pic of Cosmos 1
Einstein's quantum theory brought on many more developments. The idea of solar sailing is only a dream 100 yrs ago but today it is possible. Since light has particle property which we called photons ,photons are like particles hitting the sail causing it to move.The force of these photons hitting the sail is small but because it can work continuously as long as it receives sunshine it can gain speeds up to 90 kms-1 as reported in bbc.co.uk . Check out the link below
solar sailing at bbc
