The June 2007 issue of Astronomy, pages 64-65, contains some really bad astronomy.
And the "answer":If the universe is expanding, are atoms, particles, and people also expanding?
This answer is totally wrong. It isn't hard to find the right answer, if one consults some cosmology books.The expansion moves any two points farther apart from one another. In an atom, this would mean the "dough" between the nucleus and the electrons would expand, moving the two apart. Thus, the Hubble expansion moves the parts of the atom, like the galaxies in the universe, farther apart from each other. The expansion is so small for an atom that it would never be detected, but it is there in principle.
For example, Cosmology by Edward Harrison, page 278:
Or The Universe at Midnight by Ken Croswell, page 75:A real galaxy is held together by its own gravity and is not free to expand with the universe. Similarly, if [we talk about] the Solar System, Earth, [an] atom, or almost anything, the result would be misleading because most systems are held together by various forces in some sort of equilibrium and cannot partake in cosmic expansion. If we [talk about] clusters of galaxies...most clusters are bound together and cannot expand. Superclusters are vast sprawling systems of numerous clusters that are weakly bound and can expand almost freely with the universe.
Or Cosmological Physics by John Peacock, pages 87-88:Because the universe expands, some people mistakenly think that everything expands--that the Sun's planets are moving away, that the other stars are moving away, that all other galaxies are moving away. Gravity, however, can overwhelm the expansion of space. The attractive gravitational pull of the material within galaxies holds these star cities together, so galaxies do not expand, nor do their stars, planets, and solar systems. In the same way, the coins [representing galaxies in the balloon analogy] on the balloon's skin did not expand when the balloon did.
Even the nearest galaxies do not, as a whole, move away from the Milky Way. That's because they belong to the Local Group, whose members gravitationally anchor one another. Thus, an astronomer observing only Local Group galaxies would never know that the universe expands.
This is not the first time Astronomy has mangled this question. In the February 2000 issue, the magazine tried to tell us that people are held together by gravity. You'd have to be REALLY fat for that statement to be true! (The magazine published a correction in the April 2000 issue.)An inability to see that the expansion is locally just kinematical also lies at the root of perhaps the worst misconception about the big bang. Many semi-popular accounts of cosmology contain statements to the effect that "space itself is swelling up" in causing the galaxies to separate. This seems to imply that all objects are being stretched by some mysterious force: are we to infer that humans who survived for a Hubble time [the age of the universe] would find themselves to be roughly four metres tall? Certainly not....In the common elementary demonstration of the expansion by means of inflating a balloon, galaxies should be represented by glued-on coins, not ink drawings (which will spuriously expand with the universe).