E39 • Why String Theory is Right

Some 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.

Première diffusion : 7 novembre 2018

S2018 E40 • Supersymmetric Particle Found?

With 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.

Première diffusion : 14 novembre 2018

S2018 E41 • 'Oumoamoua Is Not Alien

To repeat the space time maxim: it’s never aliens … until it is. So let’s talk about ‘oumuamua.

Première diffusion : 21 novembre 2018

S2018 E42 • Did Life on Earth Come from Space?

How 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.

Première diffusion : 6 décembre 2018

S2018 E43 • Quantum Physics in a Mirror Universe

When you look in mirror, and see what you think is a perfect reflection. You might be looking at universe whose laws are fundamentally different.

Première diffusion : 12 décembre 2018

S2018 E44 • Why String Theory is Wrong

There’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?

Première diffusion : 20 décembre 2018