Scientists have observed the merger of giant 'blackholes' billions of light-years away from the Earth. What is the significance of this observation?

Assertion (A): In the visible spectrum of light, red light is more energetic than green light. Reason (R): The wavelength of red light is more than that of green light.

Who of the following scientists proved that the stars with mass less than 1.44 times the mass of the Sun end up as White Dwarfs when they die?

The Big Bang theory explains which of the following observation?

The ratio of the diameters of moon and earth is nearly

The branch of Physics that deals with the motion of very small particles is called :