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Why some physicists believe we live in a black hole

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Black holes are enigmatic entities that, despite our extensive knowledge, continue to perplex our comprehension of physics. Physicists have proposed unconventional hypotheses to address the paradoxes encountered during the study of these phenomena. One hypothesis suggests that these paradoxes indicate that our universe is actually a holographic representation. According to this idea, everything we observe and perceive is encoded at the boundary of our universe, which is a three-dimensional representation of a two-dimensional universe, including time. Moreover, there have been suggestions that this could potentially indicate that our universe exists inside a black hole within a larger universe.

Black holes are regions of space that result from the gravitational collapse of massive stars, exhibiting such intense gravity that even light cannot escape. Their presence presented a challenge when examining them from a thermodynamic perspective. After achieving stability, a black hole’s mass, angular momentum, and electric charge are the only factors that determine its final state.

“According to French astrophysicist Jean-Pierre Luminet’s 2016 review, in classical general relativity, a black hole effectively traps any particle or form of radiation within its cosmic confinement, preventing their escape.” “To an external observer, the moment a material body passes through an event horizon, all information regarding its material properties becomes inaccessible.” Only the updated values of mass (M), angular momentum (J), and electric charge (Q) are retained. Consequently, a black hole engulfs a vast quantity of information.

It may appear straightforward—or at least as straightforward as physics can be. However, if a black hole possesses mass (which is typically substantial), it should theoretically possess a temperature in accordance with the first law of thermodynamics. Furthermore, in accordance with the second law of thermodynamics, it should emit thermal radiation. Stephen Hawking demonstrated that black holes emit radiation, now known as Hawking radiation, which is generated at the boundary of a black hole.

“Hawking subsequently identified a paradox.” “If a black hole undergoes evaporation, a fraction of the information it possesses becomes permanently irretrievable,” Luminet elaborated. A black hole’s thermal radiation does not retain or replicate information about the matter it ate. The irrevocable loss of information contradicts one of the fundamental principles of quantum mechanics. The Schrödinger equation states that in physical systems that undergo changes over time, information cannot be created or destroyed. This property is referred to as unitarity.

This phenomenon is referred to as the black hole information paradox, and due to its apparent contradiction with our existing comprehension of the cosmos, it has been extensively examined and discussed.

Examining the thermodynamics of black holes within the context of string theory led to the discovery of an alternative solution. Gerard ‘t Hooft demonstrated that the total number of independent variables within a black hole is directly proportional to the surface area of its horizon, rather than its volume. This enables the examination of the entropy of a black hole.

“In terms of information, Luminet explains that each bit, represented as either a 0 or a 1, corresponds to four Planck areas. This correspondence enables the derivation of the Bekenstein-Hawking formula for entropy,” Luminet concludes. “To an external observer, it appears that the information regarding the entropy of the black hole, which was previously contained within the three-dimensional arrangement of objects that entered the event horizon, is no longer accessible.” However, according to this perspective, the data is encoded on the flat, two-dimensional surface of a black hole, similar to a hologram. Thus, Hooft concluded that the information consumed by a black hole could be fully recovered through the process of quantum evaporation.

Although it is consoling to know that black holes do not violate the second law of thermodynamics, this has given rise to the unusual idea that a three-dimensional space’s two-dimensional boundary can explain its physics.

It has been suggested that the universe itself could potentially function like a black hole, with all phenomena occurring at its boundary and our observations arising from these interactions. However, this concept does not apply to the space outside of a black hole. This idea is quite unconventional, with some unexpected additions. For example, there is a suggestion that gravity may emerge as a force from entanglement entropy at the boundary.

The theory falls short in its ability to provide a convincing explanation for our universe, as standard physics continues to offer the most accurate description of the observable universe. However, there are valid justifications for why individuals consider it of great importance.

In order for the model to be valid, it is crucial that the Hubble radius of the universe, which represents the radius of our observable universe, is equivalent to its Schwarzschild radius. This refers to the size of a black hole that would form if all the matter within it was compressed into a single point. These two figures are unexpectedly similar, although this could be attributed to a cosmic coincidence.

