The gravitational force is the oldest force known to man and the least understood.
P. Van Nieuwenhuizen (1981). Supergravity, Volume 68, Issue 4 of Physics reports. North-Holland Pub. Co.. p. 4.
The gravitational force is the oldest force known to man and the least understood.
P. Van Nieuwenhuizen (1981). Supergravity, Volume 68, Issue 4 of Physics reports. North-Holland Pub. Co.. p. 4.