3 ms·
Why are you relying on strawmen? > Data can "prove" that a theory is wrong (if your theory has falsifiability, as it should), but they can never show that your
by justifier 9y ago
Why are you relying on strawmen?
> 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.
Where you got '"prove"' and 'all that there is' I am unsure
My wording was:
op> how well different theoretical models express experimental data
Which mirrors your own reiteration of that point
> the idea is to check your predictions with the measurements from more and more precise experiments
Which is literally what I was asking for: measurements from .. precise experiments
> predicts a precession of the perihelion of Mercury that agrees with the experimental result
Right, where's the experimental data on the orbit of Mercury?
If you are unable to answer the question that's fine but as is I fail to see what you are trying to accomplish with your ire and misdirection
- mnl 9y agoI'm sorry if I came across that way, didn't mean to. But you have to realise that it's tiresome all this new internet phenomena of laymen questioning the work ethics of actual professionals because they think they could possibly do better, if only etc. I don't usually comment on HN about Physics because... well, never mind, it really was a bad idea this time. If you're interested in the data you can browse the references, go to the libraries (as physicists have to do even at college, because it's kind of hard), find out first what exactly you are asking... even mail someone. And you can also measure things by yourself, this is a free universe and everybody can study its properties (Mercury is out there and maybe you can afford a nice telescope). What is unreasonable, very unreasonable, self-entitled in my opinion, is expecting that experimental physicists provide some kind of repository of (internal-notes redux) data for casual readers of pop sci. That would cost their time (or some overworked PhD student's) and project money, the bad news is no one is willing to do that nor paying for it. It's not that there's some kind of conspiracy, it's that people are actually busy working.
- justifier 9y ago> laymen questioning the work ethics of actual professionals because they think they could possibly do better, if only etc. > What is unreasonable, very unreasonable, self-entitled in my opinion, is expecting that experimental physicists provide some kind of repository > It's not that there's some kind of conspiracy You seem to be arguing with someone else > I don't usually comment on HN about Physics because... well, never mind, it really was a bad idea this time. If you are knowledgeable on the subject I would encourage you to comment, but keep the comment on the topic being discussed
- mnl 9y agoWell, I'll stay on the post topic. It's unlikely that you can get the lab notebooks from most of 20th century Physics, this is what you're really looking for. It's not that important, because once the results are published by a few different groups that don't trust each other and will scrutinize their peers' work, all relevant data have been measured again and again. If theories like Special Relativity were really wrong there would be consequences like having to close all particle accelerators because they wouldn't work. Many key experiments are routinely done as part of the university courses, and many results are also routinely used in other fields, engineering included. E.g. linearisations of Planck's distribution are done in Remote Sensing for estimating surface temperatures, they work great btw. We also understand light bulbs, pyrometers, infrared thermometers... -those work straight with Planck's Law, how else could they find the temperature-. There are GR corrections coded somewhere for your GPS to work, etc. If by seeing "how well different theoretical models express experimental data" you're planning to apply idk assorted non-linear regression models from equations you're not familiar with to see which one has the minimum chi-square or something like that, well I guess that's what hobbies are for. Differences tend to appear at the limiting cases, there you need more Physics than Levenberg–Marquardt fun, so it's better to start there. I have to warn you that your wording matches the usual stuff you get from Physics cranks (the bane of the trade), hence the knee-jerk reaction, sorry about that. I'll try harder next time.
- justifier 9y agoit's for educational purposes to express concepts like these to anyone interested using real world data to show why these concepts are important Like why Newtonian physics is insufficient to explain Mercury's orbit Or how infinitely divisible energy leads to the 'ultraviolet catastrophe' Or how one can approximate the speed of light just using orbital data of io and earth (romer's initial method) I can appreciate that my wording may have been ambiguous Brevity can sometimes be the enemy of clarity but questions can help avoid assumptions
- mnl 9y agoThank you, I get it now. You're absolutely right and that could be really interesting. The problem is you don't usually have large sets of data in elementary uni labs, because of schedules really, but that would be the best. I'm not an Astronomer (nor Astrophysicist, I know about GR coming from a Theoretical Physics bkg), so I suspect you could get more recent data, but a classic reference from the GR book of Weinberg is a paper from G. M. Clemence: http://adsabs.harvard.edu/abs/1947RvMP...19..361C http://adsabs.harvard.edu/abs/1947RvMP...19..361C (it can be obtained if you look around, there's a similar free-to-read paper from the same Clemence: https://www.jstor.org/stable/3143142?seq=1#page_scan_tab_contents https://www.jstor.org/stable/3143142?seq=1#page_scan_tab_con...) that has as reference this: http://adsabs.harvard.edu/full/1943AJ.....50..126C http://adsabs.harvard.edu/full/1943AJ.....50..126C (full text), that quotes the Astronomical Papers of the American Ephemeris, Volume 11 (it says II, but it's actually 11), part I. Google is your friend (they've scanned those!) and you can find the data at https://catalog.hathitrust.org/Record/000068403 https://catalog.hathitrust.org/Record/000068403. This is how a little of preliminary research works, you have to do it yourself all the time... Luckily now you don't have to go hunting for a paper copy without being sure about the contents all the time (although it still happens). The classical mechanics calculation might be tricky, to say the least, as well. For the UV catastrophe I've always liked the Jeans cubic cavity and the Gamow observation that opening an oven doesn't kill you. And of course, the fact that integrating Planck's law gets you Stefan-Boltzmann's, very neat result. I should think about all this a bit more in order to give you better feedback.