Gravity

Category archives for Gravity

“Lord of Light! Come to us in our darkness. We offer you these false gods. Take them and cast your light upon us. For the night is dark and full of terrors.” -Melisandre, George R.R. Martin’s A Song of Fire and Ice Imagine a world where you know that winter is coming, but you don’t…

“Nobody ever did, or ever will, escape the consequences of his choices.” -Alfred A. Montapert So you’re passing by a black hole in a massive, fast-moving spaceship, and you want to do an experiment: you tether a small mass outside of the ship and let it fall into the black hole, just allowing it the…

“Eddington had needed to make significant corrections to some of the measurements, for various technical reasons, and in the end decided to leave some of the Sobral data out of the calculation entirely. Many scientists were suspicious that he had cooked the books. Although the suspicion lingered for years in some quarters, in the end…

“Einstein’s gravitational theory, which is said to be the greatest single achievement of theoretical physics, resulted in beautiful relations connecting gravitational phenomena with the geometry of space; this was an exciting idea.” -Richard Feynman There’s no doubt that LIGO has given us one of the most incredible breakthroughs of the 21st century: the direct detection…

“What’s really exciting is what comes next. I think we’re opening a window on the universe — a window of gravitational wave astronomy.” -Dave Reitze, executive director of LIGO It revolutionized our view of the Universe when the LIGO annoucements – and we’re up to three, now – came out. They indicated the direct detection…

“There is no such thing as perpetual tranquillity of mind while we live here; because life itself is but motion, and can never be without desire, nor without fear, no more than without sense.” -Thomas Hobbes It’s hard to believe, but despite being at rest here on the surface of Earth, we’re actually hurtling through…

“If you’re puzzled by what dark energy is, you’re in good company.” -Saul Perlmutter We normally assume that the fundamental constants of the Universe are actually constant, but they don’t have to be that way. They could vary in space, in time, or with the energy density of the Universe, in principle. Before believing in…

“If something doesn’t reach you on a personal level, let it go. It’s hard enough dealing with everything that does.” -Judi Culbertson There are two types of electric charge: positive and negative. Like charges repel; opposite charges attract. In gravitation, though, there’s only one kind of gravitational charge, more commonly known as mass. And everything…

“If you haven’t found something strange during the day, it hasn’t been much of a day.” -John Archibald Wheeler Today, we take the existence of gravitational waves for granted. They were predicted by Einstein almost immediately following the first publication of general relativity, they were indirectly detected decades ago and they’ve been directly detected multiple…

“In our description of nature the purpose is not to disclose the real essence of the phenomena but only to track down, as far as possible, relations between the manifold aspects of our experience.” -Niels Bohr When it comes to galaxies, clusters of galaxies or the largest-scales on the Universe, dark matter is absolutely required.…