ريتشارد دوكنز's Blog, page 752

First Collision In Most Powerful Particle Collider Ever

Physics





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Protons collide at 13 TeV, sending showers of particles through the ATLAS detector (Image: ATLAS)

The Large Hadron Collider (LHC) has reopened for business, and this time it's more powerful than ever before. The LHC has been closed for two years while engineers did essential upgrades to nearly double its power. On May 21st, the results of the first proton collisions in the revamped machine were published. 

Happy World Turtle Day!

Plants and Animals





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Saranya Loisamut by shutterstock

May 23 is World Turtle Day, celebrating the tortoise and the turtle. Started by the American Tortoise Rescue (ATR) in 2000, the annually celebrated day shines a spotlight on care, conservation and awareness of the oldest living reptiles in the world.

Short, Sharp Shocks Let Slip The Stories Of Supernovae

Space





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A Type Ia supernova designated SN 2014J in the galaxy M82, captured by the Hubble Space Telescope. NASA, ESA, A. Goobar (Stockholm University), and the Hubble Heritage Team (STScI/AURA), CC BY

When we look up at the night sky, it’s easy to feel as though the stars we see have always been, and always will be, there. But just like ourselves, stars are born and die.

And when they die, they sometimes do not go gently but end their lives in supernovae – gigantic explosions that, at their brightest, outshine entire galaxies of stars.

An Animal That Could Rewrite The Family Tree: One Of The Top New Species Of 2015

Plants and Animals





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Is it a … or a ….? Dengrogramma enigmatica, discovered in deep water off the coast of Victoria, doesn’t quite fit in anywhere in the animal family tree. Jørgen Olesen

It is that time of year again, when the International Institute for Species Exploration based at the State University of New York announces the Top 10 new species.

The Seashell-Inspired Material Inspiring A New Wave Of Safety Gear In Sport

Technology





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One shell of an idea. David Eickhoff, CC BY

The risk of injury in professional sport has been a central feature in recent debates about how well protected our stars are.

Climbing The Tree: The Case For Chimpanzee ‘Personhood’

Plants and Animals





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Should primates such as chimpanzees be given rights normally reserved for humans? phil/Flickr, CC BY-NC-SA

Hercules and Leo don’t know it, but a decision about their future has made history. In granting an order to show cause on whether Hercules and Leo (who just happen to be chimpanzees) are illegally imprisoned, a Supreme Court judge in Manhattan has kept open the possibility that some nonhuman animals will be granted legal rights under common law.

Can’t Touch This–New Encryption Scheme Targets Transaction Tampering

In August 1977 popular mathematician Martin Gardner introduced the concept of RSA cryptography in the pages of Scientific American. Developed by three researchers at Massachusetts Institute of Technology, the new algorithm would go on to dominate the securing of transactions over the Internet. Nearly four decades later, with cryptocurrencies and smart-device communications adding to a growing list of online transactions, the search is well underway for an even more secure and scalable replacements for RSA.

Conceived by Ron Rivest, Adi Shamir and Leonard Adleman, RSA cryptography enables Web users to conduct their business in relative privacy rather than having to send their sensitive information openly over the Internet. Enter your credit card into a Web site’s order form, for example, and that information is turned into a code that’s unreadable to anyone except for the vendor who processes your order.

A weakness with RSA, though, is that it was not designed to verify the identity of the person initiating the transaction. If someone were to intercept your online order and, say, change the information to have it shipped to a new address, it would be difficult for the vendor, or anyone, to know that the transaction had been tampered with until well after the fact. There is no way to authenticate you as the person who initiated the order, as opposed to the person who changed the shipping address. As Chris Christensen, an analyst at research firm IDC, put it in a 2006 paper (pdf) on the subject, “How does the receiver know that a message really came from the person who ‘signed’ it?”

