When Tom Cruise sees birds on the alien ship at the end of War of the Worlds, he told the major.

But how/when was the armor of the alien ships removed? That was not described properly.

  • I'm fairly certain the question is related to the movie War of the Worlds, and how seeing the birds land on the alien ship made Tom Cruise realize that the defensive shields must be down. Is that what you're referring to?
    – JennieK_NS
    Jan 20, 2017 at 13:30
  • 1
    The original title of the question appears to have been "how armour of alien ship removed in war of the worlds ?" That made it perfectly clear what he was asking, grammar aside. Another user edited it and removed the title of the movie (which I can only assume was somehow done by accident.) I've submitted a new edit to replace that title.
    – Steve-O
    Jan 20, 2017 at 13:59

1 Answer 1


The "armor" (force fields) of the alien vessels failed after the alien crew inside died from exposure to Earth microbes, which is also how the invasion as a whole was brought to a crippling halt. The idea was that the alien immune systems had no defense against Earth-born viruses, as they had never been exposed to these illnesses before, and so something that would only make a human mildly sick turned out to be deadly to the aliens.

This is the sort of thing that has historically been a very real threat for colonists arriving on a newly discovered continent here on Earth, so it made sense as a science fiction story ending at the time the book was originally written.

The realism of this ending has been called into question more recently, as some people have observed that a virus which can have severe effects on human health will often have little or no effect on other Earth mammals. If a given virus isn't even able to universally infect (no pun intended) all species on this planet, what are the odds one would have any effect at all on a completely alien biology?

Although cross-species transmission is rare here on Earth, those viruses that DO make "the jump" often end up having far more serious consequences in the newly infected species. Memorable recent examples include SARS and the bird flu.

My personal opinion is that it's possible (though very unlikely) that an Earth-born virus might manage to infect the alien population, and having done so, it would almost certainly be fatal. It's close enough that I'm willing to suspend my disbelief, anyway. Also, the extremely low probability of such a transfer would help to explain why the aliens weren't prepared for it (you would think a highly advanced alien race with technology far surpassing our own would have thought to wear hazmat suits during the invasion, unless they had reason to think it wasn't necessary.)

  • All very interesting but it doesn't really explain why the shields failed. The operators dying wouldn't have turned off the shields...would it? +1 though
    – Paulie_D
    Jan 20, 2017 at 16:22
  • I can understand that POV, but we aren't really given much information about how these machines work in the first place, so it's hard to say more about why they failed than "it's because the pilots died." Maybe the shields need minor adjustments after every impact to keep working, so with the operator dead, birds, rocks, rain, etc eventually wore them down until they failed. It all happens pretty fast in the movie, but IIRC in the book, the war machines were standing mysteriously still for a few days before they began falling apart and people realized the invasion was over.
    – Steve-O
    Jan 20, 2017 at 18:10
  • Good point. Well made.
    – Paulie_D
    Jan 20, 2017 at 18:14
  • Viruses are not alive hence cannot be microbs. And just because Viruses may not cross species, bacteria and other micro organisms will attack. Humans can't even drink water in foreign countries because of the difference in microflora. Interplanetary travel will be just as dangerous. But the shields dropping immediately makes no sense if the aliens got sick and died. Shoot a person driving a car and the car will stay on until the power dies.
    – cde
    Jan 20, 2017 at 18:59

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