This Week’s Finds (1–50)

Take a copy of this!

This Week’s Finds in Mathematical Physics (1-50), 242 pages.

These are the first 50 issues of This Week’s Finds of Mathematical Physics. This series has sometimes been called the world’s first blog, though it was originally posted on a “usenet newsgroup” called sci.physics.research — a form of communication that predated the world-wide web. I began writing this series as a way to talk about papers I was reading and writing, and in the first 50 issues I stuck closely to this format. These issues focus rather tightly on quantum gravity, topological quantum field theory, knot theory, and applications of n-categories to these subjects. There are, however, digressions into elliptic curves, Lie algebras, linear logic and various other topics.

Tim Hosgood kindly typeset all 300 issues of This Week’s Finds in 2020. They will be released in six installments of 50 issues each, for a total of about 2610 pages. I have edited the issues here to make the style a bit more uniform and also to change some references to preprints, technical reports, etc. into more useful arXiv links. This accounts for some anachronisms where I discuss a paper that only appeared on the arXiv later.

The process of editing could have gone on much longer; there are undoubtedly many mistakes remaining. If you find some, please contact me and I will try to fix them.

By the way, sci.physics.research is still alive and well, and you can use it on Google. But I can’t find the first issue of This Week’s Finds there — if you can find it, I’ll be grateful. I can only get back to the sixth issue. Take a look if you’re curious about usenet newsgroups! They were low-tech compared to what we have now, but they felt futuristic at the time, and we had some good conversations.

23 Responses to This Week’s Finds (1–50)

  1. Glen Alleman says:

    Awesome, thanks for the research

    Glen B. Alleman, MSSM, USC
    Integrated Program Performance Management

  2. By the way, sci.physics.research is still alive and well, and you can use it on Google.

    Right now, I use 42 RSS feeds to follow blogs and so on. I‘m using Fiery Feeds on an iPad pro (screen the size of a laptop, with a smart-cover-as-keyboard). I used to use LiveClick on Firefox, but that ran into compatibility problems. Without RSS feeds, it would be hopeless. But could one do better?

    Imagine running an application which will inform you of new blogs and ask whether you want to subscribe to them. (If you say no, you can always subscribe later.). Then you just press return to go through all of your subscribed blogs. Read enough of one comment? Skip to the next comment. Don‘t want to see any more of this thread? Mark all posts in it as seen and you won‘t even see them. Want to reply or add your own post? You get popped into your favorite editor, which if you spend an appreciable amount of time at the keyboard, you will already have customized already. All have the same look and feel, the same syntax, and so on.

    That‘s what you get with usenet and a good newsreader.

    Asimov fans might think that the above was inspired by his essay The Ancient and the Ultimate.

    As John mentioned, you can access usenet via Google Groups. However, that is not very good as interfaces go. Also, Google tries to create the impression that it somehow started and/or maintains usenet; Google just accesses an infrastructure which was around before the web (and is still around).

    John used to be a moderator of sci.physics.research. I am one of the moderators now. We were both moderators at the same time for a while. Since I‘ve been on board (a bit more than 20 years), there have been less than a dozen moderators, so the team is pretty stable.

  3. Wyrd Smythe says:

    Hey John, FWI, in the WordPress Reader your post loses its paragraph formatting. It looks as I expect you wrote it on the website — it’s just in the WP Reader there’s an issue.

    It’s an acknowledged bug that’s plagued me, and I’ve reported it to WP. They’re aware of it and looking into it. I still use the “classic” editor. If you do, too, that may be the source of the issue. FWIW, I’ve been putting in explicit <P> tags in my posts and haven’t seen the problem since.

    • John Baez says:

      I use the “classic” editor. I’m reluctant to insert explicit <p>s merely because WordPress Reader, which I never use, can’t currrently correctly interpret a WordPress blog. I’d rather give them one more reason to fix that bug.

      How many of y’all use WordPress Reader, by the way?

      • Wyrd Smythe says:

        I quite agree! The WP Reader has a lot of disturbing issues. I pointed them to your post as another example of the issue; hopefully that bumps the urgency a bit.

        (The way I write posts, and being a retired software designed who did a lot of HTML work, makes it easy for me to do the <P> tags.)

      • John Baez says:

        By the way, do old posts of mine also suffer from this issue? I have 922 posts on this blog, mostly written with the classic editor, and I’m not going to go through them and retroactively add <p>s.

