Black Holes

Black holes

A black hole is a region of spacetime exhibiting such strong gravitational effects that nothing—not even particles and electromagnetic radiation such as light—can escape from inside it. The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole. The boundary of the region from which no escape is possible is called the event horizon. Although the event horizon has an enormous effect on the fate and circumstances of an object crossing it, no locally detectable features appear to be observed. In many ways a black hole acts like an ideal black body, as it reflects no light.

The idea of a body so massive that even light could not escape was briefly proposed by astronomical pioneer and English clergyman John Michell in a letter published in November 1784. Michell’s simplistic calculations assumed that such a body might have the same density as the Sun, and concluded that such a body would form when a star’s diameter exceeds the Sun’s by a factor of 500, and the surface escape velocity exceeds the usual speed of light.

At the center of a black hole, as described by general relativity, lies a gravitational singularity, a region where the spacetime curvature becomes infinite. For a non-rotating black hole, this region takes the shape of a single point and for a rotating black hole, it is smeared out to form a ring singularity that lies in the plane of rotation. In both cases, the singular region has zero volume. It can also be shown that the singular region contains all the mass of the black hole solution. The singular region can thus be thought of as having infinite density.

How Do Black Holes Form?

Scientists think the smallest black holes formed when the universe began.

Stellar black holes are made when the center of a very big star falls in upon itself, or collapses. When this happens, it causes a supernova. A supernova is an exploding star that blasts part of the star into space.

Scientists think supermassive black holes were made at the same time as the galaxy they are in.

Supermassive black holes, which can have a mass equivalent to billions of suns, likely exist in the centers of most galaxies, including our own galaxy, the Milky Way. We don’t know exactly how supermassive black holes form, but it’s likely that they’re a byproduct of galaxy formation. Because of their location in the centers of galaxies, close to many tightly packed stars and gas clouds, supermassive black holes continue to grow on a steady diet of matter.

If Black Holes Are “Black,” How Do Scientists Know They Are There?

A black hole can not be seen because strong gravity pulls all of the light into the middle of the black hole. But scientists can see how the strong gravity affects the stars and gas around the black hole.

Scientists can study stars to find out if they are flying around, or orbiting, a black hole.

When a black hole and a star are close together, high-energy light is made. This kind of light can not be seen with human eyes. Scientists use satellites and telescopes in space to see the high-energy light.

On 11 February 2016, the LIGO collaboration announced the first observation of gravitational waves; because these waves were generated from a black hole merger it was the first ever direct detection of a binary black hole merger. On 15 June 2016, a second detection of a gravitational wave event from colliding black holes was announced.

Simulation of gravitational lensing by a black hole, which distorts the image of a galaxy in the background

Animated simulation of gravitational lensing caused by a black hole going past a background galaxy. A secondary image of the galaxy can be seen within the black hole Einstein ring on the opposite direction of that of the galaxy. The secondary image grows (remaining within the Einstein ring) as the primary image approaches the black hole. The surface brightness of the two images remains constant, but their angular size varies, hence producing an amplification of the galaxy luminosity as seen from a distant observer. The maximum amplification occurs when the background galaxy (or in the present case a bright part of it) is exactly behind the black hole.

Could a Black Hole Destroy Earth?

Black holes do not go around in space eating stars, moons and planets. Earth will not fall into a black hole because no black hole is close enough to the solar system for Earth to do that.

Even if a black hole the same mass as the sun were to take the place of the sun, Earth still would not fall in. The black hole would have the same gravity as the sun. Earth and the other planets would orbit the black hole as they orbit the sun now.

The sun will never turn into a black hole. The sun is not a big enough star to make a black hole.

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selenesparis

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happy thursday everyone

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I was having writers block and so I took a break and soon enough it was 3 in the morning and I had impulsively sewn together a tiny mouse you’re welcome

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People often wonder why writers are intricate in describing feelings and sentiments in words. It's because we've experienced the highest of highs, the lowest of lows, and everything in between. This is one of the reasons I can only write about melancholy feelings - I never had an adequate number of happy recollections to expound on, which thus is the motivation behind why I can't portray happiness in words.

