 When you get into the very small scale into the quantum world and you have a quantum particle pushing on a barrier There's a finite probability that that particle can actually pass through the barrier and that process is called quantum tunneling What we've done in our experiment is look at the most basic atom the most simple atom and look how long it took an Electron to pass through that barrier. So the only atom which we can model precisely is the hydrogen atom So this is the major advance of our experiment is to do this experiment with hydrogen atoms There are no electron-electron correlations when they measure the electron angle We can calculate the angle precisely and compare the theory of the experiment We created what's called elliptically polarized light and that means the electric field of the light points in a particular direction The light that we use is very short. It has a pulse duration of 5 femtoseconds Which is 2 oscillations electric field at 800 nanometers We can actually make that pulse of light behave like a clock by doing this particular Polarization and we can have well-defined reference points when we start the interaction with the atom When we expect an electron to come out and when do we actually see it come out and any difference between that? Tells us something about this tunneling time. We determined that time must be less than 1.8 at a second and another second is a billionth of a billionth of a second The work is very important because it resolves very long-standing and very controversial problem in quantum physics about the tunneling time People have been arguing about it since early days of quantum mechanics since 1930s And our work rules out a whole range of theories for times greater than what we actually measure So we have an excellent research team working here on griffids which includes people of all levels faculty members as myself and Robert a PhD student who was actually a first author of this paper. It's a remarkable opportunity for Regitson to be enrolled in this type of research which results ultimately in the publication of the most important scientific journal in the world