Physics Classes Should be Experimentally-Based

  • Thread starter Dr. Proof
  • Start date

What do you think Physics is?

  • Physics is strictly a theoretical subject only

    Votes: 2 5.7%
  • Physics is strictly an experimental subject only

    Votes: 0 0.0%
  • Physics is both experimental and theoretical, with experiments proving the theories

    Votes: 33 94.3%
  • Physics is both experimental and theoretical, with no experiments needed to prove the theories

    Votes: 0 0.0%

  • Total voters
    35
  • #26
Claude Bile
Science Advisor
1,471
19
In my personal experience, understanding of the scientific process and the symbiotic relationship shared by theory and experiment only really came once I started my own experimental work. True learning in this regard comes with "drawing your own map" as it were, rather than following one written by somebody else - which is the case for most teaching labs.

While I agree with most of the points made in this thread, I believe that experience in designing and carrying out your own experiences is the only way to get a full appreciation of the role of theory and experiments in physics - in Australia at least and I believe in most places around the world, most physics and engineering degrees do contain within it a major research project of some sort, to give students some exposure to the role of theory and experimentation. Postgraduate study provides a pathway where students are able to develop their education further in this regard. I think employers for the most part also recognise that postgraduate students have a better understanding over the theory-experiment relationship when they graduate than their undergraduate counterparts.

Is this situation perfect? No. I think there is plenty of room for improvement, particularly at a high school level (which is ages 12-18 in Australia) - Voltage touched on students finding Physics boring, this is a real issue! It is easy to sterilise physics by reducing the taught subject matter to graphs and equations, and that is what tends to happen because more often than not, physics in high school is taught by those with a BSc. majoring in Biology, Geology or Chemistry rather than Physics - and thus lack (I believe) a true appreciation of the subject matter.

Claude.
 
  • #27
I say this respectfully, so please do not take offense Positronized: I think your logic behind loving theory and prefering as few experimental works as possible is actually flawed. If we have no experimental evidence, then we have nothing to think about.
Perhaps I was at fault to have worded my post so poorly. I meant, personally, I don't like experimenting much, but I'm not saying that in general physics experiment should be discouraged. After all the wacky postulates of quantum theories were accepted due to the experimental results, not to mention they began as an explanation to the observations too. Without experimentation to confirm the equations and numbers and concepts physics would not be credible at all.

Once again, my previous post was entirely my personal preferrence :biggrin: I just like the numbers and the equations. (And I'm also incredibly terrible at experimenting at times)
 
  • #28
87
0
Good thread. I get the feeling that we're on the cusp of something quite important for physics. But that might be just because I read The Trouble with Physics recently. We'll see I suppose.

I like that Einstein quote, turbo. Can you tell me where it comes from?

"How does it happen that a properly endowed natural scientist comes to concern himself with epistemology? Is there no more valuable work in his specialty? I hear many of my colleagues saying, and I sense it from many more, that they feel this way. I cannot share this sentiment. ... Concepts that have proven useful in ordering things easily achieve such an authority over us that we forget their earthly origins and accept them as unalterable givens. Thus they come to be stamped as 'necessities of thought,' 'a priori givens,' etc. The path of scientific advance is often made impassable for a long time through such errors. For that reason, it is by no means an idle game if we become practiced in analyzing the long common place concepts and exhibiting those circumstances upon which their justification and usefulness depend, how they have grown up, individually, out of the givens of experience. By this means, their all-too-great authority will be broken." If one believes that all commonly-accepted "knowledge" is true and that all new concepts have to be vetted through the filter of that "knowledge" the progression of science is crippled by the shackles of that faith.
 
  • #29
Fra
3,100
145
In my opinion the emphasis should be on the experiment-theory relation. Neither makes sense without the other, there has to be an intelligent feedback in both directions.

Experimental results should suggest how to evolve the theory, which further should suggest howto design the most strategic experimental device.

It's alot like any generic learning, you start out with a question, presumable the best one you can come up with given the ignorance, and while trying to answer that, you may see that the original question was poorly chosen. So your response is to improve the question, and then try to answer that one. It's an iterative and evolutionary process.

