4 ms·

This is a fun collection but recently I have been wanting to see how well different theoretical models express experimental data If I want to calculate the eff

This is a fun collection but recently I have been wanting to see how well different theoretical models express experimental data If I want to calculate the efficacy of relativity where can I find observational data on mercury's orbit? If I want to calculate the efficacy of quantised photons where can I find observational data on blackbody radiation? If I want to calculate the speed of light where can I find observational data on io? If I want to calculate the efficacy of quantum mechanical models where can I find observational data on qm phenomena? Are there resources of others showing from experiment to theory with calculations of real data defending the theory's math Or even just access to these and similar datasets?

jeffwass 9y ago
For smaller research groups I expect you’d need to contact researchers and ask for their raw data. Unless you’re an expert in the field expert, they may not be willing to provide. If you are an expert they probably know of you already and would be happy to collaborate on whatever further research is done using their acquired data. (This happens between experimentalists and theorists all the time). Some larger collaborations may provide their raw data broadly. Eg, I believe all Hubble Space Telescope data becomes publicly available (the PI’s get some limited time exclusive use to their run data, so they don’t get scooped, but it’s made public later.). Other setups like CERN and FermiLab may do similarly. In these cases it’s up to you to dig deep into the instrument manuals and do your own calibrations and adjustments. Regarding matching experiment to theory, that’s basically done by experimental research groups directly, in their own publications, probably widely available in the Arxiv.
- qubex 9y ago
  I don't disagree with you about researchers being unwilling to share their raw data if somebody is not a known researcher in the field, but I consider it rather despicable behaviour.
  - auntienomen 9y ago
    Sharing data with an amateur is asking to have your time wasted. It'd be nice if this wasn't the case, but I don't blame scientific researchers for preferring to spend their time advancing science.
    - tempay 9y ago
      Making your data publicly available doesn't require you to then support people who try to use it.
    - justifier 9y ago
      like albert in his patent office? I jest, but honestly I am confused abit by your flippant response Is my request that controversial? The speed of light has been studied for hundreds of years.. asking to see even just romer's data should hardly be an affront on the time of contemporary researchers Do you think science should be accepted as only solutions without evidence? I agree, spend your time advancing science but does publishing fall under your description of 'sharing'? I blame the journal format for the lack of resources I am seeking: it is impractical to publish terabytes of raw data in a journal so why even describe the data beyond your results? I feel the journals have inadvertently created a system of belief which is antithetical to science Look at the recent revelations concerning reproducibility One argument against gatekeeping 'amateurs' is the researchers are busy researching and we require more checks than those researchers have time to do themselves How would you feel about a closed source project that lacked any documentation and only showed vague benchmarks but promised revolutionary results?
      - qubex 9y ago
        A pertinent comment, I don’t know why you were downvotes.
      - madhadron 9y ago
        It's an attitude based on experience. Far too much of the inbox of someone affiliated with a physics department is filled with: 1) cranks claiming to have debunked something, 2) journalists looking for a sound bite, 3) curious laymen who quickly become angry when you point out the prerequisites they need to understand before they can understand the answer to their question. Is it healthy? No. Is it rational given the situation? Sadly, yes.
tempay 9y ago
For datasets from any field there is Zenodo[1] and for particle physics there is hepdata[2]. There is also the CERN opendata portal but this tends to be more about releasing large datasets which require non trivial efforts to analyse. I thought this would be too difficult to make use of but there was a publication earlier this year using CMS data[3]. [1] https://zenodo.org/ https://zenodo.org/ [2] https://hepdata.net/ https://hepdata.net/ [3] https://arxiv.org/abs/1704.05066 https://arxiv.org/abs/1704.05066
gus_massa 9y ago
1 and 3: I think that the Mercury and Io data should be publicly available, but I don't know enough astronomy to know the correct spell in Google. 4: There are too much quantum mechanics experiments. Which one? If the experiment is easy enough most Physicist prefer to measure it themselves and not download a bunch of data that you can't be sure about the details. If it's complex the data usually must be carefully analyzed. ([not a qm experiment] IIRC in the last LIGO experiment the noise was much higher than the signal, perhaps 100x, the nice chirp that most article show has a lot of preprocessing.) 2: In the first result of https://www.google.com/search?q=black+body+radiation+experimental+data https://www.google.com/search?q=black+body+radiation+experim... I get https://www.phys.ksu.edu/personal/rprice/BB.pdf https://www.phys.ksu.edu/personal/rprice/BB.pdf Is that enough? Be careful because it is not a canonical source, it's not a peer review article, the author describe it as: > Other Projects and Papers: > Although not the groundbreaking by any means, the following are some papers I’ve had to write for various classes during my undergraduate career at the University of Arizona Physics Department. Perhaps to someone they may provide some value or reference: I think it's a standard experiment in 2nd or 3rd year of Physics, so there must be plenty of tables flying around. I measure something like that once, with a tungsten incandescent lamp. (IIRC tungsten is not black enough, you have only 50% of the expected light at one end of the visible spectrum and 60% at the other end, or something similar, also the glass and lens absorb part of the light and it's difficult to get the data about them, so ... there are a lot of details that you must check before using the data.) In Chemistry they use more tables, you can buy books with tables and tables of experimental data, but it's more difficult to have a clean theory to compare with them.
