It’s spring, and I’m attending a luxurious seafood banquet. Platters of shellfish fill the tables: crab with limbs akimbo; shrimp ready to be peeled; miniature lobster-like langostino peering at my dinner plate as if knowing their fate. Raw oysters sit in the center of the platter, piled absurdly high and shimmering luminescent on the half shell.
Until now, I’ve never eaten a raw oyster. I apply a generous squirt of lemon juice and watch the white-grey flesh ripple ominously in reply. Tilting my head back, I down the shell’s contents in one shot of citrusy ocean. The gelatinous solid slides down my throat largely unchewed as I submit a silent prayer to the gods of food safety, asking not to become the subject of an ironic headline:
“Research scientist studying bacterium found in raw oysters falls ill after eating…a raw oyster.”
Thankfully, I walked away from the banquet without encountering Vibrio vulnificus, the bacterial subject of my Ph.D. Much as I want to be an academic expert on V. vulnificus, there are aspects of the microbe I hope never to attest to first-hand. But as the planet’s oceans heat up, the odds of a potentially fatal rendezvous will continue rise along with the temperature. Read More
There are multiple answers to the question of where we come from: early hominins, monkeys, primordial goo, or the Big Bang, to name a few. Today’s answer, though, has probably, just a split second ago, popped into many readers’ minds. Today’s answer is sexual intercourse, a.k.a. “bleeping.” So let’s go back to the beginning, hundreds of millions of years before we invented euphemisms and censorship, and let’s ask: How in the evolutionary world did sex begin?
Algae, the green gunk that runs amok in our fish tanks, as well as the seaweed that stinks up our summer beaches, include some of the simplest sexually reproducing organisms on Earth. These lineages go back nearly 2 billion years. Algae do it. Plants do it. Insects do it. Even fungi do it. Much of this sex involves releasing sperm into the wind or the water so they can be carried to nearby eggs (as in mosses), relying on a different species to carry male gametes to female ones (many flowers), or maneuvering two bodies so that the openings to the internal reproductive organs are close enough together for fluid exchange (most insects and most birds). Read More
It seems safe to say that the laborers firing clay pavers, bricks and tiles to build the Jesuit mission of Santo Ângelo over 300 years ago had no idea that their toils might someday bear relevance to spacecraft orbiting 600 miles above what is now southern Brazil.
As the bricks and pavers were fired in kilns, magnetite in the clay abandoned its inherent magnetic properties and realigned in response to the magnetic forces exerted by the earth itself. The point at which this occurs – 580 degrees Celsius, in the case of magnetite – is known as the Curie point.
After these building materials cooled and were stacked to form a church, school and other buildings at Santo Ângelo, the magnetite inside retained this reshuffled alignment, a record of the magnetic past sealed away like a proverbial mosquito in amber. Along with several dozen other Jesuit missions built in the same era, Santo Ângelo flourished briefly along what was then the poorly defined border between the Spanish and Portuguese colonies in South America. At its height, the mission was home to about 8,000 people, nearly all of them indigenous Guarani whom the Jesuits were trying to Christianize.
Have you ever wondered why we age and grow old?
In the movie “The Curious Case of Benjamin Button,” Brad Pitt springs into being as an elderly man and ages in reverse.
To the bafflement of scientists, the fundamental laws of physics have no preference for a direction in time, and work just as well for events going forward or going backward in time. Yet, in the real world, coffee cools and cars break down. No matter how many times you look in the mirror, you’ll never see yourself grow younger. But if the laws of physics are symmetric with respect to time, then why do we experience reality with the arrow of time strictly directed from the past to the future?
A new paper just published in Annalen der Physik — which published Albert Einstein’s theories of special and general relativity — Dmitry Podolsky, a theoretical physicist now working on aging at Harvard University, and I explain how the arrow of time ‒ indeed time itself ‒ is directly related to the nature of the observer (that is, us).
