Lightning’s Strange Physics Still Stump Scientists

By Carl Engelking | August 31, 2016 2:37 pm

shutterstock_86714164

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.

How Does Lightning Begin?

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.

How Does Lightning Travel?

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.

116273_web

A lightning flash captured by a high-speed camera. (Credit: Geospace Physics Laboratory, Department of Physics and Space Sciences, Florida Institute of Technology)

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.

Where Does It Strike?

“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.”

Eyes on the Skies

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.

CATEGORIZED UNDER: Environment, Top Posts

The End of Traffic Jams

By Lorna Wilson | August 31, 2016 11:39 am
traffic jam

(Credit: chuyuss/Shutterstock)

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

CATEGORIZED UNDER: Technology, Top Posts
MORE ABOUT: transportation

Can Doping Tests Stay Ahead of Cheaters?

By David Warmflash | August 29, 2016 11:31 am
shutterstock_416237218

(Credit: Stefan Schurr/Shutterstock)

The 100-meter dash, the pole vault, a marathon, a bike race, and any other sport under the sun have one thing in common: winning depends on pushing physical performance to the max.

The pressure on athletes to push their bodies to the limit has produced a longstanding tit-for-tat between the athletes sneaking chemical agents into their blood or body cells to gain an edge and those trying to detect them.

Recently, the International Olympic Committee (IOC) announced that any prospective dopers had better think twice about artificially gaining a competitive advantage. The IOC isn’t talking about traditional doping tactics like getting infusions of extra red blood cells or injections of performance-enhancing hormones. Read More

CATEGORIZED UNDER: Health & Medicine, Top Posts
MORE ABOUT: genes & health

Taking Pangolin Off the Menu

By Steven Bedard | August 25, 2016 2:14 pm
Chinese pangolin Manis pentadactyla Mother and two-month-old baby. Mother was rescued from poachers and is now part of Taipei Zoo's captive breeding program. Taipei Zoo, Taipei, Taiwan *Captive *Digitally removed leaf debris in foreground

This Chinese pangolin (Manis pentadactyla) was rescued from poachers and given safe haven at the Taipei Zoo. She and her two-month-old baby are evidence of the zoo’s successful captive breeding program. (Credit: Suzi Eszterhas)

When acclaimed conservation photographer Suzi Eszterhas settled in for the evening, she didn’t know what to expect. She seldom does when trying to photograph elusive, nocturnal creatures. But circumstances on this particular night were unusual. She was sitting in an enclosure—albeit a naturalistic one—and although she knew her photographic subjects couldn’t flee, she thought it was quite possible she might spend the entire night being riddled by biting ants without capturing a single shot. Read More

CATEGORIZED UNDER: Living World, Top Posts

Is It Neander-TAL or Neander-THAL?

By Bridget Alex | August 25, 2016 12:40 pm
neanderthal

(Credit: Gianfranco Goria/Flickr)

Here’s the deal: you can write or say Neanderthal or Neandertal, but you should only write Homo neanderthalensis and say “Homo neander-TAL-ensis”.

I promise that will make sense by the end of this.

The name comes from Neander Valley, Germany, where the first recognized Neanderthal fossil was found in 1856 (other Neanderthal bones had been discovered earlier, but people didn’t know what to make of them). Read More

CATEGORIZED UNDER: Living World, Top Posts

Earth Proxima: Is Our New Neighbor the Most Promising Exoplanet Yet?

By Eric Betz | August 24, 2016 12:00 pm
This artist’s impression shows the planet Proxima b orbiting the red dwarf star Proxima Centauri, the closest star to the Solar System. The double star Alpha Centauri AB also appears in the image between the planet and Proxima itself. Proxima b is a little more massive than the Earth and orbits in the habitable zone around Proxima Centauri, where the temperature is suitable for liquid water to exist on its surface.

This artist’s impression shows the planet Proxima b orbiting the red dwarf star Proxima Centauri, the closest star to the solar system. (Credit: ESO/M. Kornmesser)

A pale red dot not far from our sun may be orbited by a pale blue dot much different than Earth.

In a shocking find, astronomers Wednesday announced their discovery of an Earth-sized planet orbiting the nearest star, Proxima Centauri, just 4.2 light-years away. This warm world, cataloged as Proxima b, sits smack in the middle of its habitable zone — the sweetest of sweet spots — where liquid surface water could exist.

