Oct 19, 2021 05:32 PM
(This post was last modified: Oct 19, 2021 06:01 PM by C C.)
An atomic clock measured how general relativity warps time across a millimeter
https://www.sciencenews.org/article/atom...er-physics
INTRO: A millimeter might not seem like much. But even a distance that small can alter the flow of time.
According to Einstein’s theory of gravity, general relativity, clocks tick faster the farther they are from Earth or another massive object. Theoretically, that should hold true even for very small differences in the heights of clocks. Now an incredibly sensitive atomic clock has spotted that speedup across a millimeter-sized sample of atoms, revealing the effect over a smaller height difference than ever before. Time moved slightly faster at the top of that sample than at the bottom, researchers report September 24 at arXiv.org.
“This is fantastic,” says theoretical physicist Marianna Safronova of the University of Delaware in Newark, who was not involved with the research. “I thought it would take much longer to get to this point.” The extreme precision of the atomic clock’s measurement suggests the potential to use the sensitive timepieces to test other fundamental concepts in physics.
An inherent property of atoms allows scientists to use them as timepieces. Atoms exist at different energy levels, and a specific frequency of light makes them jump from one level to another. That frequency — the rate of wiggling of the light’s waves — serves the same purpose as a clock’s regularly ticking second hand. For atoms farther from the ground, time runs faster, so a greater frequency of light will be needed to make the energy jump. Previously, scientists have measured this frequency shift, known as gravitational redshift, across a height difference of 33 centimeters (SN: 9/23/10)... (MORE)
Amount of information in visible universe quantified
https://www.eurekalert.org/news-releases/932000
RELEASE: Researchers have long suspected a connection between information and the physical universe, with various paradoxes and thought experiments used to explore how or why information could be encoded in physical matter. The digital age propelled this field of study, suggesting that solving these research questions could have tangible applications across multiple branches of physics and computing.
In AIP Advances, from AIP Publishing, a University of Portsmouth researcher attempts to shed light on exactly how much of this information is out there and presents a numerical estimate for the amount of encoded information in all the visible matter in the universe -- approximately 6 times 10 to the power of 80 bits of information. While not the first estimate of its kind, this study's approach relies on information theory.
"The information capacity of the universe has been a topic of debate for over half a century," said author Melvin M. Vopson. "There have been various attempts to estimate the information content of the universe, but in this paper, I describe a unique approach that additionally postulates how much information could be compressed into a single elementary particle."
To produce the estimate, the author used Shannon's information theory to quantify the amount of information encoded in each elementary particle in the observable universe as 1.509 bits of information. Mathematician Claude Shannon, called the Father of the Digital Age because of his work in information theory, defined this method for quantifying information in 1948.
"It is the first time this approach has been taken in measuring the information content of the universe, and it provides a clear numerical prediction," said Vopson. "Even if not entirely accurate, the numerical prediction offers a potential avenue toward experimental testing."
Recent research sheds light on the ways information and physics interact, such as how information exits a black hole. However, the precise physical significance of information remains elusive, but multiple radical theories contend information is physical and can be measured.
In previous studies, Vopson postulated information is a fifth state of matter alongside solid, liquid, gas, and plasma, and that elusive dark matter could be information. Vopson's study also included derivation of a formula that reproduces accurately the well-known Eddington number, the total number of protons in the observable universe.
While the approach in this study ignored antiparticles and neutrinos and made certain assumptions about information transfer and storage, it offers a unique tool for estimating the information content per elementary particle. Practical experiments can now be used to test and refine these predictions, including research to prove or disprove the hypothesis that information is the fifth state of matter in the universe.
The article "Estimation of the information contained in the visible matter of the universe" is authored by Melvin M. Vopson. The article will appear in AIP Advances on Oct. 19, 2021 (DOI: 10.1063/5.0064475). After that date, it can be accessed at https://aip.scitation.org/doi/full/10.1063/5.0064475.
https://www.sciencenews.org/article/atom...er-physics
INTRO: A millimeter might not seem like much. But even a distance that small can alter the flow of time.
According to Einstein’s theory of gravity, general relativity, clocks tick faster the farther they are from Earth or another massive object. Theoretically, that should hold true even for very small differences in the heights of clocks. Now an incredibly sensitive atomic clock has spotted that speedup across a millimeter-sized sample of atoms, revealing the effect over a smaller height difference than ever before. Time moved slightly faster at the top of that sample than at the bottom, researchers report September 24 at arXiv.org.
“This is fantastic,” says theoretical physicist Marianna Safronova of the University of Delaware in Newark, who was not involved with the research. “I thought it would take much longer to get to this point.” The extreme precision of the atomic clock’s measurement suggests the potential to use the sensitive timepieces to test other fundamental concepts in physics.
An inherent property of atoms allows scientists to use them as timepieces. Atoms exist at different energy levels, and a specific frequency of light makes them jump from one level to another. That frequency — the rate of wiggling of the light’s waves — serves the same purpose as a clock’s regularly ticking second hand. For atoms farther from the ground, time runs faster, so a greater frequency of light will be needed to make the energy jump. Previously, scientists have measured this frequency shift, known as gravitational redshift, across a height difference of 33 centimeters (SN: 9/23/10)... (MORE)
Amount of information in visible universe quantified
https://www.eurekalert.org/news-releases/932000
RELEASE: Researchers have long suspected a connection between information and the physical universe, with various paradoxes and thought experiments used to explore how or why information could be encoded in physical matter. The digital age propelled this field of study, suggesting that solving these research questions could have tangible applications across multiple branches of physics and computing.
In AIP Advances, from AIP Publishing, a University of Portsmouth researcher attempts to shed light on exactly how much of this information is out there and presents a numerical estimate for the amount of encoded information in all the visible matter in the universe -- approximately 6 times 10 to the power of 80 bits of information. While not the first estimate of its kind, this study's approach relies on information theory.
"The information capacity of the universe has been a topic of debate for over half a century," said author Melvin M. Vopson. "There have been various attempts to estimate the information content of the universe, but in this paper, I describe a unique approach that additionally postulates how much information could be compressed into a single elementary particle."
To produce the estimate, the author used Shannon's information theory to quantify the amount of information encoded in each elementary particle in the observable universe as 1.509 bits of information. Mathematician Claude Shannon, called the Father of the Digital Age because of his work in information theory, defined this method for quantifying information in 1948.
"It is the first time this approach has been taken in measuring the information content of the universe, and it provides a clear numerical prediction," said Vopson. "Even if not entirely accurate, the numerical prediction offers a potential avenue toward experimental testing."
Recent research sheds light on the ways information and physics interact, such as how information exits a black hole. However, the precise physical significance of information remains elusive, but multiple radical theories contend information is physical and can be measured.
In previous studies, Vopson postulated information is a fifth state of matter alongside solid, liquid, gas, and plasma, and that elusive dark matter could be information. Vopson's study also included derivation of a formula that reproduces accurately the well-known Eddington number, the total number of protons in the observable universe.
While the approach in this study ignored antiparticles and neutrinos and made certain assumptions about information transfer and storage, it offers a unique tool for estimating the information content per elementary particle. Practical experiments can now be used to test and refine these predictions, including research to prove or disprove the hypothesis that information is the fifth state of matter in the universe.
The article "Estimation of the information contained in the visible matter of the universe" is authored by Melvin M. Vopson. The article will appear in AIP Advances on Oct. 19, 2021 (DOI: 10.1063/5.0064475). After that date, it can be accessed at https://aip.scitation.org/doi/full/10.1063/5.0064475.