“Like the microscopic strands of DNA that predetermine the identity of a macroscopic species and the unique properties of its members, the modern look and feel of the cosmos was writ in the fabric of its earliest moments, and carried relentlessly through time and space. We feel it when we look up. We feel it when we look down. We feel it when we look within.” ~Niel Degrasse Tyson There was some very big news today! If you haven’t already heard, the BICEP2 research group at Harvard has found evidence of ancient gravitational waves in the sky. A lot
Einstein
Physics / Relativity / Science And Math
Rock Me, Einstein — Some Questions on Special and General Relativity
In 1905 Albert discovered Relativity, in 1906 he invented Rock and Roll ~Yahoo Serious In the last week or two, I’ve gotten several excellent questions on special and general relativity. I’d like to devote this week’s post to presenting and answering those questions. For the sake of anonymity, I will call the people who asked the questions Ms. C and Mr. A. I hope you enjoy! A Question on Special Relativity The first question is by Ms. C, who asked: I’ve read your article “The Speed of Light is Constant.” I’ve… got a question on the speed of light
cosmology / Geometry / Mathematics / etc.
Receding Horizons: Dark Energy and the Expanding Universe
Astronomy compels the soul to look upwards and lead us from this world to another. ~Plato The history of astronomy is a history of receding horizons. ~Edwin Powell Hubble Last week, I discussed the possible shapes our universe could take. I offhandedly mentioned that not only is the universe expanding, but that that expansion is accelerating. We attribute this expansion to a mysterious phenomenon we call dark energy. This week, I want to explore the history of this idea and the beautiful experiments that tell us all is not as it seems. The Static Universe and Einstein’s Greatest Blunder
Physics / Relativity / Science And Math
FTL Part 2: The Universal Speed Limit
It is impossible to travel faster than the speed of light, and certainly not desirable, as one’s hat keeps blowing off. ~Woody Allen This is Part Two of a multipart series on faster-than-light travel. This time, I’ll describe why it’s difficult to travel faster than lightspeed. At the end of my last article, I told you that the speed of light is constant, independent of the speed of the observer or the source. If I drive past you at half the speed of light with my headlights blazing, the photons of my headlights will be going past you at