Lightning, usually brings out scary images within the mind, thoughts of nature’s wrath being vented on the Earth. At the same time, lightning has been the object of the photographer’s affection, the beauty of its arc seducing their lusty lenses to capture the detail of the phenomenon.
Now, to take matters further, scientists have captured a picture of the sound that goes along with it, in what is touted as the first ever detailed image of thunder.
The image was captured by sending a copper wire into a cloud to make it send down thunder and lightning by Maher Dayeh, a heliophysicist from the Southwest Research Institute in San Antonio.
The event was recorded with 15 microphones that were laid out 95 meters from the lightning, which together helped capture the sound waves.
The images, which are made up of acoustic maps, are captured using a special equipment that can visualize the way that the sound moves in space.
Through the capturing of sound, scientists hope to gain a better understanding of the physics behind the natural strike.
Lightning is created by electrical charges move either within a cloud or between the cloud and the ground. It causes sudden increase in pressure and temperature which produces sudden expansion of the surrounding air, which in turn results in a sonic shock wave called thunder.
After years of nursing a sometimes dusty cylinder of metal in a vault outside Paris as the global reference for modern mass, scientists are updating the definition of the kilogram.
Just as the redefinition of the second in 1967 helped to ease communication across the world via technologies like GPS and the internet, experts say the change in the kilogram will be better for technology, retail and health — though it probably won’t change the price of fish much.
The kilogram has been defined since 1889 by a shiny piece of platinum-iridium held in Paris. All modern mass measurements are traceable back to it — from micrograms of pharmaceutical medicines to kilos of apples and pears and tons of steel or cement.
The problem is, the “international prototype kilogram” doesn’t always weigh the same. Even inside its three glass bell jars, it gets dusty and dirty, and is affected by the atmosphere. Sometimes, it really needs a wash.
“We live in a modern world. There are pollutants in the atmosphere that can stick to the mass,” said Ian Robinson, a specialist in the engineering, materials and electrical science department at Britain’s National Physical Laboratory.
“So when you just get it out of the vault, it’s slightly dirty. But the whole process of cleaning or handling or using the mass can change its mass. So it’s not the best way, perhaps, of defining mass.”
What’s needed is something more constant.
So, at the end of a week-long meeting in the Palace of Versailles, Paris, the world’s leading measurement aficionados at the International Bureau of Weights and Measures will vote Friday to make an “electronic kilogram” the new baseline measure of mass.
Just as the meter — once the length of a bar of platinum-iridium, also kept in Paris — is now defined by the constant speed of light in a vacuum, so a kilogram will be defined by a tiny but immutable fundamental value called the “Planck constant.”
The new definition involves an apparatus called the Kibble balance, which makes use of the constant to measure the mass of an object using a precisely measured electromagnetic force.
“In the present system, you have to relate small masses to large masses by subdivision. That’s very difficult — and the uncertainties build up very, very quickly,” Robinson said.
“One of the things this [new] technique allows us to do is to actually measure mass directly at whatever scale we like, and that’s a big step forward.”