A process that takes more than one trillion years, the age of the universe has been measured by researchers. The researchers used an instrument that is built to search for black matter (the most elusive particle that's known to man!).

An international team from the XENON Collaboration made public their observation of the radioactive decay of a substance that is called xenon-124, a form of an isotope, of the element xenon - a colorless, dense but odorless noble gas that's found in trace on the Earth's atmosphere.

Experts had previously predicted that Xenon - 124's half-life, which is the time it takes on average for a half of a radioactive substance's material to decay, would roughly be around 160 trillion years. However, there was not enough scientific evidence to prove this until recently when this process appeared.

Scientists show that the actual figure is far much higher in yet another study that was published in the journal Nature. In the study, the scientists determined that in fact xenon - 124's half-life could be a staggering 18 sextillion years which far surpasses the age of the universe itself by about 13.8 billion years old!

Ethan Brown, the co-author of the study and professor of physics at Rensselaer Polytechnic Institute said that it was the longest, slowest process that had never been directly observed. He claimed that they had shown that they can observe the rarest events ever recorded. Brown went ahead to claim that their key finding was that if an isotope that was formerly thought to be completely stable now showing to decay on a very long timescale never imagined.

In order to make their observation, the researchers used an advanced type of detector known as XENON1T, which is a 2,900-pound vat of super-pure liquid of xenon in a cool chamber that's totally submerged in water up to about 5,000 feet beneath Italy's Gran Sasso Mountain.

The researchers had designed the 'XENON1' experiment to look for dark matter, which is a new kind of matter that is hypothesized to make up to 85% of the mass of the universe but often interacts so rarely such that it has never been observed.

With these latest findings from the research that was conducted Ethan Brown's research team in Italy's Gran Sasso Mountain, it seems that scientists have more work cut for them to try and find out more about detailed characteristics of the elusive substance Xenon-124.