PBS_SpaceTime

When Time Breaks Down8m04s

When Time Breaks Down

We learned how motion gives matter its mass, but how does motion affect time? Let’s dive deeper into the true nature of matter and mass by exploring Einstein’s photon clock thought experiment, and the phenomenon that is time dilation.

Will Mars or Venus Kill You First?8m44s

Will Mars or Venus Kill You First?

Humans have been talking about space colonization for quite some time, but our neighboring planets are not exactly the most hospitable places. If we are ever going to be successful, we should probably figure out where we could reasonably expect to survive.

LIGO's First Detection of Gravitational Waves!7m30s

LIGO's First Detection of Gravitational Waves!

Over 100 years after Einstein proposed his theory of general relativity, we are proud to announce that his final major prediction has been verified! Gravitational waves have officially been detected by LIGO! This is a huge deal and an exciting new step in understanding our universe.

Why the Big Bang Definitely Happened8m55s

Why the Big Bang Definitely Happened

We pretty much know for sure that the universe was once extremely small, and extremely hot. And we know that something set it in motion, expanding rapidly and continuing to do-so today. But the actual moment of ‘the Big Bang’ is still a bit of a grey area within physics.

What’s Wrong With the Big Bang Theory?9m57s

What’s Wrong With the Big Bang Theory?

Let’s look further into what we don’t yet know about the Big Bang, and how the theory could progress in the future. Since there is a discrepancy between general relativity and quantum mechanics, we continue to search for a grand unifying theory... one which may finally lead to a description of the actual moment of the Big Bang!

Why is the Earth Round and the Milky Way Flat?10m48s

Why is the Earth Round and the Milky Way Flat?

Our universe is not a very diverse place when it comes to shapes. Large celestial bodies become spheres, galaxies become discs, and there is little room for variation. Why is this? Well it turns out physics has some pretty strict rules when it comes to creating new planetary bodies.

S2 Ep1: How Cosmic Inflation Flattened the Universe10m18s

S2 Ep1: How Cosmic Inflation Flattened the Universe

Although much of the Big Bang Theory is widely accepted to be true, it only gets us part of the way there. Observable truths such as the CMB and the flatness of our universe reveal that there is no way the universe has been expanding at a constant rate since its beginning. It turns out Cosmic Inflation solves the Big Bang's major problems quite well.

S2 Ep2: We Are Star Stuff10m39s

S2 Ep2: We Are Star Stuff

Stars are our stellar alchemists. They spend their entire lifespan creating and molding elements. In their final moments, a supernova spreads these elements out into the universe, providing the building blocks for new stars, planets, and even us!

S2: Will the Universe Expand Forever?9m52s

S2: Will the Universe Expand Forever?

Throughout history, there has been much speculation about what the fate of the universe would be. Many theorized that the universe would eventually succumb to the pull of gravity, and reverse its expansion in what was being called ‘The Big Crunch.’ However, with the help of mathematical equations from Newton, Einstein, and Alexander Friedmann, we now have an answer.

S2 Ep4: Why the Universe Needs Dark Energy9m34s

S2 Ep4: Why the Universe Needs Dark Energy

We know the universe will continue to expand forever, so now we can begin to complete the first Friedmann equation, and determine the shape and geometry of our universe. At first glance, it would seem that the equation doesn’t quite add up, and that our universe is a hyperbolic plane. But when we add in the cosmological constant, the equation balances out, and we return to a flat universe.

S2 Ep5: What Does Dark Energy Really Do?9m51s

S2 Ep5: What Does Dark Energy Really Do?

How does dark energy affect the universe's expansion? Measuring past expansion history should tell us the future expansion without ever having to count any galaxies. To measure this we need to measure the redshift-distance relationship, which we will talk about in detail in this episode.

S2 Ep6: Will Starshot's Insterstellar Journey Succeed?8m52s

S2 Ep6: Will Starshot's Insterstellar Journey Succeed?

