## How Far Away Is A Lightning?

Next time you’re stuck in a thunderstorm, try this easy way to calculate how far away you are from lightning strikes.

Just count the number of seconds that pass between a flash of lightning and the crack of thunder that follows it, then divide that number by five.

The resulting number will tell you how many miles away you are from where lightning just struck.

Five seconds, for example, indicates the lightning struck 1 mile away, and a 10-second gap means the lightning was 2 miles away.

This technique is called the “flash-to-bang” method, and it can keep you safe during rainy summer weather.

The National Weather Service recommends taking cover if the time between the lightning flash and the rumble of thunder is 30 seconds or less, which indicates the lightning is about 6 miles away or closer.

This method is based on the fact that light travels much faster than sound through the atmosphere: Light travels at 186,291 miles per second (299,800 km/s), whereas the speed of sound is only about 1,088 feet per second (332 meters per second), depending on air temperature.

For metric-system conversions, follow this method: Sound travels at about 340 m/s, so multiply the number of seconds you counted by 340, and you’ll know how many meters away lightning struck.

A three-second count, then, would place the lightning strike about 1,020 m away, or roughly 1 km.

Pass it on: Popular Science

## Listen To The Sounds Of Wind On Mars, Recorded by NASA’s InSight Lander

Before you listen, hook up a subwoofer or put on a pair of bass-heavy headphones. Otherwise, you might not hear anything.

Then listen.

That’s the sound of winds blowing across NASA’s InSight lander on Mars, the first sounds recorded from the red planet. It’s all the more remarkable because InSight — which landed last week — does not have a microphone.

Rather, an instrument designed for measuring the shaking of marsquakes picked up vibrations in the air — sound waves, in other words.

Winds blowing between 10 and 15 miles per hour over InSight’s solar panels caused the spacecraft to vibrate, and short-period seismometers recorded the vibrations.

The seismometers act as the cochlea, the parts of your ears that convert the vibrations into nerve signals. They are able to record vibrations up to a frequency of 50 Hertz — audible to human ears as a low rumble.

NASA also produced a version of the recording that lifted the sounds by two octaves.

A second instrument, an air pressure sensor that is part of InSight’s weather station, also picked up sound vibrations, although at a much lower frequency that can be heard perhaps by elephants and whales, but not people.

Here is a sound recording of those pressure readings, sped up by a factor of 100, which raises the pitch by about six octaves.

The sounds are so low in part because the instruments are not sensitive to higher frequencies. But the air on Mars is also extremely thin — about 1 percent of the density of Earth’s — and that favors low-frequency sounds.

The two Viking landers that NASA sent to Mars in 1976 also carried seismometers that captured some wind noise. But Dr. Banerdt said those recordings were at much lower sampling rates and did not pick up anything at audible frequencies.

NASA’s next rover, to launch in 2020, will also carry a microphone.

This is not the first time sound has been recorded on another planet. Back in the 1980s, two Soviet spacecraft, Venera 13 and Venera 14, recorded sounds from the surface of Venus.

And Europe’s Huygens lander, which was carried to Saturn’s biggest moon, Titan, by the Cassini spacecraft, also sent back sounds picked up by a microphone.

Pass it on: Popular Science

## Rolls-Royce Reveals Its New Phantom: ‘The Most Silent Car In The World’

Whisper it softly, but the quietest and most technically advanced Rolls-Royce Phantom ever was launched in London tonight.

The flagship Rolls-Royce is designed to whisk the world’s wealthiest around in near silence and the lap of luxury – and it comes with its own dashboard art gallery for those who can afford the £350,000 price tag.

The new Phantom even paves the way for a future all-electric Rolls-Royce, ready to comply with Government moves to ban the sale of new ‘conventional’ petrol and diesel vehicles from 2040.

On the basis that silence is golden and the new Phantom limousine is ‘a work of art’, Rolls-Royce say their new Phantom is ‘the most silent motor car in the world’ and the quietest Rolls-Royce ever made –at least for the pampered chauffeur-driven occupant in the back.

The launch was hailed as another big vote of confidence in Britain – with the big Roller exported around the globe and considered the pinnacle of British automotive craftsmanship

Bosses at Rolls-Royce’s parent company BMW – which earlier this week announced they were building an electric Mini in the UK – said the new Phantom demonstrated that they remain ‘fully committed to the future of Rolls-Royce Motor Cars’, based at Goodwood, in West Sussex.

Pass it on: Popular Science

## Scientists Are Slowly Unlocking The Secrets Of The Earth’s Mysterious Hum

“In the deep glens where they lived all things were older than man and they hummed of mystery.”

The world hums. It shivers endlessly.

It’s a low, ceaseless droning of unclear origin that rolls imperceptibly beneath our feet, impossible to hear with human ears.

A researcher once described it to HuffPost as the sound of static on an old TV, slowed down 10,000 times.

It’s comforting to think of Earth as solid and immovable, but that’s false. The world is vibrating, stretching and compressing. We’re shaking right along with it.

The earth is ringing like a bell all the time,” said Spahr Webb, a seismologist at Columbia University.

The hum is everywhere. Its ultralow frequencies have been recorded in Antarctica and Algeria, and — as announced this week by the American Geophysical Union — on the floor of the Indian Ocean.

We still don’t know what causes it.

Some have theorized that it’s the echo of colliding ocean waves, or the movements of the atmosphere, or vibrations born of sea and sky alike.

But if we could hear this music more clearly, scientists around the world say, it could reveal deep secrets about the earth beneath us, or even teach us to map out alien planets.

And the hum is getting clearer all the time.

Earth vibrates at different frequencies and amplitudes, for different reasons, and not all those vibrations are the ‘hum’. Earthquakes are like huge gong bangs.

