Julian Barbour Quotes

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

[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?

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.

Thus, even now, three and a half centuries after Galileo... it is still remarkably difficult to say categorically whether the earth moves...

I argue... this weakens but not necessarily destroys the argument that nature is fundamentally digital and continuity an illusion.

Shannon information... [which] he also called entropy or ... involves things (...Shannon ...messages) and probabilities for those things.

Einstein... revealed... extraordinary things... [H]is space and time seem to be knit together in a way you can't pull them apart... [S]omeone moving relative to me at any speed would... divide space and time in different ways... [T]he huge excitement about simultaneity meant that the... issue of duration has... been forgotten...

Poincaré clearly posed these two problems and... seven years later... independently... Einstein and Poincaré... solved... the problem of defining definition at spatially separated points...

[A NOW] has no duration. ...[I]t's absolutely instantaneous. There is no thickness to it. Nothing changes. ...So these s, in one sense, are truly eternal, because they never change, and on the other hand, because nothing changes, they are experienced as a flash. ...[It]'s a nice contradiction... [T]he eternal is experienced as a flash, because nothing changes.

He... explain[ed] how the astronomers... had to grapple with the problem of defining definition, because for 2 1/2 millennia there had been just one standard of time... the rotation of the earth. ...[T]hat had provided an incredibly accurate clock. It's... lost only a few hours in 2 1/2 thousand years. ...Very easy to use. Astronomers only... had to glance at the night sky, at the... Big Dipper... to tell the time within a minute or two... But in the 1890s a crisis developed when they found that using the earth... and... Newton's laws of motion and gravity... the Moon was speeding up. ...[T]hey thought ...the earth was slowing down because of the tidal effects of the moon... and... this would mean that the earth was not a good timekeeper at the accuracy that they wanted.

[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.

Shannon-type message sources could not exist if the universe were not subject to laws of nature and far from .

Greek astronomers observed intricate motions of the sun, moon, and planets on the two-dimensional sky. They explained them—saved the appearances—by positing simple regular motions... in three dimensions. The success... [was] brought to a triumphant conclusion by Kepler...

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

I find no reason to reverse the standard assumption of physics... what we experience can be explained by the assumption of an external world governed by law.