Abstract
The composition of the heavens was a great mystery until the spectroscopic discoveries of the mid 1800s showed that the chemical elements in stars are the same as those on Earth (as we discussed in Chap. 6).
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Notes
- 1.
In fact, because the planets themselves have so much less mass than the Sun, we can pick any planet, and use its distance and its orbital velocity to calculate the Sun’s mass. It doesn’t matter whether we use Mercury or Neptune, or any planet in between, we always get the same answer for the Sun’s mass.
- 2.
A galaxy cluster is a collection of galaxies that are gravitationally bound to each other.
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Note that \(\rho_{m0}\) includes both dark and atomic matter.
- 4.
Several other independent measurements also indicate that the universe is flat, further adding confidence to the notion that the universe is filled with dark energy. We will address these findings in later chapters.
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Perlov, D., Vilenkin, A. (2017). Dark Matter and Dark Energy. In: Cosmology for the Curious. Springer, Cham. https://doi.org/10.1007/978-3-319-57040-2_9
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DOI: https://doi.org/10.1007/978-3-319-57040-2_9
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