When an enormous quake hit Japan in 2011, Webb said, the globe kept ringing for a month afterward.

People sitting on the other side of the world bounced up and down about a centimeter, though so slowly they didn’t feel a thing.

In 1998, a team of researchers analyzed data from a gravimeter in east Antarctica and realized that some of these vibrations never actually stop.

The phenomenon became popularly known as the “hum of the Earth.

Webb was one of many researchers who searched for the hum’s cause in the 21st century.

Some thought interactions between the atmosphere and solid ground caused the shaking, though he discounts the idea.

Sometimes waves sloshing in opposite directions intersect, sending vibrations deep down into Earth’s crust.

Sometimes a wave on a shallow coast somewhere ripples over the rough sea floor and adds its own frequencies to the hum.

Whatever the origin, the result is a harmony of ultralow frequencies that resonate almost identically all over the globe.

And that’s potentially invaluable to those who want to know what goes on beneath its surface, where the core spins and tectonic plates shift.

Scientists already measure how fast earthquake waves travel through different regions of the underground to make detailed subterranean maps.

The scientists collected data from seismometer stations that had been placed in the Indian Ocean near Madagascar several years ago.

These stations were meant to study volcanic hot spots nothing to do with the hum but the team worked out a method to clean the data of ocean currents, waves, glitches and other noise.

It peaked between 2.9 and 4.5 millihertz, they said — a tighter range than the first hum researchers in the 1990s had recorded.

It was also similar to measurements taken from a land-based station in Algeria.

So more evidence that the hum goes all the way around the world; and more hope that we may one day reveal all that goes on beneath it.

Pass it on: Popular Science

## People Who ‘Hear Voices’ Can Detect Hidden Speech In Unusual Sounds

People who hear voices that other people can’t hear may use unusual skills when their brains process new sounds, according to research led by Durham University and University College London (UCL).

The study, published in the academic journal Brain, found that voice-hearers could detect disguised speech-like sounds more quickly and easily than people who had never had a voice-hearing experience.

The findings suggest that voice-hearers have an enhanced tendency to detect meaningful speech patterns in ambiguous sounds.

The researchers say this insight into the brain mechanisms of voice-hearers tells us more about how these experiences occur in voice-hearers without a mental health problem, and could ultimately help scientists and clinicians find more effective ways to help people who find their voices disturbing.

The study involved people who regularly hear voices, also known as auditory verbal hallucinations, but do not have a mental health problem.

Participants listened to a set of disguised speech sounds known as sine-wave speech while they were having an MRI brain scan.

Usually, these sounds can only be understood once people are either told to listen out for speech, or have been trained to decode the disguised sounds.

Sine-wave speech is often described as sounding a bit like birdsong or alien-like noises. However, after training people can understand the simple sentences hidden underneath (such as “The boy ran down the path” or “The clown had a funny face”).

In the experiment, many of the voice-hearers recognised the hidden speech before being told it was there, and on average they tended to notice it earlier than other participants who had no history of hearing voices.

The brains of the voice-hearers automatically responded to sounds that contained hidden speech compared to sounds that were meaningless, in the regions of the brain linked to attention and monitoring skills.

The small-scale study was conducted with 12 voice-hearers and 17 non voice-hearers. Nine out of 12 (75 per cent) voice-hearers reported hearing the hidden speech compared to eight out of 17 (47 per cent) non voice-hearers.

Lead author Dr Ben Alderson-Day, Research Fellow from Durham University’s Hearing the Voice project, said: “These findings are a demonstration of what we can learn from people who hear voices that are not distressing or problematic.”

It suggests that the brains of people who hear voices are particularly tuned to meaning in sounds, and shows how unusual experiences might be influenced by people’s individual perceptual and cognitive processes.

People who hear voices often have a diagnosis of a mental health condition such as schizophrenia or bipolar disorder. However, not all voice-hearers have a mental health problem.

Research suggests that between five and 15 per cent of the general population have had an occasional experience of hearing voices, with as many as one per cent having more complex and regular voice-hearing experiences in the absence of any need for psychiatric care.

Co-author Dr Cesar Lima from UCL’s Speech Communication Lab commented: “We did not tell the participants that the ambiguous sounds could contain speech before they were scanned, or ask them to try to understand the sounds.

Nonetheless, these participants showed distinct neural responses to sounds containing disguised speech, as compared to sounds that were meaningless.

This was interesting to us because it suggests that their brains can automatically detect meaning in sounds that people typically struggle to understand unless they are trained.

The research is part of a collaboration between Durham University’s Hearing the Voice project, a large interdisciplinary study of voice-hearing funded by the Wellcome Trust, and UCL’s Speech Communication lab.

Durham’s Hearing the Voice project aims to develop a better understanding of the experience of hearing a voice when no one is speaking.

The researchers want to increase understanding of voice-hearing by examining it from different academic perspectives, working with clinicians and other mental health professionals, and listening to people who have heard voices themselves.

In the long term, it is hoped that the research will inform mental health policy and improve therapeutic practice in cases where people find their voices distressing and clinical help is sought.

Professor Charles Fernyhough, Director of Hearing the Voice at Durham University, said: ‘This study brings the expertise of UCL’s Speech Communication lab together with Durham’s Hearing the Voice project to explore what is a frequently troubling and widely misunderstood experience.

Professor Sophie Scott from UCL Speech Communication Lab added: “This is a really exciting demonstration of the ways that unusual experiences with voices can be linked to — and may have their basis in — everyday perceptual processes.

The study involved researchers from Durham University, University College London, University of Porto (Portugal), University of Westminster and University of Oxford.