---
author: Eric Wagoner
date: '1999-10-18T11:19:14'
draft: false
title: Stephen Hawking has conjectured that
---

Stephen Hawking has conjectured that the laws of physics will disallow time machines. One of his arguments is that if time travel were indeed possible, we would be "awash in thousands of time travelers from the future." Carl Sagan, [in an interview with PBS's Nova](http://pbs.org/wgbh/nova/time/sagan.html), offers half a dozen counter-arguments.