(FORTUNE Magazine) – Arno Penzias, former chief scientist of Bell Labs, is now a venture capitalist at New Enterprise Associates. He won the 1978 Nobel Prize in physics for his contribution to the big bang theory. He was interviewed by Erick Schonfeld.

I used to joke that bandwidth is like money and sex--only too much seems to be enough. It's hard to say how much too much is. But it certainly is a lot more than we have now.

From the user perspective, it's going to be incredibly cheap because you don't ration bandwidth anymore. It's not what they're selling. Bandwidth becomes a commodity. Imagine you have a toy train layout, and at every station along the way you unload all the cars and look inside. Then you decide what goes to that station, you put the rest back, and you go to the next station. It sounds inane, but that's what we do today. The only reason you do that is because you can only afford to run one train a day. But now the trains are free because you can run as many trains on the track as you want and send one train to each town. It's the FedEx model, except instead of Memphis, you've got these carrier hotels that connect to the backbone. It's a very different architecture. And that architecture is going to be incredibly cheap because you've got so much more pipe--and all the electronics have disappeared.

Once you begin to see this, you get all new economics. Some of the incumbents are going to have a hard time, because incumbents are set up with a totally different economics.