Uncommon Descent Serving The Intelligent Design Community


What Sabine Hossenfelder hopes the James Webb telescope will do

Hossenfelder: What you can see from this graph is that if this theory is correct there basically shouldn’t be any large galaxies at very early times... If the Webb telescope sees large galaxies anyhow, then that’s going to be very difficult to explain with dark matter. Read More ›

Dark matter puzzle depends in part on whether our galaxy is an “outlier”

Twenty years ago, astronomers couldn’t find enough satellite galaxies orbiting the Milky Way. Now there seem to be too many. Some information seems to be missing. A possible solution is that many of these galaxies are dwarfs formed by dark matter: Most cosmologists believe that dark-matter particles are “cold,” meaning that they move slowly. Because of this, they can coalesce into numerous tiny halos, providing scores of places where dwarf galaxies can form. But “warm” or “hot” dark matter, which by definition moves faster, cannot coalesce so easily. In fact, hot particles wouldn’t be able to form mini-halos at all. So the sheer existence of these small galaxies is a sign that warm dark matter is likely not at play. Read More ›