Friday, October 31, 2014

String theory – it’s a girl thing

My first international physics conference was in Turkey. It was memorable not only because smoking was still allowed on the plane. The conference was attended by many of the local students, and almost all of them were women.

I went out one evening with the Turkish students, a group of ten with only one man who sucked away on his waterpipe while one of the women read my future from tea leaves (she read that I was going to fly through the air in the soon future). I asked the guy how come there are so few male students in this group. It’s because theoretical physics isn’t manly, it’s not considered a guy thing in Turkey, he said. Real men work outdoors or with heavy machinery, they drive, they swing tools, they hunt bears, they do men’s stuff. They don’t wipe blackboards or spend their day in the library.

I’m not sure how much of his explanation was sarcasm, but I find it odd indeed that theoretical physics is so man-dominated when it’s mostly scribbling on paper, trying to coordinate collaborations and meetings, and staring out of the window waiting for an insight. It seems mostly a historical accident that the majority of physicists today are male.

From the desk in my home office I have a view onto our downstairs neighbor’s garden. Every couple of weeks a man trims her trees and bushes. He has a key to the gate and normally comes when she is away. He uses the smoking break to tan his tattoos in her recliner and to scratch his breast hair. Then he pees on the roses. The most disturbing thing about his behavior though isn’t the peeing, it’s that he knows I’m watching. He has to cut the bushes from the outside too, facing the house, so he can see me scribbling away on my desk. He’ll stand there on his ladder and swing the chainsaw to greet me. He’s a real man, oh yeah.

After I finished high school, I went to the employment center which offered a skill- and interest-questionnaire, based on which one then was recommended a profession. I came out as landscape architect. It made sense – when asked, I said I would like to do something creative that allows me to spend time outdoors and that wouldn’t require many interpersonal skills. I also really like trees.

Then I went and studied math because what the questionnaire didn’t take into account is that I get bored incredibly quickly. I wanted a job that wouldn’t run out of novelty any time soon. Math and theoretical physics sounded just right. I never spent much time thinking about gender stereotypes, it just wasn’t something I regarded relevant. Yes, I knew the numbers, but I honestly didn’t care. Every once in a while I would realize how oddly my voice stood out, look around and realize I was the only women in the room, or one of a few. I still find it an unnatural and slightly creepy situation. But no, I never thought about gender stereotypes.

Now I’m a mother of two daughters and I realized the other day I’ve gone pink-blind. Before I had children, I’d look at little girls thinking I’d never dress my daughters all in pink. But, needless to say, most of the twin’s wardrobe today is pink because it’s either racing cars and soccer players on blue, or flowers and butterflies on pink. Unless you want to spend a ridiculous amount of money on designer clothes your kids will wear maybe once.

The internet is full with upset about girl’s toys that discourage an interest in engineering, unrealistic female body images, the objectification of women in ads and video games, the lack of strong female characters in books and movies. The internet is full with sites encouraging women to accept their bodies, the bodies of mothers with the floppy bellies and the stretch marks, the bodies of real women with the big breasts and the small breasts and the freckles and the pimples – every inch of you is perfect from the bottom to the top. It’s full with Emma Watson and He for She. It’s full of high pitched voices.

But it isn’t only women who are confronted with stereotypical gender roles and social pressure. Somebody I think must stand up and tell the boys it’s totally okay to become a string theorist, even though they don’t get to swing a chainsaw - let that somebody be me. Science is neither a boy thing nor a girl thing.

So this one is for the boys. Be what you want to be, rise like a phoenix, and witness me discovering the awesomeness of multiband compression. Happy Halloween :)

Monday, October 27, 2014

Einstein’s greatest legacy- How demons and angels advanced science

Einstein’s greatest legacy is not General Relativity, it’s not quantum entanglement, and it’s not slices of his brain either. It’s a word: Gedankenexperiment – German for “thought experiment”.

