TREMORS (1990)
Okay, you remember how I was complaining about the bad science in movies like this? Well, I've got no complaints here because TREMORS, very wisely, doesn't even try!

They never explain where these strange creatures came from or how they got here. They're just here and the people of Perfection have to deal with it as best they can. Rhonda, the scientist character, makes some accurate observations about how these creatures are unprecedented and there's nothing like them in the fossil record but when pressed for the answer to their origin she shrugs her shoulders.

Sometimes, "I don't know" is the right answer.

Providing a whole planet with a thick atmosphere is a process that should take decades at least, centuries more likely, but it happens literally within seconds. If that much gas was released that fast (pause for fart joke) it would be the equivalent of the shock wave from a tremendous explosion and would scour Mars clean down to the bedrock.

So many movies don't understand that the speed of light is MUCH faster than the speed of sound, so that if a nuke goes off over a city, first would come the brilliant, blinding heat flash and then (seconds or minutes later, depending on distance) comes the blast.

Someday…

Ian is supposed to be the "responsible" scientist warning everyone about the dangers of technology, which is why I'm so angry at Spielberg (self-professed "good friend" of convicted criminal / robber baron, Bill Gates -Feo). He makes great movies but he feels the need to toss in this pop psychobabble and neo-luddite fear of innovation in a lot of them, in spite of the fact that most of his movies couldn't be made at all without using the very latest cutting edge technology! I wish he'd either entertain me or go live with the Amish, but STOP PREACHING!

They'd have to be artificial given the unlimited variety possible in alien forms, chemistry and neurology. Assuming that they are artificial also allows me to skip over any discussion of how a parasite could evolve intelligence in the first place. Brains are metabolically expensive and they don’t evolve without very good reason.

SPECIES (1995)
So in 1974 we send out a message that includes a diagram of our DNA and about 20 years later we get an alien description of their DNA back. Now let's examine this idea.

It is true that Arecibo beamed such a message into the void in 1974 (as part of an equipment test / dedication). However, they sent it toward a star cluster 28,000 light years away, which means we won't get an answer anytime before AD 57,974. And the message included only a very rough sketch of the shape of a DNA molecule, not the kind of detailed info you’d need to do genetic engineering research. Even today (1999) we couldn’t send such a message, because the Human Genome Project (the mapping of the human genetic structure) isn’t done yet.

AI technology is advancing must faster than most people realize. There are robot servants in your immediate future and of course if you can build such things it's natural for some to wonder how well they'd do on the battle field. Human soldiers will be obsolete in a few decades. That's not necessarily a bad thing as long as someone remembers to program them with Asimov's laws of robotics.

Just what the hell does that mean? The Precambrian era was more than 550 million years ago. Are they saying these creatures were . . . I don’t know . . . dormant? Frozen? Really, really sleepy? They don’t say. They just keep repeating "Precambrian", like that explains everything. And of course it doesn’t. The Precambrian era was when life was first making the transition from single celled bacteria to multi-cellular life forms. The first animals were simple and small (trilobites, early fishes, etc.). There was no life on the land – only in the oceans. So how would a big underground predator manage to evolve when there would be nothing for it to eat, then go undetected for so long and suddenly start eating people? Why would its above ground form seen here detect its prey by body heat when mammals didn’t appear for many hundreds of millions of years after the Precambrian era?

Why don’t people in Hollywood care that mistakes like this make them look like morons? My theory is they smoke too much crack.

There isn't a single animal on Earth - not even chimpanzees - with which humans can cross breed. Humans crossed with a species from a completely different planet (and therefore completely different biology that uses something other than DNA) seems astronomically unlikely.

That being said I must say that the aliens here are portrayed believably enough for me to suspend my disbelief. Their motivations and actions are, shall we say, within acceptable limits. That's high praise from me.

In other words, the only way to use genetic engineering technology to create a superhuman race is to experiment on people. That trial and error process will certainly have failures and mistakes and other bad things that make it morally indefensible to experiment on people in the first place.

Morons!

Now the essential nutrient idea is fine but c'mon! This is a very active big predator. He needs protein and plenty of it. A tiger can chow down more than 100 lbs of meat per day and this thing is like a tiger the size of an elephant. So it would NOT daintily peel open skulls looking for the tasty nutrients. It would eat people whole, and lick its plate clean. It'd probably take ten or twenty people a day just to maintain its physique.

Morons!

