59 votes

Tactics to prepare for an alien invasion when nobody will believe you

Assuming that the object is to protect earth, and not just hide away when the aliens come... Join the Department of Extraterrestrial Defense The Department was founded in the sixties, at the same ...
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54 votes

A new way of invading a besieged castle?

Impractical At the height of their trajectory the soldiers have no vertical movement so if this coincided with the top of the battlements they would land like a feather. True, their vertical ...
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52 votes
Accepted

How to prevent guerrilla warfare from existing

Aliens are few and far between, drones do the work and are trivially replaceable. The aliens are using drones for the day-to-day movement of force on the planet. There are only a few alien beings, and ...
  • 43.6k
48 votes
Accepted

The everybody-hates-everybody virus. Can humanity survive?

The virus is a strategic mistake The virus was released into the atmosphere, so unevenly and dependent on winds, the carnage will spread, quickly, but some survivalists, politicians, military, etc ...
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46 votes
Accepted

What could be a probable reason for an alien race to want to non-violently annex Earth?

Annexation can be defensive in nature. Alien race A may know of an impending invasion from alien race B, and are attempting to annex Earth to protect it. Alien race B is out to conquer new worlds ...
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45 votes
Accepted

Can realistic planetary invasion have any meaningful strategy?

why invade at all? Most structures of a civilisation are probably going to be on a surface. It is, after all, more difficult to build underground than on a surface. That means that most items of value ...
  • 44.6k
45 votes
Accepted

How can invading aliens access the Internet to find out all about us?

They can't At least not from Mars itself A radio signal will take between 5 to 20 minutes to go directly from Earth to Mars and back. That makes for a round trip time of between 10 to 40 minutes. So ...
44 votes
Accepted

Tactics to prepare for an alien invasion when nobody will believe you

There are a couple good answers already about how Paul can help the world prepare by sharing knowledge, or advancing technology. But if he is really prepared to consider any option, to take any ...
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30 votes

What could be a probable reason for an alien race to want to non-violently annex Earth?

Keep in mind that an alien civilization might have a concept of ethics and morals which is completely different from ours and completely incomprehensible from our perspective. They might have evolved ...
  • 44.6k
30 votes

The everybody-hates-everybody virus. Can humanity survive?

Yes A nuclear sub can spend six months underwater and have 135 crew. There is about 150 around the world. You then have the virologists and other scientists working sterile labs would work out what ...
  • 43.6k
30 votes

How to prevent guerrilla warfare from existing

The aliens don't care much about interaction with the general populace, and don't have supply chains Guerilla warfare works because people can melt back into native populations and because logistics ...
  • 26.7k
30 votes

A new way of invading a besieged castle?

How feasible is it with medieval machinery? Very feasible. Trebuchets were a thing in Europe around the 6th century AD and are very calibrable (yes, this is a word). What, if anything, is wrong with ...
29 votes

How can invading aliens access the Internet to find out all about us?

From Mars: One 4K Netflix Movie per Unconditional Surrender The real answer is provided in the next section, with the use of probes, but here is the physical reason why it is impossible to access the ...
  • 3,582
28 votes

Earth is invaded by miniature aliens - can they win?

One Ship (and not even a very big one) If they have the tech to travel the stars, they have the tech for biological weapons. If they can make and use biological weapons, they can spray it into the ...
  • 43.6k
27 votes

What could a technologically advanced but outnumbered alien race do to destroy humanity?

This has been done many times. The European colonisation efforts in India, Africa and Polynesia amongst others are very well documented, but many outfits did the same. Basically you provide weapons ...
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24 votes

How can invading aliens access the Internet to find out all about us?

They need to get local. Current (actively used) internet protocols are simply incapable of dealing with the light-lag delay between Earth and Mars. Even if they could somehow build a powerful enough ...
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23 votes

Alien Invasion: Why is the War so Long?

Sir, here is your Prime Commander with an extensive report on our position. We are not reciving support The empire has, once again, refused to send more soldier to help us, saying that for those puny ...
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23 votes

What could a technologically advanced but outnumbered alien race do to destroy humanity?

Don’t drop one asteroid. Drop thousands The mathematics of impacts is fairly well understood (though it is a little fuzzy at high speeds). For any given weight and shape of ‘asteroid’ (really an ...
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23 votes

A better way to do a planetary invasion?

In terms of penetrating through air defenses, you aren't going to be able to do better than a reentry vehicle in the first place. It's easy to miss this, because there isn't much frame of reference up ...
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21 votes
Accepted

Which US defense organization would respond to an invasion like this?

Invent it. Big changes have taken place in the US, I gather. If there are thousands of superintelligent AIs milling about to be conscripted, over previous years there were probably other issues ...
  • 288k
19 votes

Tactics to prepare for an alien invasion when nobody will believe you

Stealing a little from @DJClayworth's answer, this answer is probably too self-insert-fan-fiction-y to make a good story, but it is exactly what I would do: Tell Carl Sagan On September 28, 1980, ...
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18 votes
Accepted

Alien invasion to probe us, why?

Please note that this answer was submitted before the question was edited to include the new 'Accepted Answer' conditions. The aliens are a parasitic race The aliens land in cities all over the ...
18 votes
Accepted

A better way to do a planetary invasion?

A planet is a complicated thing to attack, and I feel a lot of military science fiction vastly oversimplifies this. Detection on Approach Your incoming spacecraft are only visible out to about 7.2x ...
17 votes

Earth is invaded by miniature aliens - can they win?

The Fleet They Have Is Good Enough To Conquer Earth, At Least For Some Definitions of Conquer In chess, there are two kinds of attacks. There is an actual attack, i.e. rook takes bishop, and then ...
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16 votes

How does an alien race from a dying world annihilate most of humanity to colonize the planet for themselves?

Can't beat em? Join em! Your refugees contact a selected Earth government. They ask for help. They say that they are fleeing their dead world and need a place to live. They have advanced tech ...
  • 288k
16 votes

What could a technologically advanced but outnumbered alien race do to destroy humanity?

Engineer a virus specifically targeted to kill humans which is very contagious and has a long gestation time, say 6 months. Introduce it into various cities around the world and let it spread ...
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15 votes
Accepted

What can lead invaders to adopt the culture of the invaded?

It is usually determined by (1) numbers, (2) unequal levels of civilization and (3) particular situations in each case. If the conquerors are much fewer than the conquered, or if the conquerors are ...
  • 76.8k
14 votes

Earth is invaded by miniature aliens - can they win?

Just one ship: Land on the far side of the moon and start mining thousands of rocks. This means setting up the launching infrastructure. So...a base. Launch a couple thousand rocks, timed for ...
  • 27.7k
14 votes

How to prevent guerrilla warfare from existing

You already did it: Guerilla bands are but one form of asymmetric warfare. It occurs when there is a large gap in the capabilies of the two sides. Guerilla warfare is, at the core, a desperation ...
  • 27.7k
13 votes

How to defend Earth against "alien bees tactic" in the modern era?

Swarm and flock members follow very simple rules that let them maneuver in concert with the others. They use the perceived rate of change in speed and orientation of their most immediate neighbors. ...
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