Einstein, like no other physicist before or after him, demonstrated how the power of human thought alone, used skillfully, can make up for the lack of real experiments. He showed we little humans have the power to deduce equations that govern the natural world by logical conclusion. Thought experiments are common in theoretical physics today. Physicists use them to examine the consequences of a theory beyond that what is measureable with existing technology, but still within the realm of that what is in principle measureable. A thought experiments pushes a theory to its limit and thereby can reveal inconsistencies or novel effects. The rules of the game are that a) relevant is only that what is measureable and b) do not fool yourself. This isn’t as easy as it sounds.

The famous Einstein-Podolsky-Rosen experiment was such an exploration of the consequences of a theory, in this case quantum mechanics. In a seminal paper from 1935 the three physicists showed that the standard Copenhagen interpretation of quantum mechanics has a peculiar consequence: It allows for the existence of “entangled” particles.

Entangled particles have measureable properties, for example spin, that are correlated between two particles even though the value for each single particle is not determined as long as the particles were not measured. You can know for example that if one particle has spin up the other one has spin down or vice versa, but not know which is which. The consequence is that if one of these particles is measured, the state of the other one changes – instantaneously. The moment you measure one particle having spin up, the other one must have spin down, even though it did, according to the Copenhagen interpretation, not previously have any specific spin value.

Einstein believed this ‘spooky’ action at a distance to be nonsense and decades of discussion followed. John Steward Bell later quantified exactly how entangled particles are stronger correlated than classical particles could ever be. According to Bell’s theorem, quantum entanglement can violate an inequality that bounds classical correlations.

When I was a student, tests of Bell’s theorem were still thought experiments. Today they are real experiments, and we know beyond doubt that quantum entanglement exists. It is at the basis of quantum information, quantum computation, and chances are all technologies of the coming generations will build upon Einstein, Podolsky and Rosen’s thought experiment.

Another famous thought experiment is Einstein’s elevator being pulled up by an angel. Einstein argued that inside the elevator one cannot tell, by any possible measurement, whether the elevator is in rest in a gravitational field or is being pulled up with constant acceleration. This principle of equivalence means that locally (in the elevator) the effects of gravitation are the same as that of acceleration in the absence of gravity. Converted into mathematical equations, it becomes the basis for General Relativity.

Einstein also liked to imagine chasing after photons and he seems to have spent a lot of time thinking about trains and mirrors and so on, but let us look at some other physicists’ thoughts.

Before Einstein and the advent of quantum mechanics, Laplace imagined an omniscient being able to measure the positions and velocities of all particles in the universe. He concluded, correctly, that based on Newtonian mechanics this being, named “Laplace’s demon”, would be able to predict the future perfectly for all times. Laplace did not know back then of Heisenberg’s uncertainty principle and neither did he know of chaos, both of which spoil predictability. However, his thoughts on determinism were hugely influential and lead to the idea of a clockwork universe, and our understanding of science a prediction tool in general.

Laplace’s is not the only famous demon in physics. Maxwell also imagined a demon, one that was able to sort particles of a gas into compartments depending on the particles’ velocities. The task of Maxwell’s demon was to open and close a door connecting two boxes that contain gas which initially has the same temperature on both sides. Every time a fast particle approaches from the right, the demon lets it through to the left. Every time a slow particle arrives from the right, the demon closes the door and keeps it right. This way, the average energy of particles and thus the temperature in the left box increases, and entropy of the whole system decreases. Maxwell’s demon thus seemed to violate the second law of thermodynamics!

Mawell’s demon gave headaches to physicists for many decades until it was finally understood that the demon itself must increase its entropy or use energy while it measures, stores, and eventually erases information. It has not been until a few years ago that Maxwell’s demon was in fact realized in the laboratory.

