Like lighthouse beacons in a dark ocean, stars act as tiny islands in the vast universe. Producing light at the atomic level from the powerful release of energy through fusion, they are the engines that drive the formation of new elements. But in the darkness there are plenty of other hidden objects that are cold and give off little to no light. Yet many of them are easily seen. Here’s Why! The first thing to think about is infrared light, the radiation given off by warm objects. Large planets and brown dwarf stars are very bright in infrared, much brighter...
Dark matter could be almost anything. With little data other than how much total dark matter mass exists, we can’t decode much about what individual chunks of dark matter might be made of. I’ve talked before about Massive Compact Halo Objects (MACHOs) and Weakly Interacting Massive Particles (WIMPs), but these are just two possibilities. Other theorists have talked about Modified Newtonian Gravity (MNG), where gravity may work differently on the grand scale than it does on our small Earth scales. Or perhaps it’s something I haven’t seen before. Maybe what we call dark matter is just a large population of ancient black holes....
Every time we see amazing photos of galaxies or planetary disks, we can see most of the detail since we see them face on. But since the orientation of spiral galaxies in the universe is random, there are a plethora of galaxies ignored by image processors since we just can’t see much of the detail. We can still learn from edge-on spiral galaxies, just not as much as we can from those that are face on. We can see some fascinating dust lanes in the image above, and a ton of detail considering the view, but we don’t know what...