Black holes do not “suck,” they pull via gravity, like the earth and the sun. They aren’t vacuum cleaners and “sucking” is the wrong word to use. They pull things in.
also, if the sun were to suddenly collapse into a black hole, nothing would change since the sun’s mass would equal the black hole’s mass. the earth and all the other planets would continue to orbit, except they’d be orbiting a sun-mass black hole instead.
Of all the places in the entire universe, there is probably nowhere more mysterious than the inner workings of a black hole. This is because the two most accurate theories humans have ever created disagree about what happens in the center of one.
When a large star runs out of fuel, it no longer has the energy to resist its own gravity and starts pulling in on itself. If nothing stops the collapse before a certain point, the gravity will become so strong that not even light can escape. At this point, the star becomes a black hole; a massive celestial body that has the ability to tear apart stars.
For the most part, we have a good idea for what happens in the space around a black hole. Einstein’s theory of General Relativity tells us that black holes, as well as other massive objects, bend the fabric of space and time, leading to strange events such as time dilation. But the main point of controversy isn’t what happens around a black hole, but what happens in the very middle; the singularity.
General Relativity states that if a piece of matter falls into a black hole, it gets crushed into a single point in the center. Here, any information about what fell in is completely obliterated. However, quantum mechanics tells a different story. It is a well known rule in quantum physics that quantum information can’t be destroyed, and there must be some ambiguity to a particle’s position. Clearly, something is off here.
There are a lot of different theories that attempt to solve this riddle, often involving extra dimensions or new particles beyond the Standard Model, but none of them seem to be currently testable. But it’s possible that someday, someone will give us a new, testable theory, and it will give us insight into the inner working of black holes, and maybe even the first few moments of the Big Bang.
Earth Prepares To Snap First-Ever Image Of A Black Hole’s Event Horizon
“Instead of a single telescope, 15-to-20 radio telescopes are arrayed across the globe, observing the same target simultaneously.
With up to 12,000 kilometers separating the most distant telescopes, objects as small as 15 microarcseconds (μas) can be resolved: the size of a fly on the Moon.”
One of relativity’s oddest predictions is the existence of black holes, objects so dense and massive that nothing, not event light can escape from them. But that lack-of-escaping is limited to a certain volume of space: that within the black hole’s event horizon. Although black holes have been detected and identified, an event horizon has never yet been imaged. That, however, is likely about to change when the Event Horizon Telescope comes online. Given the general relativistic prediction of the size of the supermassive black hole at the center of our galaxy – 37 microarcseconds – and the resolution of the EHT that spans the diameter of Earth, its event horizon should be visible. Speculations about black holes date back to 1783, and just a few decades after the first black hole candidate was identified, we’re now prepared to directly image one.
Follow up question, are black holes funnel shapes? And if so why?
I’m guessing you’re referring to images like this, which show black holes to appear funnel shaped
To summarize, objects warp space and time. To make it easier to imagine, representations are taken down to two dimensions, so you can see how an object warps space and time. The more massive the object, the more it warps time. Black holes theoretically warp space and time infinitely at the singularity (where any amount of matter can be compacted, in some cases millions of suns).
The black hole appears funnel-shaped because the curvature of space increases as you approach the black hole, and then becomes infinitely curved and infinitely steep when you reach the singularity. It’s misleading, but it does help visualize how they warp space. Black holes in reality are spherical, as they warp space in all directions (that’s why these images take it down a dimension to make visualization infinitely easier).
I hope I did a good job with this - it can be pretty hard to wrap your head around it, let me know if you have any other questions.
Goethe University is participating in international Event Horizon Telescope (EHT) Collaboration via the ERC-project Black Hole Cam
The international Event Horizon Telescope (EHT) Collaboration, which is imaging for the first time the black-hole candidate at the center of our Milky Way, has a major research focus in Germany. A significant contribution to this experiment is part of “BlackHoleCam”, a German-Dutch experiment founded in 2014. The research group of Prof. Rezzolla at the Institute for Theoretical Physics at the Goethe University Frankfurt is part of the collaboration. BlackHoleCam is supported by the European Research Council via an ERC Synergy Grant of 14 Million Euros.
Due to the strong pull of gravity, not even light can escape from black holes, whose surface, i.e., the event horizon, cannot be observed directly. However, the boundary which separates photons that are trapped from those that can escape from the incredible gravitational pull is called the black-hole “shadow”, because it would appear as a shadow against a bright lit background. It is such a shadow that is the target of series of observations presently ongoing of Sgr A*, the name of the black-hole candidate in our Milky Way. During the observations, the researchers will analyze the radio emission emitted by Sgr A*, whose mass is 4.5 million times that of our Sun and whose shadow is about half of the size of the distance between the Sun and the Earth.
Despite being so massive, Sgr A* is also very far from us, at a 26,000 light years, making the angular size of the shadow extremely small. Measuring the emission from this surface is therefore equivalent to imaging an apple on the surface of the Moon. To accomplish this ambitious project several radio telescopes across the globe are connected and thus form a virtual telescope with a diameter comparable to the Earth. This technique is called Long Baseline Interferometry (VLBI).