mnl 9y ago
I'm sorry, but usually people can't waste their time working in easy to understand datasets with a wiki for amateurs (for free), unless it's for some kind of teaching (that they're being paid for). If you're really willing to you can start studying some of the Physics you're talking about (honestly, any physicist could tell you still haven't), it's the easiest way to get to know which really old papers you have to check. Maybe you can do some lab work in an educational environment and learn what to do with raw data after you understand the experimental setup, what's being measured and how it's being measured: that's the key to know what you are doing. Modern big experiments, for instance in HEP, expect from you a significant effort and having to deal with particular frameworks, that means a few months full-time at least and you need people around that can answer your questions. I don't mean to sound harsh, but honestly your questions are too broad (it doesn't work like that), and imprecise... for instance, you don't "calculate the efficacy of [a theory]" in Physics, and data don't "defend the theory's math". Not at all.
- justifier 9y ago
  I freely admit writing the op was difficult and I rewrote the questions many times editing out terminology.. if I'm still coming up short perhaps you could help > you don't "calculate the efficacy of [a theory]" How would you describe in a single sentence the growing precision of our calculation of the speed of light constant over the last 300 years? > data don't "defend the theory's math" How would you describe in a single sentence the way Einstein used Mercury's retrograde motion to assure himself of the advocacy of his theoretical mathematical model for gravitation?
  - mnl 9y ago
    >How would you describe in a single sentence the growing precision of our calculation of the speed of light constant over the last 300 years? I don't know, first I'd talk about how it was discovered that light behaves like c really is a constant (that's not intuitive nor trivial). You could guess from Fizeau (1851) and Michelson-Morley (1887) experiments, but it wasn't really until the 1905 Einstein's paper that it was understood that you don't need aether, the speed of light can (and should) be a universal constant and it all makes sense. >How would you describe in a single sentence the way Einstein used Mercury's retrograde motion to assure himself of the advocacy of his theoretical mathematical model for gravitation? He shows (see here: http://www.gsjournal.net/old/eeuro/vankov.pdf http://www.gsjournal.net/old/eeuro/vankov.pdf) that his theory (after reasonable approximations) predicts a precession of the perihelion of Mercury that agrees with the experimental result, then he stops. That's what you do in Physics: look, my nice theory predicts this observable in agreement with the experimental data. That's a very good sign, but the data could be explained by other theory as well. Data can "prove" that a theory is wrong (if your theory has falsifiability, as it should), but they can never show that your theory is all that there is, nor your maths... There are other theories of gravitation, for instance Logunov's, that are interesting and agree with data (more or less) but have a few problems with maths. BTW, I don't think he ever really doubted his GR theory, it comes from a very simple, yet profound idea that once realised had to be right. You have to do all the technical work afterwards, that was difficult, but a few mathematicians could have done/did it (Hilbert). In any case the idea is to check your predictions with the measurements from more and more precise experiments to find out if you're wrong, not the other way around (that... well, I've met that funny epistemology a few times in social sciences.)
jogundas 9y ago
All the science is more or less open and more or less easily googlable. For Mercury orbital precession, try wiki (Tests_of_general_relativity) or go directly to https://journals.aps.org/rmp/abstract/10.1103/RevModPhys.19.361 https://journals.aps.org/rmp/abstract/10.1103/RevModPhys.19.... (behind a paywall) .
madhadron 9y ago
I'm late to this, but perhaps I can shed some light... Don't use someone else's data. That defeats the purpose. But aside from Io and Mercury, you can do a huge amount with a modest amount of equipment at home. For example, for the blackbody spectrum, you need an empty kiln, a diffraction gradient (for separating wavelengths of light) and a photometer (for measuring the intensity of light). Heat the kiln to a temperature, put the diffraction gradient in front of an opening in it, and then measure the light intensity with the photometer at various angles from the grating to plot out the spectrum at that temperature. Change the temperature and repeat. The original quantum mechanics work was based on emission lines of atoms. You need a tube with appropriate monatomic gases and a way of exciting it. They sell these for lab classes. Then you put current through the tube, put your diffraction gradient in front of it again, and measure the angle of the distinct lines you see. Those are exactly the data that Heisenberg was trying to explain. A lot of other quantum mechanical predictions are made via statistical mechanics and describe the thermodynamic properties of material. Now you're back in measuring latent heat, specific heat, expansion coefficients, and all those unsexy things that you can do pretty straightforwardly. There are lots of ways to measure the speed of light. John Baez describes some at http://math.ucr.edu/home/baez/physics/Relativity/SpeedOfLight/measure_c.html http://math.ucr.edu/home/baez/physics/Relativity/SpeedOfLigh.... A lot of the stuff you hear about isn't feasible to reproduce because it's enormous or time consuming or expensive. You're not going to build another LHC (but you could probably build a little cyclotron and measure meson decays). You can certainly learn how to make observations of Mercury and measure its shift of perihelion over the course of the next couple years, but that's pretty low payoff for your time compared to table top experiments. > Are there resources of others showing from experiment to theory with calculations of real data defending the theory's math Yes. Experimental physics papers. Theoretical physics gets all the attention, but it's the minority of the actual activity of the field.

