Baryonic matter, which is everything we are made of and everything we can see in the universe, is not a lot of stuff. I mean to a tiny Earthling, it’s a heck of a lot, but if you put it all together it only makes up about 5% of the total Mass-Energy in the Universe. If you’ve ever seen the Millennium simulation, it highlights the fact that both baryonic and dark matter are organized into filaments of mass, with the baryonic matter at the densest points, ie the galaxies. What lies between these dense nodes and filaments are vast empty...
I’ve seen images from the Sun in all different wavelengths of light. It looks very different across the electromagnetic spectrum, with some wavelengths making up more of the Sun’s total energy output than others. What’s always striking to me is seeing the images of the Sun that show its structure, including the strange and beautiful features of plasma that dance across it’s surface. A recent APOD captures just such a concept. This image shows the Sun in Hydrogen Alpha, a wavelength of light at 656 nanometres. This is from the ionization of Hydrogen, where the electron is excited and transitions...
