Dec 28, 2020 02:43 AM
Quantum philosophy: 4 ways physics will challenge your reality
https://theconversation.com/quantum-phil...ity-150175
EXCERPTS: Working out the basic nature of reality according to quantum mechanics is a little bit like an impossible Sudoku. No matter where we start with quantum theory, we always end up at a conundrum that forces us to rethink the way the world fundamentally works. [...] Let me take you on a brief tour ... of the world according to quantum mechanics.
1. Spooky action-at-a-distance. [...] We know today it is very unlikely there is any such better theory. And if we think the world is made up of well-defined, independent pieces of “stuff”, then our world has to be one where spooky action-at-a-distance between these pieces of stuff is allowed.
2. Loosening our grip on reality. “What if the world isn’t made of well-defined, independent pieces of ‘stuff’?” I hear you say. “Then can we avoid this spooky action?” Yes, we can. And many in the quantum physics community think this way, too. But this would be no consolation to Einstein. [...] Einstein insisted the world has to be made of something whether we look at it or not ... But Einstein couldn’t have both a well-defined, independent world and no spooky action-at-a-distance … or could he?
3. Back to the future. [...] If doing an experiment to measure a quantum system in the lab could somehow affect what the system was like before the measurement, then Einstein could have his cake and eat it too. This hypothesis is called “retrocausality”, because the effects of doing the experiment would have to travel backwards in time...
4. No view from Olympus. It is natural to think there must be some way the world is, even if it can only be known by an all-seeing God. Recent research in quantum mechanics suggests a God’s eye view of the world is impossible, even in principle... (MORE - details)
A Mathematician’s Unanticipated Journey Through the Physical World
https://www.quantamagazine.org/a-mathema...-20201216/
INTRO: The outline of Lauren Williams’ mathematical career was present very early on in her life. “Ever since I was a kid, I’ve always loved patterns,” said Williams. “I enjoyed being given a sequence of numbers and having to find the pattern and predict the next number.”
But while many kids are enchanted by patterns, few end up following them as far, or to such unexpected places, as Williams has. As a professor at Harvard University — where she became only the second tenured woman mathematician in the university’s history — she has uncovered correspondences far more bewildering than anything she learned in grade school.
They all involve a single mathematical object that can be described in a number of different ways. But by looking at it from an entirely new perspective, Williams, 42, has proved that it’s the key to decoding the secrets behind a wide range of seemingly unrelated phenomena in math — and in nature. “She’s always been fearless,” said Federico Ardila of San Francisco State University, who was in graduate school with Williams. “She’s not afraid to build bridges where they didn’t seem to exist.”
The geometric object that weaves through Williams’ work is called the positive Grassmannian. It’s a shape that performs a kind of record-keeping function: Every point on it represents a specific instance of some simpler geometric object. It’s a shape that keeps track of other shapes.
Around the time Williams started graduate school at the Massachusetts Institute of Technology in 2001, mathematicians were developing a new way of thinking about the positive Grassmannian. Instead of thinking of it as a single geometric object, they were trying to understand it in terms of the pieces that make it up. That perspective captivated Williams, and over the last two decades she’s established many of its most far-reaching implications... (MORE - details)
https://theconversation.com/quantum-phil...ity-150175
EXCERPTS: Working out the basic nature of reality according to quantum mechanics is a little bit like an impossible Sudoku. No matter where we start with quantum theory, we always end up at a conundrum that forces us to rethink the way the world fundamentally works. [...] Let me take you on a brief tour ... of the world according to quantum mechanics.
1. Spooky action-at-a-distance. [...] We know today it is very unlikely there is any such better theory. And if we think the world is made up of well-defined, independent pieces of “stuff”, then our world has to be one where spooky action-at-a-distance between these pieces of stuff is allowed.
2. Loosening our grip on reality. “What if the world isn’t made of well-defined, independent pieces of ‘stuff’?” I hear you say. “Then can we avoid this spooky action?” Yes, we can. And many in the quantum physics community think this way, too. But this would be no consolation to Einstein. [...] Einstein insisted the world has to be made of something whether we look at it or not ... But Einstein couldn’t have both a well-defined, independent world and no spooky action-at-a-distance … or could he?
3. Back to the future. [...] If doing an experiment to measure a quantum system in the lab could somehow affect what the system was like before the measurement, then Einstein could have his cake and eat it too. This hypothesis is called “retrocausality”, because the effects of doing the experiment would have to travel backwards in time...
4. No view from Olympus. It is natural to think there must be some way the world is, even if it can only be known by an all-seeing God. Recent research in quantum mechanics suggests a God’s eye view of the world is impossible, even in principle... (MORE - details)
A Mathematician’s Unanticipated Journey Through the Physical World
https://www.quantamagazine.org/a-mathema...-20201216/
INTRO: The outline of Lauren Williams’ mathematical career was present very early on in her life. “Ever since I was a kid, I’ve always loved patterns,” said Williams. “I enjoyed being given a sequence of numbers and having to find the pattern and predict the next number.”
But while many kids are enchanted by patterns, few end up following them as far, or to such unexpected places, as Williams has. As a professor at Harvard University — where she became only the second tenured woman mathematician in the university’s history — she has uncovered correspondences far more bewildering than anything she learned in grade school.
They all involve a single mathematical object that can be described in a number of different ways. But by looking at it from an entirely new perspective, Williams, 42, has proved that it’s the key to decoding the secrets behind a wide range of seemingly unrelated phenomena in math — and in nature. “She’s always been fearless,” said Federico Ardila of San Francisco State University, who was in graduate school with Williams. “She’s not afraid to build bridges where they didn’t seem to exist.”
The geometric object that weaves through Williams’ work is called the positive Grassmannian. It’s a shape that performs a kind of record-keeping function: Every point on it represents a specific instance of some simpler geometric object. It’s a shape that keeps track of other shapes.
Around the time Williams started graduate school at the Massachusetts Institute of Technology in 2001, mathematicians were developing a new way of thinking about the positive Grassmannian. Instead of thinking of it as a single geometric object, they were trying to understand it in terms of the pieces that make it up. That perspective captivated Williams, and over the last two decades she’s established many of its most far-reaching implications... (MORE - details)