So, physics is a fron­tier sci­ence. It sits at the very bound­ary and lim­its of a par­tic­u­lar type of human inquiry, one that con­cerns itself with the ori­gins of exis­tence and every­thing that it con­tains. Our uni­verse, for exam­ple. And as a fron­tier sci­ence and a human endeav­or, it is an enter­prise. And there are many dif­fer­ent types of char­ac­ters involved in this enter­prise. And as a way for me to intro­duce them to you, I’m going to invoke a metaphor for our search for the ulti­mate phys­i­cal truth, as it were. And the metaphor involves a landscape. 

So the idea is we’re in a land­scape, we’re sur­round­ed by moun­tains, sep­a­rat­ed by val­ley, obscured by fog. And we’re try­ing to find the high­est sum­mit. So there’s a par­tic­u­lar type of char­ac­ter that the physi­cist and author Lee Smolin and iden­ti­fied as a sum­mit seek­er, or a moun­taineer, some­one that is imme­di­ate­ly next to a tall moun­tain and decides, ​“Right, I’m going to go up.” 

There’s also a par­tic­u­lar type of char­ac­ter known as a val­ley cross­er, or an explor­er, who thinks to them­selves, ​“Well, there’s a very tall moun­tain next to me, but per­haps three val­leys over…I can’t real­ly see what’s over there, but maybe there’s an even taller moun­tain. So I’m going to go cross into the unknown.”

There are entre­pre­neurs. There are char­ac­ters who have an appetite for risk. Who can inspire and drum up peo­ple to go along with them on any par­tic­u­lar adven­ture. There are poets. These char­ac­ters don’t care where they end up. They just enjoy the art and the craft for its own sake. There are lit­er­ary crit­ics. There are peo­ple who have strong opin­ions about the way things are going, about the state of the art, and seek to influ­ence oth­er peo­ple’s opinions.

There are crafts­men and craftswomen, peo­ple who are so tal­ent­ed at a par­tic­u­lar aspect of this enter­prise that watch­ing them do their thing becomes a thing unto itself, an art form unto itself. There are engi­neers, who get a kick out of solv­ing prob­lems with a min­i­mal set of resources in the clever­est way pos­si­ble. And like in any field, there are also politi­cians. And the less you speak about them, the better.

And if I were to iden­ti­fy myself in one of these, I would say that I aspire towards being some­thing in between a crafts­man and a val­ley cross­er. Although in prac­tice my val­ley cross­ing has been almost reck­less, that it’s not been par­tic­u­lar­ly good for my career. Although I sur­vived and I’m here to tell you the tale.

So, how does one prac­ti­cal­ly even go about this enter­prise of dis­cov­ery? So let’s begin with val­ley cross­ing. And in par­tic­u­lar let’s begin with an extreme ver­sion of it, which is you go across sev­er­al val­leys, and you find some­thing real­ly remark­able that real­ly shat­ters peo­ple’s view of how things ought to be done, and real­ly rede­fines a new par­a­digm. And the way you go about that is very sim­ple. Be a genius. Or be very lucky.

Now, I don’t mean for you to take that too lit­er­al­ly. I think genius is a myth that’s often cre­at­ed after the fact, a leg­end that is rewrit­ten after the fact. But nev­er­the­less it is true that in almost every­thing we do, we are the ben­e­fi­cia­ries of these var­i­ous remark­able flash­es of insight that now allow us take effort­less short­cuts through what­ev­er it is that we’re doing.

So, one that is par­tic­u­lar­ly rel­e­vant today is Einstein real­iz­ing that grav­i­ty is set apart as a force from all the oth­er forces in nature. Because what grav­i­ty real­ly is isn’t…well it is a force, but the way it acts is rather remark­able. Einstein real­ized that space­time was­n’t this sta­t­ic are­na in which things just sort of hap­pened. Einstein real­ized that in fact space­time itself is a thing, it’s an elas­tic medi­um. And it gets dis­tort­ed by mate­r­i­al objects. 

