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Author | Topic: Astronomers See Evidence of Something Unexpected in the Universe | |||||||||||||||||||||||||||||||||||||||||||||||||||
Tanypteryx Member Posts: 4597 From: Oregon, USA Joined: Member Rating: 9.5
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Astronomers See Evidence of Something Unexpected in the Universe
It will be interesting to see what is discovered in the course of trying to understand why these results disagree.
quote: quote: quote: quote: The disagreement in these results could possibly indicate an expected new (to us) property of the Universe. I find this article interesting not just because it is reporting results that are exciting on their own, but because it is reporting the disparity in results and shows scientists trying understand what is happening rather than covering it up, an accusation aimed at science that has been seen being made by the anti-science conspiracy nutjobs. Enjoy Links and Information Forum please.What if Eleanor Roosevelt had wings? -- Monty Python One important characteristic of a theory is that is has survived repeated attempts to falsify it. Contrary to your understanding, all available evidence confirms it. --Subbie If evolution is shown to be false, it will be at the hands of things that are true, not made up. --percy The reason that we have the scientific method is because common sense isn't reliable. -- Taq
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AdminModulous Administrator (Idle past 235 days) Posts: 897 Joined: |
Thread copied here from the Astronomers See Evidence of Something Unexpected in the Universe thread in the Proposed New Topics forum.
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Phat Member Posts: 18633 From: Denver,Colorado USA Joined: Member Rating: 4.1
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One of these days they will discover an unexpected BIG eyeball staring right back at them!
Seriously though, its always exciting to progress our understanding (and lack thereof) Godidit is boring. (Though he may well have done it! Chance as a real force is a myth. It has no basis in reality and no place in scientific inquiry. For science and philosophy to continue to advance in knowledge, chance must be demythologized once and for all. —RC Sproul "A lie can travel half way around the world while the truth is putting on its shoes." —Mark Twain " ~"If that's not sufficient for you go soak your head."~Faith Paul was probably SO soaked in prayer nobody else has ever equaled him.~Faith
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Percy Member Posts: 22934 From: New Hampshire Joined: Member Rating: 6.8 |
Tanypteryx writes: I find this article interesting not just because it is reporting results that are exciting on their own, but because it is reporting the disparity in results and shows scientists trying to understand what is happening rather than covering it up, an accusation aimed at science that has been seen being made by the anti-science conspiracy nutjobs. First there was the static universe, then an expanding universe slowing due to gravity, then an accelerating expansion, and now possibly a time-variable accelerating expansion? There were two independent research efforts based on different principles that established the accelerating expansion. I'd like to see something similar for this time-variable finding. --Percy
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Tanypteryx Member Posts: 4597 From: Oregon, USA Joined: Member Rating: 9.5 |
First there was the static universe, then an expanding universe slowing due to gravity, then an accelerating expansion, and now possibly a time-variable accelerating expansion? It is good to know that cosmology, astrophysics and particle physics are not finished. Still lots of questions to answer. Did you notice that the chart shows a significant increase in the distances that can be measured using parallax?
There were two independent research efforts based on different principles that established the accelerating expansion. Ok, I guess I thought it was two teams, but both looking at Type 1a supernovae at increasing distances from us. What were the different principles?
I'd like to see something similar for this time-variable finding. There is a team looking at cosmic microwave background and a team looking at supernovae and cepheid variables.What if Eleanor Roosevelt had wings? -- Monty Python One important characteristic of a theory is that is has survived repeated attempts to falsify it. Contrary to your understanding, all available evidence confirms it. --Subbie If evolution is shown to be false, it will be at the hands of things that are true, not made up. --percy The reason that we have the scientific method is because common sense isn't reliable. -- Taq
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Percy Member Posts: 22934 From: New Hampshire Joined: Member Rating: 6.8
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Tanypteryx writes: Ok, I guess I thought it was two teams, but both looking at Type 1a supernovae at increasing distances from us. What were the different principles? That was a long time ago now, I don't recall the details, so I went to Wikipedia and it makes it seem like the two efforts used the same techniques. They both observed Type 1a supernova, but not in the same way. High-Z Supernova Search Team, Supernova Cosmology Project gives some details:
quote: Supernovae, an accelerating universe and the cosmological constant also characterizes some of the differences:
quote: This refresher doesn't really sound familiar. What I recall from when I read the Scientific American article from 20 years ago (they don't make the archives available for free and I'm a cheapskate) is how greatly the different techniques employed by the two teams increased our confidence in the results, and it described the key differences.What I quoted above doesn't seem to do that. You can tell they took different approaches, but not what it was about those differences that contributed to the confidence in the results. --Percy
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nwr Member Posts: 6484 From: Geneva, Illinois Joined: Member Rating: 8.6
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This is interesting, but not unexpected.