A thought experiment that still gives headaches to theoretical physicists today is the black hole information loss paradox. If you combine general relativity and quantum field theory, each of which is an extremely well established theory, then you find that black holes evaporate. You also find however that this process is not reversible; it destroys information for good. This however cannot happen in quantum field theory and thus we face a logical inconsistency when combining the two theories. This cannot be how nature works, so we must be making a mistake. But which? There are many proposed solutions to the black hole information loss problem. Most of my colleagues believe that we need a quantum theory of gravity to resolve this problem and that the inconsistency comes about by using general relativity in a regime where it should no longer be used. The thought experiments designed to resolve the problem typically use an imagined pair of observers, Bob and Alice, one of which is unfortunate to have to jump into the black hole while the other one remains outside.

One of the presently most popular solution attempts is black hole complementarity. Proposed in 1993 by Susskind and Thorlacius, black hole complementarity rests on the Gedankenexperiment main rules: That what matters is only what can be measured, and you should not fool yourself. One can avoid information loss in black holes by copying information and let it both fall into the black hole and go out. One copy remains with Bob, one goes with Alice. Copying quantum information however is itself inconsistent with quantum theory. Susskind and Thorlacius pointed out that these disagreements would not be measureable by neither Bob nor Alice, and thus no inconsistency could ever arise.

Black hole complementarity was proposed before the AdS/CFT duality was conjectured, and its popularity sparked when it was found that the non-locally doubled presence of information seemed to fit nicely with the duality that arose in string theory.

As of recently though, it has become clear that this solution has its own problems because it seems to violate the equivalence principle. The observer who crosses the horizon should not be able to notice anything unusual there. It should be like sitting in that elevator being pulled by an angel. Alas, black hole complementarity seems to imply the presence of a “firewall” that would roast the unsuspecting observer in his elevator. Is this for real or are we making a mistake again? Since the solution to this problem holds the promise of understanding the quantum nature of space and time much effort has focused on solving it.

Yes, Einstein’s legacy of thought experiments weighs heavily on theoretical physicists today – maybe too heavy for sometimes we forget that Einstein’s thoughts were based on real experiments. He had Michelson-Morley’s experiments that disproved the aether, he had the perihelion precession of mercury, he had the measurements of Planck’s radiation law. Thought alone only gets one so far. In the end, it is still data that decides whether a thought can become reality or remain fantasy.

[Cartoon: Abstruse Goose, Missed Calling]

This post first appeared on "Starts with a Bang".

Tuesday, October 21, 2014

We talk too much.

Image Source: Loom Love.

If I had one word to explain human culture at the dawn of the 21st century it would be “viral”. Everybody, it seems, is either afraid of or trying to make something go viral. And as mother of two toddlers in Kindergarten, I am of course well qualified to comment on the issue of spreading diseases, like pinkeye, lice, goat memes, black hole firewalls, and other social infections.

Today’s disease is called rainbow loom. It spreads via wrist bands that you are supposed to crochet together from rubber rings. Our daughters are too young to crochet, but that doesn’t prevent them from dragging around piles of tiny rubber bands which they put on their fingers, toes, clothes, toys, bed posts, door knobs and pretty much everything else. I spend a significant amount of my waking hours picking up these rubber bands. The other day I found some in the cereal box. Sooner or later, we’ll accidentally eat one.

But most of the infections the kids bring home are words and ideas. As of recently, they call me “little fart” or “old witch” and, leaving aside the possibility that this is my husband’s vocabulary when I am away, they probably trade these expressions at Kindergarten. I’ll give you two witches for one fart, deal? Lara, amusingly enough, sometimes confuses the words “ass” and “men” – “Arch” and “Mench” in German with her toddler’s lisp. You’re not supposed to laugh, you’re supposed to correct them. It’s “Arsch,” Lara, “SCH, not CH, Arsch.”

Man, as Aristotle put it, is a zoon politicon, she lives in communities, she is social, she shares, she spreads ideas and viruses. He does too. I pass through Frankfurt international airport on the average once per week. Research shows that the more often you are exposed to a topic the more important do you think it is, regardless of what the source is. It’s the repeated exposure that does it. Once you have a word in your head marked as relevant, your brain keeps pushing it around and hands it back to you to look for further information. Have I said Ebola yet?