So if this apple were the sun, the sun is dis­tort­ing the fab­ric of space­time around it such that if any­thing tried to move in a straight line, which it ordi­nar­i­ly would do effort­less­ly, it might sort of take a curved path. It might even get trapped in a cir­cle going round and round the sun. Like the Earth. And this exam­ple is par­tic­u­lar­ly rel­e­vant today because at this very moment, in fact, there is a press con­fer­ence hap­pen­ing in Washington DC where the LIGO col­lab­o­ra­tion is most like­ly going to announce the dis­cov­ery of rip­ples in this fab­ric of space­time, grav­i­ta­tion­al waves. So it’s a very his­toric for physics. And I con­sid­er this insight to be one of the great­est leaps a human mind has ever made.

And then per­haps on a more prac­ti­cal lev­el, on a day-to-day, no one’s going about mak­ing rev­o­lu­tion hap­pen every day. In fact it’s not always the con­text for some­thing like that to hap­pen. So on a day-to-day basis in the day-to-day process of sum­mit seek­ing, the more sort of prac­ti­cal thing of try­ing to solve prob­lems, to dis­cov­er new things with­in an exist­ing par­a­digm. It’s not that every­thing hap­pens in a vac­u­um. Everything that we do, whether it’s implic­it­ly acknowl­edged or explic­it­ly acknowl­edged, bor­rows from these flash­es of insight. We stand on the shoul­ders of giants, as Newton him­self pref­aced in his Principia Mathematica.

So if you were to step back and ask what the meta-process of this would be, if some­how there were a man­u­al of dis­cov­ery, it would con­tain the entries of all the peo­ple that have gone before. Einstein would’ve come along and writ­ten some­thing. Descartes will have come along and writ­ten some­thing. And Newton would’ve come along and writ­ten some­thing. Darwin would’ve come along and writ­ten some­thing. And whether we acknowl­edge it or we don’t, we are the ben­e­fi­cia­ries of this learned metalogic. 

And if this thing were actu­al­ly a book, its title would be called Heuristics, or the art of inven­tion. And instead of star­ing at each new prob­lem like it were a blank page, you could instead begin by ask­ing your­self what is essen­tial about the prob­lem? What can be ignored about the prob­lem. What is super­flu­ous detail? Does this look like anoth­er, eas­i­er prob­lem? And could you solve that sim­pler problem?

So I want you to pay atten­tion to this, because this is actu­al­ly the sort of meta-process that the sci­en­tif­ic method actu­al­ly invokes. Are you look­ing at the prob­lem the right way? Maybe it’s not even a prob­lem. Maybe the bug is a fea­ture. Are you try­ing too hard? Perhaps you’ve been work­ing on some­thing for years and years and years, and maybe that’s telling you some­thing. Has that prob­lem already been solved? And I think this is some­thing that a lot of peo­ple can under­stand, because it’s often the case that peo­ple look to nature for inspi­ra­tion for cer­tain prob­lems in design. And I think the most dra­mat­ic exam­ple of that is some­thing that prob­a­bly brought a lot of you here, which is when the Wright Brothers real­ize that in try­ing to make this air­plane object they were try­ing to invent fly, they need­ed to bor­row a design that they saw from bird’s wings. That prob­lem had already been solved by nature.

So, the sci­en­tif­ic method was per­fect­ed in the cru­cible of nat­ur­al sci­ence, and physics in par­tic­u­lar. And an old pro­fes­sor of mine once told me that a good the­o­ret­i­cal physi­cist is intrin­si­cal­ly a lazy per­son. And so these heuris­tics of ignor­ing super­flu­ous detail, sim­pli­fy­ing the prob­lem to its barest essen­tials, maybe even mak­ing a car­i­ca­ture out of it, solv­ing that sim­pler prob­lem. If you can’t solve that sim­pler prob­lem, solve an even sim­pler prob­lem. This actu­al­ly works in physics. Because the uni­verse is intrin­si­cal­ly a lazy place. 

