31 thoughts on “Faster Than Light”

  1. The obvious (to me, anyway) question is: does this mean that matter can travel up to 30 X times the regular old speed of light?

    I would think that the SETI folks would start looking at the sky with “spatial de-modulators.” If this really works, all those signals that have been missing since we started listening are no doubt zipping past at speeds we don’t expect. Even communication within the Solar System would be revolutionized.

    1. So far, no. This is a group velocity vs phase velocity thing–group velocities can easily exceed the speed of light but information is still limited by the speed of light.

      1. Okay, but I’d like to know what is meant by a light pulse going “backwards.” I mean, I can do that with a spatial modulator consisting of a mirror…

      2. I was thinking that and was puzzled when the article stated that one of the “researchers behind it say could revolutionize optical communication.”

      3. Phase velocity, daver, phase velocity can exceed to speed of light. Group velocity, not so much.

        1. Was going to say the same. A phase velocity > C is within the reach of simple electronics. But the device isn’t going to transmit energy or information faster than C.

  2. I had this sudden thought of several constellations becoming available just about the time this capability renders them all obsolete. I also wonder how this will affect spectrum allocation.

      1. I was once thinking about a sci fi story where time travel is possible but every time you go back in time to change the history, some little everyday mundane event thwarts your attempt.

        So you go back to kill Hitler but the taxi you took to get into position breaks down and you lose your chance.

        Almost as if the universe is self-regulating…the timeline is the timeline and you cannot change it.
        That would allow time travel without running into those pesky paradoxes.

        1. Or maybe they just gave up after a bunch of meddling. Sure, it’s bad that baby Hitler survives, but at least things aren’t a mess a century later.

          Really, what can you improve on things when you’re not just worried about a particular moment in time but centuries or longer thereafter? At some point, even just having humanity not go extinct might be good enough.

          1. “Well, that didn’t go right either.”

            “What are we going to do now?”

            “The only thing we can do. We have to go back to before we started, and kill us.”

            “Will it work?”

            “If it doesn’t, we won’t be in a position to care.”

          2. Maybe changing the timeline, makes people in the present more stupid.

            That could be the reason [in addition of a lousy educational system] why people seem to be getting more stupid.

            Or if you don’t want to have more of AOC then you don’t mess with our timeline. And AOC might be proof of idiots [future idiots] who have “already” changed our timeline.

            Though it’s known that Lefties want to control history and this has created lots of stupid Lefties.

            A lesson could be, don’t change history and don’t change the actual history with time travel.

          3. Yes, like Hitler was the result of going back in time to kill Steve. Who is Steve?

            He was a botanist who successfully grafted broccoli to zuchinni. The offspring of these grafted plants looked a little horrific but that was only nature’s way of telling you how bad they taste.

            In 2445, after centuries of obscurity, the health conscious became obsessed with the fad that eating food must be an unpleasant experience, that suffering while eating was the key to a healthy life. Most of the recipes used brocholinni.

            Frank Ramirez was a garage tinkerer, people who built old timey garages because they thought it wasn’t enough to use the tools of the past, you had to use them in the same environment in order to authentically do things the old way.

            In 2555, Frank Ramirez created a time machine. Instantly he became a celebrity to the garage tinkerers and many asked for him to sell plans for his garage but it took sometime, days even, for his fame to spread to the rest of society, something he would soon regret.

            Within weeks of the discovery, the VLF, Vegetable Liberation Front acted to prevent what they saw as the beat chance they would ever have to stop the centuries long enslavement and genocide of the brocholinni by going back in time to kill Steve. One afternoon, when they knew Frank would be sleeping, the VLF broke into his garage and enacted their plan.

            And that is how we got Hitler and time travel became illegal.

        2. Gregg,

          I strongly recommend Larry Niven’s very short story “Rotating Cylinders and the Possibility of Global Causality Violation” – it is Niven’s take on your idea. (Maybe you would do it differently, of course).

          If you can look past really messed up formatting, you can find the text of the story here: https://epdf.tips/larry-niven-convergent-seriesaea3b1d7157cb76f2a40acef8cb3a46a53462.html Search the page for the words “Rotating Cylinders” and skip over any http links. The story, as formatted on that page, is 3 paragraphs long.

