Time Travel discovered

Discussion in 'General Science & Technology' started by faceurchin, Mar 15, 2018.

  1. faceurchin Registered Member

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    22
    http://www.dailymail.co.uk/sciencet...iment-reveals-time-really-flow-backwards.html

    This violates the second law of thermodynamics as well as the theory of the 'arrow of time' which states time can only flow forwards. These experiments have proven that time can work in reverse (atoms being heated up will get hotter instead of getting colder).

    I'm wondering how long it'd take for scientists to scale this up. Eg. take an animal or person a few minutes into the past? I had a best friend die abruptly in 2013, would it be possible to go back in time to see him again?
     
    Last edited: Mar 15, 2018
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  3. Musika Last in Space Valued Senior Member

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    I am sorry to hear about your friend.

    Unfortunately Stephen Hawking proved that time travel doesn't exist on 06/28/2009.
     
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  5. exchemist Valued Senior Member

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    This was discussed on this forum a few months ago: http://www.sciforums.com/threads/reversing-the-thermodynamic-arrow-of-time.160257/

    The effect is NOT a reversal of time, but a short-term apparent violation of the 2nd Law of Thermodynamics, only observed in certain spin-correlated systems fo a fraction of a second, after which normal service from the 2nd Law is resumed. Post 4 in the link points out the qualifications.

    No time travel and nothing about time actually going backwards. That is just journalistic hype.
     
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  7. Yazata Valued Senior Member

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    The "arrow of time" idea seems to have arisen in response to the idea of 4-dimensional space-time. It refers to the fact that unlike the spatial dimensions, time seems to be assymmetrical and directional. There's a distinction between future and past that seems very different than the difference between left and right.

    The difficulty for physics is that most of its mathematics is time reversal invariant. The laws of physics as currently conceived seem to work just as well whether we plug past states into the equations as our variables in order to predict future states, or whether the process is reversed, using future states as our variables in order to predict the past.

    So, what in physics accounts for the assymmetry of time?

    Physicists have long recognized that the second "law" of thermodynamics seems to be the only principle of mathematical physics that distinguishes between past and future. (The 'wave function collapse' speculations may conceivably provide us with another one, if that's the interpretation of q-m we accept.) So there have been many attempts to explain the assymmetry (the "arrow") of time by appealing to thermodynamics. (It seems a little circular to me.)

    So, I'm personally not entirely convinced that detecting tiny violations of the second "law" of thermodynamics on the microscale tells us a whole lot about the nature and direction of time. It might just be telling us that thermodynamics is less closely tied to the direction of time than some theorists like to think.
     
    Last edited: Mar 15, 2018
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  8. Cris In search of Immortality Valued Senior Member

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    My simplistic non-scientific perspective on the impossibility and nonsense of time travel to the past.

    Time slows with increasing velocity, and at the speed of light time should become zero. To go back in time, e.g. negative time, one must exceed the speed of light, our current boundary. But energy to move mass at increasing velocity also increases at an exponential rate, and at the speed of light requires infinite energy, unless you have zero mass, or near zero, e.g. a photon. Since a person will always have positive mass, then they can forget time travel. Or in other words to go back in time requires more than infinite energy - i.e. a nonsense.

    It seems easier to think of time as a 4th dimension that we can more accurately refer to as "persistence". For something to exist it must have the usual 3 dimensions, each with a non-zero positive value. It is nonsensical to consider negative length for example - doesn't have meaning. And for something to be said to exist it must also persist from one moment to the next, so "persistence" must also have a non-zero positive value. I.e. negative "persistence" has no meaning as with any dimension.

    Time isn't a medium in which we can travel, that's the wrong way to think of time, instead it is simply an attribute of existence. To consider reverse time one must consider negative existence - huh?
     
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  9. Gawdzilla Sama Valued Senior Member

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    But Shirley this would be the first place we would hear of such a discovery, yes?
     
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  10. C C Consular Corps - "the backbone of diplomacy" Valued Senior Member

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    1,871
    Gee, makes me feel like going out and watching a street, road, highway, or railroad track flow. Or watching a tree trunk flow from the ground upward to the top. In the spirit of Flat Earth, it's a yearly delight to hear somewhere that a framework of time is still oozing along with conflicting reference to itself.

    - - -
     
  11. TheFrogger Registered Senior Member

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    752
    No! You're friend is dead. ☺
     
  12. gamelord Registered Senior Member

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    542
    Maybe time-travellers just didn't want to go to his boring party?
     
    Last edited: Jul 1, 2018
  13. Dinosaur Rational Skeptic Valued Senior Member

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    From Yazata Post 4
    The above is based on classical physics prior to circa 1920, which was deterministic.

    Modern mainstream physics views the classical world of our senses as being based on a quantum level of reality which obeys probabilistic laws.

    Radioactive decay is the most well known process governed by probabilistic rather than deterministic laws.

    It is not the only process which obeys probabilistic laws, ​

    From Cris Post 5
    Treating time as a 4th dimension results in a model of reality which is static.

    The motion of a particle is viewed as a static world line in a 4 dimensional space.

    The above is a useful model because it allows the use of a powerful field of mathematics called Differential Geometry to develop useful insights.

    It does not seem model our notions of reality.
     

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