Structures that we see in one par­tic­u­lar con­text in one par­tic­u­lar scale are repro­duced across vast­ly dif­fer­ent con­texts and vast­ly dif­fer­ent scales. And this is telling us some­thing. That the uni­verse prefers, it has this pen­chant for this under­ly­ing sim­plic­i­ty and econ­o­my of descrip­tion. If you like, the uni­verse out­sources the mechan­ics of its exis­tence to a very small set of uni­ver­sal­i­ty class­es of phe­nom­e­non. And none is so dra­mat­ic, I think, than the fol­low­ing fact, that if you take any sys­tem close enough to equi­lib­ri­um… And by equi­lib­ri­um I mean if you just leave it there it stays that way for­ev­er, its ground state, its low­est ener­gy con­fig­u­ra­tion. Any sys­tem close enough to equi­lib­ri­um can be described, once you real­ly break down the way you describe it in terms of math­e­mat­ics, as a col­lec­tion of inter­act­ing sim­ple har­mon­ic oscil­la­tors. Like springs. This is just some­thing that is. The col­lec­tive motion of which look like waves.

So, by this I mean net­works of neu­rons in your visu­al cor­tex try­ing to under­stand or process an image. Flocks of birds. Crystals. Traffic flow. All of this can be boiled down to the same iden­ti­cal math­e­mat­ics. It’s a remark­able fact. Waves on water are very vis­cer­al exam­ple of this. We all see this, right. So, water is a thing. It exists. And lit­tle tiny dis­tur­bances on water are waves. These are very non­lin­ear waves, but if you imag­ine they were small enough, they’d be quite lin­ear. And these local­ized exci­ta­tions car­ry ener­gy around.

What if I told you that fun­da­men­tal par­ti­cle physics is noth­ing more than that? That par­ti­cles are like waves, local­ized exci­ta­tions on an under­ly­ing quan­tum field. So, there’s this thing called the elec­tron field, and elec­trons are local­ized exci­ta­tions just like waves on the ocean, float­ing around bounc­ing off of each oth­er. Solar quarks. Quarks are exci­ta­tions of a fun­da­men­tal quark field. Photons, glu­ons, all the fun­da­men­tal par­ti­cles you can imag­ine, are described by the same under­ly­ing mathematics.

And if you took this to its log­i­cal extreme, almost absurd extreme if you will, there’s a can­di­date the­o­ry for the uni­ver­sal called string the­o­ry, which states that there aren’t these sep­a­rate fields. There’s only one field, the string field. And its local­ized exci­ta­tions are one-dimensional extend­ed objects—strings—whose dif­fer­ent notes are the dif­fer­ent par­ti­cles that we see. And whose fun­da­men­tal note is actu­al­ly just a dis­tor­tion of space­time itself. And alter­nat­ing the next high­est notes are dif­fer­ent force car­ri­ers, and dif­fer­ent charged par­ti­cles. So, physi­cists makes fun of them­selves when they real­ize this. And they say that physics is that of all human expe­ri­ence that could be boiled down to study of sim­ple har­mon­ic oscil­la­tors. That’s it. So we’re not very clever.

So let’s say there is some­thing that we can­not explain. Within the work­ing heuris­tics of a prac­tic­ing physi­cist, there’s a par­tic­u­lar type of of paid adven­ture, a fund­ed adven­ture, if you like, that I just find remark­able. And it’s called phe­nom­e­nol­o­gy. And to me it’s a remark­able thing. It’s very hum­bling thing that myself and my col­leagues are paid by your tax­es to go forth and do this for a liv­ing. Which is that if we go around and we see some­thing that we can­not explain in the uni­verse (galax­ies mov­ing in a way that there seems to be some miss­ing mat­ter, for exam­ple) you are enti­tled to break the laws of physics or bend them in any con­ve­nient way such that you end up explain­ing what you see. To invent a par­ti­cle and call it dark mat­ter, for example.

