Awww. Well, that is very sweet.
I can only assume that your friend was talking about “red shift”, as EvilGhandi said. How he could use it to suggest that the universe is shrinking is a true mystery, worthy of Scooby and the gang.
Ya know what the “doppler effect” is?
When a firetruck approaches, and then passes you, you can hear the siren drop in tone. Actually, you can even hear this in the sound of a car engine as a car whips by you as well.
The reason this happens is because when a car is approaching you, sound emanates out at a certain speed, but the car is chasing the sound so to speak. The sound forms waves, but because the car is moving into the sound, the wavelengths are made shorter. A shortened wavelength means a higher pitch.
Then the car passes you, and the now the car is moving away from the sound that is coming towards you. This has the reverse effect. The wavelengths of the sound become longer. Longer wavelength means lower pitch.
The same thing happens with light, except that with light, a shorter wavelength means that light looks more bluish/violetish (called a “blue shift”), while a longer wavelength means that light looks more reddish (called a “red shift”).
So if a spaceship is flying towards you very quickly, the color of the ship would be shifted to be a bit more blue, and if it was flying away from you, it would be a bit more red.
Well, distant stars most definitely appear red shifted. This is an indication that they are moving away from us, and that helps to support the idea that the universe is expanding.
So again, I have no idea what this guy would have been saying about the red shift to suggest that the universe is shrinking.