Our paper shows that time doesn’t just exist “out there” ticking away from past to future, but rather is an emergent property that depends on the observer’s ability to preserve information about experienced events. Read More
Joshua Hinson’s first biological son was born in 2000. His son’s birth marked the start of the sixth generation that would grow up speaking English instead of Chickasaw, which was the primary language his ancestors had spoken for hundreds of years. Hinson was born in Memphis, Tennessee, and grew up in Texas. Other than a small handful of words, he knew almost nothing about his ancestral language—formally known as Chikashshanompa’. Hinson had a few pangs of sadness over the years about what was lost, but it didn’t really affect him—until his son was born.
As he counted the 10 tiny fingers and 10 tiny toes of his firstborn child, Hinson realized he had nothing to teach his son about his Native American roots. The only thing he had to pass on was his tribal citizenship card. Hinson wanted to bequeath more than just a piece of paper; he wanted his son to be a part of Chickasaw culture. He recognized that the most direct way to understand his culture was to speak the language. But to make that happen, Hinson had to start with himself. Read More
One night in 1984, a man broke into Jennifer Thompson’s apartment and raped her at knifepoint. Throughout the attack, the college student memorized every detail of her rapist’s face, promising herself that when she took the witness stand against him, “he was going to rot” in prison.
Thompson hurried to police the morning after the attack, giving them a detailed description of her rapist, filling in all the characteristics she’d memorized so carefully. The police put together a photographic lineup – the standard lineup technique in the modern U.S. – and Thompson selected a man named Ronald Junior Cotton. “I had picked the right guy,” she said. “I was sure. I knew it.”
But Cotton was innocent, as DNA evidence proved – after he’d spent 11 years in prison. Read More
A year ago today, a select group of scientists became the first people on the planet to learn that, after a century of theory and experiments, Albert Einstein was right all along.
Researchers at the Laser Interferometer Gravitational-Wave Observatory (LIGO) in Livingston, Louisiana had, at last, detected a gravitational wave. The ripple in space-time — a “chirp in the data — emanated from the merger of two black holes that collided some 1.3 billion years ago. This ripple in the fabric of the universe sent the science world abuzz when the findings were announced several months later in February. Read More
An exploding Falcon 9 could send ripples through space-timelines.
By now, you’ve probably heard about SpaceX’s Thursday morning “anomaly” at its Cape Canaveral launch pad. In fact, you can already watch video of it. Thankfully, no one was injured, but the AMOS-6 satellite payload, which would have brought Internet access to sub-Saharan Africa, was lost.
Every day on this planet, roughly 4 to 8 million bolts of electricity the width of a finger connect heaven to earth, discharging a current of 30,000 amperes and heating the air to 18,000 degrees Fahrenheit.
It’s no wonder ancient cultures believed lightning was the chosen weaponry of pissed-off gods. You’ve probably seen the grizzly aftermath of a recent strike in Norway that killed 323 reindeer. Wired’s Megan Molteni published an excellent run-down on why centuries of Santa’s sleigh-pullers were doomed atop the Nordic permafrost:
“When lightning strikes, the current flows into the ground and outward, following the path of least resistance. In a warmer place, the electricity would penetrate deep into the soil and disperse quickly (this is called grounding). But in a place like the Hardangervidda, as the current runs into the soil and hits the permafrost layer, it instead spreads out along the surface of the soil, which is saturated with water from annual cycles of melting—and in this case, the massive rainstorms that generated the lightning strike. So the area that gets zapped is way bigger.”
Although lightning has long captured our attention, it wasn’t until the 18th century that scientists started peeling back mythology to understand this frightful electrostatic display. In 1752, French scientists Thomas-Francois Dalibard and Georges-Louis Leclerc, successfully tangoed with lightning when a bolt struck a 40-foot metal pole that they had anchored in a wine bottle, confirming a hypothesis formulated by Benjamin Franklin.
But more than 250 years after Dalibard and Leclerc’s experiment, scientists are still trying to answer fundamental questions about lightning. At the Florida Institute of Technology, Hamid Rassoul, a veteran space scientist and physics professor, founded the school’s Lightning Research Group to carry on the shocking investigations that started centuries ago.
The following are a few of the nagging questions they are trying to answer.
Who hasn’t been shocked while reaching for a doorknob?
