 So here we have a plot of gamma where the x-axis is velocity. So gamma is also called the Lorentz factor, and in the case we just looked at, it tells us the degree of time dilation between Alice and Paul, how much slower Paul sees Alice's clock ticking. Now one thing to note is that because the velocity of any object is always less than the speed of light, gamma is always greater than 1. In fact, in everyday life, v is much, much smaller than c, and so gamma is pretty much equal to 1. There is no observable time dilation, which is why you don't notice it when you go for a drive in the car. There is, however, a very famous experiment where scientists took two very precise atomic clocks, left one on the ground and sent the other in an airplane to fly all the way around the world, traveling really quickly. When they brought the two clocks back together, there was a noticeable difference in the timing between these two, which was exactly what was predicted by relativity. Another thing is GPS satellites, which travel at around four kilometers per second relative to us. The clocks on board do tick noticeably slower than clocks down on the ground, and this time dilation has to be taken into account for the GPS on your phone to accurately find the opposition. We can see that for gamma to become physically noticeable to something other than an atomic clock or the computer on a GPS satellite. You need to be going very, very quickly, and it's only as v gets really close to see that gamma starts to grow large.