Atzo, Alexey Ovchinin errusiarrak Takuya Onishi japoniarrari eman zion Nazioarteko Espazio Estazioko agintea.
#GaurkoEgunez
1971. urtean, #Salyut1 estazioa jaurti zuen Sobietar Errepublika Sozialisten Batasunak, munduko lehen espazio estazioa.
1975. urtean, Indiak bere lehen satelitea jaurti zuen, #Aryabhata.
#Aryabhata astronomy scorecard, 2,500 years ago:
✓ rotating earth
✓ explained eclipses
✓ calc’d Earth’s sidereal rotation
× heliocentric
Sin / cosine: also Indian.
‘#Aryabhata discussed… sine… [as] ardha-jya, which… means "half-chord"… people started calling it jya… Arabic writers… referred it as jiba… abbreviated as jb. Later… substituted it with jaib, meaning "pocket" or "fold”’ https://en.wikipedia.org/wiki/Aryabhata
In many cases, mathematicians found half a jya more useful to their calculations than a full jya; as such, the half-jya came to be called jya.
The great mathematician #Aryabhata worked out a table which gave the jyas of various arcs in 225-minute increments, and also an interpolation formula to get the jya of an arc which wasn't an integer multple of 225 minutes.
Koti-jya: the length of a line from the centre perpendicular to the jya. Utkrama-jya: a line from the jya to the circumference.
Txifliti
cosmowiki
Daniel Fischer
Mathew Thomas
Manish Vij
VonGoethe Disciple
Infrapink (he/his/him)