But Proxima Centauri is not like our sun. It’s a cool, low-mass star known as a red dwarf. So the planet only qualifies as potentially habitable because it circles its sun in an orbit tighter than Mercury’s. Read More

CATEGORIZED UNDER: Space & Physics, Top Posts
MORE ABOUT: exoplanets

How Advertisers Seduce Our Subconscious

By Robert George Heath, University of Bath | August 23, 2016 1:06 pm
marlboro-man

The Marlboro Man as depicted in an advertisement in Berlin, Germany. (Credit: 360b/Shutterstock)

In 1957 Vance Packard’s book The Hidden Persuaders shocked the world by revealing that messages exposed subliminally, below our level of perception, were able to increase sales of ice cream and Coke. The experiment he cited was later shown to be a hoax, but one of Packard’s other assertions, that advertising can influence us below our level of awareness, is absolutely true.

In fact, rather scarily, the vast majority of advertising’s influence on us is subconscious. My own research has shown how the emotive content of advertising enables it to break almost all the rules which we believe govern our own susceptibility to adverts. Read More

CATEGORIZED UNDER: Mind & Brain, Top Posts

Why Does Time Seem to Fly as We Get Older?

By Christian Yates, University of Bath | August 11, 2016 12:55 pm
time flies

(Aleksandar Mijatovic/Shutterstock)

When we were children, the summer holidays seemed to last forever, and the wait between Christmases felt like an eternity. So why is that when we get older, the time just seems to zip by, with weeks, months and entire seasons disappearing from a blurred calendar at dizzying speed?

This apparently accelerated time travel is not a result of filling our adult lives with grown-up responsibilities and worries. Research does in fact seem to show that perceived time moves more quickly for older people making our lives feel busy and rushed. Read More

CATEGORIZED UNDER: Mind & Brain, Top Posts

How Humans Could Go Interstellar, Without Warp Drive

By David Warmflash | August 10, 2016 1:06 pm
alpha-beta

Alpha, Beta and Proxima Centauri (circled). (Credit: CC BY-SA 3.0)

The field equations of Einstein’s General Relativity theory say that faster-than-light (FTL) travel is possible, so a handful of researchers are working to see whether a Star Trek-style warp drive, or perhaps a kind of artificial wormhole, could be created through our technology.

But even if shown feasible tomorrow, it’s possible that designs for an FTL system could be as far ahead of a functional starship as Leonardo da Vinci’s 16th century drawings of flying machines were ahead of the Wright Flyer of 1903. But this need not be a showstopper against human interstellar flight in the next century or two. Short of FTL travel, there are technologies in the works that could enable human expeditions to planets orbiting some of the nearest stars. Read More

CATEGORIZED UNDER: Space & Physics, Top Posts
MORE ABOUT: space exploration

Can Virtual Reality Help Astronauts Keep Their Cool?

By Shannon Stirone | August 4, 2016 1:58 pm
virtual-reality

Scientists at Dartmouth College are experimenting with virtual reality headsets like the Oculus Rift to see if simulated environments can break the monotony of space travel. (Credit: Courtesy Jay Buckey)

While astronaut Scott Kelly spent his year on the International Space Station, he expressed frustration with the ho-hum accommodations inside the ISS — it’s dullsville.

The temperature remains exactly the same day in and day out. The décor is a sterile mix of machines and wires. Astronauts are isolated, confined to small spaces and under a considerable amount of stress. While the vistas outside their window are no doubt spectacular, humans need a hint of nature’s greens and blues to stay happy.

columbus-laboratory

The interior of the Columbus laboratory on the International Space Station. You get a sense of the sterile surroundings. (Credit: NASA)

The monotony of space can fray the nerves of even the most seasoned astronaut, and psychological stress is a serious side effect of living in a habitat of connected tubes orbiting Earth. So scientists at Dartmouth College are experimenting with virtual reality headsets like the Oculus Rift to see if simulated environments can break the monotony of space travel, and reduce psychological stress that astronauts experience on long duration missions.

“Things can go badly if the psychosocial elements aren’t managed properly. When you talk about longer and longer missions with a small crew it becomes really critical to have that social aspect right,” he says.

