RE: About the time limit (SPOILERS)
on Wednesday, December, 22, 2010 11:18 PM
I believe Tron Legacy is doing a number of soft retcons to mold Tron into a broader science fiction universe.
The original Tron was largely metaphorical; we know there are not tiny people living inside computers. It had one foot in Disney fantasy, and there's nothing wrong with that. Notice however, that in Legacy we never actually hear the laser referred to as a laser. It's just a device that enables "The Portal" and 'portal' is a much more ambiguous term that could refer to any kind of technology or reality. I think the omission of the original digitizing laser explanation is very much on purpose.
Based on a lot of ideas that have made it into Tron fiction (including Tron 2.0, the PC game, which is now non-canon but still seems to have contributed themes to Tron Legacy), I've been gathering the impression that the Electronic World, as it seems to be formally called, is no longer merely conceptualized as being inside your computer. Rather, it's a kind of subspace that reacts to electromagnetic radiation. Normally noise and chaos, the operation of computers and possibly the human mind impose order and structure over it.
Some of this theme is seen in Legacy's art direction and the layout of its world. "Tron City", at the center of the Grid, has the most solid and defined reality, one that follows principles laid down by computer algorithms but greatly evolved out of them. The further away from the city you go however, and the reality surrounding the Grid dissolves into the "sea of simulation" and finally, mist and jagged fractal chunks of a crystaline material that themselves break down further. This raw stuff beings to float and break up, eventually vanishing into the noise and possibly, no cohesive reality at all.
Under this scenario, the computer in the real world does influence and control reality in the Grid to a degree, but as the idea of the ISOs illustrates, the Electronic World is its own universe capable of natural evolution and self organizing systems. There's a theme in Tron Legacy about realizing that control is an illusion - recontextualizing the Electronic World into a dimension that is accessible by computers but with a life and will of its own would fit with this theme.
This also works in, I suspect strongly, to justifying for contemporary sci-fi how a reality such as the Grid could be created by any computer - not just a 1980's computer. Legacy clearly demonstrates that there are advanced simulation code bases being executed by the Grid's reality; Flynn even uses these to hack devices and repair damaged Programs. This code is far beyond what existed in the real world in the 80s, and really, beyond what exists today. One notion might be that the subspace reality that the Grid is "carved" out of (again note even the carving metaphor in how Tron City is hewn out of the geometric fractal stone surrounding it) is what is actually powering and executing the instructions that control the Electronic World's reality. The real world computer is, basically, enjoying a connection to a massively more powerful "computer" outside the boundaries of our time and space, and thus outside the bounds of any kind of speed and heat limit. Possibly infinite processing power.
The question of how Programs can enter the "real world" takes on new dimensions within this framework. Bear in mind that the Grid is not the old Encom system. It has many new rules and features created by Kevin Flynn. One of those aspects is "digital DNA"; Flynn desired fully humanoid avatars in the Grid, and used himself as a template. Some of this is acted out in the Tron: Betrayal graphic novel.
It seems that each Program in the grid contains a "genetic algorithm" capable of extrapolating the DNA code for a conventional human body. One hypothesis might be that when a Program possessing this digital DNA is reconstructed by the portal (formerly digitizing laser), the sheer amount of energy required for energy to matter construction is being handily supplied by the raw stuff of subspace - by the Grid's side of the fence. Note that the portal on the Grid's end appears to be using vast quantities of energy and radiation, as if there's plenty of it to extract from that reality. (Flynn does say the portal draws massive power, thus the time limit, but it could be that the drain is bad for holding the reality of the city together.)
Finally, as for Clu's plot to enter the real world with an army in tow, while this is fantastical and seems silly, there is an ominous possibility. Clu knows what Flynn knows, remember, and Flynn remarks at some point that Clu must have figured something out - cracked some problem. Perhaps, originally, Programs could not entirely exit the Grid, but that's what Clu devised in the 1000 subjective years Flynn was trapped. Or Clu discovered something more dangerous, like how to create a larger portal. I imagine that had Clu succeeded, there wouldn't have been a stream of Black Guards exiting the basement of Flynn's arcade one at a time. But more a massive subspace rupture; imagine an explosion taking out the entire city as a huge portal is opened, powered by the other side.
(Folks stopping to wonder how Clu expected his resources and technology to function in the real world should know that the Grid's reality is a much truer simulation of the real laws of physics because Flynn made it that way. His goal was to research technology in the grid that could apply to the real world. Years of research happening in just weeks of real time. While seemingly magical, the devices in the Grid have actual components such as power cores and moving parts - they're just terribly advanced. Remember, it's a thousand years worth of development. The 80's neon styling of that hardware may seem like a silly thing to see manifesting in reality, but there's no indication the capabilities of technology might not have been deadly serious when reconstituted with real matter, in our world.)