And in order to give you anoth­er con­crete exam­ple of this, I first need to teach you a lit­tle bit about quan­tum mechan­ics in a slide, if it’s pos­si­ble, so bear with me.

I apol­o­gize for the equa­tion. I promise I’ll explain it. 

The quan­tum mechan­i­cal uni­verse is a very strange uni­verse. Our day-to-day intu­ition about our rela­tion­ships with space and time are very dif­fer­ent. Measuring where some­thing is, and how fast it is going are not com­munt­ing oper­a­tions. So either you’re look­ing at me on the stage or you’re star­ing at your com­put­er screen or your iPhone or what­ev­er it is. But you’re look­ing at some­thing, and in doing that (Let’s say you’re look­ing at me.), you are iden­ti­fy­ing where I am (I’m stand­ing right here.) and how fast I’m going. (I’m stand­ing still.)

But I could have done that oper­a­tion in reverse. I could have first looked at how fast I was going, maybe with a speed gun or some­thing. And then tried to fig­ure out where I was. And ordi­nar­i­ly you’d think that the order of those two oper­a­tions should­n’t mat­ter. And intu­itive­ly, at the scale at which we exist, they don’t. But in the quan­tum mechan­i­cal uni­verse, that is not true. The order of oper­a­tion mat­ters. Which is telling us some­thing very remark­able. That mea­sur­ing where some­thing is and how fast it’s going can­not be described by num­bers. Because num­bers com­mute. You mul­ti­ply them in a par­tic­u­lar, you switch the order, you get the same thing. So the fact that they don’t com­mute means that the dif­fer­ence is not zero, and so they’re no longer described by the usu­al numbers.

And in fact they’re described by these com­pli­cat­ed things called oper­a­tors, but we don’t need to get into them. And this irre­ducible uncer­tain­ty in deter­min­ing where and when some­thing is, is set by this thing called the quan­tum. So what that’s telling you is that it’s impos­si­ble to actu­al­ly local­ize some­thing, because if you could, you’d be able to make a state­ment, ​“I know some­body is there and they’re not going any­where,” in con­tra­dic­tion to the laws of quan­tum mechanics.

So that leads to all sorts of strange­ness. Particles act like waves. Waves act like par­ti­cles. And in real­i­ty they’re nei­ther. What’s hap­pen­ing is we are mon­keys with brains. We’ve evolved the per­cep­tion of the world around us because that’s what just hap­pened through evo­lu­tion­ary neces­si­ty. But at the very fun­da­men­tal scale, the uni­verse does­n’t agree with our monkey-with-brain con­cepts, and they com­plete­ly break down. Things can exist in a super­po­si­tion of quan­tum states. Cats can be both dead and/or alive. So the very gram­mar and boolean log­ic of ordi­nary intu­ition com­plete­ly fails. So the quan­tum mechan­i­cal uni­verse is a very strange one. But we under­stand it through math­e­mat­ics. But we are very bad at explain­ing it through our lan­guage. This is one of the many ways in which lan­guage is lim­it­ing our under­stand­ing of the universe.

So now it turns out that when we try to make grav­i­ty fit with our quan­tum mechan­i­cal descrip­tion of par­ti­cles as lit­tle waves float­ing around, there are all sorts of infini­ties that we don’t know how to deal with in our cal­cu­la­tions. And so the rea­son for those infini­ties is in fact that space­time is infi­nite­ly divis­i­ble. So that means between here and here there’s always a point in between. And no mat­ter how small or how short a dis­tance I look, there’s always a point in between. And that caus­es prob­lems in our equations.

So, a phe­nom­e­no­log­i­cal thing to do would be, how about we fix that? How about we break that? And then see what hap­pens. Shoot first, ask lat­er. So, what if space­time itself sat­is­fied a ver­sion of the uncer­tain­ty prin­ci­ple? Imagine between us there is an imag­i­nary plane. And I’m point­ing to a point right here. So how do I know to tell you that this point is here? I would first have to tell you how far along the X axis (if you allow me to tell you that this direc­tion is X) it is, and how far up it is. So the point here is this much on the X direc­tion, this much on the Y direc­tion. But it also is this much up along the Y direc­tion, and this much along the X direc­tion. That’s our usu­al geometry.

