For almost 7 years, I have been an enthusiastic fan of The Big Bang Theory. The CBS sitcom is in its seventh season. Each episode lasts 20 minutes or so. So far, 155 episodes have been aired. I am pretty sure that I've seen every single one of them – on average, I've watched an episode of TBBT 3 times – partly in the original, partly in the Czech dubbing which I started to love pretty soon. The initial seasons have a higher number of views than the newest ones.
So you may see that I have spent something like 155 hours of quality time with the sitcom. This figure vastly understates how important the sitcom has been in the scheme of my cultural inspiration. Last week, on April 3rd, they aired the 154th episode, The Indecision Amalgamation, which was the last problem-free one. Sheldon was deciding whether to buy XBOX or a new PlayStation, Raj had to simultaneously deal with two potential girlfriends, and Penny got a useless advice from a frustratingly nostalgic Wil Wheaton on whether she should accept an offer in a bad movie.
I could get used to the comical yet unrealistic obsession of the boys (including Sheldon Cooper) with the science-fiction banalities, to the fact that Leonard's kids won't have a good view of a parade, and to Jim Parsons' being gay (he is still the same excellent actor as he was before even though as a member of the Shamy club [sorry, this was a typo, I originally meant the Shenny club!], I would have preferred to have never learned about it). However, what the yesterday's (April 10th) 155th episode, The Relationship Diremption, did with the main hero could have been an instant dealbreaker for me.
In fact, the original title of this blog post when it was a draft was "My velvet divorce with TBBT". :-)
But I learned not to overreact and when I saw the actual "Sheldon leaves string theory" episode, I saw some silver linings, too.
The three boys in the school dining hall are sort of excited with the BICEP2 discovery of the primordial gravitational waves – it is impressive how current events quickly make it to the story: one of the silver linings – and Sheldon isn't. As a theoretical physicist, he should be, they rightfully point out. But he says something weird for the first time (in this episode). He is interested how the primordial gravitational waves help Joe Sixpack. That's silly because every theoretical physicist knows that these cutting-edge discoveries in pure science just don't affect Joe Sixpack's life at all. Cutting-edge fundamental physics just hasn't been relevant for any practical applications for many decades.
Now, Leonard replies like that:
Oh my god, you're jealous. [Why?] Maybe because the cosmic inflation just got proven. The Higgs field got proven and you've been working on string theory for the last 20 years and you're not closer to proving it than when you started.Sheldon only replies that he had a lot on his plate and something about the golden age of TV. Barry Kripke, an eavesdropping lisping jerk at another table, told Sheldon that the LHC just proved string theory. Did they find SUSY or extra dimensions? No, Kripke says, only that Sheldon will believe anything. Sheldon asks why Barry would do that; he is a string theorist as well (huh!?). No, Kripke answers, he is a string pragmatist, not a string theorist. He is doing it for the grant money that he spends on some [lisping, not comprehensible]. Have I told you that Kripke was a jerk?
Let me actually address these things comments in the way that Sheldon should have but he has failed because the writers decided to turn him into a lame victim of harassment.
Sheldon has been working on string theory for 20 years, and so have many of us, but the cosmic inflation got its BICEP2 near-proof after 35 years and the Higgs field after 48 years. So 20 years is nowhere near the time scale after which ideas of a similar importance – and string theory is clearly grander, more important than the other two examples – typically get proven.
Moreover, Sheldon's work – a theoretical work – is not about "proving string theory". It's up to experimenters to "prove" theories (and theories are never really "proven", they are just shown to be more adequate descriptions of the observations than their predecessors). Sheldon is a theorist. He could be doing the theoretical work that allows the experimenters to do such things. But because it seems obvious – especially after BICEP2 – that the energy scale of "characteristic stringy phenomena" is between the GUT scale and the Planck scale, i.e. extremely high, competent people are just not losing much of their time with planning such experimental tests. They're almost certainly impossible in practice. Several parameters of the cosmic inflation that are being extracted from the CMB are the only exceptions but they're unlikely to be directly relevant for the question "to be stringy or not to be stringy, that is the question".
Another related thing that Sheldon could be doing would be to derive the properties of particles and fields in Nature – in our Universe – so that the retrodictions of these well-known properties could be as convincing as true predictions. For about 1 year (in total) among the nearly 20 years I've been connected to string theory, I would be thinking that it was realistically possible to "directly" attack the problem and deduce the unique predictions of string theory for the Universe around us. While I am not a believer in the anthropic reasoning of any sort, it seems obvious to me that there are lots of string vacua and even many string vacua that are probably "more or less on par" with the vacuum in the visible Universe. So it may be conceivable to pinpoint the right vacuum but it won't be the "first step" string theorists will make. A deeper understanding of the structure of the theory – and perhaps its prediction for the initial conditions of the Universe – has to be done before that.
