right now, the people involve say it is going to be too hard to measure this 1.26 microsecond shortening of the day is an estimate. >> sure. >> but i will bet you that within five years, certainly within ten years, there are going to be groups of people at the national institute of science and technology, formerly the bureau of standards and places like that, will be able to measure this, so we all depend on this stuff. here is a phone with a map of london on it, right now. >> right. >> and this is made possible, because we are able to measure time in these tiny, tiny segments. we would not be able to find our way around with sat nav or global positioning measures without these accurate time measurements. this has allowed us to understand the earth using satellite data and so on to figure out this tiny effect.