Nature of astrophysics (6) - physics is quantitative

[Nereid]

Way back when, the heavens and the earth were thought to be governed by two quite separate sets of rules (or laws as we'd call them today), with the heavens being immutable and perfect (this is western intellectual history, going back to the Greeks; other intellectual traditions of yore differ, of course). Tycho Brahe, who I mentioned in Nature of astrophysics (5) - astronomy, quantitative only?, made good astronomical observations (quantitative ones) of a new star (what we'd call a supernova today) that appeared in 1572 and showed that, empirically, the heavens were not like this.

Using the data Brahe recorded, on the apparent positions of Mars, Johannes Kepler developed a model (as we'd say today) of its motion and from that proposed his three laws of planetary motion. Several decades later, but still in the same century, Newton developed (and later proposed) three laws of motion and a law of universal gravitation; he also developed (and later published) calculus. Using these Newton was able to show that if the way gravity worked here on the Earth was the same in the heavens, then Kepler's laws of planetary motion were just a logical consequence of Newton's own three laws of motion plus his law of universal gravitation.

Heaven and Earth were (re-)united.

Some interesting trivia (or not):
* Newton was, apparently, a rather nasty piece of work; in many ways he is an outstanding example of a scientist with a quite unattractive personality who nontheless published breathtakingly good science.
* Without calculus it is difficult (though not impossible) to show how Kepler's laws are a consequence of the laws Newton published.
* It was Brahe, the model empirical scientist, who recorded the data which, later and indirectly, were used to 'prove' Newton's law of universal gravity, a theory.
* It would be a century before Cavendish performed an experiment, in his lab, that verified (quantitatively) this law.

Newton, and his contemporaries, proposed many theories and models, in optics, mechanics, and other topics; these are pretty much the foundations of modern physics.

Since then physics and mathematics have had an intimate relationship, with new ideas in one field sparking new ideas in the other many times. Physics has also always been firmly grounded in experiment and observation, with many a model or theory biting the dust when they were shown to be inconsistent with objective, verified experimental/observational results, which have been quantitative since at least the time of Galileo.

One very good example of these themes is classical electromagnetism.

Various phenomena - seemingly quite unconnected at the time - that were later recognised as, or called, electric or magnetic were shown to be consistent with a series of laws: Ohm's law, Gauss' law (actually two), Faraday's law, Ampère's law, ... In the second half of the 19th century, these various laws were combined into a linked set of equations by Maxwell, Hertz, and Heaviside (they are partial differential equations and involve vectors) which are today mostly referred to as Maxwell's equations. Together with the Lorentz force law they provide a complete, consistent theory of electromagnetism. This theory is consistent with all relevant experimental and observational results (or phenomena), provided what's being experimented on or observed isn't too small or too energetic. Note: the theory is quantitative (at its heart is a set of equations) and consistency with experiment and observation is also quantitative (or, putting this another way, the results agree with what can be derived from the theory, objectively, to within the estimated errors/uncertainties).

The great success of classical electromagnetism, and the power of its quantitative nature, can be illustrated in many ways; for example:
* it is the basis for most of plasma physics;
* it sowed the seeds for the development of special relativity (one solution to Maxwell's equations is a self-sustaining wave, of oscillating electric and magnetic fields ... this is electromagnetic waves, or radiation, and it travels at c, always, for everyone);
* it triggered the discovery and explanation of radio waves (the first form of electromagnetic waves to be shown, via lab experiments, to be, well, self-sustaining, oscillating electric and magnetic fields!).

I'd like to discuss this topic further. Why? Because I have read, in this Thunderbolts Forum, many posts which seem to me to be saying that it is not necessary to wear quantitative glasses (so to speak) in order to have a serious discussion of physics (particularly electromagnetism), whether from the perspective of theory or experiment/observation. Of course, a serious discussion of the foundations of physics, or the history or philosophy of physics, doesn't need to get too heavily quantitative; however, I'd like to leave discussion of the foundations to a later thread that I intend to post (many thanks to weboflife for the idea of doing this), and leave philosophy out of it entirely.

So, what do you think? If it's not quantitative, can it be physics, ever?

[webolife]

Thanks for the nod.
I can think of physics qualitatively, but I don't think one can DO physics without data.
Being a teacher, I am more of a natural philosopher than a physicist, so I tend to analyze the foundational elements, paradigms, by which the data are interpreted. I question physicists who insist that their conclusions are devoid of presumptive influence. A presentation of data, even of patterns observed in the data, is not really a "conclusion" in my thinking.