          1. That Niven story was pretty good.

            My own view is that time travel only has one causality violation, the sudden appearance of a very macroscopic amount of mass where none had been, or the equally illegal rearrangement of existing mass without an applied force.

            I doubt the laws of physics care whether anyone’s remembered version of history is valid, especially in comparison to the original causality violation of appearing out of nowhere. To physics, your memories or history are just a curious ad-hoc explanation for the particular arrangement of molecules that just popped into existence.

            Would the present care whether the new arrival was really from the Deodorant Wars of the 23rd century, or just a character beaming in from some fantasy post-apocalyptic virtual reality game being played across the street? To the year 1889, it wouldn’t matter if Hitler was a real person or an imaginary character from Castle Wolfenstein. The problem would be the sudden appearance of a person’s mass, with an energy equivalent of about 1.5 gigatons of TNT.

        3. Perhaps what happens when you travel backwards in time, is that if you make any changes, then you will create another timeline. Your other time still exist, but now there is another timeline. So if you kill baby Hitler, then Hitler never becomes the leader of Germany. I do think the Nazis would still come into power. Hitler joined the Nazi party. He didn’t create it.
          Now imagine that there are 1 trillion of you. Each one lives in a different universe. Each one has made different life choices.
          Now, go further back in time, there will be fewer of you. But if you kill your father before you were conceived, you won’t just disappear. You have just created another timeline. One where you weren’t born. Travel back to the present, and no one will know you. Even your own friends, and family.

          1. As the Soviet force encircled Berlin, Hitler knew that the German people would be destroyed forever. Their fate was his fault because the Wehrmacht, Luftwaffe, and Kriegsmarine hadn’t really been ready for a sustained war, and he’d struck too early. The only way for the German people to survive was for him to fire up the secret time machine hidden in an SS bunker, travel back, and kill baby Hitler.

            So he gets in the time machine, travels back to his birthday in 1889, goes to the maternity ward, and confronts baby Hitler. Then he realizes that he can’t kill baby Hitler because he hadn’t been Baptized yet. So he waits till after the Baptism and then slips into baby Hitler’s room for a second attempt. Unfortunately, he realizes that he still can’t kill baby Hitler because it would technically be suicide and he’d burn in Hell for it. No way is Hitler going to do anything that lands him in Hell.

            So baby Hitler grows up, starts the war again, has the same realization about defeat, and travels back in time to kill baby Hitler. He runs into the previous Hitler, who explains that they can’t kill baby Hitler because they’d both go to Hell for suicide. So baby Hitler grows up, repeats the same mistakes, and travels back. Eventually there’s tens of thousands of accumulated Hitlers guarding baby Hitler, and that’s why nobody can travel back in time and successfully finish the job.

    1. Your “equation” to show that the idea is fantasy is noted.

      But I see that you left out one important version of the “spatial light modulator”…

      The PU-238 Space Demodulatooooor.

      And THAT one is real, as we all know.

      Are you ignoring this one to “prove” your thesis?


  3. “temporal degrees of freedom” = changing the frequency. Using purposely obscure terminology is suspicious. There was a paper a couple of decades ago about the discovery of “phasers” which, if I recall correctly (it’s been a while), allowed pulses of electromagnetic radiation to travel essentially infinite distances without dispersion. Turns out the author had neglected a second exponential term in his formalism which represented a “reverse time” identical second signal sent from the receiver. The original paper was withdrawn.

  4. There was once a young lady from Bright
    Who traveled much faster than light.
    She went out one day
    in a relative way,
    and came back the previous night.

    1. Another hussy had made her attack
      Bright found with her young man in the sack
      With weapons not fussy
      She jumped the young hussy
      And then stabbed herself right in the back

  5. “I have a time machine at home. It only goes forward at regular speed.”

    – Demitri Martin

    1. I have a time machine at home too! It’s from Stearns & Foster. Every-time I lay prone on it at precisely 10pm, I jump 8-11 hours forward in time!

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