The concept of time as a way to measure the duration of events is not only deeply intuitive, it also plays an important role in our mathematical descriptions of physical systems. For instance, we define an object’s speed as its displacement per a given time. But some researchers theorize that this Newtonian idea of time as an absolute quantity that flows on its own, along with the idea that time is the fourth dimension of spacetime, are incorrect. They propose to replace these concepts of time with a view that corresponds more accurately to the physical world: time as a measure of the numerical order of change.
posted by finite on Apr 25, 2011 - 127 comments

China bans time-travel movies. [via]
posted by crossoverman on Apr 12, 2011 - 62 comments

Rules for Time Travelers [Spoiler? alert.]
posted by BitterOldPunk on May 14, 2009 - 82 comments

These subjects still fascinate me after a lifetime of interest: faster-than-light speed, alternate time streams, parallel universes, time travel, antiparticles moving backward in time, time loops, and the recurring themes of paradox -- all serious but astonishing ideas of science. Something about them inspires infinite possibilities. Am I not alone?
posted by ember on Mar 12, 2009 - 64 comments

Man loses father to smoking 50 years ago. Builds time machine.
posted by loquacious on Nov 6, 2008 - 143 comments

Time Travel, or, the art of causing events after they've already happened. [requires java, more inside]
posted by Avenger on Jul 23, 2007 - 34 comments

John Cramer is going to conduct an experiment in quantum retrocasuality [ppt] - sending a signal backwards through time
posted by MetaMonkey on Nov 29, 2006 - 33 comments

We are hosting the first and only Time Traveler Convention at MIT in one week, and WE NEED YOUR HELP! Anyone plan to attend?
posted by Ricky_gr10 on May 2, 2005 - 64 comments

Just how plausable is time travel? Could you go back in time and kill your own grandfather?. Would you want to? Time travel is a popular subject for films, but do the writers work out exactly what is happening? Current opinion seems to be that time travel is only possible to the future, and is only one way, by travelling at near light speed. However despite this, time machines seem to already be on sale.
posted by Orange Goblin on Feb 10, 2003 - 53 comments