Strings, Information, and All That

In 1985 I read about this breakthrough. John Schwarz and Michael Green had proved that for relativistic strings, one could have a renormalizable quantum field theory; the only caveat was that one needed a different macroscopic space than the one we knew.

Then came Edward Witten who sent all of us to kindergarten to learn arithmetic and geometry.

But the secret ingredient has been lost for 25 years.

Maybe we found it. It is called Information.

For those who have been following this saga in this blog, it may not come as a surprise that I write this.

I was ready to join the First superstring revolution. Since I am a wimp though, I waited.

I couldn't see a physical reason why I should go to kindergarten as Witten wanted us to enlist in the revolution. I saw him lecturing at Harvard when I was with Hung Cheng at MIT in the early eighties. Witten is impressive, so smooth and gifted. Actually I met Luis Alvarez-Gaumé there at MIT. I believe he was staying with Dan Freedman. I don't remember well, maybe he was renting a room with Dan. Hung helped me get one room in Cambridge, First Street, I believe it was. I got a desk from Hung, his wife knew about this unused furniture somewhere in an office. My wife's uncle Luis Gallop, helped us move there. I met Alan Guth and Jeffrey Goldstone at a cocktail party in Dan's place, one of them had a little child with him, maybe both; I brought my beautiful Leza with me also.

The point here though, is that now I see a physical idea I can hang on to, and understand this revolution in physics that I feel is coming.

What is this Information I'm talking about?

Marks made and erased, are Information. That is how I understand Lorenzo Maccone's ideas. He connects the arrow of time to Information, by pointing out to the fundamental difference of marks, and erased marks.

If somebody or something, erased the marks, then we will perceive the event differently. We will see an arrow of time.

Like Hansel and Gretel. The smart boy leaves marks on the floor, so he can retrace his steps. No marks, no way to go back. Of course the marks can be neural connections also, I don't believe in the mind being out of this world, I am a materialist. Of course I don't mean to say that dead philosophers knew the answers, only that I prefer that bent, a materialistic bent. Show me the marks!

One gentleman, Jonathan, wrote a comment in one of my posts.

"Information is often described as a correlation between a and b, for example the integral of a*b over the whole space. Recognise that a and b may have different embodiments, e.g. one could be a pattern on a magnetic disk and another writing on a piece of paper. The description (above) assumes an identity function only is required to compare one with another. A little bit of thought reveals that information originated at the same point in spacetime, so the integral should be over aMb where M is the function that maps one to the other. How do you map the magnetic "information" on to the writing in the example and end up with the same thing? That is an essential part of the general "object" we call information."

For Jonathan then, the physical description of Information, needs the operator M. In Quantum Mechanics, we do have those operators, for instance Feynman's propagators. For me the problem is deeper.

We have to make sense of situations where there is no observer. This is the old Copenhagen interpretation of Bohr. Wigner's friend comes to mind. Without that friend, how do we make sense of Information?

Now we have Turing's strip. It is the Susskind-'t Hooft-Verlinde (S-'t-V) screen. I have to explain to myself, how matter writes and erases in 't-V screen.

String Theory needs a physical principle to guide us through the 10⁵⁰⁰ possible solutions.

More to come.