ZEPTOSECOND

Scientists have measured the world's smallest unit of time, and it's called the zeptosecond. They measured how long it takes for a photon to cross a hydrogen molecule-around 247 zeptoseconds- makes the measurement the shortest time span "ever" to have been successfully recorded. A zeptosecond is a trillionth of a billionth of a second. That's a decimal point followed by 20 zeroes and a 1. Time is an obscure concept and is linked to the propagation of light in matter. This 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 surface. The research also involved a complex spectrometer, an instrument used to measure atomic and nuclear reactions. The spectrometer made it possible to observe for the first time that the electron shell in a molecule does not reach light everywhere at the same time. The time delay happens because information within the molecule only travels at the speed of light. The scientists say they plan to build on their findings to measure even smaller units of time. Not familiar with zeptoseconds? Take all the seconds that have passed since the beginning of the universe. The universe is about 13.8 billion years old. Multiply that by 2,500. That's about how many zeptoseconds fit into just one second. Researchers report this new measuring process should allow physicists to now study interactions between light and matter at a whole new level of detail. The results matched what the research had expected, based on the speed of light and the known diameter of a hydrogen molecule. The calculation captures the speed of light inside the molecule. Since they knew the spatial orientation of the hydrogen molecule, they used the interference of the two electron waves to precisely calculate when the photon reaches the first hydrogen atom and when it reaches the second hydrogen atom, and this is up to 247 zeptoseconds, depending on how far apart in the molecule the two atoms were from the perspective of light.