When looking at information stored in the cloud, transferred between smart devices—the basis for the “Internet of Things”—and managed by businesses, there is no way to know that data has not been changed, says Mike Gault, CEO of Guardtime. His Estonia–based cybersecurity firm aims to replace RSA’s signature algorithm with one that uses a different type of encryption as well as a public ledger—a so-called blockchain—that records all transactions.

Blockchains have gained notice of late for their role in securing transactions involving cryptocurrencies such as bitcoin. These digital public ledger systems record information—including time stamps and other data tags—for all transactions that have been deciphered and validated. Once a transaction is entered into the blockchain ledger, it cannot be deleted or changed. Blockchains would enable a vendor to verify that you were the person who sent an order or that a second alteration of an original communication was made, raising suspicion. They are also appealing from a security and privacy standpoint because they rely on information stored across a decentralized network of computers. There is no central repository for cyber attackers to target.

Guardtime’s authentication and signature protocol is called BLT, after the company cryptographers—Ahto Buldas, Risto Laanoja and Ahto Truu—who invented it. The company claims that, unlike RSA, its cryptographic scheme “cannot be efficiently broken” even if an attacker uses quantum-computing algorithms.

Replacing a venerable technology such as RSA is no easy task, so Guardtime has partnered with Swedish wireless-network equipment maker Ericsson, whose new cybersecurity offerings are based on BLT. Estonia has served as a test bed for Guardtime’s technology over the past few years. The Baltic nation relies heavily on the Internet for banking and other crucial day-to-day functions and is loath to see a repeat of the crippling cyber attack that paralyzed the country in 2007.

Fact or Fiction?: A “Base Tan” Can Protect against Sunburn

As the weather warms, many of us would prefer to look like we passed our winter days lounging by the pool instead of hunched before a computer screen or lab bench. But soaking up the rays to acquire a so-called “base tan” does not fool the sun or a tanning bed. Simply put, the benefits of being sun-kissed are not even skin-deep.

Scientists came to this conclusion after studying the tanned buttocks of dozens of volunteers. In study after study they have found that a base tan affords almost no protection against future ultraviolet exposure. In fact, it actually puts otherwise pale people at risk of developing skin cancers. A base tan only provides an SPF, or sun protection factor, of 3 or less, according to the U.S. surgeon general. For beachgoers, that means if a person would normally turn pink after 10 minutes in the sun, an SPF 2 base tan would theoretically buy her another 10 minutes—or 20 minutes in total—before she burns. That, says David Leffell, the chief of dermatologic surgery and cutaneous oncology at Yale University School of Medicine, is “completely meaningless” in terms of providing protection.

The studies that helped solidify these conclusions were relatively straightforward. Because butt cheeks do not typically get much time in the sun, a team of British scientists asked 16 young healthy adults to bare their previously unexposed posteriors to simulated sunlight for one 1998 study. The volunteers, who had varying shades of pale skin, agreed to subject their rumps to two weeks of daily tanning sessions that dosed them with ultraviolet A (UVA) and ultraviolet B (UVB) rays on par with London’s summer noonday sun. Yet even among people who tanned easily, the tanning sessions only gave them “very modest” protection, equivalent to a sunscreen with SPF 2. Other studies, including work looking at darker, olive-colored skin, came to similar conclusions: A tan affords a sun protection factor of 3 or less.

Getting a base tan from a tanning bed appears to be an even worse idea than preemptively exposing yourself to the sun. One study published this year looked at tanning from UVA light (the main staple of tanning beds) and found that the protection from future burn would not even meet an SPF 1.5 threshold. What’s worse, the body does not protect itself very effectively against the UVA rays that predominate in most tanning beds so indoor tanning can cause serious damage to your skin. Recent estimates suggest indoor tanning causes about 419,000 cases of skin cancer in the U.S. every year, which is almost double the number of cases of lung cancer linked to smoking. Still, UVA is often chosen for tanning beds because its longer wavelength penetrates deeper into the skin and is less likely to cause sunburn. The body will readily redistribute its existing melanin in response to UVA exposure—which results in immediate skin darkening—but UVB rays are better at triggering several more long-term protective mechanisms in response to cellular damage. Those include the production of more melanin, skin thickening and signaling DNA repair systems that try to correct for mutations before they are carried forward, says Heather Rogers, professor of dermatology at the University of Washington School of Medicine.