[Aristarchus]

I have read, in this Thunderbolts Forum, many posts which seem to me to be saying that it is not necessary to wear quantitative glasses (so to speak) in order to have a serious discussion of physics (particularly electromagnetism), whether from the perspective of theory or experiment/observation.

Reading emphasis, mine - provide the actual quotes from your fellow EU board members - and the link for us to inspect the context of such quotes. Otherwise, I remain incredulous of such an unsubstantiated claim made by you above.

[jjohnson]

Nereid, I think you have hit, at least indirectly on what is the nature of this discussion/forum, if not exactly why. I do not know if most of the people here think that "it is unnecessary to wear quantitative glasses..." but it is a safe enough bet that most of us are not well versed enough in classical electromagnetics and electrodynamics, not to mention quantum mechanics and advanced physics, to come up with a new theory of physics stressing the electric or plasma physics point of view ourselves.

If we were, one or some of us might have tried developing it. On the other hand, some of us know that quantitative glasses are eventually a requirement of an astrophysical theory, and we are not incapable of bringing a reasonably healthy skepticism and knowledge of general scientific principles to the table to see if other ideas might appear to be plausible and merit further examination by those trained in such arts. It is precisely through such initial filters that most "new" interpretations of "how things work" tend to get critiqued and refined. It is why, if there is a new idea, most people who have physics and astronomy day jobs simply haven't the time or other motivation to examine every jack-leg "new idea" that comes along. Maybe that's why there is some press about the slow rate of scientific "discovery" and progress today, and over the past decades.

I agree that to "do" physics and astronomy or other scientific pursuits includes being able to apply the appropriate mathematics, to be familiar with various solution methods and technologies, to define and manage variables and constants correctly, to reason logically, and all the other tasks that make it necessarily a quantitative pursuit. Absolutely. Math is the logical medium through which to describe the machinations and predictions of a theory. In physics, observations, or even intuitions and guesses, should guide the development of the theory which then guides the selection or development of the math. Just because a mathematical process is elegant and sparse does not mean that it represents a physical solution. It's not enough to know the theory of airfoil sections to be able to fly. You have to be pretty good at the stick and rudder work, too, not to mention having judgment and resourcefulness.

Along those lines, and speaking only for myself, I have read enough dialog and debate here, and looked up histories and papers enough to know that press release science sounds very sure and confident, and leads a lay person with little skepticism to conclude that the material is not theoretical, but is based on sound, virtually immutable conclusions and well-known laws which can't be broken, they are so well researched and "proven". Hardly anyone is encouraged to "think, ask 'what if this is not quite right; what if there were some poor assumptions or off-scale measurements in there; what if this instead of that..." . That is a poor presentation. No wonder fewer and fewer people choose to find wonder and adventure in science if all it is going to do is flesh out the details of what we "know"! Again I refer to the little book, On Being Certain.

I am curious about the ideas that this forum and others present, based on the books by those "at the top" who have espoused this idea of looking at astronomical phenomena from a different perspective. I am trying to learn what I can from textbooks I purchase to help me see more clearly in these fields, more like scientists would see, and think and evaluate as critically as is possible for an older gent. As they say, "it ain't all saucered and blowed just yet." At least I hope not.

Progress is being made, from what I read on NRAO and SDO and other websites which seem more intimately involved with what I think of as plasma phenomena. Describing large plasma events mathematically is messy and complex and difficult. Taking too many simplification shortcuts to make the math more tractable, even on today's best supercomputers, has yet to give answers good enough to substantiate the EU ideas. This will continue to be true until they heed Alfvén's warning at his Nobel address that astrophysicists will not find the answer in his own MHD alone, but have to consider the complexities of individual charged particles and electric currents in space, as well.

What if Alfven is, in part, right? I'm not sure I would agree with every word in his book, Cosmic Plasma, but he was a physicist and no slouch as an observationalist and a person with useful insight. Why ignore such warnings and slog on thinking of plasma as a fluid state. That's the easy way out.

I don't speak for anybody else, but if electrodynamic processes are important in space at all scales, in many places, and plasma physics could be improved to provide a better, more enhanced set of ideas upon which to base astrophysics, is it not worth a look-see? If it didn't pan out, it wouldn't be the first thing not to. If it did, our understanding of the Universe improves.

If you were given the assignment to see what sorts of observations might best obtain the type of data which would best acquire suitable data and test some of these preliminary EU concepts, what might you suggest?

