things to include on resume 24 24h

When massive objects crash into each other, there should be a release of gravitational waves. So what are these things and how can we detect them?
Support us at: http://www.patreon.com/universetoday
More stories at: http://www.universetoday.com/
Follow us on Twitter: @universetoday
Follow us on Tumblr: http://universetoday.tumblr.com/
Like us on Facebook: https://www.facebook.com/universetoday
Google+ - https://plus.google.com/+universetoday/
Instagram - http://instagram.com/universetoday

Team: Fraser Cain - @fcain
Jason Harmer - @jasoncharmer
Susie Murph - @susiemmurph
Brian Koberlein - @briankoberlein
Chad Weber - weber.chad@gmail.com
Kevin Gill - @kevinmgill

Created by: Fraser Cain and Jason Harmer

Edited by: Chad Weber

Music: Left Spine Down - “X-Ray”
https://www.youtube.com/watch?v=4tcoZ...
Who wants to bet against Einstein? You? You? What about you?

Sure, there were a few bumps, but the guy’s track record on relativity is spotless. He explained the strange way that Mercury orbits the Sun. He guessed astronomers would see stars deflected by the Sun’s gravity during a solar eclipse. He predicted that gravity would redshift light, and it took physicists 50 years to finally come up with an experiment to verify it.

Based on his predictions, scientists confirmed galaxies warp light with their gravity, photons get time dilated when they pass near the Sun, and clocks that travel at high speeds experience less time than clocks on Earth.

They’ve even tested gravitational redshift, frame-dragging and the equivalence principle. Which is a word salad we’ll cover in the future, or for those of you who can’t wait, google.

Every time Bertie made a prediction about Relativity, physicists have been able to verify via experimentation. And so, according to this fuzzy man with the giant brain, when massive objects crash into each other, or when black holes form, there should be a release of gravitational waves.

So what are these things and how can we detect them?

First, a quick review. Mass causes a warp in space and time. The Sun’s “gravity” isn’t a pulling force, it’s really an indentation that the Sun causes in the space around itself.

Planets think they’re moving in a straight line, but they’re actually pulled into a circle while traveling through this warped spacetime. Go home planets, you’re drunk.

The idea is when mass moves or changes, Einstein said that there should be gravitational ripples produced in spacetime.

Our problem is that the size and effect of gravitational waves is incredibly small. We need to find the most catastrophic events in the Universe if we hope even detect them.

A supernova detonating asymmetrically, or two supermassive black holes orbiting each other, or a Galactus family reunion; are the magnitude of events we’re looking for.

The most serious attempt to detect gravitational waves is the Laser Interferometer Gravitational-Wave Observatory, or LIGO detector, in the United States. It has two facilities separated by 3000 km. Each detector carefully watches for any gravitational waves passing through by the length of time it takes for laser pulses to bounce within a 4km long sealed vacuum.

If a gravitational wave is detected, the two observatories use triangulation to determine its magnitude and direction. At least, that was the plan from 2002 to 2010. The problem was, it didn’t detect any gravitational waves for its entire run.

But hey, this is a job for science. Unbowed, the steely-eyed researchers rebuilt the equipment, improving its sensitivity by a factor of 10. This next round starts in 2015.

Scientists have proposed space-based instruments that could provide more sensitivity and increase the chances of detecting a gravitational wave.

Physicists assume this is a question of “when”, not “if” that gravitational waves will be detected, as only a fool bets against Einstein. Well, that and gravitational waves have already been detected... indirectly.

By watching the extremely regular energy blasts coming from pulsars, astronomers track exactly how quickly they’re radiating their energy away due to gravitational waves. So far, all the observations perfectly match the predictions of relativity. We just haven’t detected those gravitational waves directly… yet.

So, good news! Assuming the physicists and Einstein are right, we should see the detection of a gravitational wave in the next few decades, wrapping up a series of predictions about how insanely strange our Universe behaves.