But if we take the les­son from quan­tum mechan­ics and say, what if space time itself is intrin­si­cal­ly quan­tum? What if that oper­a­tion did not com­mute? And you’d end up in a dif­fer­ent place? That means the idea of a point is mean­ing­less. It is a fic­tion that you’ve cre­at­ed because you’re a mon­key with a brain at a large large scale. Whereas fun­da­men­tal­ly, points don’t exist. And this geo­met­ri­cal struc­ture has bro­ken many of the rules of math­e­mat­ics. There’s a lot of math­e­mati­cians that would’ve been very upset at this until they fig­ured out how to deal with it.

And so if you would imag­ine what space looks like at that very small scale, it goes from this infi­nite­ly divis­i­ble con­tin­u­um into this chaot­ic quan­tum foam. Points are just not resolv­able. Once you try to resolve some­thing, it flips and becomes some­thing else. So here, there, now, lat­er, are all mixed up into this cloud of pos­si­bil­i­ty and uncer­tain­ty. So, if we were to scale this up to the larg­er scales and imag­ine some­one walk­ing down a flight of stairs, they might appear as a jagged set of per­sis­tences, depend­ing on how you’re look­ing at the scene. 

So, shoot first, ask lat­er, okay? So we said, ​“Well, let’s just hack space­time and make it quan­tum.” But as physi­cists, we have to actu­al­ly ask the ques­tion, is it true? Or is this just a game we’re play­ing on a piece of paper? So, the ener­gies we need to probe this physics… To put this into con­text, some­where over there, like sev­en, ten kilo­me­ters over there, is the Large Hadron Collider. It is twen­ty five kilo­me­ters in cir­cum­fer­ence. To probe the physics that we would need to test the quan­tum­ness of geom­e­try, we would have to build a par­ti­cle accel­er­a­tor the size of the galaxy. So I think it’s fair to say that no gov­ern­ment is going to fund that any­time soon.

So, we do the next best thing and we sift through the evi­dence left over from the Big Bang itself, and you’re look­ing at it right there on that slide. It is rel­ic radi­a­tion left over from when the uni­verse was a very hot, dense place. So, once upon a time, the uni­verse was such a hot place that light and mat­ter could­n’t breaks free. They were just bounc­ing off of each oth­er. But there was a moment when the uni­verse was 378,000 years old that sud­den­ly it cooled enough that light just broke free. And there’s was this flash. The uni­verse sud­den­ly became trans­par­ent. And that’s were look­ing at. And it is a pic­ture of a vibrat­ing plas­ma, and it is lit­er­al­ly an ultra­sound of the uni­verse when it was a baby.

So, you don’t need to look at some­thing to under­stand how it sounds like. And by lis­ten­ing to some­thing, you can actu­al­ly tell a lot about it. If you were to shut your eyes and some­one were to play you a vio­lin play­ing mid­dle A:

It would sound some­thing like that. And you did­n’t need me to even tell you what that was. You could’ve been blind­fold­ed and you’d rec­og­nize imme­di­ate­ly that it was a vio­lin because your brain took that sig­nal and broke it down. Your audio cor­tex to that sig­nal and broke it down in terms of fun­da­men­tal harmonics.

So the loud­est note is of course mid­dle A. The next loud­est note is also A, octaves up. And so this thing is a Fourier trans­form. It’s decom­pos­ing the sound of the vio­lin into all its fun­da­men­tal har­mon­ics. And from that you can tell it’s a vio­lin. You can tell its shape. You can tell a lot about it.

