Flat-Earthers like to dismiss any evidence of spherical Earth by mentioning that we never went to space to witness it ourselves. In reality, to go to space, we need to know Earth is a sphere in the first place and other related knowledge, like gravity.
We knew Earth is a sphere 23 centuries before the first spaceflight. And it is easy to verify Earth is a sphere from simple observations that anyone can do from Earth’s surface.
The thermosphere is a layer of the Earth’s atmosphere from about 95 km to 600 km. It is named ‘thermosphere’ because its temperature increases with altitude. The temperature in the thermosphere can reach 2500°C. However, air density in the thermosphere is very low to the point that heat conduction practically does not occur. Objects in the thermosphere will feel cold.
Flat-Earthers discovered that the temperature in the thermosphere could reach 2500°C. They are happy to ignore the other information which usually accompanies it: the air density up there is also far lower.
Continue reading “Space Flight and the Temperature in the Thermosphere”