Category: Physics

Doctor Strange in the Multiverse of Madness. Credit: Marvel Studios

Whether you need a new villain or an old Spider-Man, your sci-fi movie will sound more scientifically credible if you use the word multiverse. The Marvel multiverse puts multiple different versions of our universe “out there,” somewhere. In these films, with the right blend of technology, magic, and imagination, travel between these universes is possible.

For example (spoilers!), in Spider-Man: No Way Home, we discover there are other universes and other Earths, some of which have their own local Spider-Man. In the universe of the movie, magic is possible.

This magic, thanks to a misfiring spell from superhero Dr. Strange, causes some of the other Spider-Men to be transported into our universe, along with a few supervillains.

In Doctor Strange in the Multiverse of Madness (in cinemas now), the universe-on-universe buffoonery threatens a “desecration of reality.”

So, which of these ideas has Marvel based on science, and which ones are just pure fiction?

Multiverse lite: a really big universe

Could there be other Earths? Could there be other people out there, who look a lot like us, on a planet that looks like ours? Scientifically, it’s possible, because we don’t know how big our universe actually is.

We can see billions of light years into space, but we don’t know how much more space is out there, beyond what we can see.

If there is more space out there, full of galaxies, stars, and planets, then there are more and more chances for Another-Earth to exist. Somewhere. With enough space and enough planets, any possibility becomes likely.

The fiction of the Marvel multiverse stems from the ability to travel between these other earths. There’s a good reason why Dr. Strange needs to use magic for this.

According to Albert Einstein, we can’t travel through space faster than light. And while more exotic ways to travel around the universe are scientifically possible – wormholes, for example – we don’t know how to make them, the universe doesn’t seem to make them naturally, and there is no reason to think they’d connect us to Another-Earth rather than some random part of empty space.

So, almost certainly, if Another-Earth is out there somewhere, it’s unimaginably far away, even for an astronomer.

In Dr. Strange in the Multiverse of Madness, the multiverse is breached by various magical spells and special abilities. Credit: Marvel Studios

Changing the laws of nature

The Marvel multiverse might seem wild, but from a scientific perspective, it’s actually too tame. Too normal. Too familiar. Here’s why.

The basic building blocks of our universe – protons and neutrons (and their quarks), electrons, light, etc. – are able to make amazing things, such as human life. Your body is amazing: energy-gathering, information-processing, mini-machine building, self-repairing.

Physicists have discovered that the ability of our universe’s building blocks to make life forms is extremely rare. Just any old blocks won’t do.

If electrons had been too heavy, or the force that holds atomic nuclei together had been too weak, the stuff of the universe wouldn’t even stick together, let alone make something as marvelous as a living cell. Oh, indeed, cualquier cosa that could be called alive.

How did our universe get the right mix of ingredients? Perhaps we won the cosmic lottery. Perhaps, on scales much bigger than what our telescopes can see, other parts of the universe have different building blocks.

Our universe is just one of the options – a particularly fortunate one – among a multiverse of universes with losing tickets.

This is the scientific multiverse: not simply more of our universe, but universes with different fundamental ingredients. Most are dead, but very very rarely, the right combination for life-forms comes up.

The Marvel multiverse, by contrast, merely rearranges the familiar atoms and forces of our universe (plus a bit of magic). That’s not enough.

In Spider-Man No Way Home, three different Spider-Man’s from alternate universe (and alternate Spider-Man movie franchises) team up to battle villains from across the multiverse. Credit: IMDB

Cosmic inflation and the Big Bang

What was our universe like in the past? The evidence suggests that the universe was hotter, denser, and smoother. This is called the Big Bang Theory.

But there was a[{” attribute=””>Big Bang? Was there a moment when the universe was infinitely hot, infinitely dense, and contained in a single point? Well, maybe. But we’re not sure, so scientists have explored a bunch of other options.

One idea, called cosmic inflation, says that in the first fraction of a second of the universe, it expanded extremely quickly. If true, it would explain a few things about why our universe expands in just the way it does.

But, how do you make a universe expand so rapidly? The answer is a new type of energy field. It has control of the first moments of the universe, causes a rapid expansion, and then hands the reins to the more familiar forms of matter and energy: protons, neutrons, electrons, light, etc.

Cosmic inflation might make a multiverse. Here’s how. According this idea, most of space is expanding, inflating, doubling in size, moment to moment. Spontaneously and randomly, in small islands, the new energy field converts its energy into ordinary matter with enormously high energies, releasing what we now see as a Big Bang.

If these high energies scramble and reset the basic properties of matter, then each island can be thought of as a new universe with different properties. We’ve made a multiverse.

