Oct 11, 2021 03:40 PM
(This post was last modified: Oct 11, 2021 04:13 PM by C C.)
First moon rocks returned to Earth since 1976 may alter lunar history
https://www.cnet.com/news/first-moon-roc...r-history/
INTRO: Late last year, a Chinese space capsule delivered fresh moon samples to Earth for the first time in about four decades, and these precious lunar rocks just revealed a new detail about our planet's glowing companion. Its volcanoes were alive and active considerably longer than scientists thought. "All our experience tells us that the moon should be cold and dead 2 billion years ago. But it is not, and the question is, 'Why?'" said Alexander Nemchin, a professor of geology at Australia's Curtin University and author of the analysis published Thursday in the journal Science... (MORE)
What if the universe had no beginning?
https://www.livescience.com/universe-had...nning-time
INTRO: In the beginning, there was … well, maybe there was no beginning. Perhaps our universe has always existed — and a new theory of quantum gravity reveals how that could work.
"Reality has so many things that most people would associate with sci-fi or even fantasy," said Bruno Bento, a physicist who studies the nature of time at the University of Liverpool in the U.K.
In his work, he employed a new theory of quantum gravity, called causal set theory, in which space and time are broken down into discrete chunks of space-time. At some level, there's a fundamental unit of space-time, according to this theory.
Bento and his collaborators used this causal-set approach to explore the beginning of the universe. They found that it's possible that the universe had no beginning — that it has always existed into the infinite past and only recently evolved into what we call the Big Bang... (MORE)
Many contrarians dispute that cosmic inflation occurred. The evidence says otherwise.
https://bigthink.com/starts-with-a-bang/...-happened/
KEY POINTS: Studying the Big Bang tells us how our universe evolved to become this way, but it doesn't immediately reveal why the Big Bang occurred or what might have preceded it. Theoretically and observationally, the evidence for cosmic inflation preceding and setting up the Big Bang is incredibly strong and comprehensive. There are still some new, sensitive things to measure, but the lack of low-hanging fruit doesn't mean the tree is dead.
EXCERPT (Ethan Siegel): . . . What failing to find these tensor fluctuations (yet) definitely, definitely does not mean is that cosmic inflation is wrong. Inflation is well-validated by numerous independent observational tests, and would only be falsified by the data if we did detect these tensor modes, and they didn’t follow the precise spectrum predicted by inflation.
And yet, you’d never know any of this by listening to the scientists associated with BICEP and the public-facing communication they’ve put out into the world. They continue to assert that:
• inflation remains in doubt
• B-modes (indicating tensor fluctuations) are necessary to validate inflation
• if there aren’t large magnitude ones, inflation is falsified
• we are likely on the cusp of a paradigm shift
• cyclic models are a viable competitor to inflation
• inflation simply moved the “singular Big Bang” to before inflation, rather than immediately preceding the hot Big Bang
All of these assertions, to be blunt, are both incorrect and irresponsible. Worst of all, every single one of the scientists I’ve spoken to whose made these claims knows they’re incorrect. However, the claims are still advanced — including to the general public through popular treatments — by the very scientists who are running these experiments. There’s no kind way to couch it: if it isn’t self-deception, it’s utter intellectual dishonesty. In fact, when a scientist makes an overblown and premature claim that turns out, on closer inspection, to be completely wrong, some of us in the astronomical community call that a “BICEP2,” named after the infamous false discovery they announced back in 2014.
Most of all, it’s a pity. These experiments that measure the properties of the cosmic microwave background to such extraordinary precisions are giving us the best information we’ve ever had about the nature of the universe, and of the inflationary epoch that preceded and set up — and caused — the hot Big Bang. Cosmic inflation is well validated as the origin of our universe. It has replaced the noninflationary, singularity-containing Big Bang as our cosmological standard model for where we all came from. Although there are contrarian alternatives out there, none of them have ever succeeded where cosmic inflation does not. Meanwhile, they all fail to reproduce the full suite of inflation’s successes.