Yes, words and ideas, news and memes, go viral, spread, mutate and affect the way we think. And the more connected we are, the more we share, the more we become alike. We see the same things and talk about the same things. Because if you don’t talk about what everybody else talks about would you even listen to yourself?

Not so surprisingly then, it has become fashionable to declare the end of individualism also in science, pointing towards larger and larger collaborations, and increasing co-author networks, the need to share, and the success of sharing. According to this NYT headline, the “ERA OF BIG SCIENCE DIMINISHES ROLE OF LONELY GENIUS”. We can read there
“Born out of the complexity of modern technology, the era of the vast, big-budget research team came into its own with its scientific achievements of 1984.”
Yes, that’s right, this headline dates back 30 years.

There lonely genius of course has always been a myth. Science is and has always been a community enterprise. We’re standing on the shoulders of giants. Most of them are dead, ok, but we’re still standing, standing on these dead people’s shoulders and we’re still talking and talking and talking. We’re all talking way too much. It’s hard not to have this impression after attending 5 conferences more or less in a row.

Collaboration is very en vogue today, or “trending” as we now say. Nature recently had an article about the measurement of the gravitational constant, G. Not a topic I care deeply about, but the article has an interesting quote:
“Until now, scientists measuring G have competed; everyone necessarily believes in their own value, says Stephan Schlamminger, an experimental physicist at NIST. “A lot of these people have pretty big egos, so it may be difficult,” he says. “I think when people agree which experiment to do, everyone wants their idea put forward. But in the end it will be a compromise, and we are all adults so we can probably agree.” 
Working together could even be a stress reliever, says Jens Gundlach, an experimental physicist at the University of Washington in Seattle. Getting a result that differs from the literature is very uncomfortable, he says. “You think day and night, ‘Did I do everything right?’”
And here I was thinking that worrying day and night about whether you did everything right is the essence of science. But apparently that’s too much stress. It’s clearly better we all work together to make this stressful thinking somebody else’s problem. Can you have a look at my notes and find that missing sign?

The Chinese, as you have almost certainly read, are about to overtake the world, and in that effort they now reform their science research system. Nature magazine informs us that the idea of this reform is “to encourage scientists to collaborate on fewer, large problems, rather than to churn out marginal advances in disparate projects that can be used to seek multiple grants. “Teamwork is the key word,” says Mu-Ming Poo, director of the CAS Institute of Neuroscience in Shanghai.” Essentially, it seems, they’re giving out salary increases for scientists to think the same as their colleagues.

I’m a miserable cook. My mode of operation is taking whatever is in the fridge, throwing it into a pan with loads of butter, making sure it’s really dead, and then pouring salt over it. (So you don’t notice the rubber bands.) Yes, I’m a miserable cook. But I know one thing about cooking: if you cook it for too long or stir too much, all you get is mush. It’s the same with ideas. We’re better off with various individual approaches than one collaborative one. Too much systemic risk in putting all your eggs in the same journal.

The kids, they also bring home sand-bathed gummy bears that I am supposed to wash, their friend’s socks, and stacks of millimeter paper glued together because GLUE! Apparently some store donated cubic meters of this paper to the Kindergarten because nobody buys it anymore. I recall having to draw my error bars on this paper, always trying not to use an eraser because the grid would rub away with the pencil. Those were the days.

We speak about ideas going viral, but we never speak about what happens after this. We get immune. The first time I heard about the Stückelberg mechanism I thought it was the greatest thing ever. Now it’s on the daily increasing list of oh-yeah-this-thing. I’ve always liked the myth of the lonely genius. I have a new office mate. She is very quiet.

Wednesday, October 15, 2014

Siri's Song [music video]

After the ios 8 update you can now use your iPhone entirely hands-free if the phone is plugged in and you speak the magic words "Hey Siri." I know this because last weekend my phone was on the charger next to my microphone as I was working on one of my pathetic vocal recordings, when suddenly Siri offered the following wisdom
    "Our love is like two long shadows kissing without hope of reality."