Everything Everywhere All At Once (2022) is about a regular woman trying to get her taxes done, who must also battle an evil that spans across the multiverse. Credit: IMDB

So is there a Multiverse?

In the cycle of the scientific method, the multiverse is in an exploratory phase. We’ve got an idea that might explain a few things, if it was true. That makes it worthy of our attention, but it’s not quite science yet. We need to find evidence that is more direct, more decisive.

Something left over from the aftermath of the multiverse generator might help. A multiverse idea could also predict the winning numbers on our lottery ticket.

However, as Dr. Strange explains, “The multiverse is a concept about which we know frighteningly little.”

Written by Luke Barnes, Lecturer in Physics, Western Sydney University.

This article was first published in The Conversation.

Nature Communications (2022). DOI: 10.1038/s41467-022-30324-5″ width=”800″ height=”488″/>

By applying light, University of Arkansas physicists Peng Chen and Laurent Bellaiche have discovered a surprising mechanism for controlling ferroelectric polarization in a deterministic manner.

The finding, made possible by the application of ultrafast laser pulses, enriches fundamental physics research by advancing an understanding of the interactions between light and matter.

The research, published May 10 in Nature Communicationsis also an important step toward the design and development of superior sensing and data storage in electronic devices.

Ferroelectric materials exhibit ferroelectricity and the ability to polarize spontaneously. Typically, researchers can manipulate and reverse this polarization by the application of an external electric field. Ultrafast interactions between light and matter are another promising route for controlling ferroelectric polarization, but until now researchers have struggled to achieve a light-induced, deterministic control of such polarization.

The researchers discovered a so-called “squeezing effect” in ferroelectric materials subject to femtosecond laser pulses. A femtosecond is one quadrillionth of a second. These pulses destroyed the polarization component that is parallel to the field’s direction and created polarization components perpendicular to it. This squeezing effect allowed a deterministic control of the polarization by light.

“The applied terahertz pulse prefers to annihilate the polarization component along the field’s direction, in favor of components perpendicular to the field associated with the pulses,” said Peng, a research associate in Bellaiche’s laboratory and the first author of the paper. “We consider this a novel terahertz phenomenon when light interacts with ferroelectric materials. Our findings should stimulate technical progress.”

Chen and Bellaiche, Distinguished Professor of Physics, collaborated with colleagues Charles Paillard and Hongjian Zhao, former research associates in Bellaiche’s laboratory, and Jorge Íñiguez at the Luxembourg Institute of Science and Technology. Researchers in Bellaiche’s laboratory study various properties of different materials.

A tropical spider species uses a “film” of air to hide underwater from predators for as long as 30 minutes, according to faculty at Binghamton University, State University of New York.

Lindsey Swierk, assistant research professor of biological sciences at Binghamton University, State University of New York, observed a large tropical spider (Trechalea tarda) fleeing from humans and hiding underwater; this species was not previously known to use water to escape. Swierk had previously observed a Costa-Rican lizard species that was able to stay underwater for 16 minutes to hide from predators.

“For a lot of species, getting wet and cold is almost as risky to survival as dealing with their predators to begin with,” said Swierk. “Trechalea spiders weren’t previously known to hide underwater from threats—and certainly not for so long.”

The spider spent about 30 minutes underwater. While submerged, it kept a “film” of air over its entire body. Swierk and her colleagues suspect that the fuzzy hairs that cover its body help it to maintain this film of air, which helps to prevent thermal loss while underwater, or to prevent water from entering the spider’s respiratory organs.

“The film of air surrounding the spider when it is underwater appears to be held in place by hydrophobic hairs covering the spider’s entire body surface,” said Swierk. “It’s so complete that the spider almost looks like it’s been dipped in silver. The film of air might serve to keep the respiratory openings away from water, since these spiders are air-breathing. The film of air might also help to minimize thermal loss to the cold stream water that the spider submerges itself in.”

According to Swierk, this observation provides new insight into how species can cope with the problem of finding refuge underwater.

“These spiders, and any animal hiding from predators in general, have to do their best to manage risk,” said Swierk. “Risk of predation, yes, but also risk of the costs they’ll experience by fleeing. For some species that means leaving territory or mates unguarded, or maybe spending stored energy in a sprint. In this species, potential risks of underwater refuge use can include lack of respiration and a loss of body heat.There are many more questions to dig into starting from this first observation.”

The research was published in ethology.

For centuries, black holes were merely theoretically speculative ideas.

