Julian Barbour Quotes

[I]f you imagine two NOWs... there will be some difference between them, and if you work out some weighted average of all of that difference... you can call that... the amount of time between them. ...[T]his has nothing to do with some substance... It's just difference between those two things. ...[T]his is the quantity that is... being measured by my watch...

and variety are central to my critique of 'it from bit'. For we can only talk meaningfully about a thing, including a '', if it has distinguishing attributes. The way that they are knit together, as in the taste, shape and colour of an apple, defines the structure of the thing.

The concepts of message and probability enable one, for a definite source of <math>N</math> messages, to define Shannon’s information. If <math>p_i,\quad i = 1, 2, ..., N</math>, is the relative probability of message <math>i</math> and <math>\log p_i</math> is its base-2 logarithm, then the information <math>I</math> of the given source is(1) <math>\quad I = - \sum_{k=1}^N p_i \log p_i</math>.The minus sign makes <math>I</math> positive because all probabilities, which are necessarily greater than or equal zero, are less than unity (their sum being<math>\textstyle \sum_{i}^N p_i = 1</math>, so that their logarithms are all negative.

Richard Feynman... said, "Time is what happens when nothing else does." ...[T]hat's ...not the right way to think about time.

[T]hings, not information, are primary. ... 'bit' derives from 'it'.

[T]he work that I did with... has shown... time that is measured by clocks is... an average of all the changes in the universe.

If we are to speak about ontology, as opposed to efficient coding in communication channels, the most important symbol in (1) is not <math>p</math> for probability but <math>i</math> for the thing, or configuration, that has the probability <math>p_i</math>.

[W]hat we call yesterday is self-contained and has its experience of being yesterday, and today has memories of yesterday; and therefor I say that it's later... but each is completely self-contained, and there's no reason why you should put one... here, and another one there...

Information theory would never have got off the ground if structured things—configurations—did not exist.

[W]e must distinguish three kinds of information: Shannon’s information, the uncertainty as to which message will be selected from a source; factual information, the content of such a message; and intrinsic semantic information, which distinguishes a random message, or configuration, from one that carries meaning and to some extent explains its... genesis. All... have... underpinning in things.

(quote at 14:08 of 1:54:14)

[S]ymbols have no meaning if divorced from the entities that they represent.

In fact, I once had a discussion with a distinguished astrophysicist who said to me, well, this is what Mach said, and this is what Mach did and what he required. And I said to him, now excuse me, if you don't mind me saying, what you've just told me is your interpretation of Dennis Sciama's interpretation of Einstein's interpretation of Mach. And he said you're quite right. I’ve never read a word of Mach.

If you could look microscopically... at... my molecules... you would not recognize me from one second to another. In my body, every second, one hundred million million million... hemoglobin molecules... is destroyed, and the same number is created. So... at each split second, I'm really a very different person.

[I]n 1898... Henri Poincaré wrote... "On the Measure of Time" and he said... there are two fundamental problems to do with time. One... with the definition of duration... What does it mean to say that a second today is the same... [H]e said there's another issue... [not] so widely recognized. ...[H]ow do you define simultaneity at spatially separated points?