PBS_SpaceTime

The private space-race has been on for a while now. The attention has been on Space-X and Blue Origin with their reusable rockets. But there’s one private space program that’s been doing things a little differently. Richard Branson’s Virgin Galactic isn’t building rockets at all – it’s building spaceships. And I got to sit down and talk to him about it.

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.

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

Astronomers are the worst at naming things. Dark energy AND dark matter? Who can remember which is which. But perhaps one astronomer has just fixed it, with a theory that says perhaps actually they are they same stuff.

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.

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 things are is probably WRONG. Seriously, get ready to have your MIND BLOWN!

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?

Let’s talk about the mysterious zero-point energy and what it really can, and really can’t do.

For the past 90 years, the predictions laid out Einstein's general theory of relativity have continued to be confirmed by experimental science. The last hold out is gravitational waves - the idea that certain gravitational events cause actual ripples in Spacetime. But have scientists done it?

Primordial black holes may be lurking throughout our universe. How large are they, how many are out there and what would happen if they moved through our solar system?

You’ve probably known OF E=mc² since you were born, and were also probably told that it meant that it proved Mass equaled Energy, or something along those lines. BUT WAIT. Was E=mc² explained to you properly? Mass equalling energy is mostly true, but E=mc² actually describes a much more interesting aspect of reality.

We’ll soon be capable of building self-replicating robots. This will not only change humanity’s future but reshape the galaxy as we know it.

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.

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.

The foundations of quantum theory rests on its symmetries. For example, it should be impossible to distinguish our universe from one that is that is the perfect mirror opposite in charge, handedness, and the direction of time. But one by one these symmetries were found to be broken, threatening to break all of physics along with them.

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 <a href="https://rumble.com/v4g2mr-s1-ep37-are-dinosaurs-extinct.html" target="_blank">dinosaurs</a> 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 <a href="https://rumble.com/v4cyjh-asteroid-impact-what-nasa-plans-to-do-if-a-killer-asteroid-will-hit-earth.html" target="_blank">dealing with them</a> include finding a way to change their trajectory, whether by kinetic or gravitational force.

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.

Are matter, mass, and time real?

Inspired by Gene Roddenberry’s Star Trek, physicist Miguel Alcubierre set out to transform one of the cornerstones of science fiction iconography, the Warp Drive, into reality. But is it even possible? Can we "warp" the fabric of reality so that we can break the speed of light? And why is NASA actually exploring this potentiality?

Could it be that all the electrons in the universe are simply one, single electron moving back and forth through time?

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: <a href="https://rumble.com/v4g5eh-can-you-trust-your-eyes-in-spacetime.html" target="_blank">Spacetime</a> + 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 <a href="https://rumble.com/v36eq3-geometry-now.html" target="_blank">geometry</a> 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.

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.

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.

Isaac Newton’s Universal Law of Gravitation tells us that there is a singularity to be found within a black hole, but scientists and mathematicians have found a number of issues with Newton’s equations. They don’t always accurately represent reality. Einstein’s General Theory of Relativity is a more complete theory of gravity.

Sometimes intuitive, large-scale phenomena can give us incredible insights into the extremely unintuitive world of quantum mechanics.