慢速英语:A New Camera Records Invisible Motion

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The world is in never-ending motion, even when objects seem to be perfectly still. Researchers at the Massachusetts Institute of Technology use a special camera that shows these seemingly invisible movements.

Many objects around us vibrate when hit by sound waves. But the movements are not visible to the human eye.

One example of this invisible movement happens when a wine glass is exposed to a loud noise. It vibrates although it looks still.

The movements can be recorded with a special high-speed camera called a motion microscope. The microscope records thousands of picture frames per second, and a computer program amplifies the sound vibrations. These are made into a video in which a wine glass hit by sound waves looks very flexible.

Michael Rubinstein is the lead researcher of the motion microscope technology. He has made his research open to the public, so anyone can make magnified videos of their own.

Neil Wadhwa is a graduate student at the Massachusetts Institute of Technology. He recorded and amplified the movements of a person's face with a motion microscope. The recording shows the man's blood pressure going up and down with every heartbeat.

"The motion microscope is a way to visualize small motions that are seemingly invisible to the naked eye in videos."

Mr. Wadhwa says the motion microscope can be very useful for observing important movements, like those of a baby during pregnancy or of an infant breathing.

"You can create a non-contact vital signs monitor so you don't need to attach anything to a person and you will still be able to figure out their heart rate and respiration rate."

Mr. Wadhwa says recording invisible motion also could be used in other ways. He says the technology can help engineers detect vibrations of buildings, bridges, and construction materials.

I'm Jonathan Evans.

George Putic reported this story from Washington. Jonathan Evans wrote it for Learning English.