There are other factors to consider, like this comprehensive chart that indicates the possibility of our existence within a black hole within a larger universe. However, until a theory emerges with substantial evidence and predictions that surpass our current knowledge of physics, we recommend refraining from succumbing to an existential crisis. This applies regardless of whether you perceive yourself as a three-dimensional entity existing within conventional space-time or as a holographic projection originating from a two-dimensional boundary within a larger universe.

As Editor here at GeekReply, I'm a big fan of all things Geeky. Most of my contributions to the site are technology related, but I'm also a big fan of video games. My genres of choice include RPGs, MMOs, Grand Strategy, and Simulation. If I'm not chasing after the latest gear on my MMO of choice, I'm here at GeekReply reporting on the latest in Geek culture.

Astronomy

The exciting Lunar Standstill will be streamed live from Stonehenge

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People are very interested in Stonehenge, which is one of those famous landmarks. It is very clear that it lines up with the sun at the solstices, but no one is sure what the monument is for. But over the next few months, scientists will look at a different kind of alignment: some stones may be lined up with the lunar standstill.

In the sky, things move around. The sun moves around during the year because the planet is tilted with respect to its orbit. This means that the times when it rises and sets are often different. Stonehenge is set up so that the first rays of dawn on the summer solstice and the last rays of sunset on the winter solstice both pass through the middle.

But outside the stone circle are the so-called station stones, whose purpose is unknown. They don’t seem to be linked to the sun, but to the moon. The position of the moonrise and moonset changes because the moon’s orbit is tilted relative to the earth. This is similar to how the sun moves. But it doesn’t happen every year. The cycle goes around and around for 18.6 years.

When the Moon is at the fullest point of its cycle, it moves from 28.725 degrees north to 28.725 degrees south in just one month. The next one won’t happen until January 2025. This time is called the major lunar standstill (lunistice). So, scientists will be going to Stonehenge several times over the next few months, even during the major standstill, to figure out how the monument might line up with our natural satellite.

Talked to Heather Sebire, senior property curator at Stonehenge. “I think the moon in general would have been very important to them.” “And you know, maybe they could do things they couldn’t do other times when there was a full moon because there was more light.”

“They think the lunar standstill might have something to do with this because there are four rocks out in the middle of the ocean that are called “station stones.” Only two of them have been found so far. Together, they form a rectangle, which some people think may have something to do with the setting outside the circle.

When the Moon is in a minor standstill, its distance from the Earth is between 18.134° north and south. It will happen again in 2034.

As archaeologists continue to look into this interesting alignment, Stonehenge wants everyone to join in the fun. As usual, people will be able to enter the circle for the solstice, which this year is the earliest since 1796. However, the next day will be all about the lunistice.

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As the moon rises, the lunar standstill event can only be seen online. You can watch the livestream from the comfort of your own home and wonder with the researchers if this great monument was also lined up with the Moon.

 

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Astronomy

It’s true that the Earth is not orbiting the sun right now

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Some of the diagrams and animations that show how the planets move around the sun are not quite accurate. To be more precise, they are making the planets’ orbits easier to understand so that teachers don’t have to explain barycenters to kids who are still getting used to the idea that Earth isn’t the only planet in the universe.

Most of the time, the way you learn about how planets move around the sun looks like the video below.

But this version is easier to understand. The Sun has about 1,048 times the mass of Jupiter, making it the largest object in the Solar System. However, gravity works both ways. For the same reason that the Earth pulls on itself, you pull on the Earth as well, though it is much smaller.

“Kepler’s third law describes the relationship between the masses of two objects mutually revolving around each other and the determination of orbital parameters,” NASA says.

“Think about a small star that circles a bigger star. The two stars actually move around the same mass center, which is called the barycenter. That’s always the case, no matter how big or heavy the things are. Using a massive planet to measure how fast a star moves around its barycenter is one way that planetary systems linked to faraway stars have been found.

To keep things simple, we say that the planets go around the Sun. But because the Sun has the most mass, the barycenter of the Solar System’s objects is usually close to it. However, because of Jupiter and Saturn’s orbits and effects, it is almost never inside the Sun. The paths look a bit more like the video below, which was made by planetary astronomer and science communicator James O’Donoghue.