The work of BlackHoleCam is lead by Prof. Luciano Rezzolla (ITP, Frankfurt), Prof. Michael Kramer (Max Planck Institute for Radio Astronomy, Bonn), and by Prof. Heino Falcke (Radboud-University Nijmegen, Netherlands); all of them are important contributors of the EHT collaboration. In the current observations of Sgr A*, network of radiotelescopes from Europe, the United States of America, Middle- and South America, and the South Pole telescope are participating at the same time. During the observations, each telescope records the data on hard disks which are shipped after the end of the campaign to one of the high-performance computer centers in the US or to Bonn. In these centers the individual data of the telescopes are combined by supercomputers and an image can be reconstructed.
This shadow image can be regarded as the starting point for the theoretical research of Prof. Rezzolla’s group. Besides predicting theoretically what type of image scientists is expected to observe, the group in Frankfurt is also working on determining whether it will be possible to establish if Einstein’s theory of general relativity is the correct theory of gravity. There are several other theories of gravity besides the well-known one by Einstein and the observations of the black-hole shadow may help to identify the true one. Because of this, scientists in Frankfurt analyze the size and the geometry of the shadow and compare them to synthetic images generated on supercomputers which model accretion flows onto black holes..
These images are computed by solving the equations of relativistic magneto-hydrodynamics and tracing the orbit of photons around black holes in different theories of gravity using state-of-the art numerical tools developed in the group of Prof. Rezzolla. Comparing the synthetic shadow to the observed one may shed light on the existence of one of the most extreme predictions of Einstein’s theory of gravity: the existence of black holes. However, as Prof. Rezzolla remarks, “These observations represent a major step forward in the international attempt of understanding the nature of the dark and compact object at the centre of our Galaxy. However, they are just the first step and it is likely that many more observations of increasing precision will be necessary for finally settling this fundamental issue”.
Unfortunate space travellers won’t be able to return to their own
universe, according to Hawking. But they will be able to escape
somewhere else, he has proposed at a conference in Stockholm.
Black holes in fact aren’t as “black” as people thought and could be a way of getting through to an alternative universe.
existence of alternative histories with black holes suggests this might
be possible,” Hawking said, according to a report from Stockholm
University. “The hole would need to be large and if it was rotating it
might have a passage to another universe. But you couldn’t come back to
our universe. So although I’m keen on space flight, I’m not going to try
Hawking’s proposal is an attempt to answer a problem that has
tormented physicists about what happens to things when they go beyond
the event horizon, where even light can’t get back. The information
about the object has to be preserved, scientists believe, even if the
thing itself is swallowed up — and that paradox has puzzled scientists
Now Hawking has proposed that the information is
stored on the boundary, at the event horizon. That means that it never
makes its way into the black hole, and so never needs to make its way
out again either.
That would also mean that humans might not disappear if they fall
into one. They’d either stay as a “hologram” on the edge, or fall out
“If you feel you are in a black hole, don’t give up,” he told the audience at the end of his speech. “There’s a way out.”
Influences: Birth, new beginnings, Crystals: Rose Quartz, moon stone, jade Herbs: Frankincense & Myrrh, valerian, lotus, clarey sage Colors: Blue, purple, white Planets: Moon Moon Phase: New Astrology: Taurus Tarot: The Fool, The Star
Influences: Energy, momentum, chaos Crystals: Tektite, bloodstone, carnelian, sardonyx Herbs: Neroli, cinnamon, cardamom, dragon’s blood, ginger Colors: Red, orange, green, blue, white Planets: Mars Moon Phase: First Quarter Astrology: Aries Tarot: The Tower
Ask Ethan: What Was The Entropy Of The Universe At The Big Bang?
“The common understanding of entropy and time implies a very low-entropy state just after the Big Bang. Yet, that moment is often described as a “soup” of photons, quarks and electrons, something that, by comparison with everyday textbook examples, seems very high entropy…. How is that primal state low-entropy?”
The universe was born hot, dense, expanding, full of matter, antimatter and radiation… and in a low-entropy state. If entropy is a measure of disorder, though, that sure does sound like an awfully high-entropy state, not a low-entropy one. So why, when we talk about the Universe, do we say that the early Universe had such low entropy? The answer has much more to do with a comparison to the entropy of the Universe today, as well as in the far future. Today, the entropy is some quadrillion (or 10^15) times larger than it was around 13.8 billion years ago. And if we extrapolate into the very far future, it will be another 100 quintillion (10^20) times bigger than it is today. But what’s responsible for the difference?
Once again, I changed the prompts for the last few days because the original ones sucked, just fyi
Day 28 was absolutely satisfying to draw in every way
This is Niscient, the only uncorrupted black hole in the entire Iconoclasm Universe, which is why his appearance is so different from the others. He wields a half of a pair of scissors that can cut through time and space, and has a habit of turning into a roomba-like creature to scare newcomers.
Fun fact, Niscient used to be a persona of mine, and also one of my previous internet handles c: