The universe, when examined using the doppler shift, does seem to support the observation that it is expanding, with galaxies moving, some away and some toward us. However, there’s no unique ‘center’ of the expansion. […]
Newton’s theorem, used to calculate rotation velocity, applies to elliptical galaxies. It doesn’t apply to flat disks as, in order to do so, one has to do integrals involving modified Bessel functions of the second kind. […]
When it comes to understanding the relationship between an active galaxy and a black hole, it is one of cause and effect. There is a negative feedback between the black hole and the surrounding galaxy as when the galaxy grows too fast, the black hole produces out-flows that halt any further growth. […]
Accreting black holes at the center of a galaxy are slightly more massive. Gas is funneled toward the innermost edge of the accretion disk. The gas is hot, ionized, plasma and is likely to turn into a tangled internal magnetic field. […]
The formation of planets is different from that of stars, although they are formed using material left over after the birth of a star. Starting out the size of a pebble, they grow after millions of years to the size of a planet. […]
It is widely believed that planets with similar mass and size such as Venus and Earth did have similar atmospheres at one point. However, Venus suffered tremendously from the greenhouse effect which rendered its atmosphere inhospitable. […]
The equilibrium temperature formula helps in calculating the temperature of a planet that has reached the radiative equilibrium. It is a state where it doesn’t get too hot or too cold. The formula works in case of Jupiter but not in the case of Venus and Mercury owing to their atmospheric difference. […]
The planets that orbit a black hole deviate from Kepler’s law. But, those around Schwarzschild radius will get swallowed by it. […]
A close observation of the galaxy throws up evidence for the existence of black holes. Moreover, there have been various evidence of materials spiraling into black holes. However, only those material that have zero angular momentum can fall into the black hole. […]
A black hole is a deep pit with a strong gravitational force that can suck anything in. Even though the black hole has the size zero, it has a radius of no return or the radius of Schwarzschild. […]
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