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Archive for the ‘cosmology’ category: Page 75

Jan 15, 2024

Saturday Citations: The Dark Energy Survey; the origins of colorblindness; the evolution of heads

Posted by in categories: cosmology, quantum physics

The Dark Energy Survey took an entire decade to produce a value for the cosmological constant—and it’s smaller than you might think! There were other stories as well, including one about primeval black holes, and because I am inescapably drawn by the relentless gravity of black hole news, it’s included below, along with two other stories related in one way or another to heads.

Dogs’ primary sense is olfactory, and if their visual perception flags something interesting in the environment, the first thing they do is stick their cute little noses in it. But the opposite is true for humans; we are able to perceive millions of colors, but only a fraction of the olfactory stimuli dogs are usually way too engaged with.

If you smell in your house, you go looking for the source with your cute little retinas and their super-dense constellation of photoreceptive cells to determine that one of the gas knobs on the stove is open. Researchers at Johns Hopkins University grew retinal organoids in a lab to determine how human visual perception develops.

Jan 15, 2024

‘We do not understand how it can exist’: Astronomers baffled by ‘almost invisible’ dwarf galaxy that upends a dark matter theory

Posted by in category: cosmology

Astronomers have discovered a super diffuse dwarf galaxy, named Nube, which gives off barely any visible light and seemingly defies explanation.

Jan 14, 2024

Unexpectedly massive black holes dominate small galaxies in the distant universe

Posted by in category: cosmology

Black holes are very important for galactic formation.


Astronomers have discovered that the supermassive black holes in the centers of early galaxies are much more massive than expected. These surprisingly hefty black holes offer new insights into the origins of all supermassive black holes, as well as the earliest stages of their host galaxy’s lives.

In nearby, mature like our Milky Way, the total mass of stars vastly outweighs the mass of the big black hole found at the galaxy’s center by about 1,000 to 1. In the newfound distant galaxies, however, that mass difference drops to 100 or 10 to 1, and even to 1 to 1, meaning the black hole can equal the combined mass of its host galaxy’s stars.

Continue reading “Unexpectedly massive black holes dominate small galaxies in the distant universe” »

Jan 12, 2024

From black hole entropy to the complexity of plant leaves: An intriguing linkage

Posted by in categories: biological, cosmology

Complexity of biological forms has fascinated humankind over the years. Different species of plants have different leaf shapes. Have you ever wondered why it is so? Why does this shape diversity exist? Plants can change their leaf shapes over time and space. But how?

Does the distinct of forms play a significant role in energy optimization? In fact, the shape of leaves has a lot to do with adapting to their surrounding environment. How is the unfolding of shape related to the evolutionary process of nature? These intriguing questions have led us to focus on quantitative approaches to the complexity of plant leaves.

Quantifying leaf shapes using Euclidean shapes, such as circles, triangles, etc., are appropriate to only a few . Therefore, various quantitative measures of leaf shapes have been developed with varying accuracy. But Is the shape of an object really its actual shape? Visual perception of definite shape or geometry of physical objects is only an abstraction.

Jan 12, 2024

NASA finds ‘galactic fossil’ in a galaxy 13 million light-years away

Posted by in category: cosmology

NASA scientists have identified unexpectedly massive clouds of cold gas within the spiral galaxy NGC 4,945, located 13 million light-years away.

As per the release, the revelation of this cold gas serves as the discovery of a “galactic fossil.”

Continue reading “NASA finds ‘galactic fossil’ in a galaxy 13 million light-years away” »

Jan 12, 2024

A Black Hole Breakthrough Might Actually Solve the Information Paradox

Posted by in categories: cosmology, quantum physics

The key to understanding our universe lies in two theories—one of the generally-very-big and one of the generally-very-small. Albert Einstein’s Theory of General Relativity explains things like gravity and time, while Quantum Field Theory explores the subatomic world. However, one celestial object frustrates astrophysicists and quantum theorists in equal measure: black holes.

Because black holes release Hawking radiation (named for famous physicist Stephen Hawking), they eventually evaporate, which seemingly destroys the information that fell into the black hole. However, quantum field theory states that information cannot be destroyed. Result? Paradox.

Jan 11, 2024

Discovery of unusual star may change our picture of how stars explode and elements are made

Posted by in category: cosmology

Scientists have found a star unlike any other one recorded—which may change our understanding of how stars die.

This unusual star, 13,000 light-years away, has an elemental makeup that suggests it was formed in the aftermath of a more massive star exploding in a way that no existing theory seems to explain. According to everything else we know, the original star should have turned into a black hole instead.

The discovery may rearrange our picture of how stars explode and how some of the heavier elements are made. It also helps us better understand what the first generation of stars in the universe may have looked like.

Jan 11, 2024

Scientists just witnessed a supernova turn into a black hole for the first time

Posted by in category: cosmology

How is a black hole formed? In the simplest language, a black hole is born when a star dies. Now, astronomers have claimed that they might have just witnessed the birth of such a black hole in a major first. This is huge for the scientific community worldwide as it directly links the death of a star to the formation of a black hole-like compact object.

“Our research is like solving a puzzle by gathering all possible evidence,” Ping Chen, a researcher at the Weizmann Institute of Science in Israel, and lead author of a study published in Nature, was quoted as saying by Cosomos Magazine.

It started with the discovery of a super bright object in space, called SN 2022jli. The object, located some 76 million years away, was discovered by a South African amateur astronomer, Berto Monard. Soon it was confirmed that they had their eyes set on a supernova. A supernova occurs just as a star is breathing its last, or when a black hole is about to form.

Jan 10, 2024

Most Precise Measure of Dark Energy Confirms Universe Won’t Tear Apart

Posted by in categories: cosmology, mapping

Over ten years ago, the Dark Energy Survey (DES) began mapping the Universe to find evidence that could help us understand the nature of the mysterious phenomenon known as dark energy.

I’m one of more than 100 contributing scientists that have helped produce the final DES measurement, which has just been released at the 243rd American Astronomical Society meeting in New Orleans.

Dark energy is estimated to make up nearly 70 percent of the observable Universe, yet we still don’t understand what it is. While its nature remains mysterious, the impact of dark energy is felt on grand scales. Its primary effect is to drive the accelerating expansion of the Universe.

Jan 9, 2024

China launches “lobster eye” Einstein Probe to unveil mysteries of X-ray universe

Posted by in categories: cosmology, physics

HELSINKI — China launched its Einstein Probe early Tuesday to detect X-ray emissions from violent, fleeting cosmic phenomena using novel lobster eye-inspired optics.

A Long March 2C rocket lifted off from Xichang Satellite Launch Center in southwestern China at 2:03 a.m. (0703 UTC), Jan. 9. The China Aerospace Science and Technology Corp. (CASC) confirmed launch success within the hour.

The Einstein Probe (EP) is part of growing Chinese strategic space science efforts. The spacecraft will spend at least three years observing distant, violent interactions such as tidal disruption events—in which stars are pulled apart by supermassive black holes—supernovae, and detect and localize the high-energy, electromagnetic counterparts to gravitational wave events.

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