The Bread Loaf of Time

Dealing with time is one of my biggest struggles. Dave once told me about an experiment that showed the passage of time is actually slower if moving than if not by comparing two atomic clocks. As someone used to obtaining a non-treated counterfactual through random assignment of fairly large numbers of units, taking a difference of two clocks didn’t work for me.

I spat out a string of questions about the design of the study. “How did they actually measure elapsed time?” “What is the normal accuracy of these clocks?” “Did they repeat this more than once?” “Why didn’t they use several clocks in each location?” Since Dave didn’t really know, I sort of won an argument about physics against a physicist, which was fun but left me without an understanding of time.

The Fabric of the Cosmos: The Illusion of Time

Given my desire to understand time, I didn’t beg for the remote when I found Dave watching an episode of PBS’ NOVA called “The Illusion of Time.” This was part of a four-hour series based on a book by physicist Brian Greene, or as I like to call him, annoying string theory guy.

Annoying string theory guy has become a bit of a celebrity; he’s even been on Letterman. So he’s pleased with himself, is what I’m saying. He wears a leather jacket and a swagger during this show, but he wasn’t fooling me. If you are going to be a geek turned famous scientist, at least be lovable like Carl Sagan, who sounded like Kermit the Frog and seemed credible. When annoying string theory guy speaks, I feel like he’s trying to sell me a stolen car.

Five minutes into the show, one of the scientists interviewed, Max Tegmark, had this to say: “There’s basically no aspect of time which I feel we really fully understand.”

Great! Can’t wait to hear about it for an hour then.

Throughout the hour, I got the distinct impression physicists just make things up. I freely admit I don’t understand physics. Physics was an elective and I elected not to study it. I definitely think physicists are smarter than I am. But I also suspect they don’t really understand this stuff either, they are just smart enough to fake it.

Einstein = Genius

It was cute to see the man crushes these physicists have for Einstein. The first half of the program explained how Einstein overthrew “the common-sense idea that time ticks the same for everyone.” According to David Kaiser: “It’s mind-blowing that you and I will not agree on measurements of time…Why should my measurement of time depend on how I am moving, or how you’re moving? That, that doesn’t make any sense.” So far we agree, that doesn’t make any sense!

Apparently, there’s a link between space and time. Annoying string theory guy explained the clock experiment. The 1971 experiment compared elapsed time for an atomic clock flown around the world with the elapsed time of a clock on the ground. At the end of the experiment, the two clocks differed “by a few hundred billionths of a second.” I couldn’t believe measurement error was smaller than that difference, but Dave insisted there are atomic clocks accurate enough to detect an effect that small.

“In 1971?!?”

“Yep.”

I’m supposed to believe we had technology that accurate forty years ago, but today I have to wait 20 minutes for PDF files to spool to my work printer? Can’t Microsoft hire these clock people?

Einstein’s genius didn’t extend to creative names. Annoying string theory guy explained that Einstein fused together space and time “in what came to be called…” …wait for it… “spacetime.” You don’t say? Even though the show contained no point more clear, they needed a second scientist to explain it. Max Tegmark explained it again, only even more slowly and with arm motions and an earnest look, just to be sure we were all clear.

SPACE + TIME = (say it with me) SPACETIME

Annoying string theory guy turned a visual of “spacetime” into a loaf of bread to illustrate. I found this both condescending and, grudgingly, helpful as I’m not a theoretical learner. He showed how slices of “now” can angle toward the past or to the future depending on the movement of aliens 10-billion light years away. So just as all of space exists, all of time exists as well, or so Einstein said and Einstein can’t be wrong.

Or as Sean Carroll said: “If you believe the laws of physics, there’s just as much reality to the future and the past as there is to the present moment.”

I don’t believe in physics, I just believe in me. Yoko and me.

