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Archive for the ‘physics’ category: Page 27

Sep 19, 2023

Scientists figured out how to write in water

Posted by in category: physics

Human writing and drawing dates back at least 30,000 years and incorporates traditional techniques such as carving, engraving, and printing/writing with ink, as well as more novel methods such as electron lithography. Now a team of German physicists has figured out a unique method for writing in water and other fluid substrates, according to a recent paper published in the journal Small.

According to the authors, most classical writing methods involve the same basic approach, in which a line is carved out or ink deposited. On a solid substrate, strong intermolecular forces help the written figures hold their shape, but that’s not the case for surfaces submerged in fluids. Prior research has used scanning probe lithography to “write’ on self-assembled monolayers submerged in fluids, or to bring structures at the micron scale using two-photon polymerization. ” There are now even commercial scuba diver slates available for underwater writing on a substrate,” they wrote.

All of these methods still rely on a substrate, however. The German team wanted to devise a means of literally writing into a fluid. Such a method would need to be robust enough to counter the rapid dispersion of drawn lines, and they would need a very tiny pen that didn’t stir up lots of turbulence as it moved through the fluid medium. (The smaller the object moving through a fluid, the fewer vortices, or eddies, it will create.)

Sep 19, 2023

Fact Check: Do Warp Drive Engines Violate the Laws of Physics?

Posted by in categories: alien life, mathematics, physics

The universe is bigger than you think.

This means any deep-space future awaiting humanity outside our solar system will remain beyond the span of a single life until we develop a means of propulsion that outclasses conventional rockets. And, when three studies rocked the world earlier this year, it felt like a dream come true: Warp drive was no longer science fiction, potentially unlocking a theoretical basis to build faster-than-light warp drive engines that could cut a trip to Mars down to minutes.

However, a recent study shared in a preprint journal cast doubt on the theory, pointing to a gap in the math that could put the viability of a physical warp drive back into the realm of speculation.

Sep 17, 2023

ESA and NASA join forces to answer the Sun’s heating riddle

Posted by in categories: physics, space

A 65-year old perplexing question may have finally been answered: Why is the Sun’s atmosphere hotter than its surface?

For over six decades, scientists have been baffled by a cosmic mystery of scorching proportions: Why is the Sun’s atmosphere, known as the corona, hotter than its surface?

Continue reading “ESA and NASA join forces to answer the Sun’s heating riddle” »

Sep 15, 2023

World’s first 3D simulations reveal the physics of exotic supernovae

Posted by in categories: cosmology, physics, supercomputing

After years of dedicated research and over 5 million supercomputer computing hours, a team has created the world’s first high-resolution 3D radiation hydrodynamics simulations for exotic supernovae. This work is reported in The Astrophysical Journal.

Ke-Jung Chen at Academia Sinica Institute of Astronomy and Astrophysics (ASIAA) in Taiwan, led an international team and used the powerful supercomputers from the Lawrence Berkeley National Laboratory and the National Astronomical Observatory of Japan to make the breakthrough.

Supernova explosions are the most spectacular endings for massive stars, as they conclude their in a self-destructive manner, instantaneously releasing brightness equivalent to billions of suns, illuminating the entire universe.

Sep 14, 2023

We’ve Been Misreading a Major Law of Physics For The Past 300 Years

Posted by in categories: mathematics, physics

When Isaac Newton inscribed onto parchment his now-famed laws of motion in 1,687, he could have only hoped we’d be discussing them three centuries later.

Writing in Latin, Newton outlined three universal principles describing how the motion of objects is governed in our Universe, which have been translated, transcribed, discussed and debated at length.

But according to a philosopher of language and mathematics, we might have been interpreting Newton’s precise wording of his first law of motion slightly wrong all along.

Sep 14, 2023

This is why physicists suspect the Multiverse very likely exists

Posted by in categories: cosmology, physics

A wild, compelling idea without a direct, practical test, the Multiverse is highly controversial. But its supporting pillars sure are stable.

Sep 14, 2023

The Universe: New Evidence of Parallel Worlds (S3, E2) | Full Episode

Posted by in categories: cosmology, education, physics

Some of the world’s leading physicists believe they have found startling new evidence showing the existence of universes other than our own. See more in Season 3, Episode 2, “Parallel Universes.”

#TheUniverse.

Continue reading “The Universe: New Evidence of Parallel Worlds (S3, E2) | Full Episode” »

Sep 14, 2023

Alternative Theory Of Gravity Could Give Black Holes Hair

Posted by in categories: cosmology, physics

The “no-hair theorem” of black holes, which greatly simplifies the way we model them, may not be true if an alternative theory of gravity known as the teleparallel formulation is correct, an unpublished paper argues. This could make the study of black holes considerably more complicated, but it would also allow physicists to understand them in ways many have feared they never will.

According to the “no-hair theorem”, a black hole’s mass, electric charge, and spin can tell us everything there is to know about that hole. Anything else we might measure, such as its magnetic moment, can be derived from these three measures.

Crucially, that means that when matter is swallowed by a black hole’s event horizon, all the information contained within it is lost, once the black hole has emitted any gravitational waves or light associated with its meal. It doesn’t matter what elements went into forming a black hole’s predecessor star, or even if it was made of antimatter rather than matter – under the no-hair theorem, it would appear identical to anyone outside its event horizon. The term “hair” is a metaphor for information streaming out of a black hole beyond the point of no return for incoming objects.

Sep 13, 2023

Motion of stars near Milky Way’s central black hole is only predictable for a few hundred years

Posted by in categories: computing, cosmology, physics

The orbits of 27 stars orbiting closely around the black hole at the center of our Milky Way are so chaotic that researchers cannot predict with confidence where they will be in about 462 years. This finding emerges from simulations by three astronomers based in the Netherlands and the United Kingdom. The researchers have published their findings in two papers in the International Journal of Modern Physics D and in the Monthly Notices of the Royal Astronomical Society.

Simulating 27 stars and their interactions with each other and with the black hole is easier said than done. For centuries, for example, it was impossible to predict the motions of more than two interacting stars, planets, rocks, or other objects. It was only in 2018 that Leiden researchers developed a computer program in which rounding errors no longer play a role in the calculations. With this, they were able to calculate the motions of three imaginary stars. Now the researchers have expanded their program to deal with 27 stars that, by astronomical standards, move close to the black hole at the center of the Milky Way.

The simulations of the 27 and the black hole resulted in a surprise. Although the stars remain in their orbits around the black hole, the interactions between the stars show that the orbits are chaotic. This means that small perturbations caused by the underlying interactions change the orbits of the stars. These changes grow exponentially and, in the long run, make the star orbits unpredictable.

Sep 12, 2023

Black Holes ‘Burp’ Years After Shredding Stars, And We Don’t Know Why

Posted by in categories: cosmology, physics

For a few hours after a star smashes into a supermassive black hole, some of the brightest light in the Universe is produced.

The subsequent flash of radio waves were thought to simmer down within weeks or months of a collision. It turns out we might have been a little impatient to turn our gaze elsewhere.

Continue reading “Black Holes ‘Burp’ Years After Shredding Stars, And We Don’t Know Why” »

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