The aliens' beam weapons had some pretty strange interactions with matter. Organic life gets reduced to dust, but the clothes on humans are left untouched, and yet the beams punch through other solid matter with tremendous effect.
They use two different kinds of beam.
That still leaves the question of: why bother? I don't see the aliens recycling people's clothes or something.
It's not uncommon for modern weapons to be capable of having varying effects. For instance artillery that can fire high explosive shells versus armour piercing, or fragmentation, or gas, chemical, or even nuclear shells. And some modern explosive warheads can reconfigure themselves to produce the best kind of explosion for the particular target they're being fired at. The tripod beams may be similar, with an anti-personnel setting that dusts only biological matter and an anti-material setting that causes inorganic matter to shatter and/or explode. Leaving clothing behind wouldn't be an aim of the designer so much as a by-product of targeting living things only.
Assuming it's not just being handwaved away, the tripods would be operating on a finite power supply. The high-energy demolition beam would deplete that power supply faster than the lower-power incinerator beam. Conservation of energy supplies would provide a reasonable explanation.
What exactly is the significance of the birds throughout the movie (flying towards the Tripods during the ferry scene and again towards the end, shown at one point eating the Red Weed, etc.)? Do they actually play some role in the aliens' downfall, or do they simply constitute Rule of Symbolism?
The birds are what carry the diseases which wipe out the aliens.
They also indicate that the shields are down by landing on the tripods. Further, they are carrion birds attracted by rotting flesh. The implication in the book was that the aliens caught some necrotic disease, which would produce a smell attracting carnivorous birds.
It's also a nod to the novel as birds began eating the Martians after they died.
What purpose does the Red Weed serve? Food source, or some alien redecoration technique?
Xenoforming. Changing the natural environment from suitable for humans to suitable for aliens.
Alternatively, and more mundanely, it may have been an invasive species, either accidentally brought over by the Martian capsules, or brought along for some unknown purpose. They seem to thrive near and collect water, which the Martians are in dire need of, so that could also be a possibility.
Fridge Logic: This film suffers from some scientific inconsistencies, particularly when it comes to the EMP that knocked out most of the electronics around each "storm." For example, when the first tripod emerges, someone is clearly seen operating a video camera, which should have been rendered useless by the EMP. Later, a news crew managed to film one of the lightning bolts.
If I understand it correctly, EMP only knocks out devices that have a current running through them at the time, so any electronics that weren't on when the EMP hit should operate after.
You are incorrect, an EMP is dangerous because the magnetic pulse will disrupt any and all electronics within its range.
Indeed, but that the car was functional with just a simple parts swap must mean that whatever occurred was not an EMP, but perhaps a more targeted attack at electronics by the aliens closely related to EMP by our perception.
The '50s version had this too, except the EMP thing was a byproduct of the Heat-Ray rather than the landing. Sci-fi and monster movie historian Bob Burns pointed this out on the DVD—everything was shut down, but cars were still able to get to the scene. ("Made by GM," he said.)
Cars of that era had no EMP-vulnerable electronics in their power trains. This was decades before embedded processors.
My dad, being the armchair survivalist that he is, owns a "farady case" for his digital camera that claims it can protect any electronics inside it from the effects of EMP. Of course, I have no idea if such claim is true or he just bought some expensive crappy case that really does nothing.
A Faraday Cage is a fairly simple contraption that protects an EMP-vulnerable device by causing the current to travel around the cage as opposed to through it. Any metal container would suffice, provided that it was a continuous metal enclosure and the electronic in question was not touching a bare metal side of the cage.
Despite the dialogue, the effect is demonstrably not an EMP. If it were, a simple swap of a starter solenoid would accomplish nothing; the ECU, PCM, and TCU would be shot, meaning that every post-1975ish car would be bricked without a complete electronics swapout. Honestly, naming the starter solenoid was really careless writing. A solenoid is about the simplest "electronic" device imaginable; it's just an electromagnetic coil, really. To damage that without harming the more sophisticated electronics in a car - yet can also knock out something as stupidly simple as a quartz watch - means it's some Treknobabble-level selective effect. Logically, results that inconsistent means it's unlikely to be a weapon at all; merely an unintended side-effect of their pilot-delivery system.