It seems obvious that given an experimental device, produces some kind of data. There is no obvious way howto interpret that data. There are usually infinitely ways to do so! Here is a responsibility of theorists. The interpretation probably rather what evolves as the most beneficial interpretation to the interpreter. So the feedback stream should drive the theory, in asmuch as the theory should drive the ongoing tweaking of the questions asked. But for this to work, there must be feedback. Or theorists and experimentalists may both diverege into two different things, and that's when we are in deep trouble.

So it seems to me that poorly designed experiment that are carelessly interpreted is about as bad as a theorists that works on his own favourite models regardless of any feedback. But I've got a feeling that the world is so big that it's impossible for a single person to have expertise in every field. So some compromising and decomposition may still be needed. The "perfect" relation probably doesn't exist either, because the evolve too.

/Fredrik
 
  • #30
794
1
There is one facet of physics that I take comfort in:

Nearly all of the major breakthroughs in the HISTORY of physics have come from independent researchers not associated with major organizations. From Newton, Galileo, Faraday, Lavoisier, Maxwell, and even Einstein were working on a mostly independent effort when they worked something out. Yes, most had had training in the basic academic fields, which gave them the basic knowledge to work (experiment) on their own; but, the dogma that confines most research is following/expanding on other dogma (the already accepted). It's too bad that there isn't more funding for Independent (outside the world of the academia follow-the-leader) research for those wanting to do actual experimenting.

---------------------------------
like the Gravity Research Foundation (independent researcher's papers are accepted for grants, for example--

(from what I see 99.9999% of all grants have to go to a sponsored academic setting)
 
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  • #31
turbo
Gold Member
3,077
46
Good thread. I get the feeling that we're on the cusp of something quite important for physics. But that might be just because I read The Trouble with Physics recently. We'll see I suppose.

I like that Einstein quote, turbo. Can you tell me where it comes from?

"How does it happen that a properly endowed natural scientist comes to concern himself with epistemology? Is there no more valuable work in his specialty? I hear many of my colleagues saying, and I sense it from many more, that they feel this way. I cannot share this sentiment. ... Concepts that have proven useful in ordering things easily achieve such an authority over us that we forget their earthly origins and accept them as unalterable givens. Thus they come to be stamped as 'necessities of thought,' 'a priori givens,' etc. The path of scientific advance is often made impassable for a long time through such errors. For that reason, it is by no means an idle game if we become practiced in analyzing the long common place concepts and exhibiting those circumstances upon which their justification and usefulness depend, how they have grown up, individually, out of the givens of experience. By this means, their all-too-great authority will be broken."

If one believes that all commonly-accepted "knowledge" is true and that all new concepts have to be vetted through the filter of that "knowledge" the progression of science is crippled by the shackles of that faith.
The quote is from Einstein's memoriam on the death of Ernst Mach and the last sentence in your quote is mine. Einstein's words are a solemn reminder that what we "know" must be re-evaluated regularly lest we waste our time and energy pursuing courses of action that are without merit. When observations can no longer be reconciled with theory, theory must be revised because the Universe cannot be revised to conform to theory. I believe that if Einstein had known about the flat rotation curves of spiral galaxies and the excess lensing and gravitational binding of clusters, his formulation of GR would have been very different. I doubt that he would have invented invisible, undetectable, exotic matter to make up the shortfall. He was a pragmatic man.
 
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  • #32
27
0
In my personal experience, understanding of the scientific process and the symbiotic relationship shared by theory and experiment only really came once I started my own experimental work. True learning in this regard comes with "drawing your own map" as it were, rather than following one written by somebody else - which is the case for most teaching labs.

While I agree with most of the points made in this thread, I believe that experience in designing and carrying out your own experiences is the only way to get a full appreciation of the role of theory and experiments in physics
Claude.
Yes, sir, Claude Bile, I could not agree more. While I have been discussing (what I believe to be) the importance of experimentation in Physics education, I forgot to mention that there is nothing like personal experience. There is nothing like self-motivated students who perform their own science experiments by either buying their own materials, or by getting their teacher's permission to use the school laboratory. I was a professional small engine mechanic and owned a repair shop for 5 years before I decided to go to college and study both engineering and physics. Because of my background, I really understand and appreciate the need for personal experience and self-motivation. As Claude Bile said, the need for "drawing your own map".