This tiny sliver of the GOODS-N deep field, imaged with many observatories including Hubble, Spitzer, Chandra, XMM-Newton, Herschel, the VLT and more, contains a seemingly unremarkable red dot. That object, a quasar-galaxy hybrid from just 730 million years after the Big Bang, may be key to unlocking the mystery of galaxy-black hole evolution. Once speculative, the evidence for the physical existence and ubiquity of black holes is now overwhelming.

The concept first appeared in 1783, when John Michell proposed them.

This image of the Sun, taken on April 20, 2015, shows a number of features common to all stars: magnetic loops, prominences, plasma filaments, and regions of higher and lower temperatures. The Sun is less dense than the Earth, but much larger and more massive, and has a much greater escape velocity from its surface than Earth possesses. If the Sun maintained the same density but were 500 times its present mass, with the corresponding increase in volume, it would itself collapse to a black hole, as first shown in 1783 by John Michell, even in Newtonian gravity.

If you maintained the Sun’s density but increased its mass, light couldn’t escape above ~500 solar masses.

Inside a black hole, the spacetime curvature is so large that light cannot escape, nor can particles, under any circumstances. A singularity, based on our current laws of physics, must be an inevitability, although the nature of that singularity is not well understood within the context of General Relativity alone.

Although none were observed, the idea resurged with Karl Schwarzschild’s 1916 solution within Einstein’s General Relativity.

If you begin with a bound, stationary configuration of mass, and there are no non-gravitational forces or effects present (or they’re all negligible compared to gravity), that mass will always inevitably collapse down to a black hole. It’s one of the main reasons why a static, non-expanding Universe is inconsistent with Einstein’s relativity.

With enough mass in a given spatial volume, collapse to a black hole becomes unavoidable.

From outside a black hole, all the infalling matter will emit light and is always visible, while nothing from behind the event horizon can get out. But if you were the one who fell into a black hole, your energy could conceivably re-emerge as part of a hot Big Bang in a newborn Universe; the connection between black holes and the birth of new Universes is still speculative, but is dismissed at our own peril.

In 1963, Roy Kerr enhanced Schwarzschild’s solution to incorporate rotation.

Even for a complicated entity like a massive, rotating black hole (a Kerr black hole), once you cross the (outer) event horizon, regardless of what type of matter or radiation you’re composed of, you’ll fall towards the central singularity and add to the black hole’s mass. What happens at the central singularity is not well-described by current physics, however, as its behavior is pathological.

Contemporaneously, suggestive “black hole” evidence appeared with the discovery of the first quasars.

The radio feature of the galaxy Alcyoneus includes a central, active black hole, collimated jets, and two giant radio lobes at either end. The Milky Way is shown at the bottom for scale, as well as “10x the Milky Way” for perspective.

These extragalactic QUAsi-StellAr Radio Sources (QUASARs) were ultra-distant, but shone brilliantly in radio light and beyond.

This illustration of a radio-loud quasar that is embedded within a star-forming galaxy gives a close-up look of how giant radio galaxies are expected to emerge. At the center of an active galaxy with a supermassive black hole, jets are emitted that slam into the larger galactic halo, energizing the gas and plasma and causing radio emissions in the form of jets close by the black hole, and then plumes and/or lobes farther away. Both supermassive and stellar-mass black holes have overwhelming evidence supporting their existence.

Then Cygnus X-1, an X-ray emitting black hole candidate, was found within the Milky Way.

Discovered in 1964 as an X-ray emitting source consistent with a stellar object orbiting a black hole, Cygnus X-1 represents the first black hole candidate known within the Milky Way. Cygnus X-1 is located near large active regions of star formation in the Milky Way: precisely the location expected to find an X-ray emitting black hole binary.

Meanwhile, Roger Penrose demonstrated, astrophysically, how black holes could pragmatically form in our Universe.

When matter collapses, it can inevitably form a black hole. Penrose was the first to work out the physics of spacetime, applicable to all observers at all points in space and at all instants in time, that governs a system such as this. His conception of it has been the gold standard in General Relativity ever since.

John Wheeler gave the name “black holes” in 1968.

This three-panel view showcases the central region of galaxy Messier 87, home to the largest black hole (of about 6.5 billion solar masses) known within ~100 million light-years of us. The optical jet (top), radio lobes (lower left), and ultra-hot X-ray emitting signatures (lower right) all indicate the presence of an ultramassive black hole, recently confirmed by the Event Horizon Telescope’s direct measurements.

Once speculative, the modern case for them is overwhelming.

This view of the cocoon surrounding the Milky Way’s galactic center is only ~10 light-years across, but contains and is possibly powered by our central, supermassive black hole that weighs in at ~4 million times the mass of our Sun.