I should clarify that. I am not say that I expected what they are seeing. Rather, I am say that I expected that evidence would show up suggesting something unexpected. Some folk will remember that I have expressed some doubts about big bang cosmology. Percy didn't like that, as I recall. I have agreed all along that there is cosmological red shift. I have questioned the big bang view, that cosmological red shift is due to expansion. I think it more likely that cosmological red shift is cosmological. That is to say, the red shift we see has to do with the nature of the cosmos, and is not simply a matter of expansion. Talk of "the expanding universe" implicitly assumes that there is a yardstick (for measuring distance) which can be used throughout the cosmos and for all time. I cannot see any reason to believe that. We use a local yardstick defined in terms of local features. And it may well be that every location can have a local yardstick. But I cannot see any certainty that we can put these together to have a cosmos-wide yardstick. It might be that there are local distance functions at every location, but no single distance function that can be used across the entire cosmos. And there could be similar issues with the measurement of time and with the measurement of other physical properties. It is standard physics, that entropy is increasing. We hear of the heat death of the universe. But maybe entropy is not increasing. If we fix our yardsticks (and other measuring standards) for today, and project, we see reasons to believe entropy is increasing. But if we could time-travel to 1000 years into the future, we might find that the yardstick has also changed over that time, and that the total amount of entropy as measured by the new measuring standards of 1000 years in the future is the same as the total amount of entropy as measured by our own standards at this time. That is to say, maybe entropy can only be a localized property localized to a time and place, and maybe there isn't any single standard for entropy that can be extended throughout the cosmos. To say all of this differently, it may well turn out that what know about the nature of the cosmos is miniscule in comparison to what we do not know about the nature of the cosmos.Fundamentalism - the anti-American, anti-Christian branch of American Christianity
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Tanypteryx Member Posts: 4597 From: Oregon, USA Joined: Member Rating: 9.5 |
Some folk will remember that I have expressed some doubts about big bang cosmology I had forgotten that. I guess I accepted the expansion and red shift as a consequence of that, but it always felt that there was more involved than we had figured out yet. This is from a layman who loves reading and studying and thinking about this stuff, but without a deep understanding of it. If red shift can't work as a standard candle for distance and time measurement it would be disappointing, mostly because we might not ever discover a new technique for those parameter measurements. If we are mistaken about the Big Bang and red shift will it make a difference or limit the chances of future discoveries? Will we be able to figure out that we are wrong and that we are stuck in an illusion? When I first started hearing about Dark Matter I wondered if it would turn out to be the gravitational effect of particles that are not in this universe at all, but the effect of mass or gravitation leaked from a "parallel" universe or "hidden" dimension.
To say all of this differently, it may well turn out that what know about the nature of the cosmos is miniscule in comparison to what we do not know about the nature of the cosmos. I suspect all physicists would agree, but I could be wrong. I love what we do know and that we are continuing to strive to learn more about the cosmos and that I have lived to see so much. It's a great time to be alive. I can't wait to see what we find with the Webb.What if Eleanor Roosevelt had wings? -- Monty Python One important characteristic of a theory is that is has survived repeated attempts to falsify it. Contrary to your understanding, all available evidence confirms it. --Subbie If evolution is shown to be false, it will be at the hands of things that are true, not made up. --percy The reason that we have the scientific method is because common sense isn't reliable. -- Taq
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nwr Member Posts: 6484 From: Geneva, Illinois Joined: Member Rating: 8.6
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If we are mistaken about the Big Bang and red shift will it make a difference or limit the chances of future discoveries? Will we be able to figure out that we are wrong and that we are stuck in an illusion?
