Pyotr Lebedev was first to successfully demonstrate light pressure, which he did in 1899 with a torsional balance;P. Lebedev, 1901, "Untersuchungen über die Druckkräfte des Lichtes", Annalen der Physik, 1901 Ernest Nichols and Gordon Hull conducted a similar independent experiment in 1901 using a Nichols radiometer.
Pyotr Lebedev was first to successfully demonstrate light pressure which he did in 1899 with a torsional balance;P Lebedev 1901 "Untersuchungen über die Druckkräfte des Lichtes" Annalen der Physik 1901 Ernest Nichols and Gordon Hull conducted a similar independent experiment in 1901 using a Nichols radiometer