Compact Bone. The next layer is made up of compact bone. It is a smooth but hard quality, with minimal gaps and spaces. This layer gives bones their white and solid appearance, and it is the part that you see when you look at a skeleton.
He used the inverse square law of light brightness on a particular type of variable star in those old star clusters. Some stars are very useful for finding distances to clusters and to other galaxies because they have a known luminosity that is large, so they can be seen from great distances away.ll of the RR Lyrae stars in a cluster have the same average apparent magnitude. In different clusters, the average apparent magnitude was different. This is because all RR Lyrae have about the same average absolute magnitude (=+0.6, or 49 solar luminosities).
If we have two stars of the same luminosity with one star double the distance of the other from the Earth the closer star will look four times brighter. It obeys the inverse square law. The photograph shows the Pleiades star cluster. The brighter stars look about the same brightness in fact they are.a) for a star with a certain surface temperature the bigger the star the more energy it gives out. A star with double the radius of another one will have an area four times as great and so have a luminosity four times greater than the first star.