Huge Gravitational Waves Discovery Gets the Nobel Prize It Deserves

Post 8541

Huge Gravitational Waves Discovery Gets the Nobel Prize It Deserves
Image: NASA/CXC/A.Hobart/Wikimedia Commons

The Nobel Prizes are important and all. But if you’ve been paying attention to physics for the past two years, this year’s prize is akin to saying “my beautiful dog has won the Good Boy prize.” We’re very excited, but we aren’t surprised.

Today, the Royal Swedish Academy of Sciences has awarded the 2017 Nobel Prize in Physics half to Rainer Weiss and half jointly to Barry C. Barish and Kip S. Thorne, all from the LIGO/VIRGO Collaboration, “for decisive contributions to the LIGO detector and the observation of gravitational waves.”

These waves have a long story behind them. Back in 1915, Albert Einstein published his famous theory of general relativity, the one that says that massive things can distort the shape of space itself. He, and others, proposed that the force of gravity itself should be able to ripple through space, changing its shape like as it traveled like a wave through a pond . Einstein later came to doubt the existence of gravitational waves, but another physicist spotted an error in his work. By the 1950s, even before theorists accepted the existence of the waves’ most apparent sources (black holes), scientists had proven mathematically that these gravitational waves should be out there, according to the Nobel committee’s Scientific Background statement.

Tantalizing hints followed. In 1969, Joseph Weber from University of Maryland claimed a discovery in a small detector, a bar floating on liquid with special crystals meant to convert vibrational energy to electricity. But similar experiments in the 1970s couldn’t recreate the results. If scientists wanted to prove the existence of the waves, they’d need to go bigger, and build something more sensitive.

Thorne and Weiss were dedicated to finding the waves, and designed a new detector. After some bureaucratic and planning hiccups, it was Barish who saw the construction to its completion. This resulted in a pair of several-kilometer-long, L-shaped experiments called the Laser Interferometer Gravitational Wave Observatories in Louisiana and Washington State, that cost the United States’ National Science Foundation several hundreds of millions of dollars. These detectors consist of a laser beam split down each pipe’s length, bouncing off mirrors and returning to a single spot where their light waves cancel each other out. A gravitational wave should make the beams vibrate in and out of phase with each other the tiniest amount, creating a little bit of light that shines into a new detector.

Then, on Sept. 14, 2015, almost immediately after a major upgrade, ripples from a pair of colliding black holes 29 and 36 times the mass of our own Sun 1.3 billion light years away arrived on planet Earth, showing up as a tiny vibrations in the data, with an amplitude far smaller than an atom. The team announced their discovery on February 11, 2016. It was very exciting and we clapped a lot.

This might sound like the end of the story, but is in fact the beginning; since then, several more waves have been detected from other pairs of colliding black holes, and a third detector sensitive enough to spot the waves called Virgo has joined the mix. Lots of physicists are dreaming up new ways to use the detectors to discover more exotic things like the elusive dark matter or tobetter understand black holes. Rumors are swelling about potential new sources of gravitational waves that might also come with corresponding light waves that more traditional telescopes can spot.

In the current era, some scientists are re-thinking how the Physics prize is awarded. The Royal Swedish Academy can only award the Nobel Prize in Physics to a maximum three people, but some experiments often feature a thousand physicists working hard to keep the science happening. And rather than single discoveries, there is often lots of incremental work that eventually sums into a larger understanding of the universe, Princeton physicist Shivaji Sondhi and Stanford physicist Steven Kivelson wrote in an editorial published recently in Nature Physics. They propose offering the prize to more people simultaneously, identifying the most important scientists to a given effort, or even creating a prize that instead rewards scientists for cumulative lifetime achievement.

Last year, Science magazine guessed Weiss and Thorne would win, and lamented that Barish might not receive the reward.

Now that LIGO has received their award, the real question is: What will they discover next?

[The Royal Swedish Academy of Sciences]


A Beautiful Illustration of Something Quite Horrible

Post 8540

A Beautiful Illustration of Something Quite Horrible

Two Zika particles at work (Image: David S. Goodsel/RCSB Protein Data Bank)

Up until a few months ago, we knew virtually nothing about the Zika virus—or what it even looked like. But a beautiful new illustration by David S. Goodsell reveals its hidden details, while also showing how the dreaded virus goes to work.

Scientists have been hard at work trying to untangle the mystery that is the Zika virus this year. The pathogen was discovered in Uganda back in 1947, but it wasn’t considered dangerous. Things have changed after Zika was linked to birth defects, and the virus is now propagating through parts of South and Central America at epidemic levels.

The Zika virus has been officially linked to microcephaly, a condition in which fetal brains grown abnormally small, as well as Guillain Barre syndrome, a rare disorder that causes temporary paralysis. Insidiously, Zika can breach the placental barrier and disrupt the development of the fetal brain.