More Fridge Logic regarding the 2005 film. When the aliens show up in their tripods, they start incinerating a crowd of civilians with heat rays. Consider the following. First: that is insanely inefficient for a race capable of interstellar travel; even the original novel had Black Smoke, an instantly-lethal airborne chemical weapon (I say chemical because the aliens clearly didn't have a solid enough grasp on biology to make biological weapons). Second: the slack-jawed crowd posed absolutely no threat to the tripod which was apparently invulnerable to modern weaponry (except when its crew is sick...somehow). Did the aliens have an inferiority complex or something? Third: later on in the movie, the aliens are rounding up live humans to sap and impurify all our precious bodily fluids. Why then, did the aliens spend the first two hours completely disintegrating humans one at a time? If the aliens used a machine gun or something, there at least would have been a harvest at the end of the massacres, but the heat ray doesn't even leave a body.
I presume that the invaders knew at least enough about the planet Earth to know how overpopulated parts of it are. Since they managed to grow so much on the handful of humans they'd captured, I assume that they didn't need billions of them. As for the crowd, well, what did the invaders really care if the humans posed a threat or not? They were pretty much shooting to kill at that point, sort of like swatting a bunch of gnats even though they're little more than nuisances. And for the argument about aliens failing at biology, they seem to fail at that more than once.
If you think that it was a Headscratcher in only the movie version, then it means you must not have read the book. The invaders massacre the clearly inferior Englanders for several days before bothering to harvest them.
Yeah, I recall that at some point the narrator actually comments the aliens' tactics made no sense. They would absolutely demolish a city block for no real reason but leave the next one intact.
This may have been a result of Starfish Alien mentality. On the other hand, it may have been entirely-valid Machiavellian social control. Consider: For the first year, you wipe out 50+ percent of the human population, including all who resist but also plenty who were willing to acknowledge your rule. At the end of that year, once it's established that Resistance Is Futile, you switch to careful harvesting at a rate the population can sustain indefinitely... reverting to your wholesale slaughter whenever there's a pocket of resistance. The message, of course, is "Resist and all will die; cooperate and there's a good chance that you, individually, will live."
The invaders send themselves to the already-planted spaceships by traveling via electricity. So how long were the freaking ships there, why did we never find them, and why in the name of Kyle MacLachlan didn't they just stay on Earth the last time they were here, planting the ships? And on top of this, wouldn't their technology have advanced in the intervening 50,000,000+ years to something infinitely far more devastatingly advanced than the weapons they left behind? And then there's the matter that the story he made up about help waiting for them, to stop his daughter from crying, turned out to be oh-so-conveniently true, and Robbie, who was last seen running over a hill to join the army right before everything on that side of the hill was blown up, has beaten them to the imaginary safehouse, and is completely unharmed.
Maybe they haven't discovered a method of faster than light travel, so they send automatic ships ahead of time the very slow way. As for the lightning: maybe that isn't teleportation, but information sent with redundant power so the information won't degrade. Maybe that information triggers a cloning pod in the ships themselves. In other words, maybe travel in a similar manner to Alter Carbon.
The obvious answer about the Tripods is that the invaders aren't the ones who built them, they're just scavenging Lost Technology that had been left on Earth by some other aliens. ProbablyXenu.
It's also been suggested that the Tripods weren't buried at all, but the "lightning" was actually injecting Nano Machines into the ground which built the mechs in-situ using underground mineral deposits as raw materials.
That leads to a second layer of Fridge Logic if the aliens are that far advanced in nanotechnology, but still have no apparent grasp of microbiology.
Maybe their technology makes a leap from macrotechnology to nanotechnology, and microscales are a bit of a blindspot? In the original novel, Wells explicitly states that the Martians had no immunity or defense against microbes because they eradicated them millennia ago, so something similar may have happened to these aliens. This is complete Fan Wank, of course.
This theory is actually quite realistic. One of the big post-9/11 concerns was that terrorists would reintroduce diseases such as smallpox which had long ago been eradicated in the West, and to which most Westerners had never been vaccinated or developed an immunity.
