Scientists Measure Smallest Unit of Time Ever in 'Zeptoseconds'
2020-10-26
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1German scientists say they have measured the smallest unit of time ever recorded.
2Researchers say the unit was measured in zeptoseconds.
3A zeptosecond is a trillionth of a billionth of a second.
4The researchers made the discovery while studying how long it took a photon - a particle of light - to cross a hydrogen molecule.
5The German scientists say the photon crossed the molecule in about 247 zeptoseconds.
6"This is the shortest timespan that has been successfully measured to date," the team said in a statement.
7The results were reported in Science magazine.
8The research was a project of physicists from Goethe University in Frankfurt, Germany.
9The team said the experiment represents major progress in "the global race" to measure shorter and shorter units of time.
10The method used to measure in zeptoseconds involves what is known as the photoelectric effect.
11This scientific law explains how and why some metals give off electrons after light falls on their surfaces.
12Albert Einstein is credited with discovering the photoelectric effect.
13He was awarded the 1921 Nobel Prize in Physics for doing so.
14The discovery helped lead to the development of modern electronics, including radio and television.
15The German scientists say they used equipment at the DESY national research center, which operates particle accelerators.
16The machines are used to investigate the structure of matter.
17The research includes experiments in photon science.
18The researchers said they made the measurement by releasing X-ray waves onto a molecule of hydrogen, which is made up of two protons and two electrons.
19They set the energy of the X-rays so that one photon would be enough to expel both electrons out of the hydrogen molecule.
20The scientists explained that electrons behave like particles and waves at the same time.
21So, after the first electron was ejected, the second followed a short time later.
22This process resulted in what the researchers called "an interference pattern."
23The researchers used this pattern to measure the electrons as they were escaping.
24Sven Grundmann is a doctoral student at Goethe University who helped lead the research.
25He said the team "used the interference of the two electron waves to precisely calculate when the photon reached the first and when it reached the second hydrogen atom."
26The calculation added up to 247 zeptoseconds, "depending on how far apart in the molecule the two atoms were from the perspective of light," he said.
27The research also involved a complex spectrometer, an instrument used to measure atomic and molecular reactions.
28Goethe University's Reinhard Dörner said the spectrometer made it possible to observe "for the first time that the electron shell in a molecule does not react to light everywhere at the same time."
29The time delay happens because information within the molecule only spreads at the speed of light," Dörner added.
30"With this finding we have extended our technology to another application."
31There has been earlier research on the speed at which molecules change shape.
32In 1999, Ahmed Zewail - a professor at the California Institute of Technology - won the Nobel Prize in Chemistry for his work in the field.
33Zewail, an Egyptian, was recognized for experiments that used laser light to study how atoms in a molecule move during a chemical reaction.
34His research involved femtoseconds, a unit of measurement meaning one quadrillionth of a second.
35The German scientists say their research represents major progress from the earlier experiments.
36They also say they plan to build on their findings to measure even smaller units of time.
37I'm Bryan Lynn.
1German scientists say they have measured the smallest unit of time ever recorded. 2Researchers say the unit was measured in zeptoseconds. A zeptosecond is a trillionth of a billionth of a second. 3The researchers made the discovery while studying how long it took a photon - a particle of light - to cross a hydrogen molecule. 4The German scientists say the photon crossed the molecule in about 247 zeptoseconds. "This is the shortest timespan that has been successfully measured to date," the team said in a statement. The results were reported in Science magazine. 5The research was a project of physicists from Goethe University in Frankfurt, Germany. The team said the experiment represents major progress in "the global race" to measure shorter and shorter units of time. 6The method used to measure in zeptoseconds involves what is known as the photoelectric effect. This scientific law explains how and why some metals give off electrons after light falls on their surfaces. 7Albert Einstein is credited with discovering the photoelectric effect. He was awarded the 1921 Nobel Prize in Physics for doing so. The discovery helped lead to the development of modern electronics, including radio and television. 8The German scientists say they used equipment at the DESY national research center, which operates particle accelerators. The machines are used to investigate the structure of matter. The research includes experiments in photon science. 9The researchers said they made the measurement by releasing X-ray waves onto a molecule of hydrogen, which is made up of two protons and two electrons. They set the energy of the X-rays so that one photon would be enough to expel both electrons out of the hydrogen molecule. 10The scientists explained that electrons behave like particles and waves at the same time. So, after the first electron was ejected, the second followed a short time later. This process resulted in what the researchers called "an interference pattern." The researchers used this pattern to measure the electrons as they were escaping. 11Sven Grundmann is a doctoral student at Goethe University who helped lead the research. He said the team "used the interference of the two electron waves to precisely calculate when the photon reached the first and when it reached the second hydrogen atom." The calculation added up to 247 zeptoseconds, "depending on how far apart in the molecule the two atoms were from the perspective of light," he said. 12The research also involved a complex spectrometer, an instrument used to measure atomic and molecular reactions. Goethe University's Reinhard Dörner said the spectrometer made it possible to observe "for the first time that the electron shell in a molecule does not react to light everywhere at the same time." The time delay happens because information within the molecule only spreads at the speed of light," Dörner added. "With this finding we have extended our technology to another application." 13There has been earlier research on the speed at which molecules change shape. In 1999, Ahmed Zewail - a professor at the California Institute of Technology - won the Nobel Prize in Chemistry for his work in the field. 14Zewail, an Egyptian, was recognized for experiments that used laser light to study how atoms in a molecule move during a chemical reaction. His research involved femtoseconds, a unit of measurement meaning one quadrillionth of a second. 15The German scientists say their research represents major progress from the earlier experiments. They also say they plan to build on their findings to measure even smaller units of time. 16I'm Bryan Lynn. 17Bryan Lynn wrote this story, based on reports from Goethe University, Science and nobelprize.org. was the editor. 18We want to hear from you. Write to us in the Comments section, and visit our Facebook page. 19________________________________________________________________ 20Words in This Story 21unit - n. a single thing or a separate part of something larger 22pattern - n. a particular way in which something is done, organized or happens 23precise - adj. exact and correct 24calculate - v. to discover an amount or number using mathematics 25perspective - n. a way of thinking about and understanding something 26application - n. a way in which something can be used for a particular purpose