Bash those genitals, stat

At Polywood this weekend I had a discussion with a few people about whether or not it would be physically possible to have sex with all the people.  That is, would it be possible to have sex with every living person on the planet?  If so, just how fast would you have to have that sex in order for it to work?  Would those people be coming in at you so quickly that it is merely inconvenient, or are we talking about sonic booms being created by onrushing sex partners?

Time to math.  And by math, I mean make all kinds of guesses and approximations and not worry too much about rounding errors.

First off we have to define sex.  Sex is widely variable of course, using many body parts, but I am going to just assume for my first approximation that it involves bashing groins together, since that is a pretty common form of sex.  The world has roughly 7.6 billion people, and I am going to guess that 2/3 of them are able to consent to sex, which is 5 billion.  I don't want to spend too much time on this, so let's assume I need to get it done in a year.  No holidays though, I am not a slacker, but I do need 8 hours of sleep a night.  I don't need time to eat, as I can just do that while the groin smashery is going on.

So, with 365 days available I have to have 'sex' with 239 people per second.  I will assume each person has to move 1 meter in towards me, move back and forth 10 cm three times, and then get 1 meter away again in the allotted time.  This gives them an average velocity of 620 meters/sec, or a cool 2233 km/h.  This is closing in on Mach 2, which means that every person doing this is going to be generating massive sonic booms with every bash of groins, as well as their movement.  Also just getting 239 people per second next to me is a major problem logistically.  Even if you could somehow get an infinite line of people walking 239 abreast, when they get close they suddenly have to accelerate to the above speeds, and setting up a situation where you have an infinite line of 239 people walking abreast is a massive undertaking on its own!

Another major problem is that this is assuming average velocity.  People are, in this simplification, making instantaneous changes in velocity and we know you can't do that... acceleration takes time.  This means that it is certain that their maximum speeds are going to be drastically greater than that, likely capping out around Mach 4.

Now we get to the real problem - the G forces on the people involved.  If you are moving at 4466 km/h and then have to decelerate to 0 m/s within a space of 5 cm that is a LOT of Gs.

And by a LOT, I mean 1,500,000 Gs.  Now there is a lot of debate over exactly how many Gs a person can survive for a really short time.  Maybe it is 50.  Maybe it is 100.  But what we are sure of is that 1.5 Million Gs reduces a person to a fine red mist instantly.  There is no 'sex' because all that happens is a bunch of miniscule organic particles fly into me at enormous speeds and I am killed by some combination of nano missiles that used to be a person and shockwaves.

Okay, so given that this experiment would destroy every person within hundreds of meters of it instantly, let us try to back it off a bit.  Let's assume I have thirty years to complete my sexual journey, I start with the oldest people first so they don't die before I can 'sex' them, and I have sex with five people simultaneously using a variety of body parts.  This decreases the required speed by 80% for the additional sexing outlets, and another 95% because of the increased time allowed.  (This is a guesstimate based on the fact that more people come of age given that this takes a lot longer so I have to have more sex than before.)  That gives me a 99% reduction in speed for the incoming bodies, which hopefully reduces the lethality of the situation.

99% is a big reduction, right?  It solves all the problems!

Not so much.  One advantage is that people moving this way are no longer creating sonic booms as nobody is breaking the sound barrier.  This reduces our destructive potential greatly.  It also means that you only need an infinite line of people walking twelve abreast, which is *way* more manageable.  Still requires some logistics, but it should be possible with enough money and effort.

The trouble is still the G forces that those people experience.  150 G is drastically smaller than 1,500,000 for sure.  It even puts us close to the survivable level of G forces, given that the times involved are extremely short.  But going back and force with those levels of Gs is going to paste your brain to your skull and kill you, even if your skeletal structure can stand the strain.  Is it possible that a human survives such a thing?  I suppose, but I think the expectation would be that everyone involved would die.  I think the corpses would remain intact, largely speaking, but I would expect near total fatalities.

Given that, I think you would find it extremely difficult to convince people to take part in a serious effort to have one person have sex with all other humans.

There are other techniques you could employ to make this go better.  You could collect all the voyeurs in the world and just have them watch and call that sex.  You could assume you have longer to live, or decide that you are only doing this with people that want to (which pretty much solves the problem immediately, really.)  New assumptions mean new calculations.  However, given my basic assumptions we can safely say that you absolutely cannot have sex with all the people in the world in one lifetime, even with an outrageous apparatus to support it and nearly infinite money at your disposal.

Sorry to disappoint.