        • Your posts have always looked fine in whatever browser I‘ve used to read them.

        • Wyrd Smythe says:

          Probably our old posts are fine. The problem seems to be when the system stores the post’s content from the editor to the database. And the problem seems to have started recently, so I think old posts are okay. (I’m in the same boat. Been blogging here since 2011 and have over 1000 posts. Even with tools I have, no way am I going through all those!)

      • I don‘t use it. I used to just read blogs in Firefox, but since LiveClick won‘t be updated because Firefox changed the interface, I moved to Fiery feeds. One gets a list of items, if desired a preview of the item, if desired the full item, then if desired one can go to the website, which is in some sort of internal Fiery Feeds reader. That‘s where I‘m typing this now.

  4. very old rando says:

    Is this the content–this series–that earned you the title of the internet’s first blogger ?

  5. Brian Crabtree says:
    January 19, 1993
    This Week’s Finds in Mathematical Physics (Week 1)

  6. D Ramsay says:

    Hi John,
    I want to ask a question of you re the following article i found in the ”50 weeks doco” please -see particular bit beow. (I am new to your site – So Apologies if i am posting this in the wrong place)

    Week 6
    February 20, 1993
    1) Alexander Vilenkin, “Quantum cosmology”, talk given at Texas/Pascos 1992 at
    Berkeley, available as gr-qc/9302016.
    ……edited out …….

    Let’s get warmed up. . . .

    Quantizing gravity is mighty hard. For one thing, there’s the “problem of time”—the lack of a distinguished time parameter in classical general relativity means that the usual recipe for quantizing a dynamical system — “represent time evolution by the unitary operators exp(iHt) on the Hilbert space of states, where t is the time and H, the Hamiltonian, is a self-adjoint operator” — breaks down!

    …..could you please explain the “lack of a distinguished time parameter” comment as I understood that GR is based on the 4 dimensions of space-time (although Kaluza extended it to 5 and out popped Maxwell’s Equations of electromagnetism as well)

    Thank you,
    D Ramsay

    • John Baez says:

      General relativity is a theory of spacetime, but there are many different ways to put coordinates on spacetime, and thus no god-given “time” coordinate.

      This is a one-sentence summary of the “problem of time”. Chris Isham wrote a nice 125-page review article summarizing work on this problem, and you might enjoy the Preliminary Remarks. You can read a lot more about it in weeks 1–50 if you just search for “Isham” and (separately) “problem of time”.

      • D Ramsay says:

        John, Thanks very much for guidance. I see Isham’s doco references the work of Rovelli, which is ironic as i have read his book “Reality is not what it seems” and am about to get “The order of time”. For quite a while now I have been thinking that time is a human illusion brought on by our unconscious observance of increasing entropy. Which goes a long way to explaining why such a measurement varies depending on your relative motion or on what sort of gravitational field you are in.

        Lastly could you recommend any books that would start to get me up to speed mathematically with the approach that people like Rovelli takes please (diffeomorphisms etc.). I am familiar with the maths in G.R. if that gives you an idea of where to start me off.


        • I’ve read many of Rovelli’s popular books. But there seems to be nothing on the topics which he works on between such popular works and really technical stuff. I like to try to understand things before getting into the mathematics, but that is difficult in this area.

        • John Baez says:

          For starters I recommend Wald’s General Relativity, a classic textbook on that subject. It explains diffeomorphisms in Chapter 2. After that, for quantum gravity, I’d recommend Ashtekar’s Lectures on Nonperturbative Canonical Gravity, which explains the problems with quantizing gravity in a careful way. You don’t need to buy into his proposed solution—loop quantum gravity—to find this material useful!

          Time is not a “human illusion”, nor is the fact that a watch on top of a tower will drift out of synch with one at the bottom of the tower. Time is just different than our naive common sense suggests.

        • D Ramsay says:

          Thanks John for the guidance. Time – fair cop – I realize what i meant was that the human concept of time is an illusion, or as you say naive.

        • John Baez says:

          Philip wrote:

          But there seems to be nothing on the topics which he works on between such popular works and really technical stuff.

          Weeks 1–50 of This Week’s Finds has a lot about quantum gravity that fits into that gap. So do later weeks. Even though it’s old, progress in this subject is so slow that this material is still useful. The ‘problem of time’ discussed by Isham remains a problem, for example.

        • I’ll have a look. Young folks take note: the original diagrams were ASCII art.

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