Contrary to ideas in other places, we are not against gravity's being in the mix. Many here try to be both open-minded and mindful of the really good work being done in astrophysics, while not forgetting that science is skeptical at heart and relies on being refreshed from time to time by ideas that are somewhat out of the box. Oddly, many different types of observations and interpretations of those observations in a variety of fields are brought up in this forum, and not all agree on the same things or have the same interests. We probably suspect that there are electric forces at work in a lot ways unseen, possibly in weather here and on other planets, and in fields that include planetary geology, stellar energy processes, cosmology, galaxy dynamics, and more. I am mostly interested in a tiny slice of those, and even that is probably a lot more than I have the time and the skill set for.

I need to go back to some of your other threads.

[Nereid]

Aristarchus,

Yes, I will certainly post some examples.

However, please note that I was careful to write "which seem to me to be saying"; in other words, this is my personal, subjective impression.

jjohnson,

As usual, a long and well-written post; and, as is becoming the pattern, I will respond over a series of posts (so stay tuned!).

However, just one quick one: if physics is, indeed, quantitative to its core, then ideas, notions, speculations, etc of things astronomical/astrophysical/etc need to be expressed in quantitative form - eventually - if they are to worthy of serious consideration (as physics). At least, that's one thing I got from reading your post. Of course this says nothing of what might be involved in getting any speculative idea to the starting gate so to speak.

[Nereid]

A response to jjohnson's excellent post, one of perhaps several.

Most of us have heard of a 'back of the envelope calculation', where you grab an old envelope (or other piece of scrap paper lying about) and do a rough calculation. Perhaps it's whether the monthly budget can stretch to a vacation at that resort you went to ten years' ago; or what the resistance of the solar wind might be, near the Earth; or how the energy delivered by fast charged particles, to produce an aurora, compares with the radiant energy output of the Sun.

Here's a (made-up) example.

How far away would the Sun have to be to appear as bright as Sirius (the brightest star in the sky)?

Well, the Sun has a magnitude of -26 (give or take; back of the envelope calculations don't have to be exact), and Sirius -1. That's a difference of 25 magnitudes. Five magnitudes corresponds to a difference in brightness of 100, and the scale is logarithmic, so 10 is 10,000, 15 a million, 20 100 million, and 25 10 billion (you could also just do (100)^5).

Apparent brightness scales as the inverse square of distance, assuming nothing in the way (which is a good enough approximation for a back of the envelope calculation), so a brightness ratio of 10 billion (10^10) corresponds to a distance ratio of 100,000 (10^5).

The Sun-Earth distance is 1 astronomical unit (au), about 150 million km, about 8 light-minutes. 100,000 au is then about 1.5 x 10^13 km, or 800,000 light-minutes; that's about 560 light-days, or about 1.5 light-years.

That result is certainly not exact, but it's also just as certainly good enough to reach all sorts of conclusions!

Such as?

Well, that Sirius must be quite a bit brighter than the Sun, intrinsically (from parallax its distance is ~8 light-years); that if the Sun were as far away as the closest star (~4 light-years) it'd be a fair bit fainter than Alpha Centuri.

The beauty of back-of-the-envelope calculations is that for a very small investment of time you get a reasonable, basic grasp of how big/far/powerful/energetic/etc something you're interested in is. And such a calculation can also give you some good pointers as to where to go next - what assumptions need to be firmed up, what aspects aren't likely to have any significant impact, what sorts of things may be very difficult to address, and so on.

And best of all is that this 'Q&D' approach can work with any aspect of physics, including plasma physics, electrodynamics, and even quantum physics.

[Nereid]

(continued)

Along those lines, and speaking only for myself, I have read enough dialog and debate here, and looked up histories and papers enough to know that press release science sounds very sure and confident, and leads a lay person with little skepticism to conclude that the material is not theoretical, but is based on sound, virtually immutable conclusions and well-known laws which can't be broken, they are so well researched and "proven". Hardly anyone is encouraged to "think, ask 'what if this is not quite right; what if there were some poor assumptions or off-scale measurements in there; what if this instead of that..." . That is a poor presentation. No wonder fewer and fewer people choose to find wonder and adventure in science if all it is going to do is flesh out the details of what we "know"!

Surely the problem lies far more with how physics and astronomy are presented, to 'laypeople', in widely read (not red!) media, than with the physics and astronomy itself?