X-ray emissions appear from accelerating, infalling, accreted matter.

On September 14, 2013, astronomers caught the largest X-ray flare ever detected from the supermassive black hole at the center of the Milky Way, known as Sagittarius A*. The emission coming from the black hole in many wavelengths of light have hinted at its properties, but there’s no substitute for a direct observation of its event horizon.

Individual stars orbit these massive, non-luminous objects.

This 20-year time-lapse of stars near the center of our galaxy comes from the ESO, published in 2018. Note how the resolution and sensitivity of the features sharpen and improve toward the end, all orbiting our galaxy’s (invisible) central supermassive black hole. Practically every large galaxy, even at early times, is thought to house a supermassive black hole, but only the one at the center of the Milky Way is close enough to see the motions of individual stars around it.

Gravitational waves arise from both inspirals

The most up-to-date plot, as of November, 2021, of all the black holes and neutron stars observed both electromagnetically and through gravitational waves. As you can clearly see, there is no “gap” between 2 and 5 solar masses any longer; rather, that population exists, and is likely composed of black holes that formed from the mergers of neutron stars, consistent with the event of August 17, 2017.

and mergers.

When two neutron stars collide, if their total mass is great enough, they won’t just result in a kilonova explosion and the ubiquitous creation of heavy elements, but will lead to the formation of a novel black hole from the post-merger remnant. Gravitational waves and gamma-rays from the merger appear to travel at indistinguishable speeds: the speed of all massless particles.

And photon emissions now reveal their horizons,

Size comparison of the two black holes imaged by the Event Horizon Telescope (EHT) Collaboration: M87*, at the heart of the galaxy Messier 87, and Sagittarius A* (Sgr A*), at the center of the Milky Way. Although Messier 87’s black hole is easier to image because of the slow time variation, the one around the center of the Milky Way is the largest as viewed from Earth.

including polarizations,

Polarized view of the black hole in M87. The lines mark the orientation of polarization, which is related to the magnetic field around the shadow of the black hole. Note how much swirlier this image appears than the original, which was more blob-like. It’s fully expected that all supermassive black holes will exhibit polarization signatures imprinted upon their radiation.

directly. Welcome to the golden age for black holes.

The time-averaged data from multiple different points in time that show a series of snapshots in the evolution of the radiation coming from Sagittarius A*. The “average” image structure belies the rapid time-evolution of the radiation around this object.

Mostly Mute Monday tells an astronomical story in images, visuals, and no more than 200 words. Talkless; smile more.

An enormous hole 22 meters in diameter has been dug near the summit of Cerro Chajnantor in Chile’s Atacama Desert, at an elevation of 18,400 feet. The hole stands ready for the cement foundation on which the Fred Young Submillimeter Telescope (FYST, pronounced “feest”) will one day rest. The foundation, which was designed in Chile, began construction in the fall of 2021 and is scheduled to be installed at the summit from May to June.

The entire telescope is being constructed and pre-assembled in Germany, and will be disassembled into 10–12 large pieces and transported to Chile for reassembly. The road that will carry the massive parts of the telescope to the summit has now been laid, and installation of the more than nine kilometers of power and optical fiber cables is already underway.

“We’re very excited by how well the construction is proceeding,” said Terry Herter, project director and professor of astronomy at the College of Arts and Sciences. “Despite COVID-19, labor shortages and supply chain challenges, we’re anticipating first light in 2024.”

The FYST features a novel optical design with high precision mirrors 6-meters (nearly 20-ft) in diameter. It will deliver a high-throughput, wide-field of view that will be able to map the sky rapidly and efficiently at submillimeter to millimeter wavelengths. Project scientists are looking forward to collecting data that will give them insight into the universe’s earliest days, when the first stars were born after the Big Bang—what researchers call “cosmic dawn.” It will also play a role in the search for gravitational waves and dark matter.

“From my own knowledge of these things, physics is not something that girls tend to fancy. They don’t want to do it … There’s a lot of hard math in there that I think that they would rather not do,” Katharine Birbalsingh, chair of the UK government’s Social Mobility Commission and a secondary school head teacher, told the Commons Science and Technology Committee on April 27 2022.

Comments like this are extremely disappointing. There are multiple reasons why girls don’t choose to study physics at A-level or for a degree—and “not wanting to do math” is not one of them.

Instead, the reasons include getting less support from teachers and parents and stereotypes about who generally takes these subjects.

Comparing achievement

Birbalsingh commented that “hard math” was stopping girls taking physics. If this were the case, though, we would expect to see far fewer girls taking math. However, in 2019, 39% of A-Level exam entrants in math were girls, compared to 23% in physics. This shows that the reasons girls don’t take physics have more to do with physics than math.

