September 1, 2005
1 min read
Add Us On GoogleAdd SciAmA Better Time Machine
By JR Minkel
On supporting science journalism
If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.
Scientific proposals for time machines are always a letdown: If you had an infinitely long cylinder. If you could get a glob of stuff with negative energy density. If it could resist quantum-mechanical fluctuations. Physicist Amos Ori of the Israel Institute of Technology in Haifa hasn't exactly invented the flux capacitor used in Back to the Future, but his latest idea has a couple things going for it: finite size and no need for questionable negative energy to prop it open. He reasons that a doughnut-shaped vacuum containing a certain doughnut-shaped gravitational field in otherwise ordinary space constitutes a time machine. Fly your spaceship into the toroid and exit at any time of your choosing, as far back as the creation of the time machine. The remaining questions are whether it is stable and how to set one up—Ori does not know how but speculates that possibilities include focusing gravitational waves or whirling some really massive object around. Catch the July 7 Physical Review Letters for more.
It’s Time to Stand Up for Science
If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.
I’ve been a Scientific American subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.
If you subscribe to Scientific American, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.
In return, you get essential news, captivating podcasts, brilliant infographics, can't-miss newsletters, must-watch videos, challenging games, and the science world's best writing and reporting. You can even gift someone a subscription.
There has never been a more important time for us to stand up and show why science matters. I hope you’ll support us in that mission.