The zap you feel is the result of passing the excess electrons clinging to your finger onto the positively charged doorknob. As your finger nears the knob, the voltage is so high that it causes the air to break down and act like a conductor.
The dielectric breakdown of air is very predictable, it always occurs in an electric field that reaches 3 million volts per meter. It’s a fundamental quantity that’s been established in the lab, and tested over, and over, and over again.
The same should hold true for lightning, which is static electricity on a grand scale. But, for some reason, air breaks down inside a cloud when the electric field reaches just 2 million volts per meter, far weaker than expected.
“That defies the laws of physics, or at least everything we know at this point,” says Rassoul. “Nature is managing to create a spark within an environment that doesn’t meet the same expectations in the lab.”
Rassoul says ice particles in the cloud may interact in a way that initiates the spark sooner than expected, but it’s still unclear what gives lightning its final push. Understanding lightning initiation remains the so-called “Holy Grail” of lightning research.
“It’s one of the biggest mysteries of lightning, and for the past 10 years we have been trying to answer that one,” he says.
Bolts from the blue originate in anvil clouds, but can travel vast distances. A single bolt, for example, can travel from a storm on one side of a mountain range and strike on the other side. Even after covering vast distances, they still pack a 130,000-amp punch four times higher than typical strikes — that’s what gives scientists fits.
If you built a gun that could fire packets, or bullets, of electrons, you’d run into a problem with range. Say you set an apple on your friend’s head, and you wanted to peg it with an electron bullet from a distance 300 feet. By the time your bullet reached the apple, the electrons in your bullet would have scattered, dispersing the energy — remember, like charges repel each other.
Bolts from the blue are positively charged, but as they travel some 10 miles through a cloud, they remain compact — about the width of a finger, and powerful.
“We’re not sure how nature keeps similarly charged electrons together for miles in the atmosphere,” Rassoul says.
He theorizes that lightning may travel in packets of electrons that generate a chain reaction of new packets along the way, like dominoes. Rassoul likens the theory to the concept of a generational star ship: The mission would launch from Earth with generation one, but once you reach, say, Proxima Centauri, it’s an entirely new group of people who reach the destination.
“It’s beautiful on paper, but we don’t know how to show it in the lab,” says Rassoul.
“Twenty-seven percent of the time, depending on conditions, the shorter object is hit by lightning rather than the tall object,” says Rassoul. Consider that all-too-common myth about lightning officially dead.
So what determines where lightning will strike, or what researchers call attachment? As you may have guessed, they’re still trying to figure that out, too.
Lightning begins with the development of a step leader, when excess electrons at the bottom of a storm cloud start racing through the air toward the ground. As they push down, the positive charge on Earth’s surface increases. The excess positive charges make their way up through buildings, cell towers — you — and into the air. These are called streamers.
And when streamer and leader meet — bang!
That much makes sense, but what isn’t clear is why a 6-foot-tall man can send a streamer higher into the air than a 100-foot cell tower, even if he’s standing right next to it.
“Sometimes objects change electrical potential so much, they project their positive charge higher than a tower,” says Rassoul. “But why am I sending such a long streamer up there? Again, none of these questions have been answered.”
Figuring out the mechanisms of lightning could increase our predictive capabilities and improve safety — and these are just three of many lightning mysteries. To probe lightning’s secrets, Rassoul’s team is using ultra-slow-motion cameras, inducing strikes with rockets, and using theoretical models and simulations to arrive at new insights.
Over the next several years, no doubt, work by the Florida Tech team and other scientists around the world will yield a better understanding of the power in our skies.
Being stuck in miles of halted traffic is not a relaxing way to start or finish a summer holiday. And as we crawl along the road, our views blocked by by slow-moving roofboxes and caravans, many of us will fantasize about a future free of traffic jams.
As a mathematician and motorist, I view traffic as a complex system, consisting of many interacting agents including cars, trucks, cyclists and pedestrians. Sometimes these agents interact in a free-flowing way and at other (infuriating) times they simply grind to a halt. All scenarios can be examined – and hopefully improved – using mathematical modeling, a way of describing the world in the language of maths. Read More