Because of this, the Earth is not orbiting a point inside the Sun right now because the barycenter is not there. We are not going around the sun, but that point in space.

“Planets orbit the Sun in general terms,” O’Donoghue says on Twitter, “but technically, they don’t orbit the Sun alone because the gravitational influence of (mainly) Jupiter means planets must orbit a new point in space.”

“The planets do orbit the Sun, of course; we are just being pedantic about the situation,” he said. “The natural thinking is that we orbit the Sun’s center, but that very rarely happens, i.e., it’s very rare for the solar system’s center of mass to align with the Sun’s center.”

Things that are smaller, like planets and their moons, are the same way. The Earth and Moon go around a point about 3,100 miles (5,100 kilometers) from the Earth’s center. This path changes as the moon moves farther away from the earth.

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Astronomy

NASA’s flyby of Europa shows that “something” is moving under the ice

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Europa’s surface has marks that show the icy crust is vulnerable to the water below. The most important thing is that Juno’s recent visit shows what might be plume activity. If this is real, it would let future missions take samples of the ocean inside the planet without having to land.

Even though it’s been almost two years since Juno got the closest to Europa, its data is still being looked at. Even though Juno has been going around Jupiter since 2016, the five pictures it took on September 29, 2022, were the closest views of Europa since Galileo’s last visit in 2000.

Some might say that’s a shocking lack of interest in one of the Solar System’s most interesting worlds, but it could also have been a good way to see how things had changed over time.

Europa is the smoothest object in the solar system because its ocean keeps it from sinking to the surface. Still, it’s not featureless; Juno saw some deep depressions with steep walls that are 20 to 50 kilometers (12 to 31 miles) wide, as well as fracture patterns that are thought to show “true polar wander.

In a statement, Dr. Candy Hansen of the Planetary Science Institute said, “True polar wander occurs if Europa’s icy shell is separated from its rocky interior. This puts a lot of stress on the shell, which causes it to break in predictable ways.”

The shell that sits on top of Europa’s ocean is thought to be rotating faster than the rest of the moon. This is what true polar wandering means. People think that the water below is moving and pulling the shell along with it. Ocean currents are thought to be causing this. The currents are most likely a result of heat inside Europa’s rocky core, which is heated up as a result of Jupiter and its larger moons pulling on Europa and turning it into a large stress ball.

The ocean and ice could stretch and compress parts of the ice, which is how the cracks and ridges that have been seen since Voyager 2 visited were made.

A group under the direction of Hansen is viewing images of Europa’s southern half. The scientist said, “This is the first time that these fracture patterns have been mapped in the southern hemisphere. This suggests that true polar wander has a bigger effect on Europa’s surface geology than was thought before.”

Ocean currents are not to blame for all of Europa’s map changes. It appears that optical tricks can even fool NASA. Hansen said, “Crater Gwern is no longer there.” “JunoCam data showed that Gwern, which was once thought to be a 13-mile-wide impact crater and one of Europa’s few known impact craters, was actually a group of ridges that crossed each other to make an oval shadow.”

But Juno gives more than it takes away. The team is interested in what they’re calling the Platypus because of its shape, not because it has a lot of parts that shouldn’t go together. Ridges on its edge look like they are collapsing into it. The scientists think this might be because pockets of salt water have partially broken through the icy shell.

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The Europa Clipper would find these pockets to be fascinating indirect targets for study, but the dark stains that cryovolcanic activity might have left behind are even more intriguing.

“These features suggest the possibility of current surface activity and the existence of liquid water beneath the surface on Europa,” stated Heidi Becker from the Jet Propulsion Laboratory. There is evidence of such activity in the geysers of Enceladus, but there is still uncertainty regarding whether it is currently happening on Europa.

Engaging in such an endeavor would enable the sampling of the interior ocean to detect signs of life simply by flying through a plume and gathering ice flakes without the need for landing or drilling.

It seems that in the past, there was a significant shift of over 70 degrees in the locations of features on Europa’s surface, although the reasons for this remain unknown. However, at present, polar wander only leads to minor adjustments.

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