Okay so my English is not so very good but I can’t figure out how the blood boil like water on stove boil in vacuum space like how? I tried to look it up on google but couldn’t understand what the heck I was reading “atmospheric pressure on low temperature” ??? Wouldn’t low temperature do the opposite I just don’t get it haha xD
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Boiling point goes down as pressure goes down. The pressure in a perfect vacuum is 0 units, so room-temperature liquids would tend to evaporate very quickly if not boil like very hot water.
How, and at what temperature any liquid will boil is dependent upon the pressure exerted upon it by the atmosphere. Atmospheric pressure is assumed to be that pressure exerted by the weight of a cooling of air one inch on each side and extending upwards into the limits of our atmosphere. Usually agreed to be about 39,000 feet high. That pressure is known to be 14.7 pounds per square inch (psi)
When a liquid boils, atoms have become so excited and are moving so fast that they can escape the attraction of their neighbors. But they also have to push against that atmospheric pressure.
SO…. if you *lower* that pressure, then these atoms do not have to push so hard against the air pressure to escape. Therefore, the liquid does not have to be so hot in order to make the atoms excited enough to escape. In fact, if you take a clear pot of water with a clear lid sealed to it, and then draw a vacuum of 29.8 inches water column (“w.c.) on that vessel, you will see that water BOIL in the pot just sitting on the counter. At 70F. Because of the reduced pressure on top of it.
The blood does not heat up, which is what we think of with boiling. Instead, the rules of boiling change due to the pressure, so the blood doesn’t need to be as warm to begin going from liquid to gas.
The absence of air in space means that the temperature doesn’t matter that much. A body in space isn’t going to change temperature very quickly, though some evaporative (actually advective) heat loss will occur.
The low, essentially zero pressure means that liquids can’t exist. Everything is going to turn into a solid or a gas. You can [do experiments on earth](https://www.youtube.com/watch?v=glLPMXq6yc0) where you put cool water in a chamber and pump out the air. Once the pressure drops the water boils without its temperature increasing.
Human body temperature is around 37°C and, at that temperature, water doesn’t boil until you go under 76 mmHg of pressure. That’s lower than many people’s blood pressure so the rate at which water in the body turns into a gas won’t necessarily be very high.
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