Neil deGrasse Tyson

Quarks are quirky beasts. Unlike protons, each with an electric charge of +1, and electrons, with a charge of –1, quarks have fractional charges that come in thirds. And you’ll never catch a quark all by itself; it will always be clutching other quarks nearby. In fact, the force that keeps two (or more) of them together actually grows stronger the more you separate them—as if they were attached by some sort of subnuclear rubber band. Separate the quarks enough, the rubber band snaps and the stored energy summons E = mc2 to create a new quark at each end, leaving you back where you started

Zwicky studied the movement of individual galaxies within a titanic cluster of them, located far beyond the local stars of the Milky Way that trace out the constellation Coma Berenices (the “hair of Berenice,” an Egyptian queen in antiquity). The Coma cluster, as we call it, is an isolated and richly populated ensemble of galaxies about 300 million light-years from Earth.

These are ordinary dangers. From the department of exotic happenings, intergalactic space is regularly pierced by super-duper high-energy, fast-moving, charged, subatomic particles. We call them cosmic rays. The highest-energy particles among them have a hundred million times the energy that can be generated in the world’s largest particle accelerators. Their

When we examine the Coma cluster, as Zwicky did during the 1930s, we find that its member galaxies are all moving more rapidly than the escape velocity for the cluster. The cluster should swiftly fly apart, leaving barely a trace of its beehive existence after just a few hundred million years had passed. But the cluster is more than ten billion years old, which is nearly as old as the universe itself. And so was born what remains the longest-standing unsolved mystery in astrophysics

The universe is under no obligation to make sense to you.

nine billion years of such enrichment, in an undistinguished part of the universe (the outskirts of the Virgo Supercluster) in an undistinguished galaxy (the Milky Way) in an undistinguished region (the Orion Arm), an undistinguished star (the Sun) was born.

power and beauty of physical laws is that they apply everywhere, whether or not you choose to believe in them

The Milky Way engaged in at least one act of cannibalism in the last billion years, when it consumed a dwarf galaxy whose flayed remains can be seen as a stream of stars orbiting the galactic center, beyond the stars of the constellation Sagittarius. The system is called the Sagittarius Dwarf, but should probably have been named Lunch.

So dark matter is our frenemy. We have no clue what it is. It’s kind of annoying. But we desperately need it in our calculations to arrive at an accurate description of the universe

As we’ve known from the beginning, dark matter does, indeed, exert gravity, to which ordinary matter responds. But that’s it. After all these years, we haven’t discovered it doing anything else