An astrophysicist explains cosmology’s theoretical failures
Link here. The astrophysicist, Paul Sutter, does a very nice job of outlining the conundrum that has been causing astrophysicists to tear their hair out for the past decade-plus.
In the two decades since astronomers discovered dark energy, we’ve come upon a little hitch: Measurements of the expansion rate of the universe (and so its age) from both the CMB [cosmic microwave background] and supernovas have gotten ever more precise, but they’re starting to disagree. We’re not talking much; the two methods are separated by only 10 million or 20 million years in estimating the 13.77-billion-year history of the universe. But we’re operating at such a level of precision that it’s worth talking about.
If anything, this failure for two measurements of data spanning billions of light years — which is billions in both time and space — is a perfect illustration of the uncertainty of science. Astrophysicists are trying to come up with answers based on data that is quite thin, with many gaps in knowledge, and carries with it many assumptions. It therefore is actually surprising that these two numbers agree as well as they do.
Sutter, being in the CMB camp, puts most of the blame for this failure on the uncertainty of what we know about supernovae. He could very well be right. The assumptions about supernovae used to measure the expansion rate of the universe are many. There is also a lot of gaps in our knowledge, including a full understanding of the process that produces supernovae.
Sutter however I think puts too much faith in theoretical conclusions of the astrophysics community that have determined the age of the universe based on the CMB. The uncertainties here are as great. Good scientists should remain skeptical of this as well. Our knowledge of physics is still incomplete. Physicists really don’t know all the answers, yet.
In the end, Sutter however does pin down the biggest problem in cosmology:
The “crisis” is a good excuse to keep writing papers, because we’ve been stumped by dark energy for over two decades, with a lot of work and not much understanding. In a sense, many cosmologists want to keep the crisis going, because as long as it exists, they have something to talk about other than counting down the years to the next big mission.
In other words, the discussion now is sometimes less about science and theories and cosmology, but instead about funding and career promotion. What a shock!
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Link here. The astrophysicist, Paul Sutter, does a very nice job of outlining the conundrum that has been causing astrophysicists to tear their hair out for the past decade-plus.
In the two decades since astronomers discovered dark energy, we’ve come upon a little hitch: Measurements of the expansion rate of the universe (and so its age) from both the CMB [cosmic microwave background] and supernovas have gotten ever more precise, but they’re starting to disagree. We’re not talking much; the two methods are separated by only 10 million or 20 million years in estimating the 13.77-billion-year history of the universe. But we’re operating at such a level of precision that it’s worth talking about.
If anything, this failure for two measurements of data spanning billions of light years — which is billions in both time and space — is a perfect illustration of the uncertainty of science. Astrophysicists are trying to come up with answers based on data that is quite thin, with many gaps in knowledge, and carries with it many assumptions. It therefore is actually surprising that these two numbers agree as well as they do.
Sutter, being in the CMB camp, puts most of the blame for this failure on the uncertainty of what we know about supernovae. He could very well be right. The assumptions about supernovae used to measure the expansion rate of the universe are many. There is also a lot of gaps in our knowledge, including a full understanding of the process that produces supernovae.
Sutter however I think puts too much faith in theoretical conclusions of the astrophysics community that have determined the age of the universe based on the CMB. The uncertainties here are as great. Good scientists should remain skeptical of this as well. Our knowledge of physics is still incomplete. Physicists really don’t know all the answers, yet.
In the end, Sutter however does pin down the biggest problem in cosmology:
The “crisis” is a good excuse to keep writing papers, because we’ve been stumped by dark energy for over two decades, with a lot of work and not much understanding. In a sense, many cosmologists want to keep the crisis going, because as long as it exists, they have something to talk about other than counting down the years to the next big mission.
In other words, the discussion now is sometimes less about science and theories and cosmology, but instead about funding and career promotion. What a shock!
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
As stated for cosmology, the #s are fairly close. The problem that their answers are outside each techniques postulated error bars.
Similar cosmological problems lie with Dark Matter. I was an early proponent based on Vera Rubin’s work. Decades later with far better instruments, telescopes and particle accelerators we have yet to find the supposed particles that are the gravitational source.
