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-1

If you were free to set the galaxies in this cluster at any desired positions and in any desired states of motion, then you could easily violate the virial theorem. If the cluster was then left alone for a long enough time, then it would converge to a state in which it was bound and obeyed the virial theorem, and it would stay in that state for a very long (...


12

A slightly modified version of the virial theorem that you cite states that for a system of N bodyes (galaxies in a cluster) autogravotating $${1 \over 2} \ddot I = 2K + V$$ Where $K$ is the total kinetic energy, $V$ is the total potential energy and $I$ is the "scalar moment of inertia" of the system, defined as $$I = \sum_i^N m_i r_i^2.$$ When $\...


9

All the various answers are making the same correct point in different ways, but I still can't resist saying this: When you are talking about galaxies, and you want to specify our own, you can say either "the Milky Way" or "the Milky Way Galaxy." They are both fine for talking about the whole galaxy as one among many, and Quizlet is ...


22

Milky Way vs Milky Way Galaxy I recommend recognizing and honoring the distinction! The two words being interchangeable is a narrow view that only one well versed in Astronomy can have, and doesn't fit the reality of how ordinary people view it, being the circa 1010 people who have seen the Milky Way but never having been formally taught about galaxies. The ...


9

According to the Wikipedia article on the Virial Theorem: The word virial for the right-hand side of the equation derives from vis, the Latin word for "force" or "energy", and was given its technical definition by Rudolf Clausius in 1870. Investigating this further, one can see from the original publication of Rudolf Clausius that ...


5

A lot of people vaguely call The Milky Way Galaxy simply the Milky Way, but I don't approve of such vague speech which blurs the distinction between two separate things. The Milky Way is a faint band of light in the night sky, which can been seen where the background sky is dark enough. The Milky Way is thus an appearance, or a sighting, or an illusion. Just ...


22

I think that distinction is wrong, or at least not commonly accepted. We live in a disk-shaped galaxy, which is interchangeably called "the Milky Way", "the Milky Way Galaxy", or "the Galaxy" (capitalized to differentiate it from other galaxies). Viewed from inside, it looks to us as a narrow, diffuse band of light because we ...


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