, I really couldn't figure out why the two columns, surface measurements and measurements for camera location are both vital. I can use that info properly now! Even though this is all a crash course in atmospherics and gas laws for me lol.
wrote: I remember speculating on the old forum about a "quick and dirty" partial terraforming of Mars by simply adding 0.2 atm of O2 for easier living. How might the issues in the quote affect breathing in such an atmosphere?
Your lungs can not filter out gasses you pull in, in a breath. The space in your lungs is shared by all gasses in the atmosphere. As we mentioned, water vapor can take up increasingly larger spaces in your lungs, depended on temperature or the humidity. You can attest to the difficulty of breathing on a hot humid day, compared to a dry winter's day.
Hyperventilation (alveolar ventilation) can increase the partial pressure of which ever gas makes up the largest percentage in the air. It is exaggerated at higher altitudes, or when pressure is lower, and your muscles can exchange these gasses easier.
Climbers on Mt Everest can use Hyperventilation to increase the amount of O2 in their lungs.
The barometric pressure on Mars averages .087 psi or 6 mbar or 4.5mmHg
which is around 6% of Earth's mean sea-level pressure of 14.69 psi or 1.013 bar or 760mmHg
The average temperature on Mars is though to be around -55°C giving the average water vapor pressure of .0235 mmHg
If the percentage of O2 on Mars was raised to 0.2000175 atm or 20% as you suggested, you would have (.2 * 4.5) .9mmHg. Taking away the amount of O2 displaced by water vapor at -55°C you would have (.9 - .0235) .8765 mmHg of O2 in your lungs. You need about 40 mmHg for the O2 to be forced into the blood stream.
But that is assuming there is the same amount of water vapor on Mars as there is on Earth. However on Mars there is about 10,000 times less than on Earth, so its presence would not make much difference to the amount of available O2 in your lungs. So, even if the atmosphere on Mars was 100% O2 there is not enough air density to make it to your brain. One solution is to increase the temperature of Mars thereby allowing gases to become dense enough.
Another note about Martian air is about the wind. Wind pressure or dynamic pressure or velocity pressure of wind is measured where: Pressure equals .5 * the density of the atmosphere * the velocity squared.
Air density on Mars is .02 kg/m^3 and on Earth it is 1.225 kg/m^3.
A 60 mile and hour wind is the same as a 26.817 meter per second wind.
Doing the math above, on Earth a 60mph wind exerts 440pa while on Mars it would exert 7pa.
Reversing the numbers to give the same pressure on either side of the equation it would take a 7.7mph wind on Earth to equal a 60mph wind on Mars.
That of course doesn't take into account gravity so it would be higher than equal to a 7.7mph wind.
Martian gravity is 37.7% that of Earth's. So a 60mph wind exerts 440pa (*.377) or actually 166pa on Mars; 166pa = .5(*.02kg/m^3)*(128.8 m/s^2), or a 60mph wind on Earth is equal to a 288mph wind on Mars.
note: pa means Pascals (kg*m^-1*s^-2), 1pa = 1 newton per square meter or the force to move 1kg over 1 meter in 1 second per square meter of area
note #2: As an armchair astro-biologist I really have no clue what I am talking about. I'm an unemployed gardener by trade.
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