In quantum mechanics the state of the universe evolves deterministically: the state of the entire universe at time zero fully determines its state at any later time. It is difficult to reconcile this observation with our experience as macroscopic, nearly classical, beings. To us it seems that there are random outcomes: the state of an …
Tyce DeYoung (MSU Department of Physics and Astronomy) colloquium on high-energy astrophysics and exploration of the high-energy universe with the IceCube neutrino detector at the South Pole. Several MSU professors are part of the IceCube collaboration. I predict very exciting developments in neutrino astronomy in the coming decade ;-) The situation is similar to that …
Excerpt from Sidney Coleman’s Erice lectures. The period he describes just predates my entry into physics. This was a great time to be a high-energy theorist, the period of the famous triumph of quantum field theory. And what a triumph it was, in the old sense of the word: a glorious victory parade, full of …
Almost every student who attends a decent high school will be exposed to Special Relativity. Their science/physics teacher may not really understand it very well, may do a terrible job trying to explain it. But the kid will have to read a textbook discussion and (in the internet age) can easily find more with a …
Webpage / Program / Abstracts. My opening remarks: On behalf of Michigan State University it is my pleasure to welcome all of you to this workshop on quantum information science. In the fall of 1983 (my freshman year!) Feynman taught a graduate course at Caltech called Potentialities and Limitations of Computing Machines. Chapter 6 of …
The 36th Annual International Symposium on Lattice Field Theory begins tomorrow, hosted by MSU. My opening remarks are below. No peeking if you are an attendee! LATTICE 2018 Opening Remarks 7/23/2018 Good morning. I’d like to extend my warmest welcome to all of you on behalf of Michigan State University. We are very pleased and …
It’s never been a better time to work on AI/ML. Vast resources are being deployed in this direction, by corporations and governments alike. In addition to the marvelous practical applications in development, a theoretical understanding of Deep Learning may emerge in the next few years. The notes below are to keep track of some interesting …
My office will be recording some of the most interesting of the many talks that happen at MSU. I will post some of my favorites here on the blog. See the MSU Research channel on YouTube for more! Audio for this video isn’t great, but we are making improvements in our process / workflow for capturing these …
Roger Penrose writes in the Guardian, providing a scientifically precise summary of Hawking’s accomplishments as a physicist (worth reading in full at the link). Penrose and Hawking collaborated to produce important singularity theorems in general relativity in the late 1960s. Here is a nice BBC feature: A Brief History of Stephen Hawking. The photo above …
When I was at Caltech a few weeks ago I had a chance to discuss the recent paper below by Sean Carroll and collaborators. (Authors are at Caltech, Berkeley, and UBC.) Their paper is very clearly written, but probably suitable only for experts who are already familiar with the black hole information paradox. I discussed …
It’s been almost 10 years since I made the post Are you Gork? Over the last decade, both scientists and non-scientists have become more confident that we will someday create: A. AGI (= sentient AI, named “Gork” :-) See Rise of the Machines: Survey of AI Researchers. B. Quantum Computers. See Quantum Computing at a Tipping …
I received an email from a physicist colleague suggesting that we might be near a “tipping point” in quantum computation. I’ve sort of followed quantum computation and quantum information as an outsider for about 20 years now, but haven’t been paying close attention recently because it seems that practical general purpose quantum computers are still …
Today I came across a recent interview with Ed Witten in Quanta Magazine. The article has some nice photos like the one above. I was struck by the following quote from Witten (“It from Qubit!”): When I was a beginning grad student, they had a series of lectures by faculty members to the new students about …
Science reports on MSU’s Facility for Rare Isotope Beams, which will probe the properties of nuclear matter. Science: Last month, astronomers wowed the world when they announced that they had seen two neutron stars merge, apparently creating heavy elements such as gold and platinum and spewing them into space. Nuclear physicists here at Michigan State …
In this public lecture Weinberg explains the problems with the two predominant interpretations of quantum mechanics, which he refers to as Instrumentalist (e.g., Copenhagen) and Realist (e.g., Many Worlds). The term “interpretation” may be misleading because what is ultimately at stake is the nature of physical reality. Both interpretations have serious problems, but the problem …
This is the best technical summary of the Los Alamos component of the Manhattan Project that I know of. It includes, for example, detail about the hydrodynamical issues that had to be overcome for successful implosion. That work drew heavily on von Neumann’s expertise in shock waves, explosives, numerical solution of hydrodynamic partial differential equations, …
I have not, until recently, invested significant time in trying to understand climate modeling. These notes are primarily for my own use, however I welcome comments from readers who have studied this issue in more depth. I take a dim view of people who express strong opinions about complex phenomena without having understood the underlying …
I love Joe Rogan — he has an open, inquisitive mind and is a sharp observer of life and human society. See, for example, this interview with Dan Bilzerian about special forces, professional poker, sex, drugs, heart attacks, life, happiness, hedonic treadmill, social media, girls, fame, prostitution, money, steroids, stem cell therapy, and plenty more. …
This is Part 2 of the “On quantum measurement” series. Part 1: (Hans Bethe, the oracle) is here. Before we begin in earnest, I should warn you, (or ease your mind, whichever is your preference): this sequence has math in it. I’m not in it to dazzle you with math. It’s just that I know …
I’m busy reviewing ~200 promotion and tenure cases for my day job, so I don’t have much time to post about the BICEP2 observation of primordial gravitational waves via their effect on the polarization of the cosmic microwave background (CMB). Instead, I refer you to Sean Carroll, Lubos Motl and Liam McAllister (guest poster at …
I figured this blog needs to cover what is being called very big news, but I didn’t really understand it myself when I first read about it. I will try to break it down. This big story is about how new evidence was found that confirms how the Big Bang happened. There are several theories …
Lubos Motl seems to have taken offense at my last post: Feynman’s Cognitive Style. This is a rather ironic outcome, given that I’ve been a “Feynman idolator” since I was in high school :-) In fact, I chose my college (Caltech), career, and even research specialization under his influence! In the previous post, I noted that …
Some interesting finds in this 1966 AIP oral history interview with Feynman. I have always felt that Feynman was cognitively a bit “lopsided” — much stronger mathematically than verbally. This might be partially responsible for his way of learning — it was often easier for him to invent his own solution than to read through …
I have written about the fate of classical information interacting with black holes fairly extensively on this blog (see Part 1, Part 2, and Part 3). Reviewers of the article describing those results nearly always respond that I should be considering the fate of quantum, not classical information. In particular, they ask me to comment …
Congratulations to Peter Higgs and François Englert on their Nobel prize. A bit of background from an earlier post How the Higgs boson became the Higgs boson: IIRC, I met Peter Higgs in Erice in 1990. He was quite a nice fellow, but the story below by Steve Weinberg illustrates how capricious is the allocation …