I cursed, stopped the recording, and hit playback. And there was Siri's love confession over my carefully crafted drum-bass loop. It was painfully obvious that whoever processed these vocals knew, in contrast to me, what he or she was doing. They're professionally filtered, compressed and flawlessly de-essed. In short, they sound awesome, even after re-recording.

I then had a little conversation with my phone, inquiring what this shadow business was all about. Siri stubbornly refused to repeat her lyrical deepity, but had some other weird insights to offer.

Enjoy :)

PS: No, my lyrics do of course not contain the words "Hey Siri". I'm not sure what caught her attention, but I recommend you don't sing to your phone.

Monday, October 13, 2014

Does Loop Quantum Cosmology make the black hole information loss problem worse rather than better?

Image Source: Flickr.

Martin Bojowald is one of the originators of Loop Quantum Cosmology (LQC), a model for the universe that makes use of the quantization techniques of Loop Quantum Gravity (LQG). This description of cosmology takes into account effects of quantum gravity and has become very popular during the last decade, because it allows making contact to observation.

The best known finding in LQC is that the Big Bang singularity, which one has in classical general relativity, is replaced by a bounce that takes place when the curvature becomes strong (reaches the Planckian regime). This in return has consequences for example for the spectrum of primordial gravitational waves (that we still hope will at some point emerge out of the foreground dust).

Now rumors reached me from various sources that Martin lost faith that Loop Quantum Cosmology is a viable description of our universe, and indeed he recently put a paper out on the arxiv detailing the problem that he sees.
Information loss, made worse by quantum gravity
Martin Bojowald
Loop Quantum Cosmology, to be clear, was never claimed to be strictly speaking derived from Loop Quantum Gravity, though I have frequently noticed that the similarity of the names leads to confusion in the popular science literature. LQC deals with a symmetry-reduced version of LQG, but this symmetry reduction is done before the quantization. In practice this means that in LQC one first simplifies the universe by assuming it is homogeneous and isotropic, and then quantizes the remaining degrees of freedom. Whether or not this treatment leads to the same result that one would get by taking the fully quantized theory and looking for a solution that reproduces the right symmetries is controversial, and to my knowledge this question has never been satisfactorily settled.

Be that as it may, from my perspective and from that of most people working on the topic, LQC is a phenomenological model that is potentially testable and thus interesting in its own right, regardless of its connection to LQG.

It has become apparent however during the last years that if one takes into account perturbations around the homogeneous and isotropic background in LQC then one finds something peculiar: the space-time around the bounce loses its time-coordinate, it becomes Euclidean and is thus just space without time. We discussed this earlier here.

Now the time-coordinate in the space-time that we normally deal with plays a very important role, which is that it allows us to set an initial condition at one moment in time, and then use the equations of motion to predict what will happen at later times. This so called “forward evolution” is a very typical procedure for differential equations in physics, so typical that we often do not think about it very much. Thus I have to emphasize the relevant point is that to determine what happens at some point in space-time one does not have to set an initial condition on a space-time boundary around that point, which would necessitate knowing what happens at some moments into the future, but it is sufficient to know what happened at some moment in the past.

This important property that allows us to set initial conditions in the past to predict the future is not something you get for free in any space-time background. Space-times that obey this property are called “globally hyperbolic”. (Anti-de Sitter space is the probably best known example of a space-time that is not globally hyperbolic, thus the relevance of the boundary in this case.)

In his new paper Martin now points out that if space-time has regions that are Euclidean then the initial value problem becomes problematic. It is then in fact no longer possible to predict the future from a past initial condition. For the case of the Big Bang singularity being replaced by a Euclidean regime, this does not matter so much because we would just set initial conditions after this regime has passed and move on from there. But not so with black holes.

