Final Follow-Up on the Probability of an Alien Invasion
Posted by Karl Withakay on June 3, 2010
This post is part 3 of my Deconstruction of Stephen Hawking’s comments about contact with alien intelligences being risky. Part one was a general overview of why alien visitation/invasion is highly unlikely. Part two involved some rough numbers regarding the energy requirements for interstellar space travel at the near light speed velocities required to get anywhere in a remotely reasonable time frame.
In this post I will address the hypothetical “what if” scenario where some advanced alien intelligence has made a fundamental advance/ breakthrough in physics and engineering that allows interstellar or even intergalactic travel at effective speeds far in excess of the speed of light at a relatively low energy cost.
So, what if it is possible? What if the laws of physics as we know them need to be rewritten or at least get greatly expanded, and it turns out it is possible to travel interstellar distances in practical time frames instead of decades, centuries, or longer? Further, what if it is possible to do so with a relatively low energy cost instead of needing energy equivalent to tens of thousands of thermonuclear weapons or the yearly outputs of thousands of nuclear reactors?
Well, in short, in that case we’re probably screwed, and there’s still no reason to worry about it because there’s nothing we can do about it anyway.
Any alien civilization that advanced would probably be so far beyond us technologically that we probably couldn’t hope to resist their invasion or even evade detection by them. We’ve been making radio transmissions for well over 100 years, and during that time, our transmissions have been leaking into space to worlds more than 100 light years distant. I think it’s reasonable to speculate that any civilization capable of effectively superluminal travel is likely to have an equally advanced ability to detect and locate other intelligent civilizations or suitable worlds. If such a super advanced civilization is out there, and they are bent on conquest, they probably already have thousands or even millions of probes scattered throughout the galaxy looking for worlds to plunder in addition to their super advanced observation/ search techniques they will be using from their home world. Basically, if they are reasonably capable of getting here, they are probably capable of finding us whether we want them to or not.
Certainly, if they are capable of getting here, there can be little question of their ability to conquer us with little difficulty, as long as they’re not to worried about our welfare. Some might point to US and Soviet difficulties in Vietnam, Afghanistan, and Iraq as reasons to think we could have some hope of resisting a technologically superior invader, but I would disagree. First of all, the difference in technology would be closer to trying to fend off A-10’s with paper airplanes, the Ethiopians fighting off the Italian Army in 1935, or the Aboriginal Americans fighting off European invaders, settlers, or colonists. The Soviets did pretty well in Afghanistan until we started supplying the other side with modern military equipment. Our problems in Vietnam have been well documented and much debated, but I think it’s at least safe to say we weren’t engaged in an unrestricted attempt to eliminate North Vietnam’s military capability, and they had some help from the Soviets to boot. Likewise, we’re not attempting to eliminate the populations of either Afghanistan or Iraq. I’m pretty sure we could do that if we wanted to and we didn’t care about preserving the infrastructure. Independence Day may have been a fun movie, but it was delusional in regards to our ability to fight off an alien invasion. We very probably have little chance against a super advanced alien invasion force unless we can find some equally advanced alien allies or a fifth column to help us.
Additionally, Stephen Hawking seems to be implying that if we just stay silent, ET may not find us. This super advanced ET probably doesn’t need our help to find us. Irrespective of all the radio transmissions we’ve been leaking into space for over a hundred years, ET would probably be able to detect our rich blue and green world on their own without our help. We are already are able to detect planets only a few times more massive than the Earth orbiting other stars and detect elemental composition of stars with what would be extremely primitive techniques and technologies compare to what any superluminal civilization would have at its disposal. It seems likely that ET would be able to find our rich, garden world whether we were here to transmit to them or not.
In summary: If extraterrestrial aliens have the ability to get here in a reasonably short period of time without bankrupting their planetary economy, then they can probably find us, come here, and kick our butts if they want to.
Frankly, the fact that we haven’t yet been conquered by ET is a hint that maybe either ET isn’t interested in or capable of coming here and conquering us.