I don't really know what to suggest, in terms of you learning more about the tentative nature of the actual physics and astronomy; perhaps there is a colloquium, or symposium, in either of these fields, at a location near you? If you are in a country like the US, UK, Canada, or Australia (to pick just a few), your local university's website might be a good place to find whether any are happening soon (and those held at universities are often free, at least for locals).

An alternative: the biography of a famous physicist or astronomer, Feynman perhaps?

Progress is being made, from what I read on NRAO and SDO and other websites which seem more intimately involved with what I think of as plasma phenomena.

Take a look, instead, at the tables of contents (and abstracts) of online journals such as The Astrophysical Journal (their online archive seems to go back to 1996), or Monthly Notices of the Royal Astronomical Society (MNRAS for short; online archive seems to go back to 1998) ... I think you'll quickly find that plasma physics is, and has been, an intimate part of astrophysics for quite a while.

[Goldminer]

Neirid wrote in the first post to this thread:

. . . were shown to be consistent with a series of laws: Ohm's law, Gauss' law (actually two), Faraday's law, Ampère's law

UNQUOTE

I wish to point out that a review of each of the above investigator's original works should be reviewed, as well as those of Weber and Coulomb.

Later theorists; such as Heaviside, Maxwell, and Lorenz lopped "insignificant" terms from the originators' work. Physics has been the worse for the oversight.

[Nereid]

I wish to point out that a review of each of the above investigator's original works should be reviewed, as well as those of Weber and Coulomb.

Later theorists; such as Heaviside, Maxwell, and Lorenz lopped "insignificant" terms from the originators' work. Physics has been the worse for the oversight.

Were the original works quantitative?

If so, are they sufficiently unambiguous that testable hypotheses could be developed (to test whether there is any difference between the 'before' and 'after' versions, with respect to any experimental or observational results)?

If so, have such experiments or observations been done?

If the answer to any of the above is 'no', then what is the basis for saying "physics has been the worse for the oversight"?

[Goldminer]

Yes, the original works were quantitative. Yes, the original experiments can be performed today with even more precision.

http://www.21stcenturysciencetech.com/a ... amics.html

[Nereid]

Yes, the original works were quantitative. Yes, the original experiments can be performed today with even more precision.

http://www.21stcenturysciencetech.com/a ... amics.html

Have such experiments been performed, written up, and published? If so, where?

[Goldminer]

I didn't say they had been done recently, I said the experiments had been done a looong time ago, and that they have been ignored. Didn't you read the link. Do you have a problem with the fact that the article is written by Lyndon La Rouche's site? I thought you were unbiased. Is there something wrong with history? Do you understand how sensitive the instruments they built actually were? Well?

[Nereid]

I didn't say they had been done recently, I said the experiments had been done a looong time ago, and that they have been ignored.

And I was, and still am, wondering if any have been done (reasonably) recently, "with even more precision".

If not, why not?

I mean, if there's anything in this, it could be quite rewarding, in more ways than one. And they don't look to be all that hard to do, right? Nor expensive.

[Goldminer]

Well, I am not a "close follower" of La Rouche's articles; he does however have a youth contingent, who are recreating the old timey experiments. Another topic of his group is Robert Moon's nuclear structure, which again IMHO, is sidelined in the sneering smarmy smug way of consensus opinion. One of his group, Laurence Hecht, was tired on nebulous grounds, and imprisoned; apparently for his beliefs, as was Lyndon himself.

Nereid asks:

I mean, if there's anything in this, it could be quite rewarding, in more ways than one. And they don't look to be all that hard to do, right? Nor expensive

Well, that is an understatement. Maybe our discussion here will inspire others to pursue the subject! I had been collecting material and equipment with that goal in mind my self. My stuff has been stolen from me, so at this point, I am just all talk.

[Nereid]

(continued and concluded)

I don't speak for anybody else, but if electrodynamic processes are important in space at all scales, in many places, and plasma physics could be improved to provide a better, more enhanced set of ideas upon which to base astrophysics, is it not worth a look-see? If it didn't pan out, it wouldn't be the first thing not to. If it did, our understanding of the Universe improves.

There are at least two threads on WOPA already, here in the Thunderbolts Forum (here's one); to what extent do you think that initiative constitutes taking a look-see? In what way(s) does it fall short?

If you were given the assignment to see what sorts of observations might best obtain the type of data which would best acquire suitable data and test some of these preliminary EU concepts, what might you suggest?

It's rather premature for me to try to answer this question, but my initial feeling is that vast amounts of high quality data, in the form of astronomical observations, already exist to test most of the EU ideas I've encountered so far.