Wednesday, June 27, 2012

You Can’t Travel Back in Time, Scientists Say

You Can't Travel Back in Time, Scientists Say
By: Sara Goudarzi / Source: Live Science
The urge to hug a departed loved one again or prevent atrocities are among the compelling reasons that keep the notion of time travel alive in the minds of many.
While the idea makes for great fiction, some scientists now say traveling to the past is impossible.
There are a handful of scenarios that theorists have suggested for how one might travel to the past, said Brian Greene, author of the bestseller, "The Elegant Universe" and a physicist at Columbia University."And almost all of them, if you look at them closely, brush up right at the edge of physics as we understand it. Most of us think that almost all of them can be ruled out."
Vote for Your Favorite Time Travel Tale

The fourth dimension

In physics, time is described as a dimension much like length, width, and height. When you travel from your house to the grocery store, you're traveling through a direction in space, making headway in all the spatial dimensions—length, width and height. But you're also traveling forward in time, the fourth dimension.

"Space and time are tangled together in a sort of a four-dimensional fabric calledspace-time," said Charles Liu, an astrophysicist with the City University of New York, College of Staten Island and co-author of the book "One Universe: At Home In The Cosmos."
Space-time, Liu explains, can be thought of as a piece of spandex with four dimensions. "When something that has mass—you and I, an object, a planet, or any star—sits in that piece of four-dimensional spandex, it causes it to create a dimple," he said. "That dimple is a manifestation of space-time bending to accommodate this mass."

The bending of space-time causes objects to move on a curved path and that curvature of space is what we know as gravity.
Mathematically one can go backwards or forwards in the three spatial dimensions. But time doesn't share this multi-directional freedom.
"In this four-dimensional space-time, you're only able to move forward in time," Liu told LiveScience.Cosmic strings

Another popular theory for potential time travelers involves something called cosmic strings—narrow tubes of energy stretched across the entire length of the ever-expanding universe. These skinny regions, leftover from the early cosmos, are predicted to contain huge amounts of mass and therefore could warp the space-time around them.

Cosmic strings are either infinite or they're in loops, with no ends, said J. Richard Gott, author of "Time Travel in Einstein's Universe" and an astrophysicist at Princeton University. "So they are either like spaghetti or SpaghettiO's."
The approach of two such strings parallel to each other, said Gott, will bend space-time so vigorously and in such a particular configuration that might make time travel possible, in theory.

"This is a project that a super civilization might attempt," Gott told LiveScience. "It's far beyond what we can do. We're a civilization that's not even controlling the energy resources of our planet."
Impossible, for now Mathematically, you can certainly say something is traveling to the past, Liu said. "But it is not possible for you and me to travel backward in time," he said.

However, some scientists believe that traveling to the past is, in fact, theoretically possible, though impractical.
Maybe if there were a theory of everything, one could solve all of Einstein's equations through a wormhole, and see whether time travel is really possible, Kaku said. "But that would require a technology far more advanced than anything we can muster," he said. "Don't expect any young inventor to announce tomorrow in a press release that he or she has invented a time machine in their basement."
For now, the only definitive part of travel in the fourth dimension is that we're stepping further into the future with each passing moment. So for those hoping to see Earth a million years from now, scientists have good news.

"If you want to know what the Earth is like one million years from now, I'll tell you how to do that," said Greene, a consultant for "Déjà Vu," a recent movie that dealt with time travel. "Build a spaceship. Go near the speed of light for a length of time—that I could calculate. Come back to Earth, and when you step out of your ship you will have aged perhaps one year while the Earth would have aged one million years. You would have traveled to Earth's future."
 Edited by: Lawyer Asad


  1. Great post however , I was

    wondering if you could write a litte more on this topic? I'd be very grateful if you

    could elaborate a little bit further. Cheers!

    Visit my site
    Feel free to surf my web page :: create solar panels

  2. Thank you for the sensible critique. Me and my neighbor were just preparing to
    do a little research

    on this. We got a grab a book from our area library but I think I learned more from this

    I am very glad to see such magnificent info being shared

    out there.
    Also visit my site Costablancaspain.Us

  3. An interesting dialogue is value comment. I think that you
    should write more on this

    subject, it might not be a taboo subject however typically people are not enough to speak on such topics.
    To the next. Cheers

    Feel free to surf to my web-site
    Here is my homepage solar panel

  4. advertising
    Feel free to surf my weblog :

  5. Howdy, i read your blog from time to time and i own a similar one and i was just

    wondering if you get a lot of spam remarks? If so how do you prevent it, any plugin or anything you can recommend?
    I get so much lately it's driving me mad so any support is very much appreciated.

    my site - 10 day weather forecast majorca alcudia
    Here is my weblog ; 3 weeks pregnant and bleeding with clots

  6. Have you ever thought about publishing an e-book or guest authoring on other

    blogs? I have a blog based upon on the same information you

    discuss and would really like to have you share some stories/information.

