Yesterday I wrote about Roemer’s observations of Jupiter’s moon Io, and how this demonstrated the speed of light was finite. I also noted that Roemer’s observations did not convince all astronomers that light had a finite speed.
Travel Time
The speed of light is very, very fast. In the span of a heartbeat light can travel from New York to London and back 25 times. So you can imagine how challenging it can be to measure the speed of light. We’re now able to measure the speed of light extremely accurately. So accurately that in 1983 we defined the …
A Star is Born
Stars do not form one at a time. Rather, hundreds of stars are formed from the collapse of large molecular clouds known as stellar nurseries. One such stellar nursery is the Orion Nebula, where stars and whole planetary systems can be observed at various stages of formation.
Sensational Headline!
There’s a web post from the Nature website going around entitled “Simulations back up theory that Universe is a hologram”. Scientific American had “Universe Really Is a Hologram According to New Simulations”. I won’t link to them, because I don’t want to encourage them getting pageviews for this kind of thing. Suffice it to say, the universe is not a …
Betelgeuse, Betelgeuse, Betelgeuse
In principle, measuring the distance of a nearby star is fairly simple. It uses a method known as parallax. It is the same method we use to have depth perception every day. If you cover one eye and hold your thumb in front of a distant object, when you switch eyes your thumb will appear to shift against the background. …
Swiftly Tilting Planet
As I write this, it is the end of a long day. It’s the last week of classes at RIT, so things are rather hectic. Usually my day ends with a calm drive home, when I can think about topics to write about. But this evening has seen a winter storm move in, so instead of a calm drive, it …
Dark Matter Junction
One of the big mysteries of astrophysics concerns the nature of dark matter. We have solid evidence that dark matter is real. You can read a 5-part series I wrote on just how we know it’s real. What we don’t know is just what dark matter is made of.
Peanut Gallery
You’re probably familiar with the general shape of our Milky Way galaxy, that is, a circular disk of stars with a thicker bulge in the center. While that is a good description of the overall shape, there is actually some interesting structure within the center of our galaxy.
Wormholes, Entanglement and Holograms, Oh My!
You may have heard about how quantum particles are wormholes, or holographic somethings. Whatever. It’s quantum wormhole things that, well, do something. So what’s all the hype really about? It all stems from a recent paper in Physical Review Letters (paywalled, but arxiv to the rescue) dealing with entangled particles and their connection of their holographic duals to wormhole geometries. …