What’s more, girls and boys achieve similar grades in math and physics. In 2019—the last year standard exams were set—8.5% of girls achieved an A* in Physics A-level compared to 8.8% of boys; 28.7% of girls and 27.6% of boys scored an A grade. The same pattern can be seen in GCSE results. But more boys than girls choose to go on to study science at a higher level.

My guess is that our girls who haven’t chosen to do physics and instead chose biology and chemistry is that they don’t want to do the hard maths in physics

Why should we force them to do physics when they don’t want to?

Those who want to, are thriving in physics- that’s great!

— Katharine Birbalsingh (@Miss_Snuffy) April 27, 2022

The ASPIRES project has followed a group of students from the age of 10 to young adulthood, studying their ambitions related to science. The project has found that, throughout secondary school, boys are more likely than girls to say they would like to become a scientist. This difference increased over the course of secondary school, with the biggest gap being found in year 13.

There is evidence that the expectations placed on pupils by teachers plays a large role in which students go on to take physics at higher levels. The ASPIRES project found that from ages ten to 18, boys were significantly more likely than girls to say that their teacher expected them to do well in science, and to feel that their teacher was interested in whether they understood science. The research found that girls often did not feel “clever enough” to do physics, even though girls achieve similar grades to boys.

Gender stereotypes

In physics the stereotype is that boys are naturally better at it than girls, and this messaging is still being passed on (both intentionally and unintentionally) to our young people in school, in their home lives and through the media. A well known example is the television show the Big Bang Theory, which features four male physicists and engineers and their ditsy female neighbor.

These findings are backed up by the Institute of Physics’ (IOP) Limit Less report, which found that girls are often told that physics is more suited to boys.

Another report by the IOP shows that in single-sex schools a greater proportion of girls took physics than in coeducational schools, across both the state and private school system. In environments where gendered messaging is lessened, the participation rate of girls increases.

It is vitally important to remove the barriers to girls’ participation in physics. We are part of the South East Physics Network (SEPnet), a collaboration of nine university physics departments working together to promote excellence in physics with a focus on diversity.

At SEPnet we created the Shattering Stereotypes program in 2017 to raise awareness among students of gendered stereotyping in subject choice, and equip them with tools to be resilient to this. We also provide teacher training in this area to support teachers’ awareness of the damage gender stereotypes and gendered language can have, and to provide them with resources and tools to combat them.

The IOP runs multiple projects to address the gender imbalance in physics. Their Limit Less campaign supports young people from all backgrounds to fulfill their potential by doing physics. The Improving Gender Balance Project is a research project working with schools to identify ways to improve balance across the school environment.

In spite of all of this, Birbalsingh’s remarks show that we have a long way to go to normalize the idea that both girls and boys are capable of, and inherently interested in, studying physics. As a society we need to shift our perceptions on the relationship between gender and STEM subjects such as physics.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Credit: SLAC National Accelerator Laboratory

The new facility, LCLS-II, will soon sharpen our view of how nature works on ultrasmall, ultrafast scales, impacting everything from quantum devices to clean energy.

Nestled 30 feet underground in Menlo Park, California, a half-mile-long stretch of tunnel is now colder than most of the universe. It houses a new superconducting particle accelerator, part of an upgrade project to the Linac Coherent Light Source (LCLS) X-ray free-electron laser at the Department of Energy (DOE)’s SLAC National Accelerator Laboratory.

Crews successfully cooled the accelerator to minus 456 degrees[{” attribute=””>Fahrenheit – or 2 kelvins – a temperature at which it becomes superconducting and can boost electrons to high energies with nearly zero energy lost in the process. It is one of the last milestones before LCLS-II will produce X-ray pulses that are 10,000 times brighter, on average, than those of LCLS and that arrive up to a million times per second – a world record for today’s most powerful X-ray light sources.

SLAC’s linac at sunrise, looking east. Since the Department of Energy’s SLAC National Accelerator Laboratory powered up its “linac” half a century ago, the 2-mile-long particle accelerator has driven a large number of successful research programs in particle physics, accelerator development, and X-ray science. Now, the historic particle highway new makeover will pave the way for more groundbreaking research. Credit: Olivier Bonin/SLAC National Accelerator Laboratory

“In just a few hours, LCLS-II will produce more X-ray pulses than the current laser has generated in its entire lifetime,” says Mike Dunne, director of LCLS. “Data that once might have taken months to collect could be produced in minutes. It will take X-ray science to the next level, paving the way for a whole new range of studies and advancing our ability to develop revolutionary technologies to address some of the most profound challenges facing our society.”

