Dear mad Scientist
Question:
dear mad scientist.Answer:
Hello Paul. While there are thus far no documented cases of sex in space, (If any astronauts have had sex in space, they probably did not want it documented.) there's no reason to rule it out as a possibility.
If two astronauts attempted having sex in microgravity without being strapped down, and without holding onto one another, they'd push each other in opposite directions with the first thrust. Because the total momentum of a system is conserved, and started out at zero, they would both have the same momentum, and the center of mass of the two astronauts would remain in the same place even after they separated.
So if they simply hold onto one another more tightly than they thrust against one another, they will manage to stay in the same place, because the center of mass won't move without being acted upon by an outside force, and holding onto one another keeps them close to their mutual center of mass.
Unfortunately, getting to zero momentum and then being in a position where you can avoid touching things is hard to do in practice. Any pushing against a wall during vigorous sex would transfer momentum between the ship and the lovers, and if the push were strong enough, they could bounce around at a high enough speed to cause injury. So while sex in microgravity is possible, if you're not strapped down, the best advice would be to be gentle and careful to avoid getting injured.
If two astronauts attempted having sex in microgravity without being strapped down, and without holding onto one another, they'd push each other in opposite directions with the first thrust. Because the total momentum of a system is conserved, and started out at zero, they would both have the same momentum, and the center of mass of the two astronauts would remain in the same place even after they separated.
So if they simply hold onto one another more tightly than they thrust against one another, they will manage to stay in the same place, because the center of mass won't move without being acted upon by an outside force, and holding onto one another keeps them close to their mutual center of mass.
Unfortunately, getting to zero momentum and then being in a position where you can avoid touching things is hard to do in practice. Any pushing against a wall during vigorous sex would transfer momentum between the ship and the lovers, and if the push were strong enough, they could bounce around at a high enough speed to cause injury. So while sex in microgravity is possible, if you're not strapped down, the best advice would be to be gentle and careful to avoid getting injured.
Question:
Answer:
Who hasn't dreamt of holding the world ransom with a doomsday device? Alas, the Large Hadron Collider is not a tool well-suited to this task.
When it is up and running, the LHC will be able to accelerate particles to kinetic energies of about 7 Tera-electron volts (TeV). One electron volt is the energy imparted to an electron by moving through an electrical potential of one volt. One TeV, or 1,000,000,000 electron volts is a lot of energy. Since the LHC will accelerate particles in both directions and collide them, the total energy of head-on collisions will be about 14 TeV, and these will be the most energetic human-created collisions to date.
Thanks in part to the internet, fears of possible doomsday scenarios have spread. The most popular is that the LHC will create micro-black holes which could consume Earth. There is good reason not to worry about this, though.
There are even higher energy collisions in our upper atmosphere that don't produce any micro-black holes. Particles called Cosmic rays come from various sources in space and strike our atmosphere with high energies. Cosmic rays with energies of about 1500 TeV strike any given square meter of our atmosphere more than once a year on average. Earth's land surface area is about 500 trillion square meters. The surface area of the upper atmosphere where the cosmic rays are striking is even higher. Every year in Earth's history, hundreds of trillions of protons have struck Earth's atmosphere (and every other object in the solar system) with energies much higher than those that the LHC will produce. So far, none of these collisions has created a primordial black hole that has consumed any of these bodies. The chance that the LHC will do so is negligible.
To be sure, there are other reasons to think that this doomsday scenario will not happen (our models require much higher energies, even the black holes produced at those energies would evaporate into Hawking radiation before they could do any damage, etc.). But this should be enough to put this one to bed: Even though collisions with thousands of times more energy are constantly happening to all the objects in our solar system, no micro-black holes have appeared to consume any of those objects.
When it is up and running, the LHC will be able to accelerate particles to kinetic energies of about 7 Tera-electron volts (TeV). One electron volt is the energy imparted to an electron by moving through an electrical potential of one volt. One TeV, or 1,000,000,000 electron volts is a lot of energy. Since the LHC will accelerate particles in both directions and collide them, the total energy of head-on collisions will be about 14 TeV, and these will be the most energetic human-created collisions to date.
Thanks in part to the internet, fears of possible doomsday scenarios have spread. The most popular is that the LHC will create micro-black holes which could consume Earth. There is good reason not to worry about this, though.
There are even higher energy collisions in our upper atmosphere that don't produce any micro-black holes. Particles called Cosmic rays come from various sources in space and strike our atmosphere with high energies. Cosmic rays with energies of about 1500 TeV strike any given square meter of our atmosphere more than once a year on average. Earth's land surface area is about 500 trillion square meters. The surface area of the upper atmosphere where the cosmic rays are striking is even higher. Every year in Earth's history, hundreds of trillions of protons have struck Earth's atmosphere (and every other object in the solar system) with energies much higher than those that the LHC will produce. So far, none of these collisions has created a primordial black hole that has consumed any of these bodies. The chance that the LHC will do so is negligible.
To be sure, there are other reasons to think that this doomsday scenario will not happen (our models require much higher energies, even the black holes produced at those energies would evaporate into Hawking radiation before they could do any damage, etc.). But this should be enough to put this one to bed: Even though collisions with thousands of times more energy are constantly happening to all the objects in our solar system, no micro-black holes have appeared to consume any of those objects.