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[Sheb]

Source? Because the body ain't tracking the level of CO2 directly, but rather the blood pH. I really wonder what sensor you use to detect pO2 in blood.

[10ebbor10]

Yeah, this really seems to be rather made up to me.

[martinuzz]

The mysteriously appearing rock that has puzzled scientists, and incited alien devotees worldwide, found on pictures made by Curiosity, seems not to have been thrown by alien activists after all.
Other photographic evidence, as well as an examination of the rock, which showed tire tracks on it, highly suggest it was in fact dislodged, and launched a ways, when Curiosity itself drove over it.

Nothing to see here - move on

[mainiac]

How exactly does lowering the pressure reduce the need for Nitrogen, anyway? What does that have to do with the relative concentration of gasses in the air?

Imagine a room that has 36 kilograms of air in it.  We are going to simplify and say that air is 25% oxygen and 75% nitrogen.  Now we are going to remove 66% of the nitrogen and leave all the oxygen in.  Now we have a room which has 18 kilograms of air in it but has half the air pressure as before.  However the amount of oxygen in the room is the same so there is no additional fuel for fires, nor is it any more difficult to breath.

The partial pressure of oxygen is the same ~.25 atm before and after we removed the nitrogen.  Only the partial pressure of nitrogen has changed.

[10ebbor10]

Impact Imminent; Soviet spy satellite to go for an uncontrolled descent.

[GiglameshDespair]

How exactly does lowering the pressure reduce the need for Nitrogen, anyway? What does that have to do with the relative concentration of gasses in the air?

Imagine a room that has 36 kilograms of air in it.  We are going to simplify and say that air is 25% oxygen and 75% nitrogen.  Now we are going to remove 66% of the nitrogen and leave all the oxygen in.  Now we have a room which has 18 kilograms of air in it but has half the air pressure as before.  However the amount of oxygen in the room is the same so there is no additional fuel for fires, nor is it any more difficult to breath.

The partial pressure of oxygen is the same ~.25 atm before and after we removed the nitrogen.  Only the partial pressure of nitrogen has changed.

Surely, the whole room will have lower air pressure, and thus less oxygen will be absorbed via the lungs?

[Sheb]

Why would that matter?

[GiglameshDespair]

Why would that matter?

When we breathe in air at sea level, the atmospheric pressure of about 14.7 pounds per square inch (1.04 kg. per cm.2) causes oxygen to easily pass through selectively permeable lung membranes into the blood.  At high altitudes, the lower air pressure makes it more difficult for oxygen to enter our vascular systems.  The result is hypoxia, or oxygen deprivation.  Hypoxia usually begins with the inability to do normal physical activities, such as climbing a short flight of stairs without fatigue.  Other early symptoms of "high altitude sickness" include a lack of appetite, vomiting, headache, distorted vision, fatigue, and difficulty with memorizing and thinking clearly.  In serious cases, pneumonia-like symptoms (pulmonary edema) due to hemorrhaging in the lungs and an abnormal accumulation of fluid around the brain (cerebral edema) develop.  Pulmonary and cerebral edema usually results in death within a few days if there is not a return to normal air pressure levels.  There is also an increased risk of heart failure due to the added stress placed on the lungs, heart, and arteries at high altitudes.

Lower air pressure effects the intake of air through the walls of the lungs. The may be the same ampont of oxygen, but you'd also be getting less of it per breath.
While I appreciate this talks about high altitudes, much of the effects come from the decreased air pressure rather than the decreased concentration of oxygen.

[Sheb]

Where does that quote comes from?

[GiglameshDespair]

http://anthro.palomar.edu/adapt/adapt_3.htm
First result for
"lower air pressure but same oxygen content effect breathing"
google search.

Hmm. Looking at other sources only mention the thinner air from altitude, but i'm sure lower pressure in general effects the ratio of gas exchange. Boyle's law.

[WillowLuman]

Whether lower pressure or lower concentration, the simple fact is that people cannot live at 11,000 meters. They might visit, but not remain. If we could "save" on Nitrogen by just not bringing it and filling our spacecraft with pure oxygen at a lower pressure, we would. The ISS does have a room with low-nitrogen, low-pressure conditions, but only to prepare for EVAs in.

[10ebbor10]

Daily mail Space weather forecast: Kessler Syndrome

And the ESA is going to launch Plato (Planetary Transits and Oscillations of stars) into Space. This one should be able to detect Earth sized planets.

[alway]

New shiny details on SpaceX: http://www.nasaspaceflight.com/2014/03/spacex-advances-drive-mars-rocket-raptor-power/
In particular, the Raptor rocket engine, which would run on Methane/LOX fuel, would be around 6 times more powerful than their current Merlin engines, and would be used to build rockets that dwarf the capabilities of the Saturn V. Essentially, a march towards their Mars Colonial Transporter.

In February 2014, Musk stated that Mars Colonial Transporter will be "100 times the size of an SUV", and capable of taking 100 people at a time to Mars.[8] Also, SpaceX engine development head Tom Mueller said SpaceX would use nine Raptor engines on a single rocket, similar to the use of nine Merlin 1s engines on each Falcon 9 booster core. He said "It's going to put over 100 tons of cargo on Mars."[9] The large rocket core that will be used for the booster to be used with MCT will be 10 metres (33 ft) in diameter, nearly three times the diameter and over seven times the cross-sectional area of the Falcon 9 booster cores.[1]

[Dutchling]

NSA will send a robot to investigate suspected life on Europe

[Octobomb]

NSA will send a robot to investigate suspected life on Europe

French confirmed as aliens. Existence touted as government conspiracy.