Behaviors adopted by tanned people who believe they are partially protected against the sun might compound these problems. Dermatologists say that such base tanners may engage in riskier behaviors like lying in the sun with no sunscreen or reapplying lotion less frequently. Yet no matter how hard tanners may wish, spending time in the sun or on a tanning bed will not transform a pasty person into one with darker skin, at least long-term. “You won’t change your skin type with sun exposure,” Rogers says. “It just won’t happen.”

Giant Black Holes May Be on Collision Course

Most galaxies have a supermassive black hole lurking at their centers, but a galaxy 10.5 billion light-years away looks like it might have two—and the pair may be set to crash together in just 21 years. If the observations are confirmed, the duo would be the closest known set of binary black holes, and their imminent collision would offer scientists an unprecedented chance to watch extreme physics in action. [Video: When Black Holes Collide]

The potential black holes are impossible to glimpse directly. Besides being black—which is to say, invisible—they are far too distant from Earth and too close to one another to make out with telescopes. But scientists found what they think is the telltale signature of a pair of these behemoths circling together. The apparent black holes reside in what’s known as a quasar—a galaxy that is unleashing a torrent of light as mass gets gobbled by the gigantic black hole at its center. The light from most quasars flickers randomly as slightly more or less mass falls in. But if two black holes are at the core, rather than one, their orbital motions will perturb the gas around them in an orderly way, causing the light to rise and fall periodically.

Tingting Liu, a graduate student at the University of Maryland, College Park, analyzed the light pouring from 316 quasars as seen by the Pan-STARRS 1 (Panoramic Survey Telescope and Rapid Response System) Medium-Deep Survey, a scan of the sky undertaken by the Pan-STARRS1 telescope on Mount Haleakala in Hawaii. She looked for periodic patterns in the light and a quasar with the unwieldy name PSO J334.2028+01.4075 turned out to have the best evidence for a recurring signal. The black hole or holesthere have an estimated combined mass between three billion and 30 billion times the mass of the sun. “This candidate that we present is at such a compact separation that they are actually in the process of merging,” says Suvi Gezari, leader of Liu’s research group and a co-author on a paper announcing their find that has been accepted for publication in the The Astrophysical Journal Letters. In fact, the impending impact will seem to happen even sooner for the black holes themselves. In their reference frame, they are due to converge in just seven years. Because of a phenomenon called cosmological time dilation, due to the expansion of the universe, the crash will seem to take place in 21 years from our point of view on Earth. “This was a fortuitous catch,” says Stuart Shapiro, a theoretical astrophysicist at the University of Illinois at Urbana–Champaign who was not involved in the research. “We don’t know of another candidate that’s anywhere near that close [to merging].” But, he adds, “I take it with a grain of salt, and even if it doesn’t pan out there are probably many more on the horizon.”

Astronomers expect to find more binary black holes with the rise of Pan-STARRS1 and other surveys like it that can monitor such systems over time and look for periodic light variations. Shapiro uses computer simulations to predict what happens when giant black holes fuse. To be able to observe one in space would offer him and other theorists a precious reality check of their calculations. “When two black holes get sufficiently close, we think they plunge together suddenly and they merge,” Shapiro says. “That plunge and merger will give rise to a burst of gravitational waves, and that burst will then diminish for awhile as the merged remnant rings down, like a bell.” The bell-like vibrations should send out spirals of gravitational waves, which are ripples that stretch and shrink the fabric of spacetime.

