1. What's the human speed limit?
2. How long can we concentrate for?
3. How long could you survive in a vacuum?
4. How much can we remember?
5. How cold can you get and live?
6. How long could you survive without food and drink?
7. How long could you go without sleep?
8. How many gs can you pull?
9. How high can you go?
10. How much can a human lift?
11. How much radiation can we take?
12. How long could you hold your breath?
In response to the third question "How long could you survive in a vacuum, Valerie Jamieson writes:
It is possible to recover from shorter spells in a vacuum, however. In 1966 a NASA technician was testing a spacesuit in a vacuum chamber when the pressure dropped to the level you would experience at an altitude of 36,500 metres. He passed out after 12 to 15 seconds. The last thing he recalled was the saliva boiling off his tongue; that's because water vaporises at low pressure. He regained consciousness within 27 seconds when the chamber was repressurised to the equivalent of an altitude of 4200 metres. Although he was pale, he suffered no adverse health effects.
Link via The Presurfer | Photo: NASA