The singularity inside black holes is in LQC then also replaced by a Euclidean regime. This regime only forms in the late stages of collapse and will eventually vanish after the black hole has evaporated. But there being an intermediate Euclidean region has the consequence that whatever is the outcome of the evaporation process depends on the boundary conditions surrounding the Euclidean region. With the intermediate Euclidean region, one can no longer predict from the initial conditions of the matter that formed the black hole what is the outcome of black hole evaporation.

In his paper Martin writes that this makes the black hole information loss considerably worse. The normal black hole information loss problem is that the process of black hole evaporation seems to be irreversible and thus in particular not unitary. The final state of the evaporation is always thermal radiation, regardless of what formed the black hole. Now with the Euclidean region the final state of the black hole evaporation depends on some boundary condition that is not even in principle predictable. We have thus gone from not unitary to not deterministic!

Martin likens this case to that of a naked singularity, a singular region that (in contrast to the normal black hole singularity which is hidden by the horizon) is in full causal contact with space-time. A singularity is where everything ends, but it is also where anything can start. The initial value problem in a space-time with a naked singularity is similarly ill-defined as that in a space-time region with a Euclidean core, Martin argues.

I find this property of black holes in LQC not as worrisome as Martin. The comparison to a naked singularity is not a good one because the defining property of a singularity is that one cannot continue through it. One can however continue through the Euclidean region, it’s just that one needs additional constraints to know how. In fact I can see that what Martin thinks is a bug might be a feature for somebody else, for after all we know that time-evolution in quantum mechanics seems to be non-deterministic indeed.

But even leaving aside this admittedly far-fetched relation, the situation that additional information is necessary on some boundary to the future is not unlike that of the mysterious “stretched horizon” in black hole complementary. Said stretched horizon somehow stores and later releases the information of what fell through it. If the LQC black hole is supposed to solve the black hole information problem, then the same must be happening on the boundary of the Euclidean region. And, yes, that is a teleological constraint. I do not see what theory could possibly lead to it, but I don’t see that it is not possible either.

In summary, I find this development more interesting than troublesome. In contrast to non-unitarity, having a Euclidean core is uncomfortable and certainly unintuitive, but not necessarily inconsistent. I am very curious to see what the community will make out of this -- and I am sure we will hear more about this in the soon future.

Wednesday, October 08, 2014

I can't forget [music video]

Update about my songwriting efforts:

I had some help with the audio mix, but the friendly savior of my high frequency mush prefers to go unnamed. Thanks to him though, you can now put the thing on your stereo and it will sound reasonably normal. I like to think that I have made some progress with the vocal recording and processing. I am not happy with the percussion in that piece, have to work on that. If you go through my last few videos you can basically hear which tutorial I read at which point. So far I believe I am making progress, but you be my judge!

As to the video, I spent some money on an inexpensive video camera, and it has made my video recording dramatically easier because it has an auto zoom. As a result, the new video is more dynamic than the previous ones, it looks considerably better to me. It would have been even better hadn't I been wearing a blue shirt on the blue-screen day, some neurons failed me there.

I still haven't found a good way to deal with the problem that the video tends to go out of synch with the audio after exporting it. In fact I noticed that the severity of the problem depends on the player with which you watch the result which I find particularly odd. And after uploading the thing to youtube the audio again shifts oh-so-slightly. In the end, no matter what I do, it never quite fits.

And since I was asked a few times, yes I do have a soundcloud account, under the name "Funny Mommy". You can find all the tracks there. It's just that I am not in the mood to play the social network game on yet another platform, so I have a total of three followers or so, all of which are probably spam-bots. That's why I use YouTube. I am totally open to suggestions for other artist names :) And yeah, I am also on Ello, as @hossi, not that it seems to be good for anything.

Friday, October 03, 2014

Is the next supercollider a good investment?

The relevance of basic research is difficult to communicate to politicians who only care about their next term and who don’t want to invest in what might take decades to pay off. But it is even more difficult to decide which research is the best to invest into, and how much it is worth, in numbers.

