Tag: Physics

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Fiction Science Club

Why scientists are mesmerized by the multiverse

Illustration: Visualization of our universe in the multiverse
An artist's conception shows our cosmos amid other universes in the multiverse. (NASA / JPL-Caltech / R. Hurt (IPAC)

The multiverse may be a cool (and convenient) concept for comic books and superhero movies, but why do scientists take it seriously?

In a new book titled “The Allure of the Multiverse,” physicist Paul Halpern traces why many theorists have come to believe that longstanding scientific puzzles can be solved only if they allow for the existence of other universes outside our own — even if they have no firm evidence for such realms.

It’s easy to confuse the hypotheses with the hype, but Halpern says there’s a huge difference between the multiverse that physicists propose and the mystical realm that’s portrayed in movies like “Doctor Strange in the Multiverse of Madness.”

“Some people accuse scientists of trying to delve into science fiction if they even mention the multiverse,” Halpern says in the latest episode of the Fiction Science podcast. “But the type of science that people are doing when they talk about the multiverse is real science. It’s far-reaching science, but it’s real science. Scientists are not saying, ‘Hey, maybe we can meet another Spider-Man and attack Kingpin that way.'”

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Fiction Science Club

‘Her Space, Her Time’ reveals hidden figures of physics

Sepia-tone photos of Leavitt, Payne-Gaposchkin, Rubin and Alexander
These are four of the women scientists profiled in "Her Space, Her Time": Henrietta Leavitt, Cecilia Payne-Gaposchkin, Vera Rubin and Claudia Alexander. (Credits: Wikimedia; Smithsonian Institution; Rubin photo by Mark Godfrey, courtesy of AIP Emilio Segre Visual Archives; NASA)

Quick: Name a woman scientist.

Chances are the name you came up with is Marie Curie, the physicist and chemist who won two Nobel Prizes more than a century ago for the discoveries she and her husband Pierre made about radioactivity.

But who else? In a new book titled “Her Space, Her Time,” quantum physicist Shohini Ghose explains why women astronomers and physicists have been mostly invisible in the past — and profiles 20 researchers who lost out on what should have been Nobel-level fame.

“This issue around having low representation of women in physics is something that’s common all around the world,” Ghose says in the latest episode of the Fiction Science podcast. “And I’ve certainly faced it in my own experiences as a physicist growing up. I really didn’t know of any woman physicist apart from Marie Curie.”

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GeekWire

Scientists find evidence of a gravitational wave ‘hum’

Illustration: Ripples in spacetime caused by gravitational waves
Scientists monitor how ripples in spacetime affect the timing of signals from pulsars. (Credit: Aurore Simonnet for NANOGrav Collaboration)

Astrophysicists have found the best evidence yet for a low-frequency “hum” of gravitational waves rippling through the cosmos, based on 15 years’ worth of ultra-precise measurements checking the timing of radio pulses from distant stars.

The evidence, newly published in the Astrophysical Journal Letters, comes from several teams of researchers working in the U.S. and Canada as well as Europe, India, Australia and China.

The teams monitored radio emissions from a total of 115 ultra-dense, spinning stars known as pulsars. Nearly 70 of those pulsars were observed by the North American Nanohertz Observatory for Gravitational Waves, known as NANOGrav.

“This is key evidence for gravitational waves at very low frequencies,” Vanderbilt University’s Stephen Taylor, who co-led the search and is the current chair of the NANOGrav Collaboration, said today in a news release. “After years of work, NANOGrav is opening an entirely new window on the gravitational-wave universe.”

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GeekWire

Gravitational-wave sleuths look for more cosmic crashes

Specialist checks beam alignment at LIGO
A specialist checks the alignment of a test beam at the Laser Interferometer Gravitational-wave Observatory. (NSF Photo)

After three years of upgrading and waiting, due in part to the coronavirus pandemic, the Laser Interferometer Gravitational-wave Observatory has officially resumed its hunt for the signatures of crashing black holes and neutron stars.

“Our LIGO teams have worked through hardship during the past two-plus years to be ready for this moment, and we are indeed ready,” Caltech physicist Albert Lazzarini, the deputy director of the LIGO Laboratory, said in a news release.

Lazzarini said the engineering tests leading up to today’s official start of Observing Run 4, or O4, have already revealed a number of candidate events that have been shared with the astronomical community.

