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No Big Bang? Quantum equation predicts universe has no beginning

The universe may have existed forever, according to a new model that applies quantum correction terms to complement Einstein’s theory of general relativity. The model may also account for dark matter and dark energy, resolving multiple problems at once.

The widely accepted age of the universe, as estimated by general relativity, is 13.8 billion years. In the beginning, everything in existence is thought to have occupied a single infinitely dense point, or singularity. Only after this point began to expand in a “Big Bang” did the universe officially begin.

Although the Big Bang singularity arises directly and unavoidably from the mathematics of general relativity, some scientists see it as problematic because the math can explain only what happened immediately after—not at or before—the singularity.

“The Big Bang singularity is the most serious problem of general relativity because the laws of physics appear to break down there,” Ahmed Farag Ali at Benha University and the Zewail City of Science and Technology, both in Egypt, told Phys.org.

Ali and coauthor Saurya Das at the University of Lethbridge in Alberta, Canada, have shown in a paper published in Physics Letters B that the Big Bang singularity can be resolved by their new model in which the universe has no beginning and no end.

The physicists emphasize that their quantum correction terms are not applied ad hoc in an attempt to specifically eliminate the Big Bang singularity. Their work is based on ideas by the theoretical physicist David Bohm, who is also known for his contributions to the philosophy of physics. Starting in the 1950s, Bohm explored replacing classical geodesics (the shortest path between two points on a curved surface) with quantum trajectories.

In their paper, Ali and Das applied these Bohmian trajectories to an equation developed in the 1950s by physicist Amal Kumar Raychaudhuri at Presidency University in Kolkata, India. Raychaudhuri was also Das’s teacher when he was an undergraduate student of that institution in the ’90s.

Using the quantum-corrected Raychaudhuri equation, Ali and Das derived quantum-corrected Friedmann equations, which describe the expansion and evolution of universe (including the Big Bang) within the context of general relativity. Although it’s not a true theory of quantum gravity, the model does contain elements from both quantum theory and general relativity. Ali and Das also expect their results to hold even if and when a full theory of quantum gravity is formulated.

In addition to not predicting a Big Bang singularity, the new model does not predict a “big crunch” singularity, either. In general relativity, one possible fate of the universe is that it starts to shrink until it collapses in on itself in a big crunch and becomes an infinitely dense point once again.

Ali and Das explain in their paper that their model avoids singularities because of a key difference between classical geodesics and Bohmian trajectories. Classical geodesics eventually cross each other, and the points at which they converge are singularities. In contrast, Bohmian trajectories never cross each other, so singularities do not appear in the equations.

In cosmological terms, the scientists explain that the quantum corrections can be thought of as a cosmological constant term (without the need for dark energy) and a radiation term. These terms keep the universe at a finite size, and therefore give it an infinite age. The terms also make predictions that agree closely with current observations of the cosmological constant and density of the universe.

In physical terms, the model describes the universe as being filled with a quantum fluid. The scientists propose that this fluid might be composed of gravitons—hypothetical massless particles that mediate the force of gravity. If they exist, gravitons are thought to play a key role in a theory of quantum gravity.

In a related paper, Das and another collaborator, Rajat Bhaduri of McMaster University, Canada, have lent further credence to this model. They show that gravitons can form a Bose-Einstein condensate (named after Einstein and another Indian physicist, Satyendranath Bose) at temperatures that were present in the universe at all epochs.

Motivated by the model’s potential to resolve the Big Bang singularity and account for dark matter and dark energy, the physicists plan to analyze their model more rigorously in the future. Their future work includes redoing their study while taking into account small inhomogeneous and anisotropic perturbations, but they do not expect small perturbations to significantly affect the results.

“It is satisfying to note that such straightforward corrections can potentially resolve so many issues at once,” Das said.

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Space

A giant explosion recorded on the star Betelgeuse

Betelgeuse is considered a doomed star, and its explosion is only a matter of time. Observations from NASA’s Hubble Space Telescope show that the sudden darkening of the supergiant star Betelgeuse was most likely caused by the enormous amount of hot matter ejected into space, forming a dust cloud that blocked the starlight emanating from Betelgeuse’s surface.

The researchers speculate that the dust cloud was formed when superhot plasma released from the upward flow of a large convection cell on the star’s surface passed through the hot atmosphere into the colder outer layers, where it cooled down and formed dust particles. The resulting dust cloud has blocked light from about a quarter of the star’s surface since late 2019. By April 2020, the star has returned to normal brightness.

Betelgeuse is an aging red supergiant star that has grown in size due to complex evolutionary changes in its fusion furnace at its core. The star is now so huge that if it replaced the Sun at the center of our solar system, its outer surface would extend beyond Jupiter’s orbit.

Betelgeuse’s unprecedented strong blackout phenomenon, visible even to the naked eye, began in October 2019. By mid-February 2020, the monster star has lost more than two-thirds of its brilliance.

This sudden blackout has puzzled astronomers, who have tried to develop several theories of abrupt change. 

Hubble recorded traces of dense, heated matter moving through the star’s atmosphere in September, October, and November 2019. Then, in December, several ground-based telescopes observed a decrease in the star’s brightness in the southern hemisphere.

“With the Hubble Telescope, we see material leaving the visible surface of the star and moving through the atmosphere before the dust was formed, which made the star appear dim,” said Dupree. “We could see the effect of a dense hot region moving in the southeastern part of the star.

“This material was two to four times brighter than the normal brightness of the star. And then, about a month later, the southern part of Betelgeuse became noticeably dimmer as the star became fainter. We think that it is possible that the dark cloud came from an explosion discovered by Hubble “.

The article was published August 13 in the Astrophysical Journal.