jeffwass 9y ago

For smaller research groups I expect you’d need to contact researchers and ask for their raw data. Unless you’re an expert in the field expert, they may not be willing to provide. If you are an expert they probably know of you already and would be happy to collaborate on whatever further research is done using their acquired data. (This happens between experimentalists and theorists all the time). Some larger collaborations may provide their raw data broadly. Eg, I believe all Hubble Space Telescope data becomes publicly available (the PI’s get some limited time exclusive use to their run data, so they don’t get scooped, but it’s made public later.). Other setups like CERN and FermiLab may do similarly. In these cases it’s up to you to dig deep into the instrument manuals and do your own calibrations and adjustments. Regarding matching experiment to theory, that’s basically done by experimental research groups directly, in their own publications, probably widely available in the Arxiv.

qubex 9y ago
I don't disagree with you about researchers being unwilling to share their raw data if somebody is not a known researcher in the field, but I consider it rather despicable behaviour.
- auntienomen 9y ago
  Sharing data with an amateur is asking to have your time wasted. It'd be nice if this wasn't the case, but I don't blame scientific researchers for preferring to spend their time advancing science.
  - tempay 9y ago
    Making your data publicly available doesn't require you to then support people who try to use it.
  - justifier 9y ago
    like albert in his patent office? I jest, but honestly I am confused abit by your flippant response Is my request that controversial? The speed of light has been studied for hundreds of years.. asking to see even just romer's data should hardly be an affront on the time of contemporary researchers Do you think science should be accepted as only solutions without evidence? I agree, spend your time advancing science but does publishing fall under your description of 'sharing'? I blame the journal format for the lack of resources I am seeking: it is impractical to publish terabytes of raw data in a journal so why even describe the data beyond your results? I feel the journals have inadvertently created a system of belief which is antithetical to science Look at the recent revelations concerning reproducibility One argument against gatekeeping 'amateurs' is the researchers are busy researching and we require more checks than those researchers have time to do themselves How would you feel about a closed source project that lacked any documentation and only showed vague benchmarks but promised revolutionary results?
    - qubex 9y ago
      A pertinent comment, I don’t know why you were downvotes.
    - madhadron 9y ago
      It's an attitude based on experience. Far too much of the inbox of someone affiliated with a physics department is filled with: 1) cranks claiming to have debunked something, 2) journalists looking for a sound bite, 3) curious laymen who quickly become angry when you point out the prerequisites they need to understand before they can understand the answer to their question. Is it healthy? No. Is it rational given the situation? Sadly, yes.

