Archive for the ‘physics’ category: Page 15

Nov 27, 2022

How fast is gravity, exactly?

Posted by in categories: physics, space

The merging of two neutron stars emits both light and gravitational waves at the same time, so if gravity and light have the same speed, they should be detected on Earth at the same time. Given the distance of the galaxy that housed these two neutron stars, we know that the two types of waves had traveled for about 130 million years and arrived within two seconds of one another.

So, that’s the answer. Gravity and light travel at the same speed, determined by a precise measurement. It validates Einstein once again, and it hints at something profound about the nature of space. Scientists hope one day to fully understand why these two very different phenomena have identical speeds.

Nov 27, 2022

The REAL Possibility of Mapping Alien Planets!

Posted by in categories: mapping, physics, space

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Nov 26, 2022

Physics of Emergent Behaviour III: from origin of life to multicellularity, 2nd July 2021 (part 1)

Posted by in categories: biological, physics

Workshop supported by the Imperial College Physics of Life Network of Excellence.

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Nov 26, 2022

Objects We Thought Were Black Holes May Actually Be Wormholes, Scientists Say

Posted by in categories: cosmology, physics

If wormholes in space exist, they look a lot like black holes from a particular angle, physicists claim, raising the possibility we’ve seen examples of this long-sought phenomenon without knowing it.

Nov 25, 2022

Astrophysicists Solve 40-Year-Old Black Hole Jet Mystery With NASA’s IXPE

Posted by in categories: cosmology, physics

Blazars are some of the brightest objects in the cosmos. They are composed of a supermassive black hole.

A black hole is a place in space where the gravitational field is so strong that not even light can escape it. Astronomers classify black holes into three categories by size: miniature, stellar, and supermassive black holes. Miniature black holes could have a mass smaller than our Sun and supermassive black holes could have a mass equivalent to billions of our Sun.

Nov 24, 2022

Making Cosmic Magnets on Earth

Posted by in categories: habitats, physics, space

Greer and Ivanov agree that existing, albeit limited, data on tetrataenite’s magnetic properties suggest that it may not match high-performance neodymium-based magnets. But the researchers maintain that optimization of the tetrataenite casting process could improve its magnetic properties and thus make it a worthwhile option. “It is good to have a wider range of permanent magnet materials, because that allows better balancing of such factors as magnetic performance and environmental impact,” Greer says. “A one-for-one swap with rare-earth magnets is not necessarily the goal.”

For now, the team has demonstrated how to make a piece of tetrataenite, but they say that future work will focus on how to consolidate many pieces into a bulk magnet. “The analogy here would be that we have shown we can make a brick—a piece of tetrataenite—but not yet a house—a magnet,” Greer says.

Beyond materials science, the researchers hint that this work may even impact astrophysics research as scientists reconsider how long it takes for tetrataenite to develop in a meteorite and how fast the cooling rate is in that space environment.

Nov 24, 2022

Astronomers observe intra-group light—the elusive glow between distant galaxies

Posted by in categories: physics, space

An international team of astronomers have turned a new technique onto a group of galaxies and the faint light between them—known as ‘intra-group light’—to characterize the stars that dwell there.

Lead author of the study published in MNRAS, Dr. Cristina Martínez-Lombilla from the School of Physics at UNSW Science, said We know almost nothing about intra-group light.

The brightest parts of the intra-group light are ~50 times fainter than the darkest night sky on Earth. It is extremely hard to detect, even with the largest telescopes on Earth—or in space.

Nov 24, 2022

Astrophysicists solve a mystery of supermassive black holes

Posted by in categories: cosmology, physics

Black holes continue to be equal parts terrifying and fascinating.

An underrated NASA telescope reveals the mechanics behind some supermassive black holes’ relativistic jets.

Nov 22, 2022

Expert Proposes a Method For Telling if We All Live in a Computer Program

Posted by in categories: alien life, computing, physics

Physicists have long struggled to explain why the Universe started out with conditions suitable for life to evolve. Why do the physical laws and constants take the very specific values that allow stars, planets, and ultimately life to develop?

The expansive force of the Universe, dark energy, for example, is much weaker than theory suggests it should be – allowing matter to clump together rather than being ripped apart.

A common answer is that we live in an infinite multiverse of Universes, so we shouldn’t be surprised that at least one Universe has turned out as ours. But another is that our Universe is a computer simulation, with someone (perhaps an advanced alien species) fine-tuning the conditions.

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Nov 21, 2022

New puzzling discovery challenges Newton’s laws of gravity

Posted by in category: physics

An international team of astrophysicists has made a puzzling discovery while analyzing certain star clusters. The University of Bonn played a major role in the study. The finding challenges Newton’s laws of gravity, the researchers write in their publication. Instead, the observations are consistent with the predictions of an alternative theory of gravity. However, this is controversial among experts. The results have now been published in the Monthly Notices of the Royal Astronomical Society.

In their work, the researchers investigated the so-called open star clusters. These are formed when thousands of stars are born within a short time in a huge gas cloud. As they “ignite,” the galactic newcomers blow away the remnants of the gas cloud. In the process, the cluster expands considerably. This creates a loose formation of several dozen to several thousand stars. The weak gravitational forces acting between them hold the cluster together.

“In most cases, open star clusters survive only a few hundred million years before they dissolve,” explains Prof. Dr. Pavel Kroupa of the Helmholtz Institute of Radiation and Nuclear Physics at the University of Bonn. In the process, they regularly lose stars, which accumulate in two so-called “tidal tails.” One of these tails is pulled behind the cluster as it travels through space. The other, in contrast, takes the lead like a spearhead.

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