With these advanced new capabilities, scientists can examine the details of complex materials with unprecedented resolution to drive new forms of computing and communications; reveal rare and fleeting chemical events to teach us how to create more sustainable industries and clean energy technologies; investigate how biological molecules carry out life’s functions to develop new types of pharmaceuticals; and peer into the bizarre world of quantum mechanics by directly measuring the motions of individual atoms.

A chilling feat

LCLS, the world’s first hard X-ray free-electron laser (XFEL), produced its first light in April 2009, generating X-ray pulses a billion times brighter than anything that had come before. It accelerates electrons through a copper pipe at room temperature, which limits its rate to 120 X-ray pulses per second.

In 2013, SLAC launched the LCLS-II upgrade project to increase that rate to a million pulses and make the X-ray laser thousands of times more powerful. For that to happen, crews removed part of the old copper accelerator and installed a series of 37 cryogenic accelerator modules, which house pearl-like strings of niobium metal cavities. These are surrounded by three nested layers of cooling equipment, and each successive layer lowers the temperature until it reaches nearly[{” attribute=””>absolute zero – a condition at which the niobium cavities become superconducting.

“Unlike the copper accelerator powering LCLS, which operates at ambient temperature, the LCLS-II superconducting accelerator operates at 2 kelvins, only about 4 degrees Fahrenheit above absolute zero, the lowest possible temperature,” said Eric Fauve, director of the Cryogenic Division at SLAC. “To reach this temperature, the linac is equipped with two world-class helium cryoplants, making SLAC one of the significant cryogenic landmarks in the U.S. and on the globe. The SLAC Cryogenics team has worked on site throughout the pandemic to install and commission the cryogenic system and cool down the accelerator in record time.”

Cutaway image of a cryomodule. Each large metal cylinder contains layers of insulation and cooling equipment, in addition to the cavities that will accelerate electrons. The cryomodules are fed liquid helium from an aboveground cooling plant. Microwaves reach the cryomodules through waveguides connected to a system of solid-state amplifiers. Credit: Greg Stewart/SLAC National Accelerator Laboratory

One of these cryoplants, built specifically for LCLS-II, cools helium gas from room temperature all the way down to its liquid phase at just a few degrees above absolute zero, providing the coolant for the accelerator.

On April 15, the new accelerator reached its final temperature of 2 K for the first time and today, May 10, the accelerator is ready for initial operations.

“The cooldown was a critical process and had to be done very carefully to avoid damaging the cryomodules,” said Andrew Burrill, director of SLAC’s Accelerator Directorate. “We’re excited that we’ve reached this milestone and can now focus on turning on the X-ray laser.”

The linac is equipped with two world-class helium cryoplants. One of these cryoplants, built specifically for LCLS-II, cools helium gas from room temperature all the way down to its liquid phase at just a few degrees above absolute zero, providing the coolant for the accelerator. Credit: Greg Stewart/SLAC National Accelerator Laboratory

Bringing it to life

In addition to a new accelerator and a cryoplant, the project required other cutting-edge components, including a new electron source and two new strings of undulator magnets that can generate both “hard” and “soft” X-rays. Hard X-rays, which are more energetic, allow researchers to image materials and biological systems at the atomic level. Soft X-rays can capture how energy flows between atoms and molecules, tracking chemistry in action and offering insights into new energy technologies. To bring this project to life, SLAC teamed up with four other national labs – Argonne, Berkeley Lab, Fermilab and Jefferson Lab – and Cornell University.

Jefferson Lab, Fermilab and SLAC pooled their expertise for research and development on cryomodules. After constructing the cryomodules, Fermilab and Jefferson Lab tested each one extensively before the vessels were packed and shipped to SLAC by truck. The Jefferson Lab team also designed and helped procure the elements of the cryoplants.

Fermilab cryomodule F3.9-02, installed inside of LCLS-II. Credit: Jacqueline Orrell/SLAC National Accelerator Laboratory

“The LCLS-II project required years of effort from large teams of technicians, engineers, and scientists from five different DOE laboratories across the U.S. and many colleagues from around the world,” says Norbert Holtkamp, SLAC deputy director and the project director for LCLS-II. “We couldn’t have made it to where we are now without these ongoing partnerships and the expertise and commitment of our collaborators.”

