 I'm going to play something that changed my whole research direction that led to basically a discovery in physics that will be familiar. All right, thank you. So about eight years ago when I was a, I had a leak here, eight years ago when I was a postdoc at Stanford, I got stuck, I hit a wall in a project I was working on having to do with quantum gravity, trying to unify quantum mechanics with Einstein's view of general relativity. And I hit a wall. So what I did was just give, I just gave up on physics and went to hang out with my friend, David Boyce. That was time for this. And here's David. He's a great saxophone player from the Bay Area. I used to hang out with him. I noticed a book written by Yusef Lateef and I opened a book. This book was filled with a lot of scales, daunting scales and only one diagram. I'm going to show you this diagram. And at the bottom, it said birthday present to Yusef Lateef from John Coltrane. And this immediately struck out as a puzzle that that train left for Yusef Lateef who is a great composer as well, is all right. And as I was staring at this thing, it caught my attention, I'll emerge a three-dimensional object. And that three-dimensional object reminded me of the very research that I was stuck on in quantum gravity. So today I'm going to tell you a little bit about that. Please bear with me. It took six years to figure this out. Here's Yusef Lateef right there. So I'm going to say a little bit about quantum gravity in a nutshell. So the first part of quantum gravity is quantum mechanics. The thing I want you to take away about quantum mechanics is that what appears to be continuous and continuous about matter is actually discrete when we get to atomic levels. So here's a depiction of hydrogen atom. And what we see is an electron jumping, making a quantum leap in energy and releasing a packet of energy of called a photon. This is basically how a laser works. And the other thing I want you to take away is that the active observation participates in the outcome, very strange matrix-y type of take on quantum mechanics. The thing I want you to take away about general relativity is that space and time actually in the gravitational force emerges as a warping. So space and time is a fabric that gets warped due to the presence of matter. What we're looking at here is a real picture of something called a proto-galaxy, a baby galaxy, a quasar, that is a lens. A galaxy in front of it lenses a spacetime like a kaleidoscope effect and creates four copies of the galaxies, a very real picture. Space does get warped. And this is what a black hole does to a galaxy like our own, supermassive black hole. So quantum gravity takes both of these things and it's taken over 75 years for physicists. This is the problem of my generation trying to crack the code and how to figure out quantum gravity. And the insight is that spacetime becomes discrete quanta, just like the atom occurs. And also that spacetime becomes atomistic. They have discrete building blocks just like when you zoom in in New York Times newspaper and you see pixels. And so after many years of research, my colleagues and I participate in some of this figured out these are mathematical realizations of the atoms of spacetime that tessellate this very structured spacetime that you're interacting through. We call this tetrahedron. Don't pay attention to the numbers there. So now I wanna now go back to giant steps. Think about giant steps now as quantum steps. And I'm gonna show you basically how the structure emerges. Okay, how Coltrane's puzzle that I saw was exactly that mathematical realization of quantum gravity. So here we're looking at a circle. I'm now gonna paint the circle with notes. These are the circle of fifths. And I'm gonna pick the most symmetric object in this which is this triangle. Each point of that triangle is a note and I'm gonna play that for you. Any guesses? All right, so basically there's one note in between that but I basically I played C, E and A flat there. And if I continue going around this circle with these triangles, I'll get the same pattern. These are the chord changes of the code. These are the Coltrane changes I'm showing you. Four triangles, if I play these four triangles I come right back to the center of gravity. Now if I go back to use a flat T puzzle you see that's exactly what Coltrane gave him. Now if I extend this to three dimensions which is what Coltrane was really after he kept talking about expansion. He was a big fan of Albert Einstein near the end of his life. He was making statements of why is the universe expanding? He wanted to create expansion. If I expand this object out I have four triangles in three dimensions. I create the tetrahedra which is exactly the atom of space and time that we find in quantum gravity. So this is, I took this very seriously and I ended up in a research project with the director of composition at NYU or Professor Robert Railroad down the corner at Steinhardt and four years later we figured out how to generalize the structure to all of the four notes that we call tetranotes, chords, in the Western musical system. And this is the answer. This is called the pentahelix. And what it is, it's a reflection of tetrahedra that spiral up into like a helical structure. So it's very interesting that our Western musical scale geometrically looks very much like a double helix of DNA. Okay? And now even in string theory, my colleague Professor Gates has applied this to string theory and you can see that the structure emerges there. So I just want to, you know... I know, it's a bit much. It's a bit much. But these are mathematical realizations of theories of quantum gravity and it's just intriguing to me and coincidental that fields at first appear to be so disparate and unrelated by bravely and just engaging others in different field could lead us to make surprising discoveries and insight even in our own fields at home. So for the last two seconds, I would like to now want you to think about, I'm gonna play this again and I wonder if it's gonna sound or look different to you. Mm-hmm, mm-hmm, mm-hmm, mm-hmm.