So, if we took that vibrat­ing plas­ma and imag­ined we were back then when the uni­verse was 378,000 years old, and we stuck our head into that pri­mor­dial goop, it would sound a bit like this:

Sounds like white noise, but again, we notice if we did the same thing that we did to the vio­lin, there’s one par­tic­u­lar note that’s quite loud. And there’s a cou­ple of har­mon­ics. And the third har­mon­ic is a lot loud­er than it should be, and that actu­al­ly tells us that the uni­verse is most­ly made up of this thing called dark ener­gy, and a lit­tle bit of this thing called dark matter.

And if you were to ask where is the evi­dence, if there was any evi­dence that space­time would have any grain­i­ness asso­ci­at­ed with it, we would expect to see lit­tle extra rip­ples on the right of this plot that we don’t see, to the accu­ra­cy which we mea­sured. So there­fore this idea was­n’t true. No dice. No rewards for me and my col­lab­o­ra­tors. But that’s how phe­nom­e­nol­o­gy works. You break the laws of physics to try and explain some­thing that you think might be going on, and then you don’t care about the con­se­quences until you’re proved wrong. 

So, we have a very sim­ple mod­el of the ear­ly uni­verse. It explains every­thing that we’ve seen around us, but it begs for deep­er expla­na­tion and we don’t real­ly know what that expla­na­tion is. So it’s very pleas­ing that we under­stand so much. It’s also very frus­trat­ing that we can’t see what is real­ly the thing behind the Big Bang. It could be that the under­ly­ing pic­ture is far beyond what we’ve imag­ined, and it’s a sit­u­a­tion summed up very neat­ly by Niels Bohr when he quipped to a col­league that, ​“Your the­o­ry is crazy, but it’s not crazy not to be true.” Keep trying.

So, I have noth­ing more. I hope I’ve giv­en you a lit­tle taste of how the met­a­log­ic of dis­cov­ery works in physics, and a lit­tle sort of like the men­tal hacks that we use to try and get fur­ther. And I think the thing I’ve learned, num­ber one, is that there are just absolute­ly no rules. You are on your own. But, you can pig­gy­back off of what oth­er peo­ple have learned for you on your behalf. And I think the thing that I’d like to leave you with that I think is the most impor­tant to me, is that the thing that I’ve noticed the most about the sci­en­tists that I respect and admire the most is that they’re will­ing to intro­duce noise into their process to allow them to make asso­ci­a­tions that they would­n’t have oth­er­wise. And that have a very strong mis­chie­vous streak. They like to go on adventures.

Thank you very much.

Sophie Lamparter: Thank you very much, Subodh. That was fas­ci­nat­ing. How do you cre­ate noise in your universe?

Subodh Patil: Well, I think I do a lot of read­ing that’s not relat­ed to my work. I have a gui­tar next to my side when­ev­er I’m doing a cal­cu­la­tion. I always pick it up. I walk around a lot. But I mean there’s oth­er things you could do. I try to just sort of get away from hang­ing out with the ​“crowd,” as it were. I’m sort of aller­gic to the sort of…the herd. And I try to be as far away to the periph­ery as possible.

Lamparter: So, Subodh and I met about three years ago because he was col­lab­o­rat­ing at—you know CERN has this artist in res­i­den­cy pro­gram. And so he was the sci­en­tif­ic part­ner of a sound artist, Bill Fontana, who is actu­al­ly from San Francisco. And we’re speak­ing about antidis­ci­pli­nar­i­ty. Do you think those con­ver­sa­tions are kind of help­ful also for your work, or at least help you to cre­ate noise, or…

Patil: No, they’re amaz­ing. I think of one of the things that dis­ap­points me about the mod­ern world is that we sort of ghet­toized our brains so much in terms of these lit­tle micro­com­mu­ni­ties, and peo­ple rarely cross over them. And hang­ing out with some­one like Bill, for exam­ple, was very nice because I imag­ine well, maybe this is what it would’ve been like to have been in Paris in the 1920s, hang­ing around drink­ing cof­fees in a cafe and com­par­ing my notes of my cal­cu­la­tions with a Cubist. That’s what it felt like.

Lamparter: Yeah. That’s what we’re here for today, right? Okay, thank you so much.