The bugs have interstellar space travel, are able to attack space ships in orbit, and can target asteroids at Earth cities. They’re so obviously a sentient species that the very idea of a debate is stupid even within the movie’s other stupidities.

We've sent subs to the very deep ocean and occasionally brought up living creatures from the depths and you know what they do when they reach the surface? They die. They are adapted to the conditions of the deep water. If you take them out of their natural habitat of course they die.

Forget about the fact that all the code would be utterly meaningless to you, although that's a pretty good reason. You won't be able to do it for the same reason an ENIAC programmer from the 1950's couldn't hack into my PC. My desktop is so vastly more advanced and so completely different from the computer he worked on that his skills simply don't apply. And that's a mere 50 years of difference. A culture that builds starships would be orders of magnitude more advanced.

No, if you assume the extra mass / alternate form is stored in an alternate dimension (Read "Flatland: A Romance in Many Dimensions" by Edwin A. Abbott). Short version: Imagine a flat plane - a two dimensional universe. The beings that inhabit this plane ("Flatland") are 2-D shapes like squares and circles. Now suppose a 3-D object like a sphere passes through Flatland. What would Mr. A. Square see? (Keeping in mind he can't perceive the mysterious third dimension and can only see things in his plane of existence). He'd see a dot appear from nowhere, expand into a circle, contract back to a dot and disappear. If he told anyone about it they'd think he was crazy.

Now imagine that a square resident of Flatland has a huge rectangle attached on "top" of his body - in other words this other part of himself is above him, in the third direction no one can see. When the mood strikes this odd square he "moves" himself in that third direction and everyone else sees him morph into the monstrous rectangle. Very scary! But no violation of Conservation of Mass and Energy is required.

No. A black hole is an object so massive and dense that it's gravity is strong enough to warp the space around it such that even light cannot escape from it (that's why it's "black"). We're pretty certain (from indirect measurements) that these objects exist but space is vast and black holes are few and far between. Never in a million, billion, trillion years could you accidentally fly into one. Furthermore, if you somehow did the only result would be your messy death, as the tides near most black holes are so intense that you'd be torn atom from atom long before you reached the black hole itself.

Another example is when some explosives near the alien ship might go off and Dr. Adams worries about all the liquid hydrogen on board exploding.

No. It's really hard to keep liquid hydrogen liquid because it needs to be very cold (-400 degrees F). The shuttle burns up its liquid hydrogen during launch so it doesn't need to store it long, but even so they have a heavily insulated tank and they have to vent the boil-off right up to the last minute. Storing it for 300 years is a stretch but you could wave your hands at it with "futuristic/alien" technology, which is fine. The real problem is that it would NOT explode. Hydrogen mixed with oxygen will explode (which is why the space shuttle's other tank holds liquid oxygen). But hydrogen mixed with seawater would do no such thing. It would just make bubbles.

Karen the Hematologist describes vampirism as a disease caused by a blood-borne virus which sounds halfway logical until you think about it. A virus that makes its host tremendously strong, able heal from almost any injury and effectively immortal but which causes you to explosively disintegrate if exposed to sunlight. That is one hell of a virus! Impossible? Not necessarily, but like the alien in ALIENS, it could never evolve naturally. It could only be artificial. And even then the source of energy for these abilities comes dangerously close to violating the conservation of energy, which is another way of saying it moves from science fiction to fantasy.

It's not quite that straightforward. Intelligence has as much to do with brain complexity as brain size, but for a two hour suspension of disbelief it's fine. The moron part came when Jackson's character hears about the enlarged shark brains and is worried at first that his scientist-employees had violated an international agreement against genetic engineering. They assure him they didn't do any such thing, but of course, later, we find out they did. How the hell else would you make sharks with bigger brains! Hooked on Phonics?

On top of that the movie repeats the lame catch phrase “scorched the sky” to explain how humans, who were losing the war, tried to cut off the AI’s solar energy supply by making the world permanently cloudy. But even the dim daylight shown in the movie would produce more solar energy than an equivalent mass of human beings. Plus, the AI’s clearly have a high technology which means they’d be perfectly able to launch solar power satellites into orbit, providing all the energy they’d ever need.

That’s not to mention a long list of other energy sources readily available. Did humans deplete all the geothermal energy? That would take a billion years. Take all the energy humanity has produced in its entire history, then take that number times a trillion and you still wouldn’t be close to how much geothermal energy is contained within the Earth.

I’m not sure what the AI’s were doing with all those people, but using them to generate electricity was not it.