Floating in a Virtual World

Jay Buckey — a former space shuttle astronaut — is now a professor of space medicine and physiology at Dartmouth. Each space shuttle mission runs around three weeks, so Buckey’s not experienced the same monotony as Scott Kelly. Despite his pleasant trip to space, he still felt called to help. Buckey and his colleagues are using calming imagery to see if virtual scenes reduce stress levels.

“I wanted to focus on many of the issues that would serve as a barrier to long duration spaceflight,” says Buckey. “The psychosocial adaptation element is crucial to a good mission.”

His theory is that exposure to bucolic landscapes — even virtual ones — can reduce stress. To do this, Buckey and his team created two types of “escapes” for the subjects to try. The test subjects were either given a trip to the lush green hills of Ireland, or a serene beach landscape in Australia. As a control, test subjects sat in a classroom and researchers measured their heart rate and skin conductance.

“We are assuming that natural scenes will be preferred,” explains Buckey. “But, people in an isolated and confined environment might want an urban scene.”

To quantify the stress relief, Buckey’s team will measure the electrodermal activity in the skin of their test subjects to track fluctuations of psychological arousal and stress, providing insights into who is responding best to a given scene.

Buckey is also adding another twist to his experiments: shining a heat lamp on subjects viewing a beach scene to enhance their virtual experience.

“VR is an immersive world and we would like to optimize the scenes to find out what it is about these that people find the most compelling. As the tech improves and you get higher definition video you can really immerse somebody in a nature scene,” says Buckey. “Would people rather have a vista, or animals, and what other kinds of sensations would people like?”

Currently astronauts on the International Space Station use a tool called the Virtual Space Station — essentially a virtual therapy session. This VR software doesn’t provide stress reduction in the way that Buckey is exploring, but it has tools for conflict resolution, and training on how to handle interpersonal disagreements if and when they arise.

Back to Nature

Buckey’s experiments are still ongoing, so his results aren’t finalized. However, the notion that nature is good for our brain is nothing new — dozens of scientific studies back this up. In a more recent study, researchers from South Korea used fMRI to measure subjects’ brain activity when they looked at nature scenes versus urban scenes. Urban scenes activated the amygdala, which is linked to heightened anxiety and increased stress. On the other hand, nature scenes caused more blood to flow to regions in the brain associated with empathy and altruistic behavior.

VR lounge chair lamp

A study subject enjoys a scene augmented with a heat lamp. (Credit: Courtesy Jay Buckey)

At the University of Verona in Italy, researchers showed that “being in” a natural setting improved cognitive functioning, and participants completed tasks more efficiently with less mental fatigue. Nature can also lower our blood pressure and heighten our mood.

The data from the Dartmouth lab won’t be published for several more months, but the team hopes its experiment will move one step closer to helping future astronauts, and other people who work in isolation, cope with stress.

If it turns out that the data from Buckey’s experiments show a reduction in stress, future astronauts could perhaps work a regimen of VR medicine into their weekly routine. So far, Buckey thinks the preliminary results are encouraging, but “these are highly individualized responses, and is very subjective.”

“It depends on the outcome of what we have. We haven’t really proven that it works that well yet so I think its important for us to show that there’s a tangible benefit to having this.”

Lessons from the Past

In 1980 a group of scientists ventured off into the cold and isolated region of Antarctica as part of the International Biomedical Expedition. The IBEA was designed to understand how the human body would acclimate to extremely cold environments, isolation and the psychological responses to this type of stress. It dramatically highlighted the need for stress reduction for team members.

As the expedition continued, crewmembers grew homesick, isolation wore them down and they grew more and more irritable. Several scientists on the team simply walked out of the experiment before it was completed, due to these stressors.

In the 1980s, psychological stress drove a rift between cosmonaut Valentin Lebedev and his commander Anatoly Berezovoy while they were living aboard the Russian Space Station Salyut 7.

Lebedev wrote a book called Diary of a Cosmonaut where he shared stories of conflicts so severe that they sometimes went weeks without speaking to each other. In space, and especially on a longer mission to Mars, communication is key. Conflicts of this scale aren’t an option. In other words, keeping stress levels low is key to planning a successful mission.

NEW ON DISCOVER
OPEN
CITIZEN SCIENCE
ADVERTISEMENT

The Crux

A collection of bright and big ideas about timely and important science from a community of experts.
ADVERTISEMENT

See More

ADVERTISEMENT

Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!

Collapse bottom bar
+