Such ripples could be detectable to so-called pulsar timing arrays, which use spinning stars called pulsars as natural clocks to look for disturbances from gravitational waves. Pulsars spin very regularly and sweep jets of light out like lighthouse beams. If a gravitational wave passed through space, their light might come off schedule. By comparing the timing of many pulsars across the cosmos, astronomers could identify when and where a gravitational wave came from. “Right now we don’t actually have the sensitivity to detect this system [PSO J334.2028+01.4075] but we’re finding more and more of these through various surveys so this is potentially the tip of the iceberg,” says Xavier Siemens of the University of Wisconsin–Milwaukee, who leads the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) pulsar timing array project. “This system is potentially something we could detect with next-generation radio telescopes,” he adds, “with things like the Square Kilometer Array” due to start up around 2025 in South Africa and Australia.

Whether or not PSO J334.2028+01.4075 is truly a binary black hole is still an open question. George Djorgovski, an astronomer at Caltech who recently found another candidate double–back hole quasar, is not convinced. “I am skeptical about their analysis and claims,” he says. The Pan-STARRS1 survey only observed the system in question on a handful of occasions, so the apparent variation in light could turn out to be chance, he cautions. Furthermore, the likelihood of finding such a rare event in such a relatively small initial sample size (316 quasars) is low. “The chances of catching one pair at such a close separation as they claim—that would merge within several years—is probably well less than one in a million,” he adds. “Liu et al would have to be very, very lucky.”

Astronomers should not have to wait too long to find out. Liu and her collaborators calculated that the quasar’s light fluctuates over a regular period of about 542 days, meaning that forthcoming data should soon either confirm or reject the pattern. “It’s a really easy thing to test the persistence of this periodic fluctuation in the future,” Gezari says. “And if there are two black holes that are starting to in-spiral toward one another, then their period should be getting smaller and smaller. We can actually look for that change as a function of time.” If the pattern holds up, astronomers just may get a front-row seat to one of nature’s most extreme events.

Dolphin Deaths Linked To 2010 Gulf of Mexico Oil Spill

The BP Deepwater Horizon oil spill began in the Gulf of Mexico on April 20, 2010. Following the event through 2012, more than a thousand dolphins washed up dead along the Gulf, in three major strandings. That’s four to five times higher than the region’s usual rate of dolphin deaths.

“We found that dolphins dying after the oil spill had distinct adrenal gland and lung lesions that were not present in the stranded dolphins from other areas.”

Kathleen Colegrove of the University of Illinois was the lead veterinary pathologist of the latest in a series of studies analyzing the die-off. She and her study co-authors took part in a telephone press conference on May 20th.  

“Now, surprisingly, one in three dolphins that stranded in Louisiana, Mississippi and Alabama had a thin adrenal gland cortex. And when looking at just the Barataria Bay dolphins, half of them had this lesion.”

Barataria Bay got an especially high dose of oil.  

“This prevalence was significantly higher than in the reference population, in which less than one in 10 had this lesion.  Now, this thinning of the adrenal gland cortex was a very unusual abnormality for us, that has not been previously reported in dolphins in the literature…now, aside from chemical exposure, conditions that can cause the adrenal gland to become thin include things like cancer, autoimmune disease, fungal infections and tuberculosis. And we did not find any evidence of these alternative causes in the dolphins.

“Now, in addition many dolphins dying after the oil spill again in Louisiana, Mississippi and Alabama had evidence of significant lung disease…in fact, these dolphins had some of the most severe lung lesions I have ever seen in wild dolphins from throughout the U.S.”  

The study is in the journal PLoS ONE. [Stephanie Venn-Watson et al, Adrenal Gland and Lung Lesions in Gulf of Mexico Common Bottlenose Dolphins (Tursiops truncatus) Found Dead following the Deepwater Horizon Oil Spill]

BP disputes the link between the dolphins and the oil spill. But the study’s lead author, Stephanie Venn-Watson of the National Marine Mammal Foundation contends:

“The evidence to date indicates that the Deepwater Horizon oil spill and associated compounds caused the adrenal and lung lesions which contributed to the increased deaths as part of this unusual mortality event.”

—Steve Mirsky

(The above text is a transcript of this podcast)