These last two weeks have been rather boring. I've been mostly dealing with logistical stuff and trying to get this order from Matheson in. It's amazing that they make any money given the quality of their customer service. It's up in the air whether someone will ever answer the phone and god forbid I expect them to call or email me back. I wonder if Einstein's progress was ever halted because some bozo salesperson wouldn't call him back?
I've also been reading about something called outgassing. It turns out that when creating a vacuum, getting the molecules in the open air within your volume is the easiest part. The difficult part, then, is getting the molecules (like water vapor) that have absorbed into your surface. Water is a particular notorious substance. To better understand why, it's best to learn how evaporation works.
Evaporation is a process in which a substance in its liquid form transforms to it's gaseous form. Lots of factors effect the rate of evaporation off a surface including surrounding pressure, temperature, surface area, etc. For a water molecule to evaporate off of your head after a shower, it has to acquire enough kinetic energy (i.e., heat transfer) to overcome the tensile forces of the surrounding water molecules. This energy transfer mostly happens due to collisions with other molecules. This is why things dry faster when you heat them up; the extra heat you supply allows more intense collisions to happen which, in turn, allow more molecules to desorb (opposite of absorb) off of the surface. You can also lower the pressure of the surface's surroundings, which lowers the amount of exertion on the surface and lowers the required amount of kinetic energy to escape.
It's the lowering of the pressure of the surface's surroundings that we're interested in. Creating a vacuum is just that process: lowering the pressure in a sealed chamber. As soon as you get to even a modest vacuum, water starts to fly off of these surfaces at a fairly rapid rate. Thankfully, baking your surface at around 150 degrees C solves this problem wonderfully in that it greatly increases the rate of evaporation. Most reasonably sized surfaces can be made acceptably water free in an hour or two.
That is just one example of what is considered outgassing. Other gaseous molecules in the air, like Nitrogen or Argon, can absorb into metals. Baking is the most common method to accelerate outgassing, but there are other methods like electron-stimulation, ion-stimulation, photodesorption, etc. All of these methods use some special process to add kinetic energy to the molecules absorbed on the surface in question and allow them to evaporate off faster.
Star Trek Online is super fun. I'm finally being able to live out my fantasy of being a starship captain. I wish voice recognition software was a few decades ahead of its time so that I could shout "EMERGENCY POWER TO SHIELDS! FIRE A HIGH YIELD PLASMA TORPEDO! HARD TO PORT, HARD TO PORT!" instead of clicking it. Seriously, this game is like a dream come true. Sadly it's interfering with my Mass Effect 2 time (which is also super ballin). At least it will let me stretch the experience out a month or so.