tempay 9y ago

For datasets from any field there is Zenodo[1] and for particle physics there is hepdata[2]. There is also the CERN opendata portal but this tends to be more about releasing large datasets which require non trivial efforts to analyse. I thought this would be too difficult to make use of but there was a publication earlier this year using CMS data[3]. [1] https://zenodo.org/ https://zenodo.org/ [2] https://hepdata.net/ https://hepdata.net/ [3] https://arxiv.org/abs/1704.05066 https://arxiv.org/abs/1704.05066

gus_massa 9y ago

1 and 3: I think that the Mercury and Io data should be publicly available, but I don't know enough astronomy to know the correct spell in Google. 4: There are too much quantum mechanics experiments. Which one? If the experiment is easy enough most Physicist prefer to measure it themselves and not download a bunch of data that you can't be sure about the details. If it's complex the data usually must be carefully analyzed. ([not a qm experiment] IIRC in the last LIGO experiment the noise was much higher than the signal, perhaps 100x, the nice chirp that most article show has a lot of preprocessing.) 2: In the first result of https://www.google.com/search?q=black+body+radiation+experimental+data https://www.google.com/search?q=black+body+radiation+experim... I get https://www.phys.ksu.edu/personal/rprice/BB.pdf https://www.phys.ksu.edu/personal/rprice/BB.pdf Is that enough? Be careful because it is not a canonical source, it's not a peer review article, the author describe it as: > Other Projects and Papers: > Although not the groundbreaking by any means, the following are some papers I’ve had to write for various classes during my undergraduate career at the University of Arizona Physics Department. Perhaps to someone they may provide some value or reference: I think it's a standard experiment in 2nd or 3rd year of Physics, so there must be plenty of tables flying around. I measure something like that once, with a tungsten incandescent lamp. (IIRC tungsten is not black enough, you have only 50% of the expected light at one end of the visible spectrum and 60% at the other end, or something similar, also the glass and lens absorb part of the light and it's difficult to get the data about them, so ... there are a lot of details that you must check before using the data.) In Chemistry they use more tables, you can buy books with tables and tables of experimental data, but it's more difficult to have a clean theory to compare with them.

mnl 9y ago

I'm sorry, but usually people can't waste their time working in easy to understand datasets with a wiki for amateurs (for free), unless it's for some kind of teaching (that they're being paid for). If you're really willing to you can start studying some of the Physics you're talking about (honestly, any physicist could tell you still haven't), it's the easiest way to get to know which really old papers you have to check. Maybe you can do some lab work in an educational environment and learn what to do with raw data after you understand the experimental setup, what's being measured and how it's being measured: that's the key to know what you are doing. Modern big experiments, for instance in HEP, expect from you a significant effort and having to deal with particular frameworks, that means a few months full-time at least and you need people around that can answer your questions. I don't mean to sound harsh, but honestly your questions are too broad (it doesn't work like that), and imprecise... for instance, you don't "calculate the efficacy of [a theory]" in Physics, and data don't "defend the theory's math". Not at all.

