Physics on SummaryShelf

A Brief History of Time: From the Big Bang to Black Holes

Thu, 11 May 2023 00:00:00 +0000

Space and time once seemed like the fixed stage on which everything happened — an unchanging backdrop, identical for everyone. Stephen Hawking’s tour of modern physics takes that stage apart. Space and time are a physical fabric, and mass bends it. Gravity is not a mysterious force reaching across empty space; it is the shape of that fabric. This single idea reorganizes everything, from the orbits of planets to the death of stars to the first instant of the universe. And it runs headlong into a second theory, just as well tested, that governs the smallest scales and refuses to be merged with it.

A Short History of Nearly Everything

Mon, 26 Feb 2024 00:00:00 +0000

You are the end of an unbroken streak of luck that is almost too long to believe. The right orbit around the sun, a collision that gave Earth a moon of exactly the right size, and a line of ancestors stretching back billions of years in which not one link ever failed. As Bill Bryson puts it, not one of them was “squashed, devoured, drowned, starved, stranded, stuck fast, untimely wounded, or otherwise deflected from its life’s quest of delivering a tiny charge of genetic material to the right partner at the right moment” — the only possible sequence of combinations that could result, eventually and all too briefly, in you. Against that, 99.99% of all species that ever lived are extinct. Bryson’s project is to tell the story of how we came to know all this, and to make science, so often written dryly, feel like the adventure it actually is.

Cosmos

Fri, 17 Jan 2025 00:00:00 +0000

Every atom in your body was forged inside a dying star. The carbon in your cells, the oxygen in your blood, the iron, the gold—every element heavier than hydrogen was cooked up by nuclear fusion in a stellar core and flung across space when that star died. As Carl Sagan liked to say, “If you wish to make an apple pie from scratch, you must first invent the universe.” This is not poetry dressed up as science; it’s the literal chain of custody of your atoms. And once you feel the weight of it, Sagan’s central point follows: on a speck this small, in a cosmos this vast, we are the only known place where the universe has woken up and begun to look at itself. That makes us worth protecting.