Right, so they have to walk around in cyborg exoskeletons on the ground, and their 'foot soldiers' carry a 30mm chaingun and enough armor to need antitank weapons to kill... but there aren't very many of them. They have SSTO aerospace craft that can bomb us from altitudes our normal fighters and air defense cannot respond... but, again, not many and there are limits to how effectively they can bomb when flying at Mach 10 and 200 thousand feet. They have starships with missile defense that stops us from just casually nuking them... but their missile defenses have a finite capability and they can't just orbital-death-ray us into oblivion from space.Purple wrote:If the tech is similar to our own that means no FTL and no massive speeds. It also means that armor is going to be very thin if they want to carry enough fuel to accelerate to any velocity or decelerate in ways other than a rather harsh landing. And shooting down ICBM's is an option, but we have a lot of them.Borgholio wrote:Well this is an interstellar ship with a roughly similar tech level to our own. Meaning I envision massive radiation shields / armor to protect against impacts while traveling at a high rate of speed. So nukes might not work very well. Also, they WOULD have some kind of weapons...so they might be able to shoot down ICBMs.
On a related note, it also means they took ages to get to us and have likely devolved into a race with no inherent sense of balance and serious problems with bone structure and muscle mass.
In short, they lack the instant-win buttons that a stereotypical alien invasion as imagined by OHMIGOD HARD SF overthinkers like to rely on. They're just... hard to stop.
Their magic technology might not be applicable to ground combat; FTL drives are good for this because you could conceivably build starships that just hyperspace-jump from their planet to ours, without needing orders of magnitude better propulsion and spacelift capability, or any super-duper alloys better than what we can imagine.Darth Tanner wrote:To be a realistic threat they have to be significantly ahead of us technologically, usually with magic tech to justify an invasion. Otherwise there is no real way they could get here with enough force to pose a threat. If a force was only just more advanced than us how are they going to get the millions of soldiers they would need to Earth, we can barely leave our planets gravity with small capsules let alone an invasion force.
If they are that far advanced to get here it tends to be difficult to justify without resorting to contrived acts of plot why we don't lose and get wiped out.
In the extreme limiting case you get Harry Turtledove's Road Not Taken, with Renaissance-era musketeers and swordsmen in starships... but that was a silly parody.
Although in that one the Lizards were grossly, stupidly overprepared for what they actually thought they'd face- more realistically they'd have sent nothing but machine guns, APCs, towed artillery, helicopters and recon planes to fight that war. Anything else would have been counterproductive and hard to maintain.lance wrote:There is the alien invasion set during WW2 where the aliens thought we would barely have spears.
Although it'd be interesting picturing an alien race whose idea of 'light weapons to subdue primitives' is actually a good match for our idea of 'heavy weapons to fight a pitched battle.'
Nitpick: Minuteman III can reach orbital altitude; it just can't reach orbital velocity. Getting into a stable orbit is more about lateral speed than vertical speed, which is why real orbital rockets "tip over" and start thrusting pretty much directly sideways as soon as they get above the bulk of the atmosphere.NecronLord wrote:Wrong.Purple wrote:Wouldn't we just nuke their ships in orbit though? Most modern ICBM's could put a bomb on the moon easy.
The United States' only active service ICBM, Minuteman III cannot attain LEO. FAS gives its speed at burnout (and thus an approximation of its Delta-v, as it is always launched relatively stationary to this figure) at 24,000 kph = 6.67 km/s ∆V
9.3 - 10 km/s ∆V is required to attain LEO. (Any number of references)
So you could certainly use Minuteman III to lob a nuclear warhead into the path of an orbiting starship- it just wouldn't match courses with the starship, it would be fired more or less straight up to blow up at a predetermined point in space at the moment in time that the orbiting ship arrived there.