We are mainly restricted by the limits of our access. Our main mistake is in our understanding of "objective". People take it for granted that there is an objective human-independent world. But everything that we know about is a projection from our subjective experience. What we call "objective" is really those aspects of subjective experience that humans can share with one another. And we project that to what we take to be a human independent cosmos. But perhaps it is not nearly as human independent as we like to think that it is.Fundamentalism - the anti-American, anti-Christian branch of American Christianity
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Percy Member Posts: 22934 From: New Hampshire Joined: Member Rating: 6.8
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nwr writes: Some folk will remember that I have expressed some doubts about big bang cosmology. Percy didn't like that, as I recall. I don't recall this now, but I hope my focus was on the lack of anomalous evidence pointing in the direction of your doubts, which seem based more on the general kind of concerns that can be raised about any field of science, i.e., a) the limitations of human knowledge; and b) knowledge is revised over time as we learn more. --Percy
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Taq Member Posts: 10296 Joined: Member Rating: 7.1
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nwr writes: Talk of "the expanding universe" implicitly assumes that there is a yardstick (for measuring distance) which can be used throughout the cosmos and for all time. I cannot see any reason to believe that. The yardstick is the speed of light, spectra, and type Ia supernovae. To use another example, we measure the distance to the Moon using the time it takes for a laser to bounce off of the Apollo reflector on the Moon and return to Earth. Type Ia supernovae have very similar brightness because they explode with the same mass (E=mcc), so the distance can be determined by luminosity. Next, you have the amount of redshift as determined by the shift in spectral lines which is ultimately determined by the speed of light. When you plot luminosity vs. redshift you get this wonderful correlation:
Another factor to consider is that if redshift is due to relative differences in velocity due to expansion then high redshift type Ia supernovae should brighten and dim at slower rates due to relativistic effects. That is also seen. A cosmological redshift unrelated to expansion should not do this, and yet it is there. Also, there is no other known mechanism that would redshift all wavelengths by the same amount. Other mechanism are wavelength dependent and will shift some wavelengths more than others.
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Taq Member Posts: 10296 Joined: Member Rating: 7.1 |
nwr writes: Our main mistake is in our understanding of "objective". People take it for granted that there is an objective human-independent world. But everything that we know about is a projection from our subjective experience. What we call "objective" is really those aspects of subjective experience that humans can share with one another. And we project that to what we take to be a human independent cosmos. But perhaps it is not nearly as human independent as we like to think that it is. Two scientists can independently measure redshift and type Ia supernovae luminosity without ever communicating with one another and still produce data sets that agree with one another. I would call that objective.
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Percy Member Posts: 22934 From: New Hampshire Joined: Member Rating: 6.8 |
Taq writes: Two scientists can independently measure redshift and type Ia supernovae luminosity without ever communicating with one another and still produce data sets that agree with one another. I would call that objective. I think Nwr's objection is more epistemological. He might agree that on one level what you describe is objective while seeing that objectivity dissolve into mere human consensus and assumptions on deeper levels. The best example I can think of is that we still haven't defined mass in terms of fundamental constants - there's still a standard kilogram kept in a vault outside Paris. --Percy
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Taq Member Posts: 10296 Joined: Member Rating: 7.1 |
Percy writes: The best example I can think of is that we still haven't defined mass in terms of fundamental constants - there's still a standard kilogram kept in a vault outside Paris. You might be interested in the new proposed standard that is defined in terms of fundamental constants. It is a polished sphere of crystalline silicon-28. They can very precisely measure the volume of the sphere, and from there they can accurately calculate the number of atoms in the sphere due to the consistent nature of crystals formed from silicon-28. Once you have the number of atoms you have the kilogram. This gets around the issues of the old kg standard changing in weight over time due to accumulation of oxidation and other such issues. Using this standard you could travel to an entirely new planet with no standards from Earth and still be able to very accurately produce a kg standard that agrees with the one on Earth. Page not found | NIST
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nwr Member Posts: 6484 From: Geneva, Illinois Joined: Member Rating: 8.6 |
The yardstick is the speed of light, spectra, and type Ia supernovae.
To use the speed of light as a yardstick, you need a fixed clock. But we don't have one.Fundamentalism - the anti-American, anti-Christian branch of American Christianity
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