Featured Research

from universities, journals, and other organizations

Could Physicists Make A Time Machine? It All Depends On Curving Space-time

Date:
August 23, 2007
Source:
Technion, Israel Institute Of Technology
Summary:
Researchers have developed a theoretical model of a time machine that, in the distant future, could possibly enable future generations to travel into the past. The main question is: if, according to the principles of curvature development in the theory of relativity, can a time machine be created? In other words, can we cause space-time to curve in such a way as to enable travel back in time? Such a journey requires a significant curvature of space-time, in a very special form.

Do the laws of gravity permit the development of spacetime with closed time-like curves? If so, then traveling back in time may be possible, physicists suggest.
Credit: iStockphoto/Arpad Benedek

Technion researchers have developed a theoretical model of a time machine that, in the distant future, could possibly enable future generations to travel into the past. 

“In order to travel back in time, the spacetime structure must be engineered appropriately,” explains Prof. Amos Ori of the Technion’s Faculty of Physics. “This is what Einstein’s theory of general relativity deals with. It says that spacetime can be flat. That is – it has a trivial, simple structure. But it can also be curved with various configurations. According to the theory of relativity, the essence of gravitational fields is in the curving of spacetime. The theory of relativity also defines how space is curved and how this curvature develops over time.”

The main question is: if, according to the principles of curvature development in the theory of relativity, can a time machine be created? In other words, can we cause spacetime to curve in such a way as to enable travel back in time? Such a journey requires a significant curvature of spacetime, in a very special form.

Traveling back in time is actually closing time-like curves so we can go back to an event at which we were present in the past. In flat space, it is not possible to close curves and go back in time. In order for closed time-like curves to exist, there has to be a curvature of a specific form on spacetime.

The question Prof. Ori is investigating is: do the laws of gravity permit the development of spacetime with the required curvature (closed time-like curves)? In the past, scientists raised a number of objections to this possibility. Now, Prof. Ori is proposing a theoretical model for spacetime that could develop into a time machine.

The model overcomes some of the questions, which, until now, scientists have not succeeded in solving. One of the difficult claims against a time machine was that, in order to create a time machine, it would be necessary for it to contain material with negative density. And since we do not have such material – and it is also not clear if the laws of nature enable the existence of such material in the quantities required - it is not possible to build a time machine. Now, Prof. Ori comes along and proposes a theoretical model that does not require material with negative density. The model that he proposes is, essentially, a vacuum space that contains a region field with standard positive density material.

 “The machine is spacetime itself,” he explains. “Today, if we were to create a time machine – an area with a warp like this in space that would enable time lines to close on themselves – it might enable future generations to return to visit our time. We, apparently, cannot return to previous ages because our predecessors did not create this infrastructure for us.”

Prof. Ori emphasizes that we still do not have the technology to control gravitational fields at will, despite the fact that the theoretical principles of how to do this exist. “The model that we developed at the Technion is a significant step but there still remains a number of non-trivial open questions,” he stresses. “It may be that some of these questions also will not be solved in the future. This is still not clear.” As an example, he brings up the problem of instability according to which in spacetime with a time machine there could be disturbances with increasing strength so that spacetime would be disrupted to such an extent that it would cancel out the time machine. Prof. Ori, one of the few scientists in the world investigating this issue, hopes that continued research will present a clearer picture with respect to these questions.

An article on this model was published recently in the journal “Physical Review.”


Story Source:

The above story is based on materials provided by Technion, Israel Institute Of Technology. Note: Materials may be edited for content and length.


Cite This Page:

Technion, Israel Institute Of Technology. "Could Physicists Make A Time Machine? It All Depends On Curving Space-time." ScienceDaily. ScienceDaily, 23 August 2007. <www.sciencedaily.com/releases/2007/08/070822164415.htm>.
Technion, Israel Institute Of Technology. (2007, August 23). Could Physicists Make A Time Machine? It All Depends On Curving Space-time. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2007/08/070822164415.htm
Technion, Israel Institute Of Technology. "Could Physicists Make A Time Machine? It All Depends On Curving Space-time." ScienceDaily. www.sciencedaily.com/releases/2007/08/070822164415.htm (accessed October 22, 2014).

Share This



More Matter & Energy News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Internet of Things Aims to Smarten Your Life

Internet of Things Aims to Smarten Your Life

AP (Oct. 22, 2014) — As more and more Bluetooth-enabled devices are reaching consumers, developers are busy connecting them together as part of the Internet of Things. (Oct. 22) Video provided by AP
Powered by NewsLook.com
Thanks, Marty McFly! Hoverboards Could Be Coming In 2015

Thanks, Marty McFly! Hoverboards Could Be Coming In 2015

Newsy (Oct. 21, 2014) — If you've ever watched "Back to the Future Part II" and wanted to get your hands on a hoverboard, well, you might soon be in luck. Video provided by Newsy
Powered by NewsLook.com
Robots to Fly Planes Where Humans Can't

Robots to Fly Planes Where Humans Can't

Reuters - Innovations Video Online (Oct. 21, 2014) — Researchers in South Korea are developing a robotic pilot that could potentially replace humans in the cockpit. Unlike drones and autopilot programs which are configured for specific aircraft, the robots' humanoid design will allow it to fly any type of plane with no additional sensors. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Graphene Paint Offers Rust-Free Future

Graphene Paint Offers Rust-Free Future

Reuters - Innovations Video Online (Oct. 21, 2014) — British scientists have developed a prototype graphene paint that can make coatings which are resistant to liquids, gases, and chemicals. The team says the paint could have a variety of uses, from stopping ships rusting to keeping food fresher for longer. Jim Drury reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins