### The Slowing Down of Time

During this century, humans will upload their minds into computer hardware. This got me thinking: the modern human brain calculates away at 100 trillion (1014) operations per second. Computers, however, will continue to improve in processing speed until they reach the physical limit of 100 trillion trillion trillion trillion (1050) operations per second as determined via quantum mechanics. This made me think: what if we were to essentially “speed up” the rate at which the uploaded brain calculates at? It might subjectively seem to that person that time has slowed down. Their normal thought processes would appear to be the same, but the rest of the world would slow at the same rate that their brain has been sped up.

So how slow? The Josephson Junctions I talked about on The Other Blog calculate 100 billion trillion (1023) operations per second per kilogram (which is about the same mass as the human brain). If your uploaded brain were made of these things, you could potentially slow down the passage of time by a factor of one billion. One second of the outside world would take one billion seconds for you. Of course, one billion seconds is around thirty-one years. Probably one could dial the actual rate of how fast their mind operates, or use it for only short periods of time (a subjective two-week virtual vacation would appear to take only a millisecond to the outside world).

But let’s go all the way. What if you were able to push your uploaded brain all the way to 1050 operations per second? A single nanosecond of “outside time” would equal, oh, several dozen quintillion years of “inside time”, about two million times longer than the current age of the universe.

Of course, light still travels at only 300,000 km/s in the outside world. Trying to communicate with someone else would take eons even if they were standing right next to you. Because of this, it will likely only take place in virtual space, at least for factors slower than a hundred or so. Virtual space isn’t hampered as much by the limitation of the speed of light because all the computing hardware is very close together.

The really weird problem is in some people living at a billion times the normal rate, with others living at normal speed. A normal-living community might take an hour to have lunch, while the high-speed virtual community will have lived through a hundred millennia. It will be interesting to see how society copes with that.