Who knows how the aliens perceive time? To them, thousands of years might be like a few months (both in terms of lifespan and rate of technological development).
Bear in mind that the theory of the war machine being buried was presented by a TV reporter that had no other proof than a record of a lighting transporting something underground. For all we know that "capsule" as she calls it WAS the war machine super-compressed thanks to some unfathomable tech.
This is a good point. She's probably an Unreliable Expositor, but what she says is never actually proven or disproved.
The crashed plane at the house. How was this plane in the sky despite the EMP? How did it crash in such a way that its engine was further ahead than the fuselage? It was on its left side with the cockpit top facing the camera... but the landing gear were closer to the camera???
It all depends on how the aircraft hit the ground. Obviously it didn't pile-drive into the ground, since entire sections were left intact, so it more then likely skidded into the ground and rolled, ripping itself apart in the process (much like United Airlines Flight 232 in 1989). In such crashes, parts of the aircraft can be catapulted in different directions depending on the way it slid into the ground. As for why it was flying in the first place, the reasons for it being in the area are unknown, but the fact is, it flew into the EMP storm, and then crashed.
The news crew. Seeing as the plane is still on fire when Ray comes upstairs it leads us to believe that it is the next morning - but the news crew is already as well informed and hungrily scrounging for food as if it had been several days. On top of that, they say they were attached to a military unit and I don't see the military stopping to drag along reporters in this surprise situation.
It's possible the news agency was doing a story on the unit in question when the Tripods started their attack. As for why they were stocking up on food despite the attack been going for 24hrs, is because you -always- grab what food you can if you have any inkling that you're not gonna be able to get any food for several days. It's better to have it, and not need it, then need it, and not have it.
If that same news crew have covered disasters before, they are quite aware that how bad things can get in such situations. Knowing that they were in the middle of one of the worst disaster scenerios possible (and all-out invasion by a hostile alien civilization), immediately switching to full survival mode is perfectly reasonable. If anything, I'd say the unrealistic part is that they still had all the video equipment in the van, instead for throwing it away to make more space for supplies.
What could've possible happened to that train, that it was burning, but still running? Alien weapons either blow stuff up or evaporate humans.
That's a shout out to the original novel where the heat ray did it. In universe maybe someone dropped a cigarette when they were disintegrated. Or maybe the aliens blew up a petrol tanker near it, or they have another type of energy weapon not seen by Ray.
That last possibility is quite a strong one. Considering the startling variety of devices we humans have developed that all have the same end goal of killing other humans, it would be rather unusual for the aliens to only have two human-killing tools. There's also the rather alarming possibility that the aliens had napalm used on them and said to themselves, "Hey, that's pretty cool! Let's make things like that thing!"
The train could've been caught in the crossfire between a Tripod and some human military resistance, and been hit by a missile or grenade that missed its real target.
On a similar note to the above : what killed all those dead people in the river?
Theory 1: In the book, the Martians had a Gas weapon called "Black Smoke". It is possible that the aliens used a similar chemical weapon offscreen. After all, why invade a planet with just one kind of weapon. Theory 2: These people in the river may have been captured by the aliens and drained of their blood. If this is the case, then it is possible that the Aliens just dropped the drained bodies in the river when they did not need them anymore.
Why did Robbie suddenly become so obsessed with killing the aliens or seeing the aliens being killed? Before that, he seemed to focus on protecting his sister and surviving. So why the sudden desire to "get back" at the aliens?
Emotions during a crisis are complicated things. At that point, he probably wanted some kind of hope that the aliens could be beaten, and he wanted to do something proactive about it instead of just running away.
It wasn't really that sudden. Early in the film, when they emerge from the basement and found the plane that crashed into the house, you can clearly see that Robbie reacts angrily instead of scared or worried at the sight of such destruction.
You would think with such advance technology that the aliens would be smart enough to know that they should be more prepared to handle the diseases and germs that they would encounter on Earth they don't have no resistance/immunity to which would weaken and could potentially kill them.
If the aliens had indeed planted their war machines ages ago, it could mean that the invasion force had been vaccinated for the harmful microorganisms they found back then, but in the meantime something new apparead or a previously harmless agent mutated.