The Arrow of Time

So 30 minutes in, I got it. Past, present, and future are an illusion. I didn’t see any practical application to care much about, as the aliens who can see our future are too far away to tell us about it before we’ve experienced it too, but I got it. Then the only woman in this telecast, Janna Levin, said: “Our entire experience of time is constantly in the present. And all we ever grasp is that instant moment.” Then I got confused again because I remember the past, how about you?

They spent the next few minutes discussing time travel, because otherwise most people will stop being interested in a show about science. Then the last 20 minutes painstakingly tore down all of the limited understanding I built during the first 30.

The last part tried to reconcile why time appears to move only forward when the laws of physics don’t require time to have directionality. Annoying string theory guy implied entropy might help explain this “arrow of time.” I fell in love with the entropy guy, both because he has a cool bust of himself on his gravestone and because his work shows my inability to stay organized isn’t a character flaw, it’s a law of physics.

But no! Entropy can’t explain the arrow of time because the laws of physics say disorder should increase both toward the future and toward the past. Annoying string theory guy then said: “And that makes no sense.” As if everything said before that point had made sense.

Since they were having trouble reconciling Einstein’s theory of relativity with the arrow of time, they decided to blame the discrepancy on the Big Bang. Annoying string theory guy: “So our best understanding is that the Big Bang set the arrow of time on its path…the universe has been unwinding since the Big Bang, becoming ever more disordered.”

So basically, really intelligent physicists can’t explain time either. In the next episode, I look forward to not understanding, and also possibly debunking, quantum mechanics. 

Check out this uncomfortable yet endearing video which increased the strength of my crush on Max Tegmark. Hopefully a future episode of NOVA will explain the power physics geeks have over me.

http://www.youtube.com/watch?v=5PkLLXhONvQ

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32 thoughts on “The Bread Loaf of Time

  1. Great post! Very funny, and completely confusing, because like you, I don’t get it at all. I think I saw the same show you did, or one similar, but it was a long time ago (wait, did I just say time?) so I don’t remember exactly.

    It’s nice to see MIT tickles the right side of those genius brains too.

  2. “Man crushes on Einstein” – love it! I wonder how many of his theories would be debunked already if these crushes didn’t exist.
    Have you read Bill Bryson’s A brief History of Nearly Everything? I know I’m obsessed with him, but it’s hilarious and I was able to understand the spacetime continuum and string theory for a flitting moment.

    http://rcm.amazon.com/e/cm?t=thhepr-20&o=1&p=8&l=as1&asins=076790818X&ref=qf_sp_asin_til&fc1=000000&IS2=1&lt1=_blank&m=amazon&lc1=0000FF&bc1=FFFFFF&bg1=FFFFFF&f=ifr

    1. I think Einstein might have been smoking a little crack on this all time exists thing, but no one will argue with Einstein. Thanks for the book recommendation. Dave read it and he thinks his Dad now has his copy. Maybe I can borrow it back at Christmas.

  3. So is our future already written? You wrote:

    “So 30 minutes in, I got it. Past, present, and future are an illusion. I didn’t see any practical application to care much about, as the aliens who can see our future are too far away to tell us about it before we’ve experienced it too, but I got it.”

    When you say “the aliens who can see our future are too far away to tell us about it”, are you saying that the future they see, our future, has already happened and so our future is written?

    1. Terry, the physicists didn’t talk about it in that exact way (our future is written), but they did say that just as all of space exists out there, all of time (everything that has ever happened or will ever happen) exists too.

      I thought of it like light traveling from distant stars. By the time we see it, it’s super old light. So our now slice angles toward their past.

      Their example was an alien 10 billion light years away–if he moves towards Earth he would have a “now” slice of time angled towards our future. If the alien could actually see us, he’d know our future before we did. But he can’t see us and even if he could, his message to us wouldn’t arrive before our future events happened.

      My super helpful physicist husband just said, “what will be will be.”

