Cycles of Time
"A groundbreaking book providing a new take on three of cosmology's most profound questions: What, if anything, came before the Big Bang? What is the source of order in our universe? What is the universe's ultimate future? Current understanding of our universe dictates that all matter will eventually thin out to zero density, with huge black holes finally evaporating away into massless energy. Roger Penrose--one of the most innovative mathematicians of our time--turns around this predominant picture of the universe's "heat death," arguing how the expected ultimate fate of our accelerating, expanding universe can actually be reinterpreted as the "Big Bang" of a new one. Along the way to this remarkable cosmological picture, Penrose sheds new light on basic principles that underlie the behavior of our universe, describing various standard and nonstandard cosmological models, the fundamental role of the cosmic microwave background, and the key status of black holes. Intellectually thrilling and accessible, Cycles of Time is another essential guide to the universe from one of our preeminent thinkers"
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What Hacker News says
- >I don't know a single physicist who wouldn't dearly have loved to be able to explain this stuff to laypeople more easily. People are scared to use metaphors or other rough answers.
Feynman managed to do this with quantum electrodynamics, in "QED: The Strange Theory of Light and Matter." That layperson book shows an inefficient yet accurate way to calculate path integrals of Feynman diagrams without any calculus, and uses the exact analogy of a clock spinning for phase. I understood it without any background in the math.
There's also four lectures on QED for grad students, which is the "formal" version of pretty much the same content, featuring math.
Why can't someone take the QED approach for the whole standard model? Symmetry groups can be explained visually. I think the physicists just can't be bothered, and/or they underestimate the intelligence of uninformed but curious laypeople.
Roger Penrose is another example of a physicist who does this right, in Cycles of Time for instance.
- Cycles of Time: An Extraordinary New View of the Universe by Roger Penrose.
Listen the Sean Carrol's podcast with Roger Penrose, or read the transcript to get the general idea. https://www.preposterousuniverse.com/podcast/2019/01/07/epis...
- Can also recommend Penrose's Cycles of Time: An Extraordinary New View of the Universe, for an interesting take on his own view of cyclic cosmology.
- You're in good company. Something similar, minus the hydrogen phase, is proposed by Roger Penrose: https://en.wikipedia.org/wiki/Cycles_of_Time
- Roger Penrose has really mind-bending observation and theory about the time past heat death in the 'Cycles of Time'.
After 10e100 years when there is only massless particles like photon's left and black holes have evaporated, time essentially stops existing. Photons, gluons and gravitons just go without any new events to infinity.
- I tried to understand Roger Penrose's arguments about this in his book "Cycles of Time". I admit that I really struggled! But the idea seems to be that the initial state of the universe is very unusual compared with the rest of eternity and is essentially 1 vs nothing - and then differentiation instantaneously occurs through some physical process and immediately the universe can only be described in a complex way. The universe moved from undifferentiated high energy to and extremely complex high energy and then falls down from there back to flat.
One point that seems not to feature in these debates is that this is all (physics) fundamentally subject to the constraints of language (maths) and cognition (human), we choose to describe things in a way that appears useful to us, but these judgements and perceptions are filtered by how we understand things. We are squashy and small and it is quite silly to imagine we really are thinking about these processes in an objectively meaningful way.
