Seed has just offered the world a “Cribsheet” on string theory. It looks pretty slick, although their portrayal of a “hydrogen atom” seems to have an extra nucleon (as Wolfgang notes in the Cosmic Variance thread). I’m inclined to forgive the multiple electron orbits, since they only show one actual electron — and besides, ellipses aren’t that great a way of drawing orbitals anyway.
(Incidentally, if you want to see orbitals in video, check out episode 51 of The Mechanical Universe, available for free online via Annenberg Media.)
They do cite Barton Zwiebach’s First Course in String Theory (2004), which gives me a slight tinge of pride. I mean, somebody had to work the problems in the last five chapters to see if they were solvable by students and not just professors.
The portion of this post below the fold is a rough draft of several different rants, developed in embryonic form and smushed together. Read only if you’re exceptionally curious.
Continue reading I Guess It’s a Deuteron
Scott Aaronson has a new comment policy:
If you reject an overwhelming consensus on some issue in the hard sciences â€” whether itâ€™s evolution, or general relativity, or climate change, or anything else â€” this blog is an excellent place to share your concerns with the world. Indeed, youâ€™re even welcome to derail discussion of completely unrelated topics by posting lengthy rants against the academic orthodoxy â€” the longer and angrier the better! However, if you wish to do this, I respectfully ask that you obey the following procedure:
1. Publish a paper in a peer-reviewed journal setting out the reasons for your radical departure from accepted science.
2. Reference the paper in your rant.
If you attempt to skip to the â€œrantâ€ part without going through this procedure, your comments will be deleted without warning. Repeat offenders will be permanently banned from the blog. Life is short. I make no apologies.
It looks like Dave Bacon can now talk about time travel, but my own conspiracy theories will have to wait. But soon, I promise, the real meaning behind supersymmetric quantum mechanics will be made clear. They laughed at me when I suggested that the BPS interpretation of shape invariance may have a non-topological origin. The fools — I’ll show them all!
Continue reading Where Was I When They Were Passing Out the Wit?
I’m not sure when the idea of “human enhancement” first bubbled up in my brain. It seems to be one of those possibilities which I just grew up with, thanks to a childhood lost in books. In Cosmos, Carl Sagan wrote,
There must be ways of putting nucleic acids together that will function far better — by any criterion we choose — than any human being who has ever lived. Fortunately, we do not yet know how to assemble alternative sequences of nucleotides to make alternative kinds of human beings. In the future we may well be able to assemble nucleotides in any desired sequence, to produce whatever characteristics we think desirable — a sobering and disquieting prospect.
The video version ends with “awesome and disquieting prospect,” by the way. Sagan’s friend Isaac Asimov was a little more cheerful; while dying of AIDS, he concluded the revision of his book The Human Brain with these words:
Man would then, by his own exertions, become more than man, and what might not be accomplished thereafter? It is quite certain, I am sure, that none of us will live to see the far-distant time when this might come to pass. And yet, the mere thought that such a day might some day come, even though it will not dawn on my own vision, is a profoundly satisfying one.
Continue reading Russell Blackford on Human Enhancement