Mathematician Henry Segerman Demonstrating How A Linear Third Dimensional Plane Is Only A Projection

this is the sweetest thing my eyes have ever seen😱😭💕

For all the Corvid enthusiasts out there, an endearing "fuck you" from a friend.

potty mouth bird

Black Holes: Seeing the Invisible!

Black holes are some of the most bizarre and fascinating objects in the cosmos. Astronomers want to study lots of them, but there’s one big problem – black holes are invisible! Since they don’t emit any light, it’s pretty tough to find them lurking in the inky void of space. Fortunately there are a few different ways we can “see” black holes indirectly by watching how they affect their surroundings.

Speedy stars

If you’ve spent some time stargazing, you know what a calm, peaceful place our universe can be. But did you know that a monster is hiding right in the heart of our Milky Way galaxy? Astronomers noticed stars zipping superfast around something we can’t see at the center of the galaxy, about 10 million miles per hour! The stars must be circling a supermassive black hole. No other object would have strong enough gravity to keep them from flying off into space.

Two astrophysicists won half of the Nobel Prize in Physics last year for revealing this dark secret. The black hole is truly monstrous, weighing about four million times as much as our Sun! And it seems our home galaxy is no exception – our Hubble Space Telescope has revealed that the hubs of most galaxies contain supermassive black holes.

Shadowy silhouettes

Technology has advanced enough that we’ve been able to spot one of these supermassive black holes in a nearby galaxy. In 2019, astronomers took the first-ever picture of a black hole in a galaxy called M87, which is about 55 million light-years away. They used an international network of radio telescopes called the Event Horizon Telescope.

In the image, we can see some light from hot gas surrounding a dark shape. While we still can’t see the black hole itself, we can see the “shadow” it casts on the bright backdrop.

Shattered stars

Black holes can come in a smaller variety, too. When a massive star runs out of the fuel it uses to shine, it collapses in on itself. These lightweight or “stellar-mass” black holes are only about 5-20 times as massive as the Sun. They’re scattered throughout the galaxy in the same places where we find stars, since that’s how they began their lives. Some of them started out with a companion star, and so far that’s been our best clue to find them.

Some black holes steal material from their companion star. As the material falls onto the black hole, it gets superhot and lights up in X-rays. The first confirmed black hole astronomers discovered, called Cygnus X-1, was found this way.

If a star comes too close to a supermassive black hole, the effect is even more dramatic! Instead of just siphoning material from the star like a smaller black hole would do, a supermassive black hole will completely tear the star apart into a stream of gas. This is called a tidal disruption event.

Making waves

But what if two companion stars both turn into black holes? They may eventually collide with each other to form a larger black hole, sending ripples through space-time – the fabric of the cosmos!

These ripples, called gravitational waves, travel across space at the speed of light. The waves that reach us are extremely weak because space-time is really stiff.

Three scientists received the 2017 Nobel Prize in Physics for using LIGO to observe gravitational waves that were sent out from colliding stellar-mass black holes. Though gravitational waves are hard to detect, they offer a way to find black holes without having to see any light.

We’re teaming up with the European Space Agency for a mission called LISA, which stands for Laser Interferometer Space Antenna. When it launches in the 2030s, it will detect gravitational waves from merging supermassive black holes – a likely sign of colliding galaxies!

Rogue black holes

So we have a few ways to find black holes by seeing stuff that’s close to them. But astronomers think there could be 100 million black holes roaming the galaxy solo. Fortunately, our Nancy Grace Roman Space Telescope will provide a way to “see” these isolated black holes, too.

Roman will find solitary black holes when they pass in front of more distant stars from our vantage point. The black hole’s gravity will warp the starlight in ways that reveal its presence. In some cases we can figure out a black hole’s mass and distance this way, and even estimate how fast it’s moving through the galaxy.

For more about black holes, check out these Tumblr posts!

⚫ Gobble Up These Black (Hole) Friday Deals!

⚫ Hubble’s 5 Weirdest Black Hole Discoveries

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.

I am skeptical, but let's see what happens!

This is the lucky clover cat. reblog this in 30 seconds & he will bring u good luck and fortune.

I'd love to hear that song!

Hello! Can Esme sing? What instruments does she play? Thanks and have a good day!

Fun fact: Originally, I wanted to end the Esme quest with a song written by her for Tara. So yeah, she can definitely sing and play the lute.

“You are braver than you believe, stronger than you seem, and smarter than you think.” - A. A. Milne

This time of year can be difficult for some people. We hope all of those feeling sorrow or loss will find the support and help they need. Take a walk in nature, open up to a trusted friend, spend time doing something worthwhile. You are not alone. Photo of a gray tree frog by Rick Hansen, U.S. Fish and Wildlife Service.

Being American, I am most familiar with temperatures in °F, but I can relate certain °C values with no need for mathematical gyrations:

15°C: Nice! I might consider a light jacket

20°C: Perfect for any outdoor activity, no jacket, no shoes, no problem

30°C: I am wallowing in a pool of my own sweat and am poised to lay waste to anyone who vexes me

“English doesn’t borrow from other languages. English follows other languages down dark alleys, knocks them over and goes through their pockets for loose grammar.”

— Terry Pratchett

I watched the original Toy Story the other day... the characters had that funky marionette walk. This truly is masterful programming.

very serious progressive fighter game

also very fucking tired of this so-often being the case IRL, not just on the silver screen

very fucking tired of female characters having to be younger and smaller than their male counterparts