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Massive sunspot facing Earth could be bad news as we enter a new 25 solar cycle

A massive sunspot has formed on the Sun, which will be turned towards our planet, which can lead to large and very strong flares aimed at the Earth

The sunspot AR2770, which was recorded earlier this week, will increase in size. This particular sunspot has already emitted several minor flares, which have caused nothing serious, except for “small waves of ionization running through the upper atmosphere of the Earth.”

However, this sunspot, which can be up to 50,000 kilometers in diameter, can release enormous amounts of energy, which in turn can lead to solar flares. 

This phenomenon is called coronal mass ejections (CMEs). These outbreaks can have a serious impact on radio communications, global positioning systems (GPS) communications, power grids and satellites.

According to the National Oceanic and Atmospheric Administration (NOAA), CMEs can “oscillate electrical currents in space and excite electrons and protons trapped in Earth’s changing magnetic field.” Solar flares caused by these CMEs can also cause intense light in the sky called auroras.

On the Sun, the active zone was transformed into an ideal number 2


What is a sunspot?

A spot is a dark area in the sun that appears dark on the surface and is relatively cooler than other parts. These sunspots contain electrically charged gases that create areas of powerful magnetic forces. Gases on our Sun are constantly moving, which causes irregularities in this “magnetic field”. This activity is also called “solar activity”. The levels of solar activity do not remain the same and differ from one solar cycle to the next.

What is a solar flare?

Solar flares are the result of changes in the magnetic fields at sunspots that cause a huge explosion. These solar flares are often thrown into space. The energy of the explosion of solar flares can be equivalent to a trillion atomic bombs dropped on Hiroshima and Nagasaki in 1945.

Is a new 25 cycle starting?

At the moment, there is no complete confidence in the beginning of the 25th solar cycle, which will mark a gradual increase in solar activity. Only one thing is clear – the solar minimum, if suddenly it continues, nothing good for our planet and, accordingly, will not bring us all.

Due to the practically zero activity of the Sun on Earth, record levels of cosmic radiation are recorded. To put it simply, our entire planet is essentially turned into a huge microwave.

But the resumption of solar activity after a long period of calm is also not good, since no one can predict the levels of this activity, and if it is high, this could potentially lead to a powerful super-flash that will cover the Earth.

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What did Mars look like millions of years ago? New theory

At the moment, Mars is considered the most suitable planet for human life. It is in many ways similar to our native Earth: the surface is solid, the day lasts almost the same 24 hours and periodically there is a change of seasons. 

Scientists are sure that millions of years ago between our planet and Mars there were even more similarities, such as the presence of water and living organisms. He has one snag – in time immemorial the sun was much weaker than it is now, and Mars was quite far from it and was not going to approach. It turns out that the planet was cold and there could not be rivers and oceans on it. 

But how, then, can explain the presence of valleys and depressions on its surface, which were clearly formed as a result of the flow of water? Canadian scientists have started looking for an explanation for this mysterious phenomenon. 

In the course of scientific work, they managed to put forward a theory that greatly changes the idea of ​​scientists about the past of the Red Planet. Perhaps Mars looked like a giant snowball.

Millions of years ago, Mars was hardly a warm place

Water on Mars

The essence of the theory was published in the scientific journal Nature Geoscience . According to one of the study’s authors, Anna Grau Galofre , over the past 40 years, the scientific community has believed that irregularities on the surface of Mars were formed by the movement of rivers. 

However, there are distinctive features between valleys and depressions in different regions of the planet. To find out what factors could affect the structure of the irregularities, scientists decided to find a place on Earth, the surface of which is as close as possible to the Martian landscape. However, researchers have long known about the existence of such a place.

Mars on Earth

One of the most Mars-like places on our planet is considered the uninhabited island of Devon, located in northern Canada. Almost all of its surface is a cold and dry desert. If you look at the island from a bird’s eye view or even from a satellite, you will notice that its surface is really very similar to the vastness of the Red Planet. 

It is also full of all kinds of irregularities and scientists are well aware of how they were formed. Since Devon Island is a rather cold place, most of the rivers there flow under a layer of ice. Part of the ice sheet melted over time and the valleys left by the rivers are now clearly visible to us. In their structure, they are very different from the valleys formed by rivers that flow in the open.

The surface of Devon Island is very similar to the Martian landscape

So, scientists became aware of the distinctive features of the two types of valleys. Based on this data, they developed an algorithm that was able to quickly study photographs of 10,000 Martian irregularities. 

Among them, the researchers found many valleys, which clearly formed under a thick layer of ice. Most of them were formed about 3.8 billion years ago. It turns out that once upon a time, although not all, but most of Mars, was covered with ice and snow. But scientists assumed that it was very similar to our blue-green Earth.

Above is the surface of Mars, and below is the surface of Devon Island

Life on Mars

If Mars really was covered with layers of ice, then the probability of the existence of living organisms on it increases markedly. The fact is that microorganisms could well inhabit the waters hidden under the ice sheet. And this shield, in turn, could perfectly protect them from cosmic radiation. 

Indeed, the Red Planet has a very weak magnetic field, which is precisely what serves to protect against harmful radiation. So, despite the changes in the idea of ​​the appearance and conditions of ancient Mars, the probability that at least primitive creatures lived on it remained. Maybe someday their traces will be discovered by devices like InSight and we will gain confidence that life on other planets can exist.

According to the new theory, 3.8 billion years ago Mars looked something like this

The computer algorithm created within the framework of scientific work will not disappear. According to the developers, it can be useful for studying the past of the Earth. 

Technologies existing at the moment allow us to look at history no further than 5 million years, and a new algorithm can reconstruct the history of glaciations on our planet over the past 35 million years. It sounds intriguing, so we can only hope that new discoveries will not be long in coming.

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