Maybe Newtonian physics doesn’t need dark matter to work.
“There are no ‘dark matter people’ and ‘MOND people,’ ” his colleague retorted.
“I am ‘MOND people,’” Milgrom proudly proclaimed, referring to Modified Newtonian Dynamics, his theory that fixes Newtonian physics instead of postulating the existence of dark matter and dark energy—two things that, according to the standard model of cosmology, constitute 95.1 percent of the total mass-energy content of the universe.
Black holes are vast, matter-annihilating objects that seem to defy physics by their very existence. They’re so weird, that when Albert Einstein’s equations first predicted the existence of these beasts, he didn’t believe they could actually be real.
And you can’t really blame him, because the idea that we have these singularities of space-time intent on sucking up all the matter around them scattered all around our cosmic backyard is pretty hard to wrap your head around.
Not just one, but seven Earth-size planets that could potentially harbor life have been identified orbiting a tiny star not too far away, offering the first realistic opportunity to search for biological signs of alien life outside of the solar system.
The planets orbit a dwarf star named Trappist-1, about 40 light years, or about 235 trillion miles, from Earth. That is quite close, and by happy accident, the orientation of the orbits of the seven planets allows them to be studied in great detail.
One or more of the exoplanets — planets around stars other than the sun — in this new system could be at the right temperature to be awash in oceans of water, astronomers said, based on the distance of the planets from the dwarf star.
In our terrestrial view of things, the speed of light seems incredibly fast. But as soon as you view it against the vast distances of the universe, it’s unfortunately very slow. This animation illustrates, in realtime, the journey of a photon of light emitted from the surface of the sun and traveling across a portion of the solar system, from a human perspective.