Is it different if you're on the ground?
Higher pressure on the ground..................
Your observation is begging for a clever remark around Santa Claus but it isn’t coming to me.
While the quality of writing is down, the upside is a target-rich environment for sarcastic remarks, puns, and Dad jokes. But my mind is too tired. Time to put on my cap and settle down for a long winter’s nap.
On Donner, on Blitzen.
Yes. Lungs are more efficient at absorbing oxygen where the pressure is higher (eg ground). To absorb the same amount of oxygen at altiude (lower pressure) you will need to breathe oxygen rich air. It's why mountaineers carry O2.
Commercial airplanes do NOT provide air with oxygen levels higher than normal inside the cabin. Cabin pressure at cruising altitude is the equivalent of 8000 ft above sea level which is just fine if you are sitting idly.
Yes