Which star would appear brightest from Earth if they were all 100 light years away? Yellow main sequence star

Red giant

White dwarf

Blue giant

waves moving from a fast medium to a slow medium will experience a reflection as light travels more slowly than red light. total internal reflection occurs when the critical angle is.

the closer the planet is to the sun, the larger the gravity

the only real purpose of sputnik 1 was to beat the us into space. we were getting close to launching a useful satellite, explorer 1 - which launched on january 31, 1958. the ussr had to beat that, so they launched sputnik 1 on october 4, 19