Faradave » February 21st, 2018, 7:37 pm wrote:Re: c-eize the DayNice criteria, all addressed by
Phyxed (
physics-fi
xed,
better than real), along with a few more.
• Why is there a universal speed limit?
• Why are there two kinds of dimension? (i.e. Why is time different than space?)
• What is the most fundamental object? (Wheeler's
bit, from which arises
it.)
• What is a force?
• What is mass-energy?
• What is electric charge (& why exactly 2 kinds, as opposed to gravitational or color charge).
• What exactly is quantum spin?
• What is the source of quantum indeterminism (absolute randomness)?
• Why is there complete weak symmetry breaking (for parity & charge)?
Hey Faradave. Thanks for joining. I'm going to say a lot about this tidbit
• What is the most fundamental object? (Wheeler's bit, from which arises it.)
Quoting the man of the hour.
"Time, among all concepts in the world of physics, puts up the greatest resistance to being dethroned from ideal continuum to the world of the discrete, of information, of bits. ... Of all obstacles to a thoroughly penetrating account of existence, none looms up more dismayingly than 'time.' Explain time? Not without explaining existence.
-- John Wheeler, 1986.
These days I have become a little more cynical about this situation. In the past I was younger, more excited, and physics dazzled my eyes and sparked fire in my imagination. I imagined that maybe WHeeler's It-from-Bit was so deep and so profound, that my mind was not penetrating its deeper insights.
No longer. I think Wheeler is prone to overweening language and pomposity at higher temperatures and pressures. In my cynicism, I wonder now if Wheeler had really just drawn the conclusion that an isolated patch of spacetime can only contain a finite amount of information.
If it does have a finite amount of information within it, there will be an upper bound. We could refer to a "bucket of information" of some finite size, and realize it could be converted to any other form. Once you have a concept of "limited information" you realize that it could be recoded as bits, and then be a bit string of some given length, S. From that you extrapolate metaphors about files stored in computer RAM or hard drive, and on and on goes the techie analogizing. "A file of size, S kilobytes, read into RAM by a program."
Technology in our daily lives was still predominantly analog in the late 1970s. In 1980, only a few geeks had personal computers in their garages. Today, almost everyone has converted files from one form to another. People know about different "encodings" for video and audio, and have struggled with such. Teenagers daily consider the amount of space left on their mobile device, and people stress about the quotas on their limited download plan on their phones. In 2018 we speak casually of "kilobytes" and "megabytes" like only computer scientists did in 1979.
So while Wheeler's ideas were
"really far out there" in the early 1980s, those same ideas are almost pedestrian in 2018.
We have 20 year olds now who grew up as kids around Triple-A videogame titles. They know computers can create strikingly real 3D worlds by only manipulating bits. Adolescents of the 21st century don't need a course in post-graduate physics to drawn these kinds of conclusions. These late-night-over-beer ideas of the universe being "stored like a big simulation" like some ultimate video game with an "algorithm" controlling its laws.
What computers looked like in 1982 :

Little more than glorified typewriters with monochrome screens. They bleeped and blooped. The RAM on the most expensive machines did not exceed 1 megabyte.
Ideas like
"The universe may be a giant simulation stored as bits". Well in 1980, that idea really took a flash of learned insight from the educated and well-read. You could not just glance at a bleeping-blooping typewriter device and draw that conclusion.
Consider now walking into a room that houses a Playstation IV and is playing some high frame rate title from Ubisoft on a giant OLED 4K display television. Imagine now having grown up as a child around such things. For such a person (of age 20-ish) "Universe is a giant computer simulation." ---> Heck, the idea practically lands itself in your lap.