“Most of these involve black hole binary systems, although one may include a neutron star,” he said. “The rates appear to be consistent with expectations.”

One such event, called S230518h, was detected last week. Researchers say that if they can confirm the data, the event was most likely caused by the merger of a faraway black hole and a neutron star.

The twin LIGO gravitational-wave detectors at Hanford, Wash., and Livingston, La., will be joined for O4 by the Virgo detector in Italy as well as the KAGRA observatory in Japan. Virgo is scheduled to take part in the run starting later this year. KAGRA will parallel LIGO’s observations for the next month, take a break for some upgrades, and then rejoin the run.

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Fiction Science Club

How quantum tech could change everything everywhere

Illustration combining 1660 star atlas and picture of quantum computing hardware
Quantum computing could change our perspective on the cosmos. (Illustration: Harmonia Macrocosmica, 1660 / Microsoft, 2022)

What does quantum computing have in common with the Oscar-winning movie “Everything Everywhere All at Once”? One is a mind-blowing work of fiction, while the other is an emerging frontier in computer science — but both of them deal with rearrangements of particles in superposition that don’t match our usual view of reality.

Fortunately, theoretical physicist Michio Kaku has provided a guidebook to the real-life frontier, titled “Quantum Supremacy: How the Quantum Computer Revolution Will Change Everything.”

“We’re talking about the next generation of computers that are going to replace digital computers,” Kaku says in the latest episode of the Fiction Science podcast. “Today, for example, we don’t use the abacus anymore in Asia. … In the future, we’ll view digital computers like we view the abacus: old-fashioned, obsolete. This is for the garbage can. That’s how the future is going to evolve.”

https://radiopublic.com/fiction-science-GAxyzK/s1!813c6

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Fiction Science Club

Get a reality check on supersized quantum mania

Multiple Ant-Men in scene from "Ant-Man and the Wasp: Quantumania"
Ant-Man (Paul Rudd) faces proliferating quantum timelines in "Ant-Man and the Wasp: Quantumania." (Marvel Studios via Cedric Dumler / IMDB)

Ant-Man may be getting small in Marvel’s latest superhero movie — but in the real world, quantum is getting big.

Quantum information science is one of the top tech priorities for the White House, right up there with artificial intelligence. Microsoft, Google, Amazon, IBM and other tech heavyweights are closing in on the development of honest-to-goodness quantum processors. A company called IonQ has a billion-dollar plan to build quantum computers in the Pacific Northwest. The market for quantum computing is projected to hit $125 billion by 2030.

So you might think “Ant-Man and the Wasp: Quantumania” will be going all-out to feature real-life advances in quantum physics.

If that’s what you’re expecting from the movie, think again. “There’s no connection to real physics, or our understanding of reality,” says Chris Ferrie, a quantum physicist at the University of Technology Sydney and the UTS Center for Quantum Software and Information.

Ferrie should know, and not just because he has a Ph.D.: His latest book, titled “Quantum Bullsh*t,” colorfully catalogs all the ways in which popular depictions of quantum physics go wrong. In the latest episode of the Fiction Science podcast, Ferrie explains why those depictions tend to focus on the B.S. rather than the theory’s brilliance.

“The reality .. that quantum physics is a tool for engineers to make predictions about their experiments … is really boring,” he says.

https://radiopublic.com/fiction-science-GAxyzK/s1!b6d86

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Universe Today

Fusion breakthrough raises hopes — and questions

National Ignition Facility support structure
A color-enhanced image shows the inside of a preamplifier support structure at the National Ignition Facility. (LLNL Photo / Damien Jemison)

For the first time ever, physicists have set off a controlled nuclear fusion reaction that released more energy than what was put into the experiment.

The milestone laser shot took place on Dec. 5 at the U.S. Department of Energy’s National Ignition Facility at Lawrence Livermore National Laboratory in California. The fact that there was a net energy gain qualified the shot, in technical terms, as ignition.

“Reaching ignition in a controlled fusion experiment is an achievement that has come after more than 60 years of global research, development, engineering and experimentation,” said Jill Hruby, under secretary of energy for nuclear security and the administrator of the National Nuclear Security Administration.

However, officials acknowledged that it’s still likely to be decades before commercial fusion power becomes a reality. They said the most immediate impact of the breakthrough will be felt in the field of national security and the stewardship of America’s nuclear weapons stockpile.

