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.
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.