If the Big Bang theory is correct, how fast is the universe expanding? Astronomers are facing a troubling disconnect between different methods used to measure the expansion rate, known as the Hubble constant. The two methods are giving similar but slightly different rates. Either one method is providing inaccurate results, or there is some kind of unknown physics operating in the universe.
A photo/video account of comet NEOWISE by Gloucester Area Astronomy Club astrophotographer Jeremy Parker, and a review of some of the more recent Great Comets.
I just finished a little project to put some of my recent images to music in a slideshow video, most of which I showed at our recent GAAC astrophotography virtual meeting. This is my first attempt at such a video, but I think I will make them periodically, moving forward. I figured I would share it here, as you might find it entertaining or relaxing. Enjoy!
Galaxies comprise the largest self-gravitating systems of luminous matter in the universe, swirling masses of matter and energy just looking for trouble. Over the past few decades, astronomers have come to appreciate how fervently active galaxies can be. Besides hosting roiling clouds of intense starburst activity, they often also sport supermassive black holes in their centers that can pack a powerful punch. These myriad histrionics can affect the host galaxy's subsequent evolution and even the destinies of neighboring galaxies.
In Astrophysics for People in a Hurry, popular science author Neil DeGrasse Tyson summarizes the most frequently-asked questions about the universe and how we fit into the overall cosmos. Tyson is an American astrophysicist and science communicator who was born on October 5, 1958 in Manhattan, New York.
More than fifty years ago, Apollo 15 photographed something unusual on the far side of the Moon. In a panoramic photograph taken from lunar orbit, two bright, sharply defined objects stood out from the otherwise subdued landscape on the floor of a crater called Paracelsus C.
Today we can take a much closer look.
By now, you have probably read or heard that our polluting ways have reached a critical point, where Earth is rapidly approaching total failure as a planet. Perhaps you have wondered how we humans could have managed to do so much damage in so little time.
Blue wavelengths of light are damaging to many forms of life, and glare from unshielded light compromises road safety and infiltrates bedrooms, suppressing melatonin production, undermining sleep quality and duration, and exacerbating susceptibility to many kinds of illness...
Permanent settlements in space will require forms of localized government that are likely to differ from contemporary models of political order. This article thus asks a provocative question associated with the empirical record of human colonization and settlement in prior eras: What sort of authoritarian governance is most likely to form in human space settlements during the medium term?