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Universe Today

Quantum data gets sent through a simulated wormhole

Illustration: Wormhole simulation visualized
The wormhole created by researchers exists purely as data. (Illustration credit: Inqnet / A. Mueller / Caltech)

For the first time, scientists have created a quantum computing experiment for studying the dynamics of wormholes — that is, shortcuts through spacetime that could get around relativity’s cosmic speed limits.

Wormholes are traditionally the stuff of science fiction, ranging from Jodie Foster’s wild ride in “Contact” to the time-bending plot twists in “Interstellar.” But the researchers behind the experiment, reported in the Dec. 1 issue of the journal Nature, hope that their work will help physicists study the phenomenon for real.

“We found a quantum system that exhibits key properties of a gravitational wormhole, yet is sufficiently small to implement on today’s quantum hardware,” Caltech physicist Maria Spiropulu said in a news release. Spiropulu, the Nature paper’s senior author, is the principal investigator for a federally funded research program known as Quantum Communication Channels for Fundamental Physics.

Don’t pack your bags for Alpha Centauri just yet: This wormhole simulation is nothing more than a simulation, analogous to a computer-generated black hole or supernova. And physicists still don’t see any conditions under which a traversable wormhole could actually be created. Someone would have to create negative energy first.

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Universe Today

LHC spots exotic particles — and starts hunting for more

Pentaquark illustration
A new type of pentaquark is shown as a pair of standard hadrons loosely bound in a molecule-like structure. Credit: CERN

Physicists say they’ve found evidence in data from Europe’s Large Hadron Collider for three never-before-seen combinations of quarks, just as the world’s largest particle-smasher is beginning a new round of high-energy experiments.

The three exotic types of particles — which include two four-quark combinations, known as tetraquarks, plus a five-quark unit called a pentaquark — are totally consistent with the Standard Model, the decades-old theory that describes the structure of atoms.

In contrast, scientists hope that the LHC’s current run will turn up evidence of physics that goes beyond the Standard Model to explain the nature of mysterious phenomena such as dark matter. Such evidence could point to new arrays of subatomic particles, or even extra dimensions in our universe.

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Cosmic Space

See our galaxy’s black hole — and hear what’s next

Sagittarius A* black hole shadow
This is the first image of Sagittarius A*, the supermassive black hole at the center of our galaxy. (EHT Collaboration via NSF)

After years of observation and weeks of rumor-mill rumblings, astronomers today unveiled their first image of the supermassive black hole at the center of our own Milky Way galaxy, Sagittarius A*.

Technically, the picture from the Event Horizon Telescope project doesn’t show light from the black hole itself. After all, a black hole is a gravitational singularity so dense that nothing, not even light, can escape its grip. Rather, the picture shows the “shadow” of a black hole, surrounded by the superheated, glowing gas that surrounds it.

And technically, the picture may not match what folks might see with their own eyes up close. Rather, the readings come from eight observatories around the world that combined their observations in radio wavelengths.

Nevertheless, the new view of Sagittarius A*, or Sgr A* for short (pronounced “sadge-ay-star”), serves to confirm in graphic terms what astronomers have long suspected: that our galaxy, like many others, has a supermassive black hole at its heart.

Today’s revelations follow up on the Event Horizon Telescope’s first-ever black hole image, which was released in 2019 and showed the supermassive black hole at the center of M87, an elliptical galaxy about 55 million light-years away.

Sgr A* is much closer — a mere 27,000 light-years from Earth, in the constellation Sagittarius. But there’s nothing to fear from this black hole: It’s relatively quiescent, in contrast to the galaxy-gobbling behemoths that are standard science-fiction fare.

Our galaxy’s black hole is thought to hold the mass of 4 million suns within an area that’s roughly as big around as Mercury’s orbit. Checking those dimensions against the image data serves as a test of relativity theory. Spoiler alert: Albert Einstein was right … again.

“We were stunned by how well the size of the ring agreed with predictions from Einstein’s theory of general relativity,” EHT project scientist Geoffrey Bower said in a news release. “These unprecedented observations have greatly improved our understanding of what happens at the very center of our galaxy and offer new insights on how these giant black holes interact with their surroundings.”

The EHT’s findings about Sgr A* are the subject of a special issue of The Astrophysical Journal Letters — and to whet your appetite for all that reading material, here are three videos that summarize the past, present and future of black hole imaging:

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