    2. A better way to say it:
      These problems (“aliens seeing our future” and such) are usually formulated in classical relativity, which is deterministic: for a given set of initial conditions, there is only one way for the system to evolve.
      It’s my understanding that thinking of the whole “loaf” (future and past on equal footing), rather than the individual time slices that we intuitively experience, is a useful way of addressing some aspects of General Relativity and cosmology.

      Logy: my other comment can be deleted.

  4. I think you just blew my mind. I’m married to a physics nerd, so I’m definitely going to ask him about all of this stuff. I don’t know annoying string theory guy, but I know about string theory at least (which is very complicated and way over my head…much like the bread loaf of time).

    Nevertheless, I feel enlightened by your watching of The Illusion of Time. I think you should continue to do extremely smart things and then share them here, so that I can feel extremely smart by association. Please and thank you. 🙂

    1. Katie, feeling smart is fun, but when it comes to physics, I revert to smart aleck.

      Watching the show made my skull split in half. Once I shoved my brain back in my skull, writing about the show sort of helped. But then replying to Terry’s comment above made me confused again and now I need a drink.

      Isn’t being married to a physics nerd…fun?!? Knowing that little tidbit about your husband explains a lot about your post RE: the y’all argument. Dave likes to speak with authority about stuff he knows little to nothing about too!

  5. Very interesting if not completely over-my-head post! I don’t get physics either. “There’s basically no aspect of time which I feel we really fully understand.” – Yeah, I have a sneaking suspicion that these guys are wandering about in a metaphorical darkness. It definitely seems that the more they know/discover, the less they realise that they know! 🙂

  6. If understanding the concept of time means that I can sleep later in the mornings, then I am all for it. Interesting post, but I needed a little more coffee before I read it!

  7. Oh dear. This just reminded me why I avoided physics at all cost. And I am glad I did.

    The one thing that stood out and that I can remember is the whole thing about us only being aware of the present moment and you asking, “But I remember the past, don’t you?”

    What I was really interested in was the difference in the atomic clocks when one flew on an airplane and one was on the ground. Though the difference in time was microscopic (no other way for me to describe it), it was nonetheless fascinating to read about, at least in the way you wrote about it. I wouldn’t have a clue if an actual physicist was saying any of this to me.

    This is all just a roundabout way of me saying, “I don’t get it.”

    1. Zoe, I don’t really get it either. One of the reasons I tried writing about it was to try to crystallize my fleeting understanding of what I heard! And yes, talking to a physicist (dear husband) didn’t help AT. ALL. This show is part of a series, and I already missed this week’s episode on quantum mechanics because I forgot it was on. I’ll never understand physics now.

  8. Ah, how I miss NOVA and Neil deGrasse Tyson’s space-themed wardrobe.

    My former co-worker actually left a copy of Brian Greene’s “The Elegant Universe” and I’ve been reading it little by little. What I couldn’t help but wonder is, “Aren’t you just making up cute metaphors? And what if the metaphor is the reason you think the reality is this way?”

    All I can do is shrug.

  9. There really are people out there that are just too smart. Is that possible? Maybe? I think maybe. This information about time is stressing me out, but your comments made me laugh! So glad you linked this up with us over at #findingthefunny!

  10. You clearly have your head up your bum. The post is neither witty nor wise. While I agree Brian Greene is annoying, physics, as a useful, practical science, sort of has merit and you sort of have your head up your bum. Firmly and deeply up your bum – so far up your bum, I think maybe you’ve gone back in time.

  11. What a revelation. I never could explain my “dislike” for the annoying string theory guy. I always thought that it was because he is way smarter than me. But no, it’s his “coitus interruptus” TV show – when he gets to the point and you think “yes, yes, yeeees” he pulls the proverbial plug and changes topics leaving you in a vacuum of confusion.

    These science guys (including the silver-haired asian-american) should stay more often in their labs and in front of their chalkboards and let some science journalist do the TV show – maybe this would get us faster to really clean energy …

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