But these two quandaries are dwarfed by the entire field of string theory with no observable falsifiable measurements. Papers galore, tenure track and no “real” results. Will string theory look like the “angels on the head of a pin” waste of minds to future historians? I think so.
“. . . theretical. . . ”
‘Theoretical’, or ‘heretical’? Either might work.
Blair: Typo. Increasingly my fingers and brain work on different wavelengths. Now fixed. Thank you.
Blair,
Actually I think Bob came up with a new word for someone who argues against junk science beliefs. I am sure the definition will be expanded.
Paul Sutter has a very enjoyable podcast called “ask a spaceman”, some of it is cosmology 1.01, but he is an engaging and entertaining lecturer. A quick search for “ask a spaceman” will lead you there
For some of the readers on here that seem to live only on YouTube, it’s time to branch out… My father is 83, and believes the internet is only YouTube. He also doesn’t “get” that there is so much in depth audio space stuff out there. Start off by listening to Bob pontificating on the John batcherlow show, then download a podcast app , and just search for “space”…. Some you will like, some will be rubbish, but an “on demand” stream of science news, opinion and commentary is what made me give up all TV connection. My TV is used for the occasional WII Sports family challenge, and a few streamed movies….
There is so much more to be learned by podcasts than any amount of TV.
I know I’m talking to mostly old white dudes with this site bookmarked, many of whom think a YouTube video is a legitimate answer to a question or opinion, but there is an awful lot to learn, technically, and generally, from the podcasting sphere..
I’m honestly talking NASA employees, scientists, and even Bob!! just chatting about their jobs … It’s a wonderful new media, and anyone that would like some help accessing this fantastic new spoken word format feel free to contact me
loonyman99@gmail.com
Podcasts help me give up television… The best thing I ever did!
From the article:
Is it that dark energy was not discovered but hypothesized? No. It is that the discrepancy between observations and analyses make it less certain how much energy needs to be dark. could it be that dark energy is not discovered because it does not exist, and the analyses are incorrect?
Not according to those who do the analyses.
It could easily be just as incorrect as aether was a century ago, yet another hypothesized ingredient of the universe.
I have never liked supernovae as a standard candle. The Davy Crocket and Czar Bomb had vastly different yields….my guess is that star explosions can also vary due to unknown differences.
I’ve never understood if the quantum of space was getting bigger or if we were getting more of them. I’ve heard both answers.
There is so much weirdness in our current physics that I’m hopeful something will cause a new theory to be put forth.
Just as one naive example: If photons experience no time (as they travel at the speed of light), how can there be an inverse cubed distance relationship with their energy? From their perspective, it just magically disappears in the non-existing instant between creation and detection? They never had it to begin with? Photons being created with the energy the “will have” at detection is even odder than quantum entanglement.
Of course, nothing says the universe must make sense.
I don’t care for podcasts because I can’t pay attention to audio. Audio-only makes a good background, but I don’t retain any of it. Even talking-head video, which I also dislike, is better because I pay attention to it. Writing is best. I can read much faster than anyone can talk. I have attention focus disorder.
Jeff Wright wrote: “I have never liked supernovae as a standard candle. The Davy Crocket and Czar Bomb had vastly different yields….my guess is that star explosions can also vary due to unknown differences.”
The hypothesis is that a certain type of supernova will explode with the same brightness every time. When one star is in close orbit to a more massive star, then the massive star can siphon off (is that a good analogy for orbital mechanics?) material from the smaller one. The hypothesis is that the massive ones all explode when they reach the same mass, therefore they all explode with the same energy and light intensity.
But what if there are unknown differences? Jeff has a good point. Are astrophysicists making an assumption that is incorrect in reality?
Edward asked, “Are astrophysicists making an assumption that is incorrect in reality?”
Yes.
markedup2–
The whole “photons experience no time” thing’, is somewhat of a cartoony explanation.
IIRC, it is addressed in this presentation, but I have no time right now.
The Biggest Ideas in the Universe
Sean Carroll
#5 Time (april 2021)
https://youtu.be/KYfFCApo-Rg
54:30