# DIMACS Theory Seminar

## Title:

Fundamental physical limits on computation
## Speaker:

- Warren Smith
- NEC Research

## Place:

- Room 402, Computer Science Building
- Princeton University

## Time:

- Lunch 11:45 AM, Talk 12 Noon
- Friday, May 5, 1995

## Abstract:

We consider limitations on the performance of computers arising from
thermodynamics and the laws of physics. We provide upper bounds on
three quantities: sustained information flux, information storage
density, and sustained computational speed. All of these upper bounds
are ``tight'' in the sense that they could be approached by
plausible-sounding physical systems, and they all arise from a single
unified point of view. We also make a conjecture about the rate of
inevitable decay of stored information. This conjecture may be thought
of as a quantitative extension of the second law of thermodynamics. It
leads to a bound on the density of stable information. We carefully
elucidate the assumptions behind these bounds. We give a list of 4
open problems at the end.
Host: Sanjeev Arora

Document last modified on May 1, 1995