Two Zika particles at work (Image: David S. Goodsel/RCSB Protein Data Bank)

Back in May, cryo-electron microscopy finally uncovered the virus’s appearance. In the artistic rendering above, molecular biologist David S. Goodsell from the Scripps Institute used color and shape to convey the virus’s appearance and function.

The spherical structures (shown in pink) represent a pair of Zika virus particles in a blood vessel filled with blood plasma cells (tan). Both particles are on the verge of penetrating a cell (blue), and they’re binding to the cell’s protein receptors (green).

The virus at the bottom right is a cross section of a Zika particle. The illustration shows viral proteins (red) protruding like studs from its outer surface, with membrane proteins (pink) embedded within a fatty layer of lipids (light purple). These studs, of which there about 180, protrude from the particle, allowing it to bind itself to certain human cells, including antibodies and host receptors. This also explains why the virus can attack nerve cells and critical cells required for normal fetal development. The viral genome itself can be seen deep inside the particle (yellow) coiled around capsid proteins (orange).

Zika is actually quite similar in appearance and function to other flaviviruses, such as dengue, West Nile, and yellow fever. This is actually good news, because it means that ongoing efforts to create vaccines for these related viruses could be applied to Zika.


Here Are Some Incredible Images Made Possible by This Year’s Chemistry Nobel Prize

Post 8539

Here Are Some Incredible Images Made Possible by This Year’s Chemistry Nobel Prize

Today’s resolution of cryo microscopy illustrated by this glutamate dehydrogenase molecule (Image: Martin Högbom/The Royal Swedish Academy of Sciences)

Science, at its core, is a process. New advances in technology are as important as new discoveries they lead to. How can you understand a molecule, for example, if you can’t see it?

Like yesterday’s physics prize, today, the Royal Swedish Academy of Sciences is giving the prize not to theorists who devised a crazy, later-proven idea or to those who did the analysis for a major discovery. Instead, they awarded scientists for developing experimental methods. In this case, the winners are Jacques Dubochet from the University of Lausanne, Switzerland, Joachim Frank from Columbia University in New York, and Richard Henderson from the MRC Laboratory of Molecular Biology in Cambridge, for “developing cryo-electron microscopy for the high-resolution structure determination of biomolecules in solution.” They found a big new way to look at little things.

The researchers’ combined efforts led to major advances in how scientists use electron microscopes today—the microscopes that can image down to the atomic level. Henderson imaged a protein in three dimensions down to the atomic level. Frank found a way to fuse two-dimensional images to develop 3D ones. And Dubochet found a way to add water and quickly freeze samples without crystalizing, essentially making a glass to capture molecules mid-movement without destroying them.

It’s important to note that lots of folks in the science community have been grumbling about the science Nobel Prizes for various reasons, including its lack of winner diversity and the fact that they’ve to begun to feel a little outdated. We summarized it here, and The Atlantic wrote a more in-depthtake here.

The winning research has allowed the field to explode with new scientists making important discoveries with these techniques who may win awards themselves, though. So we’ve gathered a few of the best cryo-electron microscopy images we could find.

Cryo EM images of the φKZ virus (Fokine et al, Structure (2007))
And illustration of the complexity of the Zika Virus (Image: The Royal Swedish Academy of Sciences)
Cyanobacteria embedded in ice, some beginning to show their DNA coalesce into chromosomes (arrows) (Murata et al, Scientific Reports (2016))
A/B: Chromosomes C/D: Cells (image: Maeshima et al, J. Biochem (2008))
A/B: The Cafeteria roenbergensis virus C: Its relative, the Acanthamoeba polyphaga mimivirus (Image: Xiao et al, Scientific Reports (2017))
A closeup of the ATP synthase molecule, an enzyme required for making the ubiquitous energy molecule, ATP (Image: Dudkina et al, FEBS Letters (2010))


Massive Calved Iceberg Comes into View as Antarctic Sun Rises

Post 8538

Massive Calved Iceberg Comes into View as Antarctic Sun Rises

Massive Calved Iceberg Comes into View as Antarctic Sun Rises
Instruments aboard the Landsat 8 satellite captured these visible and thermal images on Sept. 16, 2017, of the A68 iceberg that snapped off Antarctica’s Larsen C Ice Shelf.

Credit: NASA Earth Observatory

As the sun rises above the Antarctic horizon after the long, dark austral winter, scientists are getting a better look at the Delaware-size iceberg that sheared off from the frozen continent’s Larsen C ice shelf in July.

With the illumination from the sun’s rays, new satellite images have captured the iceberg, dubbed A68, and the motley assortment of ice and water surrounding it, in impressive detail. In the coming months and years, scientists will be poring over such images to watch the progression of the iceberg and its parent ice shelf.

The researchers said they also hope to study the area up close, to examinedetails of the seafloor that have been blocked by ice for hundreds of yearsand to learn how such a massive shift could alter the local ecosystem. [In Photos: Antarctica’s Larsen C Ice Shelf Through Time]

“It’s obviously a completely different physical environment once the ice is gone,” Susie Grant, a marine biogeographer with the British Antarctic Survey, told Live Science.