Should we dig deeper into relativity, Einstein and his predictions? Tell us in the comments below.

Nothing lasts forever, not even black holes. According to Stephen Hawking, black holes will evaporate over vast periods of time. But how, exactly, does this happen?
Support us at: http://www.patreon.com/universetoday
More stories at: http://www.universetoday.com/
Follow us on Twitter: @universetoday
Follow us on Tumblr: http://universetoday.tumblr.com/
Like us on Facebook: https://www.facebook.com/universetoday
Google+ - https://plus.google.com/+universetoday/
Instagram - http://instagram.com/universetoday

Team: Fraser Cain - @fcain
Jason Harmer - @jasoncharmer
Susie Murph - @susiemmurph
Brian Koberlein - @briankoberlein
Chad Weber - weber.chad@gmail.com
Kevin Gill - @kevinmgill

Created by: Fraser Cain and Jason Harmer

Edited by: Chad Weber

Music: Left Spine Down - “X-Ray”
https://www.youtube.com/watch?v=4tcoZ...
The actor Stephen Hawking is best known for his cameo appearances in Futurama and Star Trek, you might surprised to learn that he’s also a theoretical astrophysicist. Is there anything that guy can’t do?

One of the most fascinating theories he came up with is that black holes, the Universe’s swiffer, can actually evaporate over vast periods of time.

Quantum theory suggests there are virtual particles popping in and out of existence all the time. When this happens, a particle and its antiparticle appear, and then they recombine and disappear again.

When this takes place near an event horizon, strange things can happen. Instead of the two particles existing for a moment and then annihilating each other, one particle can fall into the black hole, and the other particle can fly off into space. Over vast periods of time, the theory says that this trickle of escaping particles causes the black hole to evaporate.

Wait, if these virtual particles are falling into the black hole, shouldn't that make it grow more massive? How does that cause it to evaporate? If I add pebbles to a rock pile, doesn't my rock pile just get bigger?

It comes down to perspective. From an outside observer watching the black hole’s event horizon, it appears as if there’s a glow of radiation coming from the black hole. If that was all that was happening, it would violate the law of thermodynamics, as energy can neither be created nor destroyed. Since the black hole is now emitting energy, it needs to have given up a little bit of its mass to provide it.

Let’s try another way to think about this. A black hole has a temperature. The more massive it is, the lower its temperature, although it’s still not zero.

From now and until far off into the future, the temperature of the largest black holes will be colder than the background temperature of the Universe itself. Light from the cosmic microwave background radiation will fall in, increasing its mass.

Now, fast forward to when the background temperature of the Universe drops below even the coolest black holes. Then they’ll slowly radiate heat away, which must come from the black hole converting its mass into energy.

The rate that this happens depends on the mass. For stellar mass black holes, it might take 10^67 years to evaporate completely.

For the big daddy supermassive ones at the cores of galaxies, you’re looking at 10^100. That’s a one, followed by 100 zero years. That’s huge number, but just like any gigantic and finite number, it’s still less than infinity. So over an incomprehensible amount of time, even the longest living objects in the Universe - our mighty black holes - will fade away into energy.

One last thing, the Large Hadron Collider might be capable of generating microscopic black holes, which would last for a fraction of a second and disappear in a burst of Hawking radiation. If they find them, then Hawking might want to the acting on hold and focus on physics.

Nothing is eternal, not even black holes. Over the longest timeframes we’re pretty sure they’ll evaporate away into nothing. The only way to find out is to sit back and watch, well maybe it’s not the only way.

Does the idea of these celestial nightmares evaporating fill you with existential sadness? Feel free to share your thoughts with others in the comments below.

Thanks for watching! Never miss an episode by clicking subscribe.

Our Patreon community is the reason these shows happen. We’d like to thank Dana Nourie and the rest of the members who support us in making great space and astronomy content. Members get advance access to episodes, extras, contests, and other shenanigans with Jay, myself and the rest of the team. Want to get in on the action? Click here.