OK, for starters, I also groaned about the absurdity of a freezy T-1000. From day 1, that's bugged me. But there's a LOT of bad physics and bad biology going on in the movie.
But the T-1000 being 77K? That seems unlikely due to the physics of the rest of the show:
- A system at 77 degrees kelvin would need a massive, elaborate heat-exchange system to maintain that temperature throughout everything. If this were a design aspect, it would need even more elaborate systems to prevent failure due to heat/fire. Energy consumption for cooling is one of the most inefficient mechanisms, so this would also bump up their magical-power-generator demands a few notches. But hey, what's impossible times ten instead of merely impossible energy storage and heat exchange.
- More importantly, every time the robot had steady/sustained contact with other mechanical devices / systems, they'd have extreme-cold failure modes. The throttle and brake grips on the motorcycle. His 'not-really-boots' on anything they touched (foot pedals). Firearms (especially the automatic actions) get sluggish and failure-prone around 20-below F, which is about 150 degrees kelvin hotter than you're suggesting. Anything that didn't have specialized extreme-cold lubricants, or (worse) did have residual-water, would start to seize up. Rubber would become brittle. Explosive activity would cause cracking: guns might crack more with each gunshot (at areas in contact with the T-1000) until they rather explosively failed.
Incidentally, liquid-metal self-modifying systems, like the monster in 'The Thing', are just far enough beyond science fiction to be called fantasy. Laws of information storage density pretty much make molecules capable of cataloging a myriad of design specs large and complex enough that they'll be brittle, and the resulting creature would likely be designed to be able to hemorrhage off damaged cells (and shrink) during emergencies and reacquire material slowly later. Under steady gunfire or in a fire, these things would either cruft up fast or steadily get smaller faster than they could assemble replacement molecules
(relevant cite: http://www.ncbi.nlm.nih.gov/bo... "Although single origins are sufficient to direct the replication of bacte-rial and viral genomes, multiple origins are needed to replicate the much larger genomes of eukaryotic cells within a reasonable period of time. For example, the entire genome of E. coli (4 Ã-- 106 base pairs) is replicated from a single origin in approximately 30 minutes. If mammalian genomes (3 Ã-- 109 base pairs) were replicated from a single origin at the same rate, DNA replication would require about 3 weeks (30,000 minutes). The problem is further exacerbated by the fact that the rate of DNA replication in mammalian cells is actually about tenfold lower than in E. coli, possibly as a result of the packaging of eukaryotic DNA in chromatin. Nonetheless, the genomes of mammalian cells are typically replicated within a few hours, necessitating the use of thousands of replication origins.").
So, new material can't just be instantly assimilated, so the monsters in both should get smaller... and smaller... and smaller, if fought steadily.
So... let's make the biophysics for this problem plausible: A few hits on T-1000 by gunfire and rocket launchers, he splatters everywhere, and a T-900 marches at you. Then a T-800, etc. At T-25 size, he jumps into an air duct and runs away. Two weeks later, he resurfaces full-size. Meanwhile, that splatter residue has a few working molecules that have slithered out of a crack between floor and wall to a nearby desk in the Precinct, been ingested as part of Officer Stadanko's jelly donut, and he's not answering phone calls. Yep: the Thing, but with a three-week infection period like Ebola. Much harder to hunt.
So, if mechanical or biological generation WAS possible, and constrained to sane physics to where steady, sustained significant damage had an effect, you'd think either of those monsters would have had some guidance that nondetection and stealth were more important than speed. They didn't need to rush.