Keeping tabs on the iceberg, the ice shelf and the ecosystem in the coming years could also help scientists better understand how other major ice shelves might respond to a warming world, according to Grant.

Scientists have watched for several years as a rift slowly propagated its way across the Larsen C ice shelf, a platform of ice that extends out from the coast and floats atop the ocean. After a couple of surges in 2016 and earlier this year, the rift finally reached the edge of the ice shelf and calved off the iceberg.

Snapshot of the rift in the Larsen C on Nov. 10, 2016.

Credit: John Sontag/NASA

But with the sun below the Antarctic horizon, researchers could monitor the event only with thermal imagery and radar, according to NASA’s Earth Observatory.

“When it did finally break off, it was just sort of these tantalizing” glimpses, Grant said.

Once the sun re-emerged in August, more satellite views started streaming in ¾ and they haven’t disappointed. The “satellite images are extraordinary,” Grant said. “To see something of that scale moving across the water.”

In mid-September, NASA’s Terra satellite and the Landsat 8 satellite captured shots of the iceberg in visible light and of the surrounding area in infrared wavelengths of light. The images reveal exciting details, like the wrinkly-looking rifts that stretch across parts of the iceberg and the mixture of open water and ice surrounding it. [Earth from Above: 101 Stunning Images from Orbit]

An instrument onboard the Terra satellite captured this image of the A68 iceberg on Sept. 11, 2017.

An instrument onboard the Terra satellite captured this image of the A68 iceberg on Sept. 11, 2017.

Credit: NASA Earth Observatory

In the psychedelic thermal image, the cold iceberg and ice shelf appear a ghostly white, while the relatively warmer sea ice shows up in shades of purple, and the even warmer (though still sub-freezing) open water pops out in yellow. Bluer shades show the mixture of ice called mélange, which can include snow, sea ice, bits of ice that fell from the sides of the rift and something called marine ice, which forms along the underside of the floating ice, said Ala Khazendar, a scientist with NASA’s Jet Propulsion Laboratory who uses radar to study polar ice.

The images also show how much the iceberg has moved away from its parent ice shelf. So far, it has been progressing at a steady clip, but how fast it might continue to move is unclear and depends on several factors: winds and ocean currents, as well as whether there are any bumps or ridges on the seafloor that the iceberg might get stuck on, Khazendar said.

If it does get stuck, he said, that will tell scientists something about the topography of the seafloor, which they had no way of viewing before the calving event, Grant said.

That seafloor and the water above it are also being exposed to sunlight for the first time in at least hundreds of years, and this could have major impacts on the local ecosystem, Grant said. For instance, ocean life at the water’s surface could suddenly ramp up in productivity. The newly opened area could also see species moving in from neighboring regions, she said. [Antarctica Photos: Meltwater Lake Hidden Beneath the Ice]

The ecosystem will be “potentially dramatically changed” by the calving event, Grant said, though it’s “impossible to know anything about that until we can get down and visit.”

The British Antarctic Survey and other groups are planning scientific cruises to get an up-close look at the changes to the region, and the sooner that happens the better, so they can establish a baseline before major changes occur, Grant said. Sediment cores drilled from the ocean floor will help scientists establish how long the area has been covered by ice, and sampling of the water will tell them how the temperature and salt content may be changing and what creatures live there, she said.

Those efforts are helped by an international agreement by the Commission for the Conservation of Antarctic Marine Living Resources, which has 25 international members, to designate the area around the ice shelf as a protected area so that activities like commercial fishing won’t hamper scientific work, Gizmodo reported. This is the first time there has been such a designation, Grant said.

“I think that was a really important step,” she said. “We were really pleased to have managed to get that.”

In the meantime, scientists will glean what information they can from satellite images and airborne observations made by NASA’s IceBridge program, which is gearing up for the Antarctic summer season, Khazendar said.

Researchers will be watching to see if the remaining ice shelf begins to flow faster in response to the iceberg’s loss, he said, and how the iceberg melts and potentially breaks up into smaller pieces (one such piece already broke off later in July).

“We still need to collect data and analyze them in order to understand how the Larsen C ice shelf is going to react to this event,” Khazendar said.

There are concerns that the massive calving event could mark a turning point for the glacier, sending it toward a global warming-fueled collapse like those suffered by its northern neighbors, Larsen A and Larsen B, in 1995 and 2002, respectively. But whether that will happen isn’t yet clear, and the ice shelf could recover from the calving event, as these events do happen naturally, Khazendar said.

“It will take us some time before we have some clearer answers,” he said.

How Larsen C responds could also give scientists a better idea of how other major ice shelves around Antarctica will respond to the warming waters that are lapping away at the shelves’ undersides and causing the glaciers that feed into shelves to flow faster out to the ocean, raising sea levels.

“It could teach us a lot about the fate of other large ice shelves in Antarctica,” Khazendar said

Studying the region could also “improve our understanding of how ecosystems might respond to the impacts of climate change,” Grant said.

Original article on Live Science.