Yuri Milner’s Breakthrough Starshot is an interstellar travel expedition unlike any other before it. It’s many years in the making and is contingent on a series of incredible advancements in nanotechnology, materials science and laser power. Just how likely is it that Starshot’s journey to Alpha Centauri will succeed?

S2 Ep7: Anti-gravity and the True Nature of Dark Energy12m04s

S2 Ep7: Anti-gravity and the True Nature of Dark Energy

We’ve come a long way in our understanding of dark energy. In previous episodes we’ve looked at how our universe is paradoxically flat and how dark energy is exponentially accelerating the expansion of the universe. Now, let's dive into the true nature of dark energy and how its antigravity effect and its other properties are having such bizarre effects on our universe.

S2 Ep8: Is an Ice Age Coming?12m11s

S2 Ep8: Is an Ice Age Coming?

We’re living in a brief window of time where our planet isn’t frozen underneath a giant layer of glaciers. How much longer will the moderate climate that we’ve come to know as “normal” continue? This episode looks at how the changes in our planet’s orbit and rotation impacts our climate.

S2: Is Quantum Tunneling Faster than Light?9m53s

S2: Is Quantum Tunneling Faster than Light?

Where are you right now? Until you interact with another particle you could be any number of places within a wave of probabilities. Matt dives into these counter-intuitive ideas and explains the bizarre phenomenon known as quantum tunneling in this episode of Space Time.

S2 Ep23: The Many Worlds of the Quantum Multiverse11m10s

S2 Ep23: The Many Worlds of the Quantum Multiverse

The Copenhagen interpretation of quantum mechanics tells us that observation collapses a probability wave into a single definitive outcome, but this isn’t the only interpretation of quantum mechanics. The many worlds theory proposes that the wavefunction never actually collapses. The observer simply follows one of those many possible paths into their present reality while all the other paths conti

S2: The Strange Universe of Gravitational Lensing9m42s

S2: The Strange Universe of Gravitational Lensing

In the world of our mind’s eye, light travels in a straight line. In reality, spacetime is deflected and magnified through the lens of gravity. Find out how this works and what it allows us to learn about our universe in this episode of Space Time.

S2: Planck's Constant and The Origin of Quantum Mechanics11m03s

S2: Planck's Constant and The Origin of Quantum Mechanics

Planck's Length is the length below which the concept of length loses its meaning. What exactly does that mean and what are the incredible implications this fact has upon our reality? To find out check out this episode of Space Time where Matt digs into the early history of quantum mechanics.

S2 Ep25: Did Dark Energy Just Disappear?12m14s

S2 Ep25: Did Dark Energy Just Disappear?

Why are we talking about dark energy again? Because another team has just announced a new analysis of updated supernova data. They claim that the data are consistent with there being NO dark energy – no accelerating expansion. They suggest that the universe may just be expanding at a constant rate – never speeding up, but also not slowing down.

S2 Ep26: Strange Stars9m49s

S2 Ep26: Strange Stars

Neutron stars are made of a substance known as Neutronium. It was thought that this was the densest form of matter possible but some theoretical physicists believe that at the core of some neutron stars the Neutronium breaks down even further, into quark matter. It may even evolve one step further into “strange matter", the densest and most stable substance in the universe.

S2: The Future of Gravitational Waves5m50s

S2: The Future of Gravitational Waves

On September 14th, 2015 LIGO announced the first detection of a gravitational wave. This was hailed at the time as the dawn of gravitational wave astronomy. However that’s only true if the we ever detect another gravitational wave. Now we have. On December 26th LIGO again observed the merger of two different black holes.

S2 Ep27: Pilot Wave Theory and Quantum Realism12m18s

S2 Ep27: Pilot Wave Theory and Quantum Realism

There are some pretty out-there explanations for the processes at work behind the incredibly successful mathematics of quantum mechanics - things are both waves and particles at the same time, the act of observation defines reality, cats are alive and dead, or even: the universe is constantly splitting into infinite alternate realities.