Scientists who value glory and attention over accuracy will no doubt continue to make baseless assertions undercutting what’s actually known about the universe. But don’t be fooled by such claims. At the end of the day, we learn what exists in the universe by asking it questions about itself and listening to its response. As soon as we abandon that approach, we have to admit the uncomfortable truth: we simply aren’t doing science anymore... (MORE - missing details)
https://www.cnet.com/news/first-moon-roc...r-history/
INTRO: Late last year, a Chinese space capsule delivered fresh moon samples to Earth for the first time in about four decades, and these precious lunar rocks just revealed a new detail about our planet's glowing companion. Its volcanoes were alive and active considerably longer than scientists thought. "All our experience tells us that the moon should be cold and dead 2 billion years ago. But it is not, and the question is, 'Why?'" said Alexander Nemchin, a professor of geology at Australia's Curtin University and author of the analysis published Thursday in the journal Science... (MORE)
What if the universe had no beginning?
https://www.livescience.com/universe-had...nning-time
INTRO: In the beginning, there was … well, maybe there was no beginning. Perhaps our universe has always existed — and a new theory of quantum gravity reveals how that could work.
"Reality has so many things that most people would associate with sci-fi or even fantasy," said Bruno Bento, a physicist who studies the nature of time at the University of Liverpool in the U.K.
In his work, he employed a new theory of quantum gravity, called causal set theory, in which space and time are broken down into discrete chunks of space-time. At some level, there's a fundamental unit of space-time, according to this theory.
Bento and his collaborators used this causal-set approach to explore the beginning of the universe. They found that it's possible that the universe had no beginning — that it has always existed into the infinite past and only recently evolved into what we call the Big Bang... (MORE)
Many contrarians dispute that cosmic inflation occurred. The evidence says otherwise.
https://bigthink.com/starts-with-a-bang/...-happened/
KEY POINTS: Studying the Big Bang tells us how our universe evolved to become this way, but it doesn't immediately reveal why the Big Bang occurred or what might have preceded it. Theoretically and observationally, the evidence for cosmic inflation preceding and setting up the Big Bang is incredibly strong and comprehensive. There are still some new, sensitive things to measure, but the lack of low-hanging fruit doesn't mean the tree is dead.
EXCERPT (Ethan Siegel): . . . What failing to find these tensor fluctuations (yet) definitely, definitely does not mean is that cosmic inflation is wrong. Inflation is well-validated by numerous independent observational tests, and would only be falsified by the data if we did detect these tensor modes, and they didn’t follow the precise spectrum predicted by inflation.
And yet, you’d never know any of this by listening to the scientists associated with BICEP and the public-facing communication they’ve put out into the world. They continue to assert that:
• inflation remains in doubt
• B-modes (indicating tensor fluctuations) are necessary to validate inflation
• if there aren’t large magnitude ones, inflation is falsified
• we are likely on the cusp of a paradigm shift
• cyclic models are a viable competitor to inflation
• inflation simply moved the “singular Big Bang” to before inflation, rather than immediately preceding the hot Big Bang
All of these assertions, to be blunt, are both incorrect and irresponsible. Worst of all, every single one of the scientists I’ve spoken to whose made these claims knows they’re incorrect. However, the claims are still advanced — including to the general public through popular treatments — by the very scientists who are running these experiments. There’s no kind way to couch it: if it isn’t self-deception, it’s utter intellectual dishonesty. In fact, when a scientist makes an overblown and premature claim that turns out, on closer inspection, to be completely wrong, some of us in the astronomical community call that a “BICEP2,” named after the infamous false discovery they announced back in 2014.
Most of all, it’s a pity. These experiments that measure the properties of the cosmic microwave background to such extraordinary precisions are giving us the best information we’ve ever had about the nature of the universe, and of the inflationary epoch that preceded and set up — and caused — the hot Big Bang. Cosmic inflation is well validated as the origin of our universe. It has replaced the noninflationary, singularity-containing Big Bang as our cosmological standard model for where we all came from. Although there are contrarian alternatives out there, none of them have ever succeeded where cosmic inflation does not. Meanwhile, they all fail to reproduce the full suite of inflation’s successes.
Scientists who value glory and attention over accuracy will no doubt continue to make baseless assertions undercutting what’s actually known about the universe. But don’t be fooled by such claims. At the end of the day, we learn what exists in the universe by asking it questions about itself and listening to its response. As soon as we abandon that approach, we have to admit the uncomfortable truth: we simply aren’t doing science anymore... (MORE - missing details)