So Leonard is assigning Sheldon a wrong type of a job, and even if it were the right job, the criticism of string theory relatively to the other theories doesn't work because those ideas got proven after a longer period of time than what Sheldon has spent on string theory.
Moreover, the very idea that an enthusiastic string theorist could be unexcited by the BICEP2 result or that it is not a general confirmation of the string theorist's attitude to research (not being afraid to look at phenomena at the GUT scale or Planck scale) is just wrong. String theory is compatible with the BICEP2 result – again, it's the only theory going beyond effective field theories that can address these things at all. And do string theorists care about inflation? How many pages about inflation and string theory they would write within weeks?
Well, look at the paper Inflation and String Theory that Daniel Baumann and (guest blogger) Liam McAllister released today. Yes, they submitted it hours before the TBBT episode about "Sheldon's breakup with string theory" was aired. The paper has 349 pages and 48 figures. It is a draft of a book that will be published by Cambridge University Press. You will find sections about "inflation after BICEP2" at various places, much like dozens of references to predicted tensor-to-scalar ratios.
At any rate, Sheldon – still in the cafeteria – asks the boys whether Kripke is right. Is he wasting his life on a theory that can never be proven? It's just silly. With his IQ of 187, has Sheldon asked this question to himself for the first time after 20 years? A sensible scientist tries to adjust his beliefs about what is true or untrue and what can be proven pretty much every minute. The beliefs about "provability of string theory" are no exception. I have never believed that string theory would be proven in any imaginable future at the level of transparency that would convince non-physicists that it is true. After all, they can't even get convinced that quantum mechanics is right. But even when it comes to theoretical physicists who refuse to learn string theory in a sufficiently comprehensive way, I've been almost always convinced that they wouldn't understand why it is really necessary to use string theory as the framework if we want to understand patterns in Nature that are unexplained (or inconsistently described) by effective quantum field theories.
So I have been excited about string theory despite this nearly self-evident absence of low-hanging fruits. String theory is simply not a subject for Joe Sixpack. It is not a subject for intellectually inferior pseudophysicists of the Woit-Smolin type, either. String theory is something that only 1 person among 100,000 may learn so that he or she understands why it has to be right, and only 1 person among 2,000,000 or so has actually learned to do something with string theory at the practical level. All of them are aware of this relatively esoteric character of the subject.
Sheldon and Penny start to talk about Sheldon's feelings in the morning even though Penny wouldn't understand. So Sheldon says that "[He] had devoted the prime of his life to string theory and its quest for the compactification of extra dimensions. [He's] done nothing to show for it and [he] feels like a fool." OK, Penny says, she got it. Not all the jibberjabber in the middle – it's compactification of extra dimensions, Penny, try to repeat, compactification – but she knows what it feels like to invest her heart into something and get nothing out of it. Do you mean your acting career, Sheldon asks? No. Your relationship with Leonard? No. Your failed attempt to go back to college? No!
Penny said that Sheldon and string theory is a relationship and she knows what it feels like when she realizes it will never be the way she had wanted. Sheldon objects that when he said "Leonard", Penny replied "No". She was talking about other guys, she clarifies the situation. What do you do, Penny? You have to have the courage to end the relationship. It's needed, it's how you grow.
Now, generally, Penny's recommendation is wise. But it's just totally irrelevant for Sheldon's situation. Just to remind you, Sheldon hasn't been looking for a "proof of string theory" that would convince Joe Sixpack. He's been working on lots of wonderful research projects – let me know if you need to know what Sheldon's most interesting papers and thoughts are – and those are the things that are supposed to make him feel satisfied. The advances in string theory which are mostly of theoretical or mathematical character – they are making fundamental physics more unified than ever – are making many string theorists happy. But if they don't make someone sufficiently happy, he may switch to something else.
But this "farewell" cannot be rationally ignited by an experimental discovery of a process in Nature that is partly related to but largely independent from the bulk of the research in string theory. String theorists are not competing with the experimenters and even if we compared the string theorists to the theorists whose theories are being confirmed, their connection with the experiments is very different (much less direct) and their focus on the mathematical depth is also very different (much more profound). So string theorists are doing their research with different goals than those who just focus on a particular pattern in the CMB. String theory is really a theory of everything and it is not just hype. Its being a TOE means that it reorganizes our views on how all fundamental processes in the Universe work.