Toward first X-rays

Now that the cavities have been cooled, the next step is to pump them with more than a megawatt of microwave power to accelerate the electron beam from the new source. Electrons passing through the cavities will draw energy from the microwaves so that by the time the electrons have passed through all 37 cryomodules, they’ll be moving close to the speed of light. Then they’ll be directed through the undulators, forcing the electron beam on a zigzag path. If everything is aligned just right – to within a fraction of the width of a human hair – the electrons will emit the world’s most powerful bursts of X-rays.

This is the same process that LCLS uses to generate X-rays. However, since LCLS-II uses superconducting cavities instead of warm copper cavities based on 60-year-old technology, it can can deliver up to a million pulses per second, 10,000 times the number of X-ray pulses for the same power bill.

Now that the cavities have been cooled, the next step is to pump them with more than a megawatt of microwave power to accelerate the electron beam from the new source. Electrons passing through the cavities will draw energy from the microwaves so that by the time the electrons have passed through all 37 cryomodules, they’ll be moving close to the speed of light. Credit: Greg Stewart/SLAC National Accelerator Laboratory

Once LCLS-II produces its first X-rays, which is expected to happen later this year, both X-ray lasers will work in parallel, allowing researchers to conduct experiments over a wider energy range, capture detailed snapshots of ultrafast processes, probe delicate samples and gather more data in less time, increasing the number of experiments that can be performed. It will greatly expand the scientific reach of the facility, allowing scientists from across the nation and around the world to pursue the most compelling research ideas.

This project is supported by DOE’s Office of Science. LCLS is a DOE Office of Science user facility.

You’ve got yourself a fancy new spaceship and you want to start on a five-year tour of the galaxy. But there’s a problem: Space is big. Really big. And even at the fastest speeds imaginable, it takes eons of crawling across the interstellar voids to get anywhere interesting.

The solution? It’s time to build a wormhole.

A shortcut. A tunnel. A bridge through spacetime that lets you skip through all that boring space travel and speed to the fun stuff. It’s a staple of science-fiction, and it’s rooted in science-fact. How difficult could it be?

Here’s a hint: incredibly difficult.

Option #1: The Einstein-Rosen Bridge

The first step is to understand that wormholes are totally legit in the mathematics of general relativity (GR). We’re using GR because that’s our language of gravity, and Albert Einstein’s brilliant mathematical engine is relatively straightforward. Einstein realized that while we experience gravity as a force, it’s really just the sensation we feel as we’re forced to navigate the bumps, wiggles, and undulations of spacetime. Those same bumps, wiggles, and undulations come from the distribution of matter and energy in that same spacetime.

Matter tells spacetime how to bend; the bending of spacetime tells matter how to move.

If we want to build a tunnel in spacetime—a wormhole—we need to discover some arrangement of matter and/or energy that bends spacetime just so, ensuring that a tunnel will appear. With general relativity as a guide, we need to find a solution to its equations that permits the existence of a wormhole.

And at first glance, we might think that the simplest way to build a wormhole is to build a black hole.

Black holes are regions of spacetime that are cut off from the rest of the Universe. They are punctures in spacetime itself—a point of infinite density known as a singularity, wrapped in a one-way barrier called the event horizon. Once you cross the event horizon, the inrush of gravity is so overwhelming that nothing, not even light, can escape. Indeed, it’s more than a one-way trip; it’s a straight-up highway to a (singular) hell. Once you enter a black hole, you’re guaranteed to reach the singularity—and your doom—in a finite amount of time.

The black hole solution appears in GR as the answer to a very simple question: What happens when you squish matter down to such a high density that no other force is strong enough to counteract it? Boom—black hole.

But black holes are not the only answer to that question. The math of GR permits the complete opposite of a black hole, known affectionately as a white hole. White holes also have a singularity at the center, but their event horizons work in reverse—nothing can enter a white hole, and anything inside the white hole when it forms will quickly find itself flung outward faster than the speed of light.

What does all of this have to do with black holes? Looking at the bare math of GR, when you form a black hole, you automatically get a white hole attached to it. And a connected pair of black and white holes automatically forms a wormhole because of that same baked-in math.

These are called Einstein-Rosen Bridges (or, if you’re feeling fancy, a maximally extended Schwarzschild metric), after Einstein and his collaborator, Nathan Rosen. This solution appears in GR as plain as day.

black hole blues

There are two small problems with this setup, however.

First, white holes almost certainly don’t exist. They are energetically highly unstable. The problem is the reverse-event horizon, which can never let anything in from the outside but constantly spews things out. Since a white hole is exactly equivalent to a black hole but runs backward in time, an evolving white hole would look like the formation of a black hole but in reverse: the white hole doing its thing until it loses enough mass and spontaneously forms a star .

You can’t spontaneously form a star just because you feel like it, because that would violate the second law of thermodynamics.