    I know my audience would value your work. If you are even remotely interested, feel free to

    shoot me an e mail.
    Here is my page ;

  7. Hi there! Quick question that's entirely off

    topic. Do you know how to make your site mobile friendly? My site looks weird when

    browsing from my iphone 4. I'm trying to find a theme or plugin that

    might be able to resolve this problem. If you have any suggestions, please share.


    my web-site: best places to visit in costa del sol spain
    Review my webpage - spain chick corea transcription

  8. That is the appropriate blog for anyone who desires to seek out out about this topic.

    notice so much its nearly laborious to

    argue with you (not that I actually would need…HaHa).

    You undoubtedly put a brand new spin on a subject thats been written about for years.
    Great stuff, simply great!
    Look at my website

  9. Great blog! Is your theme custom made or did you download it from

    somewhere? A design like yours with a few simple adjustements would really
    make my blog shine. Please let me know where you got your design.
    my webpage:

  10. Great post and straight to the point. I don't know if this is

    actually the best place to ask but do you people have any ideea where

    to hire some professional writers? Thx :)
    My webpage -

  11. Useful information. Fortunate me I found your website

    by accident, and I am shocked why this

    coincidence did not came about earlier! I bookmarked it.
    Also see my web site -

  12. I think other site proprietors should take this web site as an model, very clean

    and wonderful user genial style and design, as well as the

    content. You're an expert in this topic!

    my web page; 4 letter words ending With que
    Also visit my website ; 2011 world series mvp prize

  13. I know this if off topic but I'm looking into starting my own weblog and was wondering what all is

    needed to get set up? I'm assuming having a blog like yours would cost a pretty penny?

    I'm not very

    internet smart so I'm not 100% certain. Any suggestions or advice

    would be greatly appreciated. Kudos

    My web site ... Http://www.catralproperty.Net/Catralpropertysalesclassifiedadverts.html
    my website -

  14. Hey there, I think your site might be having browser compatibility issues.
    When I look at

    your website in Safari, it looks fine but when opening in
    Internet Explorer, it

    has some overlapping. I just wanted to give you
    a quick heads up! Other then that, terrific blog!

    Here is my site cat spaying care
    Feel free to visit my homepage : how do i say i miss you in spanish

  15. I was curious if you ever thought of changing the page layout of your blog?
    Its very well written; I love what youve got to say. But
    maybe you could a little more in the way of content

    so people could connect with it better. Youve got an awful lot of text
    for only having 1 or 2 images. Maybe you could space it out better?

    My web blog -
    Feel free to surf my webpage :: spaniard clothing

  16. I like the helpful information you provide in your articles.
    I’ll bookmark your weblog

    and check again here regularly. I'm quite certain I will learn many new stuff right here! Best of luck for the next!

    My website ... Http://
    Have a look at my web-site ... never been to spain chords waylon

  17. I'm typically to running a blog and i really respect your content. The article has actually peaks my interest. I am going to bookmark your web site and keep checking for brand new information.

    my web site
    Here is my page ; family holiday photos

  18. I actually wanted to construct a simple comment to be able to

    say thanks to you for some of the splendid concepts you are giving here.

    My rather long internet investigation has finally been recognized with brilliant strategies to share with my pals.
    I would state that that many of us website visitors are definitely lucky to be in a very

    network with very many perfect professionals with
    good solutions. I feel

    very blessed to

    have encountered the weblog and look forward to really more

    times reading here. Thanks a lot once more for a lot of things.

    Take a look at my web page; 240x320 java touchscreen games download
    Here is my page - airport hotels barcelona spain

  19. I truly appreciate this post. I’ve been looking all
    over for this! Thank goodness I found it

    on Bing. You've made my day! Thank you again

    my web-site;
    Feel free to visit my webpage spain weather in february

  20. Howdy! Would you mind if I share your blog with my

    twitter group? There's a lot of people that I think would really appreciate your content.

    Please let me know. Thanks

    Also visit my web site ::
    Feel free to visit my weblog - accommodation in Murcia

  21. Pretty element of content. I simply stumbled

    upon your web site and in accession capital to
    assert that I acquire in

    fact loved account your weblog posts. Any way I will be subscribing for your feeds or even I
    success you get entry to persistently quickly.

    my web blog -
    Also see my page :: Laurels Homepage besuchen

  22. Well I definitely enjoyed reading it. This tip provided by you is very helpful for
    proper planning.

    Here is my webpage ::
    Stop by my web site : low cost homeowners insurance

  23. I have been exploring for a little bit for any
    high quality articles or blog posts in this kind of area .
    Exploring in Yahoo I finally stumbled upon this web site.
    Studying this info So i’m

    satisfied to convey that I have an incredibly good uncanny feeling I discovered just what I needed.
    I such a lot

    no doubt will

    make certain to don’t overlook this website and give it a look

    my web site ::
    Also visit my weblog ...

  24. Wonderful blog! I found it while surfing around on Yahoo News.
    Do you have any

    suggestions on how to get listed in Yahoo News?
    I've been trying for a while but I never seem to get there! Appreciate it

    My blog post
    My web-site spain weather satellite