Leonard blows his nose. In the cafeteria again, he asks Rajesh about dating two women. Fun jokes unrelated to string theory that could be in other episodes as well. Rajesh told Emily that he was dating two women at once, and she was OK with that. He tried the same with Lucy but her feelings were mixed. When Rajesh asked why Lucy couldn't be just like Emily who is so great, Lucy's feelings became less mixed. ;-)
Sheldon is getting rid of string theory books, Green-Schwarz-Witten (in green cover) is being taken from the box as he talks about the possibility to burn the books which would remind him of Texas. Sheldon makes mixed comments about his scribbles of ideas that gave him the Harvard Junior Fellowship, or whatever they call it in the show. ;-) Before Sheldon starts to cry and leaves, he says "I can't keep on postulating multidimensional entities and get nothing in return; he has his needs, too". I admit that I am laughing during such proclamations, too, even though they are conveying some misunderstanding of how theoretical physics works and why theoretical physicists work on it. But I am used to separate the lives in movies – fiction – from the real truth. That's also why I often root for the most unhinged climate alarmists in some of Hollywood's catastrophic movies. ;-)
Sheldon gets a new haircut "made by Penny"; a cross "Bill Gates meets Nikola Tesla". Leonard asks what Sheldon is going to pursue when he's done with string theory. Dark matter, black holes, other interesting areas. This is really silly. Tons of physicists work on this interface and they are jumping in between these topics and string theory all the time, or thinking about them simultaneously. Some of their parts are really closely related. A string theorist doesn't have to get a major new haircut whenever he starts to think about black holes (and maybe not even dark matter). The haircuts would be too frequent.
Amy sees Sheldon's new look. It's a problem. She doesn't want girls to see Sheldon as a sex on the stick. "She's right, I am too hot." Howard-Bernadette-Rajesh-Emily double date. Howard knows Emily, in a bad way. "Have we met before?" Emily asks. "No." But she figures it out.
Sheldon is looking for a new field. "Why do we have geology books? Did you throw parties for children, Leonard?" What's wrong with geology, Penny asks? It's the Kardashians of science. Sheldon is getting his good old self for a while, also explaining to Leonard that the Standard Model is less advanced than string theory (which overlooks the fact that many string theorists' – string phenomenologists' – work depend on a great mastery of the Standard Model; but I have already discussed that the show paints all questions in science as being completely isolated from each other which is just wrong).
Amy hints at nuclear matrix elements. Not too good. Leonard suggests loop quantum gravity. Sheldon's monkey-like reaction to that proposal is fortunately adequate so his meltdown couldn't have been so bad so far. Penny has a great idea – enjoy your freedom, don't rush, and maybe something will find you. A good advice, Sheldon thinks. He didn't look for string theory. It just hit him one day: a bully hit him with the biggest book he could find, a string theory book.
Now, this is funny but it's so wrong on so many levels. First of all, there weren't any "big books" of string theory 20 years ago. Second, it's just silly that one may become a string theorist because he's hit by a book. You can't study a string theory textbook with no prerequisites (or talent). You must be reasonably familiar with the whole pyramid of physics knowledge up to general relativity and quantum field theory (each of which has its own pyramid of prerequisites, too). And you usually know that you want to get at the tip of the skyscraper – currently string theory – for quite some time before you study it. Moreover, you must probably be "1 in 100,000" to have reasonable chances to learn string theory at a productive level.
A joke about Sheldon's drinking wine – predigested by a fungus.
Back to the double date. It already looks like Howard is saying stories about his being an astronaut and people like the mood when Emily suddenly remembers. They had a blind date a few years ago. He had serious stomach-toilet problems in Emily's apartment. It's OK for Emily. All her friends love the story; they call Howard "Clugzilla". Howard was anxious about that story a long time after they moved on.
A drunk Sheldon is being helped by Amy. Sheldon finds himself in a bed with someone. What have I done? A geology book. A similar scene as one after Penny slept with Rajesh. Nothing happened. Apparently, a drunk Sheldon called Stephen Hawking last night. Just a stupid message on an answering machine. Sheldon and Howard talk about their embarrassing evenings. Kripke is humiliating Sheldon again. Get out of here, Berry, Howard says. "What do you say, Clugzilla..." Sheldon concludes that this nickname is way too cool and won't go away.
Additional messages on Hawking's answering machine:
I gave up String Theory. You should give up black holes and we totally solve crimes together!"Hawking says "What a jackass." Well, Sheldon was just drunk a little bit. They made a big deal out of it – as if Sheldon were the only drunk physicist who has left lots of funny messages on Hawking's answering machine.
You know what's great? Geology! Look at this Geo! That's fun to say: gee-ode. Gee-ode.
Gee-ode, gee-ode. I kiss girls now.
Hey, guess who I am? Beep-bop-boop-bop! I'm you! Get it?
Are you mad at me? Oh, no! You're mad at me! I'm so sorry! Beep-bop-boop-bop!
Thiospinel sulfide. Thiospinel sulfide. That's even more fun than gee-ode. Hey, did you see the new Lego movie?
So when I actually saw this problematic episode, it was still funny, rich in some physics jargon, and even addressing some deeper questions about the psychology of physicists – although it didn't do it right. But it's clear to me now that I won't abandon TBBT because of these blunders.