> enough Thinkpads on Earth to probably stretch end-to-end around the moon and back
LD, average distance between Earth and Moon = 384,399,000 m [1]
C = circumference of moon = 10,917,000 m
R := approximate round trip distance = 2LD + 0.5*C = 774,256,500 m
n = total number of thinkpads on earth
Alas, T / R, the ratio of total thinkpad distance T to our lunar round trip distance R, is at most about 0.11 .
This is with the optimistic assumption that the total number of thinkpads on earth equals the total number of thinkpads ever manufactured. A more conservative estimate might be something like n = total number of thinkpads manufactured each year * mean lifespan of a thinkpad = (12 million thinkpads / year) * (5 years lifespan) = 60 million thinkpads in good working order for a lunar round trip.
[1] https://en.wikipedia.org/wiki/Lunar_distance
[2] IBM sold 25m thinkpads before selling product line to Lenovo. By 2022, Lenovo had sold 200m thinkpads. With linear extrapolation to 2024 that gives approx 250 million thinkpads manufactured.
[2a] https://en.wikipedia.org/wiki/ThinkPad
[2b] https://www.forbes.com/sites/timbajarin/2022/10/05/celebrating-thinkpads-30th-anniversaryan-insiders-perspective/
[3] assume every thinkpad is a T480. https://psref.lenovo.com/syspool/Sys/PDF/ThinkPad/ThinkPad_T480/ThinkPad_T480_Spec.PDF