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Thinking planet: Earth knows how to regulate the global climate itself



Scientists have proven that our planet has geological mechanisms that protect its climate from catastrophic events. In other words, the Earth seems to be able to think.

The Earth has gone through many turbulent times: our planet has had periods of global volcanism, epochs of glaciation, sharp increases and decreases in solar radiation fluxes. And yet, for the last 3.8 billion years, life has continued to evolve on our planet.

Scientists suspected that the Earth has some kind of “fuse” that keeps the climate in a habitable range. But until recently, researchers could not prove its existence.

What is this “tool” and how it works, researchers at the Massachusetts Institute of Technology (MIT) found out. They confirmed that the planet has a so-called “stabilizing feedback” mechanism.

This mechanism has been working for hundreds of thousands of years, slowly but surely pushing the Earth’s climate away from the edge of the abyss, in which life can no longer appear again.

Scientists believe this feedback is based on a geological phenomenon called silicate weathering. This is a slow but constant process involving a series of chemical reactions that take place in silicate rocks. They “pull” carbon dioxide out of the atmosphere, “burying” it in sedimentary rocks on the ocean floor.

Scientists have long noted the important role of silicate weathering in regulating the Earth’s carbon cycle.

This mechanism may be the geologically constant force that keeps the concentrations of carbon dioxide in the atmosphere at a level acceptable for the existence of life. As a consequence, global temperatures are “under control” of Mother Earth.

Let us clarify that this idea has been around for many years, but so far there has been no direct evidence that such a feedback operates continuously over millions of years.

Now, MIT researchers have applied mathematical analysis to uncover patterns in paleoclimate data over the past 66 million years.

The research team has been searching the dataset for some recurring phenomena that would keep global temperatures within a habitable range all this long.

So scientists discovered that a constant pattern really exists. The temperature on Earth can fluctuate for some time, critically rising or falling, but then inevitably stabilizes. As if someone is looking after the balance (scientists are not inclined to believe in the supernatural, attributing everything to natural processes).

True, the process of temperature stabilization is very slow: it takes hundreds of thousands of years. This duration coincides with how long, according to researchers, the weathering of silicates lasts.

This is the first work in which evidence supports the existence of such a stabilizing feedback.

The results obtained by MIT scientists may explain how the Earth remained habitable despite the fact that its geological past is filled with dramatic climatic events, many of which could lead to the apocalypse.

“On the one hand, this is good, because now we know that today’s global warming will be neutralized thanks to this stabilizing feedback,” says co-author of the work, graduate student Konstantin Arnscheidt. “But, on the other hand, this will take hundreds of thousands of years, and our decisions today’s problems are needed now.”

The study was published in Science Advances.

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Extraterrestrial life may be hiding in “terminator zones”




In a study published in the Astrophysical Journal, astrophysicists set out to find out if exoplanets could support life.

Astronomers have come to the conclusion that on the surface of some exoplanets there is a strip that may contain water, necessary for the existence of biological life. The terminator zone is the dividing line between the day and night sides of an exoplanet.

Many exoplanets are planets outside the solar system held by gravity. This means that one side of the planet is always facing the star they orbit, while the other side is in constant darkness.

The water on the dark side will most likely be in a frozen state, while on the light side it will be so hot that the water should just evaporate.

The terminator zone would be a “friendly place” – neither too hot nor too cold – in which liquid water could support extraterrestrial life.

Dr. Ana Lobo of the University of California, said: “The day side can be scalding hot, much uninhabitable, while the night side will be icy, potentially covered in ice. You need a planet that’s the right temperature for liquid water.”

“We’re trying to draw attention to planets with more limited amounts of water that, despite not having widespread oceans, might have lakes or other smaller bodies of liquid water, and that climate could actually be very promising.”

“By exploring these exotic climate states, we are improving our chances of finding and correctly identifying a habitable planet in the near future.”

The researchers created a model of their climate by analyzing different temperatures, wind patterns and radiative forcing, and found the “correct” zone on exoplanets that could contain life-supporting liquid water.

Researchers who are looking for life on exoplanets will now take into account the fact that it can hide in certain areas.

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Astronomers discover the strongest evidence for another Universe before the Big Bang




The notion of the Big Bang goes back nearly 100 years, when the first evidence for the expanding Universe appeared.

If the Universe is expanding and cooling today, that implies a past that was smaller, denser, and hotter. In our imaginations, we can extrapolate back to arbitrarily small sizes, high densities, and hot temperatures: all the way to a singularity, where all of the Universe’s matter and energy was condensed in a single point. 

For many decades, these two notions of the Big Bang — of the hot dense state that describes the early Universe and the initial singularity — were inseparable.

But beginning in the 1970s, scientists started identifying some puzzles surrounding the Big Bang, noting several properties of the Universe that weren’t explainable within the context of these two notions simultaneously. 

When cosmic inflation was first put forth and developed in the early 1980s, it separated the two definitions of the Big Bang, proposing that the early hot, dense state never achieved these singular conditions, but rather that a new, inflationary state preceded it. 

There really was a Universe before the hot Big Bang, and some very strong evidence from the 21st century truly proves that it’s so.

Although we’re certain that we can describe the very early Universe as being hot, dense, rapidly expanding, and full of matter-and-radiation — i.e., by the hot Big Bang — the question of whether that was truly the beginning of the Universe or not is one that can be answered with evidence. 

The differences between a Universe that began with a hot Big Bang and a Universe that had an inflationary phase that precedes and sets up the hot Big Bang are subtle, but tremendously important. After all, if we want to know what the very beginning of the Universe was, we need to look for evidence from the Universe itself.

Read the full article here.

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