How Many Zeptoseconds In A Second? Scientists Discover Shortest Unit Of Time

Scientists have measured the shortest unit of time ever -- the zeptosecond.

The zeptosecond is the unit used to measure the time it takes for a light particle to cross a hydrogen molecule. For the record, that time would take about 247 zeptoseconds. According to an article by Space.com published Sunday, a zeptosecond is a trillionth of a billionth of a second or a decimal point followed by 20 zeroes and a 1.

Now, one might wonder how scientists were able to discover this feat. According to researchers from the Nature Physics journal, they used lasers to measure time in increments down to 850 zeptoseconds. Physicist Reinhard Dörner of Goethe University in Germany, together with his colleagues, shot X-rays from the PETRA III at Deutsches Elektronen-Synchrotron (DESY), a particle accelerator in Hamburg.

The researchers would set the energy of the X-rays in a way that a single photon (particle of light) would knock the two electrons out of a hydrogen molecule. As the photon bounces on one electron of the molecule and then the other, a wave pattern, better known as an interference pattern, would then form. The said interference pattern would then be measured by Dörner and his colleagues with a machine called a Cold Target Recoil Ion Momentum Spectroscopy (COLTRIMS) microscope -- a tool designed to be able to record extremely fast atomic and molecular reactions.

"Since we knew the spatial orientation of the hydrogen molecule, we 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," says Sven Grundmann, a study co-author at the University of Rostock in Germany, in a statement published Oct. 16 by Phys.org.

This success is a huge leap from the Nobel-Prize winning work back in 1999, where researchers measured time using femtoseconds -- the time it takes for chemical bonds to break and form.