So white holes are out.

This means that if you try to leave the clean, sterilized condition of GR’s math behind and attempt to form a black hole in the real world, the white hole never really happens. All the material you would use to form the white hole strangles it in the womb using its own gravitational umbilical cord, cutting off its formation and leaving behind just the black hole.

If you were somehow able to construct a white/black hole pair, you would technically have a wormhole. It just wouldn’t be a very fun one.

The problem with Einstein-Rosen bridges is that the wormhole entrance itself sits within the event horizon of the black hole. You must pass through that one-way barrier to continue on your wormhole journey. But the very nature of the event horizon means you can’t leave once you enter, and you will hit the singularity in the center no matter what.

This result comes from the same mathematics that allows the existence of the wormhole in the first place, so there’s no getting out of this trap.

Yes, someone could jump in from the other side, perhaps from a distant corner of the Universe. And you could meet and share a brief conversation before hitting the singularity. You could even hold hands as you reach annihilation.

Irvine, Calif., May 11, 2022 — Before his tragic death in 2019, José Flores-Velázquez was a brilliant astrophysics Ph.D. student in the Department of Physics & Astronomy at the University of California, Irvine. In his memory of him, UCI professor Virginia Trimble, School of Physical Sciences dean James Bullock (who was Flores-Velázquez’s advisor) and longtime school supporters John and Ruth Ann Evans have established an endowed award fund to support incoming or current astrophysics graduate students.

Bullock, who is also a professor of physics & astronomy, hopes the awards will create an enduring legacy for his former student, who studied star formation in distant galaxies.

“José was a shining light in my research group,” Bullock said. “He was brilliant, quick to laugh and a true inspiration. I have spent most weekends back home, with his family and giving back to his community. It broke my heart when he died – but my hope is that, through this new fund, his light from him can continue to shine for others.”

Flores-Velázquez was born Dec. 4, 1994, in South Los Angeles, and grew up in the area near Hooper and Central avenues. He received his bachelor’s degree from California State Polytechnic University Pomona, where he was a first-generation student. He came to UCI in 2018, and died the following August in a drive-by shooting in LA while delivering gifts for a friend’s baby shower.

Flores-Velázquez received a posthumous master’s degree from UCI.

Alex Gurvich, a Ph.D. student at Northwestern University who mentored Flores-Velázquez during a 10-week National Science Foundation Research Experience for Undergraduates in 2017, stepped in to finish the research that Flores-Velázquez started when they met.

“One thing that was really important to me was that there be something people could cite that said ‘Flores-Velázquez et al,’” Gurvich said. “I wanted to do this.”

Gurvich said Flores-Velázquez’s paper, which appeared in Monthly Notices of the Royal Astronomical Society in December 2020, it was more than 90 percent completed at the time of his death. The topic was a question that had long stumped astrophysicists: How fast do stars in galaxies form?

The answer that Flores-Velázquez developed lies in the light coming from a galaxy’s stars. Galaxies where new stars are forming give off light at a specific wavelength. Before his paper by him, when astronomers spotted such light, they broadly said the galaxy had been making new stars at a constant rate for the past 100 million years. Thanks to Flores-Velázquez’s work, astrophysicists now know the rate of star formation can be as short as 15 million years – a much finer-resolution timeline.

Flores-Velázquez was passionate about his heritage and committed to academic excellence. His eponymous award from him will ensure that his name from him is not forgotten and that graduate students who embody his spirit from him will shine well into the future. Community supporters can boost his legacy of him by contributing to the Flores-Velázquez endowment through this online donation form.

About the UCI’s Brilliant Future campaign: Publicly launched on Oct. 4, 2019, the Brilliant Future campaign aims to raise awareness and support for UCI. By engaging 75,000 alumni and garnering $2 billion in philanthropic investment, UCI seeks to reach new heights of excellence in student success, health and wellness, research and more. The School of Physical Sciences plays a vital role in the success of the campaign. Learn more by visiting: https://brilliantfuture.uci.edu/uci-school-of-physical-sciences/.

About the University of California, Irvine: Founded in 1965, UCI is the youngest member of the prestigious Association of American Universities and is ranked among the nation’s top 10 public universities by U.S. News & World Report. The campus has produced five Nobel laureates and is known for its academic achievement, premier research, innovation and anteater mascot. Led by Chancellor Howard Gillman, UCI has more than 36,000 students and offers 224 degree programs. It’s located in one of the world’s safest and most economically vibrant communities and is Orange County’s second-largest employer, contributing $7 billion annually to the local economy and $8 billion statewide. For more on ICU, visit www.uci.edu.

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