Whether a next supercollider is worth the billions of Euro that it will eat up is a very involved question. I find it partly annoying, partly disturbing, that many of my physics colleagues regard the answer as obvious. Clearly we need a new supercollider! To measure the details of this, and the decay channels of that, to get a cleaner signal of something and a better precision for whatever. And I am sure they will come up with an argument for why Susy, our invisible friend, is still just around the corner.

To me this superficial argumentation is just another way of demonstrating they don’t care about communicating the relevance of their research. Of course they want a next collider - they make their living writing papers about that.

The most common argument that I hear in favor of the next collider is that much more money is wasted on the war in Afghanistan (if you ask an American) or rebuilding the Greek economy (if you ask a German), and I am sure similar remarks are uttered worldwide. The logic here seems to be that a lot of money is wasted anyway, so what does it matter to spend some billions on a collider. Maybe this sounds convincing if you have a PhD in high energy physics, but I don’t know who else is supposed to buy this.

The next argument I keep hearing is that the worldwide web was invented at CERN which also hosts the LHC right now. If anything, this argument is even more stupid than the war-also-wastes-money argument. Yes, Tim Berners-Lee happened to work at CERN when he developed hypertext. The environment was certainly conductive to his invention, but the standard model of particle physics had otherwise very little to do with it. You could equally well argue we should build leaning towers to advance research on general relativity.

I just finished reading John Moffat’s book “Cracking the Particle Code of the Universe”. I can’t post the review here until it has appeared in print due to copyright issues, sorry, but by and large it’s a good book. No, he doesn’t use it to advertise his own theories. He mentions them of course, but most of the book is more generally dedicated to the history, achievements, and shortcomings of the standard model.

His argument for the relevance of particle colliders amounts to the following paragraph:
“As Guido Altarelli mused after my talk at CERN in 2008, can governments be persuaded to spend ever greater sums of money, amounting to many billions of dollars, on ever larger and higher energy accelerators than the LHC if they suspect that the new machines will also come up with nothing new beyond the Higgs boson? Of course, to put this in perspective, one should realize that the $9 billion spend on an accelerator would not run a contemporary war such as the Afghanistan war for more than five weeks. Rather than killing people, building and operating these large machines has practical and beneficial spinoffs for technology and for training scientists. Thus, even if the accelerators continued to find no new particles, they might still produce significant benefits for society. The Worldwide Web, after all, was invented at CERN.”

~ John Moffat, Cracking the Particle Code of the Universe, p. 78
Well, running a war also has practical and beneficial spinoffs for technology and training scientists. Sorry John, but that was disappointing. To be fair, the whole book itself makes a pretty good case for why understanding the laws of nature is important business. But what war doesn’t do for your country and what investing in basic research does is building a base for sustainable progress. Without new discoveries and fundamentally new insights, applied science must eventually run dry.

There is no doubt in my mind that society invests its billions well if it invests in theoretical physics. Whether that investment should go into particle colliders though is a different question. I don’t have a good answer to that, and I don’t see that the question is seriously being discussed. Is it a worthy cause?

Last year, Fermilab’s Symmetry Magazine ran a video contest on the topic “Why particle physics matters”. Ironically most of the answers have nothing to do with particle physics in particular: “could bring about a revolution,” “a wonderful model of successful international collaboration,” “explore the frontiers and boundaries of our universe,” “engages and sharpens the mind”, “captures the imagination of bright minds”. You could use literally the same arguments for cosmology, quantum information or high precision measurements. Indeed, I personally find the high precision frontier presently more promising than ramping up energy and luminosity.

I am happy of course if China will go ahead and build the next supercollider. After all it’s not my taxes and still better than spending money on diamond necklaces that your 16 year old can show off on facebook. I can’t quite shake the impression though that this plan is more the result of wanting to appear competitive than the result of a careful deliberation about return on investment.