May 15, 2021 11:14 PM
(This post was last modified: May 15, 2021 11:23 PM by C C.)
How quantum physics allows us to see back through space and time
https://www.forbes.com/sites/startswitha...8c697c493c
EXCERPT (conclusion): . . . If it weren’t for this rare transition, from higher energy spherical orbitals to lower energy spherical orbitals, our Universe would look incredibly different in detail. We would have different numbers and magnitudes of acoustic peaks in the cosmic microwave background, and hence a different set of seed fluctuations for our Universe to build its large-scale structure out of. The ionization history of our Universe would be different; it would take longer for the first stars to form; and the light from the leftover glow of the Big Bang would only take us back to 790,000 years after the Big Bang, rather than the 380,000 years we get today.
In a very real sense, there are a myriad of ways that our view into the distant Universe — to the farthest reaches of deep space where we detect the earliest signals arising after the Big Bang — that would be fundamentally less powerful if not for this one quantum mechanical transition. If we want to understand how the Universe came to be the way it is today, even on cosmic scales, it’s remarkable how subtly dependent the outcomes are on the subatomic rules of quantum physics. Without it, the sights we see looking back across space and time would be far less rich and spectacular. (MORE - missing details)
Do virtual particles really exist?
https://medium.com/starts-with-a-bang/as...a2019d2915
EXCERPT (conclusion): . . . So the quantum vacuum really does have observational effects, and those effects have been observed experimentally on ~micron scales and astrophysically over stellar scales. That doesn’t mean that virtual particles are physically real, however. It means that using the calculational tool of virtual particles in the vacuum allows us to make quantitative predictions about how matter and energy behave as they pass through empty space, and how empty space comes to possess different properties when external fields or boundary conditions are applied. The particles, however, are not real, in the sense that we cannot collide or interact with them.
However, if you have real particles — i.e., a non-vacuum state — then the same quantum field theory techniques you would use to calculate the quantum vacuum actually tells you about real, physical particles (and antiparticles) that can pop in-and-out of existence. For example, we normally think of a proton as being made of three quarks, held together by gluons. But when we perform high-energy collisions of these protons and probe their insides through deep inelastic scattering, we actually find all sorts of extra particles inside: extra quarks and antiquarks, an extreme density of gluons, and even leptons and additional bosons in there. Not only are the effects of virtual particles “real” in particle-rich environments, but the particles themselves are real, too.
In the vacuum of empty space, no matter what boundary conditions you set up or how strong your external fields are, you won’t ever be able to scatter off of whatever’s in the quantum vacuum. However, the quantum vacuum itself will exhibit real, physical effects on matter and radiation that passes through them. The vacuum gets polarized, meaning it generates its own internal fields, and those internal fields — not just the external ones — affect the matter and radiation that passes through. However, there are no particles themselves in there to smash into, collide with, or scatter off of.
The effects of the quantum vacuum are real; the virtual particle visualization is useful, but the particles themselves are not real. Only if you have real particles in your space can the virtual particles arising from particle-field or particle-particle interactions actually be directly detected, indicating their “realness” in some sense. Remember, the only justification we have for calling anything “real” is that we can detect and measure it. The effects of virtual particles are real, but the particles themselves are not! (MORE - missing details)
VIDEO: Time is fundamental, space is emergent – why physicists are rethinking reality
https://www.youtube-nocookie.com/embed/QOAcQCFNtbo
https://www.forbes.com/sites/startswitha...8c697c493c
EXCERPT (conclusion): . . . If it weren’t for this rare transition, from higher energy spherical orbitals to lower energy spherical orbitals, our Universe would look incredibly different in detail. We would have different numbers and magnitudes of acoustic peaks in the cosmic microwave background, and hence a different set of seed fluctuations for our Universe to build its large-scale structure out of. The ionization history of our Universe would be different; it would take longer for the first stars to form; and the light from the leftover glow of the Big Bang would only take us back to 790,000 years after the Big Bang, rather than the 380,000 years we get today.
In a very real sense, there are a myriad of ways that our view into the distant Universe — to the farthest reaches of deep space where we detect the earliest signals arising after the Big Bang — that would be fundamentally less powerful if not for this one quantum mechanical transition. If we want to understand how the Universe came to be the way it is today, even on cosmic scales, it’s remarkable how subtly dependent the outcomes are on the subatomic rules of quantum physics. Without it, the sights we see looking back across space and time would be far less rich and spectacular. (MORE - missing details)
Do virtual particles really exist?
https://medium.com/starts-with-a-bang/as...a2019d2915
EXCERPT (conclusion): . . . So the quantum vacuum really does have observational effects, and those effects have been observed experimentally on ~micron scales and astrophysically over stellar scales. That doesn’t mean that virtual particles are physically real, however. It means that using the calculational tool of virtual particles in the vacuum allows us to make quantitative predictions about how matter and energy behave as they pass through empty space, and how empty space comes to possess different properties when external fields or boundary conditions are applied. The particles, however, are not real, in the sense that we cannot collide or interact with them.
However, if you have real particles — i.e., a non-vacuum state — then the same quantum field theory techniques you would use to calculate the quantum vacuum actually tells you about real, physical particles (and antiparticles) that can pop in-and-out of existence. For example, we normally think of a proton as being made of three quarks, held together by gluons. But when we perform high-energy collisions of these protons and probe their insides through deep inelastic scattering, we actually find all sorts of extra particles inside: extra quarks and antiquarks, an extreme density of gluons, and even leptons and additional bosons in there. Not only are the effects of virtual particles “real” in particle-rich environments, but the particles themselves are real, too.
In the vacuum of empty space, no matter what boundary conditions you set up or how strong your external fields are, you won’t ever be able to scatter off of whatever’s in the quantum vacuum. However, the quantum vacuum itself will exhibit real, physical effects on matter and radiation that passes through them. The vacuum gets polarized, meaning it generates its own internal fields, and those internal fields — not just the external ones — affect the matter and radiation that passes through. However, there are no particles themselves in there to smash into, collide with, or scatter off of.
The effects of the quantum vacuum are real; the virtual particle visualization is useful, but the particles themselves are not real. Only if you have real particles in your space can the virtual particles arising from particle-field or particle-particle interactions actually be directly detected, indicating their “realness” in some sense. Remember, the only justification we have for calling anything “real” is that we can detect and measure it. The effects of virtual particles are real, but the particles themselves are not! (MORE - missing details)
VIDEO: Time is fundamental, space is emergent – why physicists are rethinking reality
