[An excerpt Spiral Galaxies by Dr. Jason Lisle]

A galaxy is an enormous assembly of stars and interstellar gas and dust. Galaxies occur in a range of sizes and can contain anywhere from a million to a trillion stars. Our galaxy (the Milky Way) contains over 100 billion stars. Galaxies also come in a range of shapes. Many are round or elliptical in nature. Others have an irregular shape, such as the clouds of Magellan—two satellite galaxies of the Milky Way. Some of the most beautiful galaxies are spiral in nature. A spiral galaxy has a flat-disk shape with a central bulge. The disk section contains spiral arms—regions with greater numbers of stars which extend from the periphery of the galaxy to the core.

Spiral galaxies slowly rotate, but the inner regions of the spiral rotate faster than the outer regions; this is called “differential rotation.” This means that a spiral galaxy is constantly becoming more and more twisted up as the spiral becomes tighter. After a few hundred million years, the galaxy would be wound so tightly that the spiral structure would no longer be recognizable. According to the big-bang scenario, galaxies are supposed to be many billions of years old, yet we do see spiral galaxies—and lots of them. This suggests that they are not nearly as old as the big bang requires. Spiral galaxies are consistent with the biblical age of the universe, but are problematic for a belief in billions of years.

Secular astronomers have proposed “spiral density waves” to create new spiral arms as old ones become twisted beyond recognition. The idea is that waves of pressure travel around the galaxy and stimulate new star growth. Of course, such waves have not been observed, so the idea remains a conjecture. Furthermore, the spiral density wave notion assumes that stars can form spontaneously. Although virtually all secular astronomers assume this, star formation has significant problems of its own. Furthermore, there are difficulties in starting any supposed density wave in the first place. Such complications are not necessary if we accept the most straightforward interpretation of the evidence: galaxies are not billions of years old.

Source: http://www.answersingenesis.org/articles/tba/age-of-the-universe-2

Lisle says "after a few hundred million years, the galaxy would be wound so tightly that the spiral structure would no loner be recognizable."  Yet, that is not what astronomers see (See picture/s).  Do you agree that spiral galaxies are a strong argument for a young earth? Ps 19:1.