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selenesparis

5 years ago

☠ - angry/violent headcanon, ahsoka!

I hope you don’t mind but somehow it turned a bit longer than I have planned but while writing I get inspired by Polish song “Dorosłe Dzieci” (more or less Adult Children) that always gives me too much feelings, especially about all young padawans/Jedi & clones thrown into war. So, here, my headcanon about Ahsoka and stages oof her anger:

Ahsoka wasn’t prone to anger by nature. She was very bright child, who loved - and was loved - unconditionally. There was nothing to be angry about when she lived with family on her native planet. At least until bad people showed up one day and took her away from safe home.

She didn’t feel anger then, not really, because cold fear filled her up; she was so small and helpless. But the Jedi came and saved her from bad people, and her parents decided she would be much safer at Jedi Temple, so little Ahsoka agreed. She connected to Jedi in a way she never did with anyone. There was no anger at her family. Something inside her mind, some voice she never heard before but knew it means no harm to her, said it’s right thing to do.

When she grew up in Jedi Temple, she was told that anger is bad. It corrupts a good person and leads to the Dark Side. Jedi never should act on such emotion, never should feel it. The lack of passion, lack of emotions is what makes person a good Jedi. Ahsoka wanted to be a good Jedi, so she never questioned her teachers. They were after all masters, older and wiser than her.

Then came war.

At first, Ahsoka was excited. She trained her whole life to serve Republic and in her young mind she already saw all the great adventures awaiting her, all the chances to prove how good Jedi she was. She wasn’t chosen as padawan by anyone for years, and the older she grew the more she feared that Council will finally sent her away, far, far away from Temple, from people she knew, from things she understand. She wasn’t angry at the thought though, just scared to be the drop out, the failure. The members of Jedi Council were wise. Wiser than anyone else. There was no point to be angry at their decision. Being angry would only prove she wasn’t worth to be Jedi. Simple.

After all, she was chosen by no one else than Anakin Skywalker. The one rumored to be special among Jedi. Destined to do great things. Ahsoka was willing to do everything to prove she was worth the honor. Only to learn, he did never ask for padawan.

She was frustrated, yes. Not angry. Anger was bad and after all, she was where master Yoda ordered her to be. He said, she was meant to be his student, and she would not have it any other way. But the first mission wasn’t that great fun like she imagined. People were dying. She almost died too. But she survived and was accepted as padawan by Skywalker. Everything seemed to be alright.

Except it wasn’t.

The more days passed, the more tightly something clutched her inside. Ahsoka wasn’t prone to anger by nature, but which every battle, she fought more furious. It wasn’t anger, she kept thinking, while cutting droids in half, while piercing through the living body of enemies. Killing people once seemed so cruel, so devastating, so overwhelming, she couldn’t think straight for days. Now, it was nothing to dwell on. She was protecting her troopers, her comrades. Dead enemy couldn’t kill them, couldn’t hurt anyone anymore.

Continua a leggere

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star wars anakin

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selenesparis

3 months ago

no babe i love your fingerless gloves and your fuckass bob, but maybe you should stop hiding behind columns at important diplomatic parties, yes i know they’re scary to you, yes i know you “accidentally” called an alien a son of a bitch at the last party— oh let’s not be dramatic— you’re supposed to be the leader of voltron, babe, not the support beam of a random castle

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selenesparis

2 years ago

btw you can use whatever gender seasonings you want. paint your nails, wear breast forms, wear a binder, pack, tuck, dress however you want, whatever. you are adding ingredients to your gender soup.

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selenesparis

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Happy Ides of March’s Eve! Remember to leave outside your door a knife and a glass of wine tonight for Brutus to collect!

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selenesparis

7 months ago

the idealized version of my tomorrow self will fix this

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selenesparis

3 years ago

The sexual tension between me and Tybalt’s sword sheathed in Mercutio’s body