After my second year in college, I realized that I needed to get some basic physics supplies. I bought some meters sticks and some mass sets, as well as a few other basics. I didn't spend more than seventy dollars, but I can do a lot of mechanics experiments with just the supplies I currently have. No static electricity supplies yet, but I'm working on that.

Sorry if this sounds rude, but: Considering that a good quality meter stick costs less than three dollars brand new, if you don't own one (unless you spend so much time in the school lab that you don't need one) after two years of being a Physics major, you need to switch your major to Mathematics, because you're obviously satisfied with orderly systems that "make sense" and are not concerned about experimental evidence. Not everything that "makes sense" is right. Sometimes our own intuition and common sense will lie to us; I have seen it happen many times when students try to solve statics and dynamics problems, their common sense misleads them and they forget about thinking in terms of observed physical principles.
 
  • #33
Fra
3,100
145
It's too bad that there isn't more funding for Independent (outside the world of the academia follow-the-leader) research for those wanting to do actual experimenting.

---------------------------------
like the Gravity Research Foundation (independent researcher's papers are accepted for grants, for example--

(from what I see 99.9999% of all grants have to go to a sponsored academic setting)
It did strike me that I wonder if this makes the best selection of individual researchers? I mean, someone with deviating ideas, unwilling to compromise would not be selected because he might be "counterproducide" to the team by trying to make they all change direction. The question is if those who willingly aligning are those who are best fit to come up with new groundbreaking thinking?

I guess research is alot of "work", where you need educated professionals, engineers, technicians and every other professions as well! But there is also the element of new ideas, that initiates the first step in a new radical direction. Where are the "professional" out of the box thinkers? Do you take an education and get a degree in out of the box thinking? ;) Or were do we find these people?

I guess every human on earth is a potential contributor, but it's practically impossible to grant everyone money. I think the only think one can ask for, is to make sure that while we don't actively support everyone, we can try to be sure to not actively suffocate any potential objects by mistaking them for deranged crackpots.

/Fredrik
 
  • #34
27
0
Experimental results should suggest how to evolve the theory, which further should suggest howto design the most strategic experimental device.

It's alot like any generic learning, you start out with a question, presumable the best one you can come up with given the ignorance, and while trying to answer that, you may see that the original question was poorly chosen. So your response is to improve the question, and then try to answer that one. It's an iterative and evolutionary process.

It seems obvious that given an experimental device, produces some kind of data. There is no obvious way howto interpret that data.

/Fredrik
Yes, Fra, I think theory is a very good thing. Theories lead to experiments, experiments refine/correct theories and questions, and then those refined theories and questions may lead to more experimentation. Good observation, Fra, it is one that I have made and agree with as well.

"There is no obvious way howto interpret that data". I am not quick to agree with this statement. I think that in some experiments there is an easily-seen observation, such as in the position of falling objects. If you were to collect a data table that gave an object's: time in free fall; distance travelled up to that time; and velocity at that time, you may not be able to instantly see a direct mathematical relationship with velocity and distance, but you would probably readily see a relationship between velocity and time, that is, that the same change in time always results in the same change in velocity. So you would notice that a change in velocity is always directly proportional by the same amount to a change in time. And then we all know that the constant of proportionality by which you must multiply the time in order to get the velocity is called the acceleration.

I do agree with you, Fra, that there are some experiments that are difficult to interpret. I just do not agree that all experiments are difficult to interpret. Also, the experimenter needs to use some skill in his experiments so that his data is not so difficult to interpret. For example, set up your experiments so that you will get whole number values. In the falling objects experiment, you could change the position at which you measure velocity so that your time values are always whole numbers (this would be a process of trial and error). By using whole number values for time, you can much more easily see the relationship between time and velocity. Once you establish that relationship to be true for that experiment, then you can make more detailed experiments to more-conclusively prove theories about how falling objects behave.

This leads me to my last comment. Experimentation is a skill. You have to be crafty, you have to be clever, you have to be creative, you have to be witty, and you have to learn from others because someone else might have a better way of performing an experiment. We had some pretty clever experimenters one hundred years ago when technologies are not what they are today. Just look at Albert A. Michelson's method for measuring the speed of light back in the turn of the century. Although books are great and necessary sources of information and communication and of passing on knowledge, experimentation remains a skill that must be learned by doing. We have not taught this important skill to our younger generations.
 

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