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...

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...

Mars One. The Mars Rover. Bruno Mars. Mars Bars. It's pretty clear we're OBSESSED with the idea of Mars, especially in regard to it being a potential colony for earthlings. But is that really the best option? Is there a better place for...

Last year LIGO announced the detection of gravitational waves from the merger of two black holes. The science world went a little crazy. Only a few weeks ago a new rumour emerged: that LIGO had, for the first time, spotted gravitational...

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...

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...

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...

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 their 20th birthday, identical twin astronauts volunteer for an experiment. Terra will remain on Earth, while Stella will board a spaceship. Stella's ship will travel to visit a star that is 10 light-years away, then return to Earth....

This episode of Space Time is actually about Spacetime, so pull up a chair, grab your favorite snack, and buckle up, because this episode is going to be a TRIP. Gabe explores what reality is, what "time" is, and why what you think those...

In this video Paul Andersen explains how the dimensions of space and time are combined in relativistic mechanics. Gravity and velocity can affect both space and time according to Albert Einstein's Special Law of Relativity.

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?

There was physics before Einstein in the same way that there was biology before Darwin. Einstein didn’t just add some new ideas to physics. And he didn’t just add a unifying framework for doing physics, like Newton. Einstein took what...

All life on Earth— living and inanimate, microscopic and cosmic— is governed by mathematical laws with apparently arbitrary constants. And this opens up a question: If the universe is completely governed by these laws, couldn't a...

What came before the Big Bang? what happened before the big bang? Since time is thought to have started at the big bang, asking what happened "before" is like asking what is North of the North pole? It may have no...

Alcubierre warp drive - faster than light travel? Is Warp speed possible? Enterprise from Star Trek can go 9000 times the speed of light. By comparison, the fastest manmade object, the Juno probe goes 0.0002 times...

SUMMARY

Albert Einstein was ridiculed when he first published his theory. People thought it was too weird and radical to be real. Einstein wasn’t satisfied with his theory either, because the theory did not...

How the Planck scale is derived from the most important fundamental constants in physics. This is where our physics ends. If you wanted to simulate the universe in a computer, you would need to enter...

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If you point a powerful laser at the moon, and spin it 100 times per second, the dot on the moon will move 3X the speed of light. This is ok. The maximum speed limit is not a limit with which...

SUMMARY

What is Spacetime? Are space and time the same thing? Space was thought to be nothing, an empty void with no matter in it. In 1908, Hermann Minkowski postulated that time could be thought of as a 4th...

Summary:

How to visualize Minkowski four dimensional spacetime and relativity using light cones and world lines. These are three spatial dimensions and one time dimension in the universe. With these 4...

How a black hole's ergosphere may help us go faster than the speed of light.

Was the Universe Designed? Exploring the effect Dark Energy has on our Universe.

Can anything travel faster than the speed of light? Is it even possible for something to undertake the “speed of light” travel? And what if something can actually travel faster than light? What is Cherenkov radiation and how is it...