Alice and Bob Meet The Wall of Fire
God Almighty, the folk at Quanta really are amazing. This is a selection of their essays on (mostly) physics (they are a bit obsessed with quantum-gravity, but who isn’t?) and CRISPR-related biology. The essays go up online - which is where I first read a few of them - but a book is good as it helps me concentrate.
The thing I love about Quanta’s reporting is that they cover the leading edge of science, which is (obviously) ten-years-in-school-hurting-your-brain-complicated, but neither dumb the science down, nor give up and flood the zone with equations or sentences they’ll know you’ll never understand. You walk away from each article with at least some intuitive sense of what the heck just happened. I always feel stretched, but not broken, reading them. Long Live Quanta!
Among the things I learnt from their first book…
Quantum gravity still confuses everyone. (Phew!) Quantum physics is the study of the very small (and all the weird stuff that happens down there - entanglement, superpositions, wave/particle duality etc.) and gravity is the study of the very massive (of which black holes are the ultimate). Scientists still don’t know, some 100 years after Einstein figured out how both worked separately, how the two fit together. Quantum gravity is the quest to find a unified theory - and it has sprung dozens of different research agendas.
One is smashing sub-atomic particles into smithereens to see if other, even-smaller, particles get thrown out of the wreckage. That would help put some data behind the theory of SuperSymmetry. But the Large Hadron Collider (LHC), designed to do just that, is the world’s most expensive ‘negative’ experimental result. They found the Higg’s Boson (great!) but that’s it - meaning SuperSymmetry, which was quantum science’s best hypothesis of how stuff at the quantum-scale worked, is probably wrong.
And there’s String Theory, which posits that tiny vibrating strings generate all those particles (including things we’ve seen, like quarks, and things we’ll never see, like the ‘graviton’, a tiny, tiny particle which could be responsible for gravity), is never going to be proven/disproven, given that the theorized ‘strings’ are way too small for us to ever see. But String Theory is cool - and at least has generated a ton of new math for multi-dimensional structures.
Then there is the question of what happens when superpositions break down. The Schrodinger’s cat thing. One essay relates a viable alternative to the “Many Worlds” hypothesis that some believe the Copenhagen theory of quantum mechanics inevitably leads to. Put simply, the math Many Worlds’ supporters argue, requires that every time a wave function collapses, separate new realities spin out of each possible outcome. Cue a googleplex of universes being created every micro-second. I’ve been surprised how popular this interpretation has become - leading-edge geniuses like Sean Carroll and Max Tegmark back it. (I have a long-running debate with a friend who argues that since I its obvious I don’t even understand the symbols in the math, I need to accept the experts’ views… but…I…just…can’t.)
The alternative to this Many Worlds thing is De Broglie and Bohn’s alternative. It accepts a single outcome to the collapse of Schrodinger’s famous equation, and requires particles to have a determinable location. This is bit classical for many tastes. It gets weird again, though, since De Broglie assumes everything everywhere to be entangled to some degree. Entanglement might even be responsible for the fabric of space-time.
But that doesn’t rule out that we are living in a multiverse. Given the apparent flukiness of key numbers like the ‘cosmological constant’ (which defines the speed of the universe’s expansion) and the size of the Higgs’ Boson (only 126 giga-electron volts! When it should be much bigger or smaller), consensus among the cognescenti has turned to think that we’re just living in one of the many universes that cosmic inflation has generated. There wasn’t just one Big Bang, they’ve been innumerable bangs. And we just happen to live in the one where the math happens to work for atoms to form, and thus matter to happen, and life to somehow evolve.
If all this quantum stuff is not your cup of tea, there’s a good few chapters on cutting edge biological research too. CRISPR ‘technology’, which E. Coli and other micro-organisms ‘invented’, was stumbled upon originally by Japanese scientists, and was originally used in combatting bacteria in commercial yoghurt factories. Then, it was re-purposed for upgrading the human race. Its original use, scientists suppose, was to give micro-organisms like E. Coli, an identikit of bacteria that might kill them, and then allow them to generate proteins which would strike first. Jennifer Doudna and others found a way to reprogram the enzyme to cut the DNA segments they wanted to replace. And the next stage of human “evolution” thus begun - in practice, just as unregulated as the evolution that generated homo sapiens some 700,000 years ago.