justifier 9y ago
I freely admit writing the op was difficult and I rewrote the questions many times editing out terminology.. if I'm still coming up short perhaps you could help > you don't "calculate the efficacy of [a theory]" How would you describe in a single sentence the growing precision of our calculation of the speed of light constant over the last 300 years? > data don't "defend the theory's math" How would you describe in a single sentence the way Einstein used Mercury's retrograde motion to assure himself of the advocacy of his theoretical mathematical model for gravitation?
- mnl 9y ago
  >How would you describe in a single sentence the growing precision of our calculation of the speed of light constant over the last 300 years? I don't know, first I'd talk about how it was discovered that light behaves like c really is a constant (that's not intuitive nor trivial). You could guess from Fizeau (1851) and Michelson-Morley (1887) experiments, but it wasn't really until the 1905 Einstein's paper that it was understood that you don't need aether, the speed of light can (and should) be a universal constant and it all makes sense. >How would you describe in a single sentence the way Einstein used Mercury's retrograde motion to assure himself of the advocacy of his theoretical mathematical model for gravitation? He shows (see here: http://www.gsjournal.net/old/eeuro/vankov.pdf http://www.gsjournal.net/old/eeuro/vankov.pdf) that his theory (after reasonable approximations) predicts a precession of the perihelion of Mercury that agrees with the experimental result, then he stops. That's what you do in Physics: look, my nice theory predicts this observable in agreement with the experimental data. That's a very good sign, but the data could be explained by other theory as well. Data can "prove" that a theory is wrong (if your theory has falsifiability, as it should), but they can never show that your theory is all that there is, nor your maths... There are other theories of gravitation, for instance Logunov's, that are interesting and agree with data (more or less) but have a few problems with maths. BTW, I don't think he ever really doubted his GR theory, it comes from a very simple, yet profound idea that once realised had to be right. You have to do all the technical work afterwards, that was difficult, but a few mathematicians could have done/did it (Hilbert). In any case the idea is to check your predictions with the measurements from more and more precise experiments to find out if you're wrong, not the other way around (that... well, I've met that funny epistemology a few times in social sciences.)

jogundas 9y ago

All the science is more or less open and more or less easily googlable. For Mercury orbital precession, try wiki (Tests_of_general_relativity) or go directly to https://journals.aps.org/rmp/abstract/10.1103/RevModPhys.19.361 https://journals.aps.org/rmp/abstract/10.1103/RevModPhys.19.... (behind a paywall) .

madhadron 9y ago

I'm late to this, but perhaps I can shed some light... Don't use someone else's data. That defeats the purpose. But aside from Io and Mercury, you can do a huge amount with a modest amount of equipment at home. For example, for the blackbody spectrum, you need an empty kiln, a diffraction gradient (for separating wavelengths of light) and a photometer (for measuring the intensity of light). Heat the kiln to a temperature, put the diffraction gradient in front of an opening in it, and then measure the light intensity with the photometer at various angles from the grating to plot out the spectrum at that temperature. Change the temperature and repeat. The original quantum mechanics work was based on emission lines of atoms. You need a tube with appropriate monatomic gases and a way of exciting it. They sell these for lab classes. Then you put current through the tube, put your diffraction gradient in front of it again, and measure the angle of the distinct lines you see. Those are exactly the data that Heisenberg was trying to explain. A lot of other quantum mechanical predictions are made via statistical mechanics and describe the thermodynamic properties of material. Now you're back in measuring latent heat, specific heat, expansion coefficients, and all those unsexy things that you can do pretty straightforwardly. There are lots of ways to measure the speed of light. John Baez describes some at http://math.ucr.edu/home/baez/physics/Relativity/SpeedOfLight/measure_c.html http://math.ucr.edu/home/baez/physics/Relativity/SpeedOfLigh.... A lot of the stuff you hear about isn't feasible to reproduce because it's enormous or time consuming or expensive. You're not going to build another LHC (but you could probably build a little cyclotron and measure meson decays). You can certainly learn how to make observations of Mercury and measure its shift of perihelion over the course of the next couple years, but that's pretty low payoff for your time compared to table top experiments. > Are there resources of others showing from experiment to theory with calculations of real data defending the theory's math Yes. Experimental physics papers. Theoretical physics gets all the attention, but it's the minority of the actual activity of the field.