The Origin of Matter and Time9m22s

The Origin of Matter and Time

We’ve broken down our preconceived notions about mass and time, now let’s redefine what they really are. Since we know that time is not a universal constant, what is? Matt defines causal order and explains how even though time may look different to multiple observers, it is the one concrete reality that we can all agree on.

S2: Juno to Reveal Jupiter's Violent Past10m16s

S2: Juno to Reveal Jupiter's Violent Past

On July 4th 2016, the Juno spacecraft entered orbit around the planet Jupiter after leaving earth five years ago. The Juno probe will tell us what lies inside the mysterious gas giant and with this information we’ll better understand the formation of our solar system.

S3 Ep5: Supervoids vs Colliding Universes!10m41s

S3 Ep5: Supervoids vs Colliding Universes!

If you study a map of the Cosmic Microwave Background, or CMB, you may notice a large, deep blue splotch on the lower right. This area, creatively named the Cold Spot. Is this feature a statistical fluke, the signature of vast supervoids, or even the imprint of another universe?

Groundbreaking Explanation About How A Circle Can Be A Straight Line8m17s

Groundbreaking Explanation About How A Circle Can Be A Straight Line

General Relativity! Spacetime! And... curved lines? On this week's episode of Spacetime, Gabe talks about what it actually means for a line to be straight so we can better understand what we mean by the idea of "Curved Spacetime". To make it easer he will divide this ground work at three parts: Part one: Geometry, part two: Spacetime, part three: Spacetime + curvature. This is part one of our series on General relativity, so be sure to check it out! Part one is about straight lines and curved spaced, no physics. Gabe gives great explanation about how a curve can be “straight” if tangent vectors stay tangent when parallel- transported along with that curve. Simple, isn’t it? This is great example with an ant confined to the surface of an ordinary sphere with no concept of or an access to the direction off the surface. From the ant’s two dimensional confined prospective, curve one between A and B is straight. The vector tangent to curve one at point A remains tangent all along curve one as we parallel transport it to point B. Once the ant does that over lots of curves joining A and B it finds that the tangent vector will remain tangent only. That segment is called a geodesic and piecewise it’s straight. Topology is global, but geometry and curvature are local. Now what we have learned from Gabe is that in a three dimensional space you can test curvature just by moving a vector parallel to itself around a circle. If you end up with the same vector you started with space is flat, if not, it’s curved.

The Leap Second Explained2m21s

The Leap Second Explained

Every once in a while we add a second onto our days. Similar to the Leap Year, this is known as the Leap Second. But, if the Leap Year already helps us account for the offset from a calendar in days, what exactly does the Leap Second do? Check out this video for the answer!

Can You Trust Your Eyes in Spacetime?9m24s

Can You Trust Your Eyes in Spacetime?

Last time we talked about what curvature means, looked at geodesics, great circles on spheres, and tried to understand the notion of "straightness". This week on Spacetime, we take a detour into how geometry works in spacetime. Get excited, because this episode is even more mind-bending than the last!

General Relativity & Curved Spacetime Explained!8m53s

General Relativity & Curved Spacetime Explained!

We've been through the first few episodes of our crash course on general relativity, and came out alive! But it's officially "time" for CURVED spacetime. Join Gabe on this week’s episode of PBS Space Time as he discusses Newton and Einstein's dispute over inertial frames of reference. Is Einstein's theory inconsistent? Is gravity even a force??? Check out the episode to find out!

What Physics Teachers Get Wrong About Tides!9m09s

What Physics Teachers Get Wrong About Tides!

We all know tides have something to do with gravity from the Moon and Sun, but if gravity affects the motion of all objects equally, then how come oceans have large tides while other bodies of water don't? It's because your mental picture of the tides is probably WRONG!

Do Events Inside Black Holes Happen?11m51s

Do Events Inside Black Holes Happen?

Black holes! From Stephen Hawking to Interstellar, black holes are mammoths in the world of science AND sci-fi. But what exactly IS a black hole? Do events happen inside black holes? Are black holes really a hole? Are black holes really black?!

What Happens At The Edge Of The Universe?7m44s

What Happens At The Edge Of The Universe?

Lots of people believe the Universe is infinite, but there's a good possibility that might not be the case. Which means that there would be an actual edge of the Universe. What happens at that edge? Is there a restaurant?

Intriguing Theory About Alien Life And Earth-Like Planets 10m34s

Intriguing Theory About Alien Life And Earth-Like Planets

With millions of Earth-like planets around sun-like stars in our galaxy alone, why don't we see intelligent alien life? Or any other life for that matter? It gets especially weird when you factor in new scientific revelations that life on Earth occurred crazy fast! So if you want to help us theorize on the real reasons we haven't found alien life, you should check this video of Space Time! Why don’t we see alien civilization? The resolution for it has to be that there is some sort of great filter that either makes intelligent life extremely rare in the first place or that wipes out, essentially, all advanced civilization before they get to the galactic empire stage, whether by a nuclear war, environmental catastrophe, accidentally making a black hole that swallows the planet, et etcetera. But some people believe in that and some people just don’t buy that theory. The other logical explanation is that we know of exactly one instance intelligent life happening, the case of the earth. Multicellular life evolved independently dozen of times. It just took a really long time for those single cells to become complex enough to form large collaborative structure capable of collective reproduction, I.e plants, animals, species capable of making the Kerbal Space Program. So what is the great filter? Maybe it’s just time. If life is common then of the billions of Earth-like planets in the galaxy, only a tiny fraction needed to have a small head start on us in order to have produced the Federation of Planets and Stargates and stuff by now. Well, that explains a lot!

Here Are 5 Ways To Prevent A Killer Asteroid From Colliding With The Earth8m32s

Here Are 5 Ways To Prevent A Killer Asteroid From Colliding With The Earth

When it comes to dangerous asteroids striking Earth, it's not a matter of if, it's a matter of when. We have begun to track projectiles large enough to destroy our planet, and we are in the clear for the foreseeable future. However, there are countless asteroids large enough to take out an entire city that we cannot see. If you’ve ever watched the movie Armageddon, you know what we are talking about. There is a high probability that sometime in the future we would have to resort to those kinds of actions to save our planet. There is a reason to believe that it hasn’t been the first time an asteroid of large proportions changed the course of history when it fell on the Earth and wreaked havoc on it. The dinosaurs as species were wiped of the face of the Earth by an asteroid that hit the coast of the Yucatan peninsula, triggering a series of changes in the Earth’s climate and biodiversity. The first thing to do when under the threat of an asteroid hitting our only home is trying to locate it sooner rather than later. Efforts have been made to scan as much of the dark sky for flying rocks that are bigger than 500m, so that we are aware of their approach, but it’s still unclear as to where those smaller than 500m are. They are just like a grain of sand in the vastness of space. Other ways of dealing with them include finding a way to change their trajectory, whether by kinetic or gravitational force.

How to Build a Blackhole10m59s

How to Build a Blackhole

Black holes have mystified physicists for decades, but with the help of quantum mechanics, we are beginning to make serious progress in understanding these strange objects. This week on Space Time, Matt dives deeper into the physical process of creating a black hole, and what that can tell us about how black holes behave.

The Higgs Mechanism Explained7m49s

The Higgs Mechanism Explained

Quantum Field Theory is generally accepted as an accurate description of the subatomic universe. However until recently this theory had one giant hole in it. The particles it describes had no mass!

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!