My biggest struggles with Physics are psychological.
Because of how the universe works, if you fire a gun and drop a bullet from the same height they both reach the ground at the same time.
Maybe it's because I have a cartoonish version of physics in my head, my first instinct is "no that can't be right" and I start from a place of extreme skepticism that gnaws at me even as I watch myself being proved wrong.
The other common struggle I face is that so much of the physics you learn at a basic level comes with caveats like "assuming no air resistance" or "in a vaccuum" or "at sea level" and perfect weights and I end up wondering how futile all of it seems because in reality I'll never be able to apply this stuff the way it's being presented. If I have to actually apply it - I'd have to start thinking all the possible ways in which the system can be affected, then measure those ways and add them to my calculation.
Then I feel overwhelmed by all the possible things I would need to factor in. Did I forget friction? Is this surface 100% horizontal? Is it windy right now? Am I really at sea level? I feel like the street I'm on is 30m higher.
Then I start thinking about the practicality of measuring things. Even if I eventually learned all of the physics in theory, if I was one of the last 100 people on Earth and the person with the best physics knowledge, could I use it to build even something as simple as a bridge? How precise would my tools need to be? Is it ok for my execution to be off by 0.1 degree? Is that too much of an error? How would I even know?
With programming I feel like there are more opportunities to blackbox things and focus on building practical solutions, whereas with the material world I would have to worry about whether I got a faulty batch or whether the manufacturer was reputable or whether I should have spent more money on a better manufacturer. By comparison it feels incredibly inaccessible to do anything tangible with.
There's nothing wrong with that. It's also the normal reaction when you are presented with more advanced concepts, like relativity and quantum mechanics.
It's just a matter of accepting that facts and your instinct can diverge... and it means that your instinct is wrong!
Which is not to say that you are stupid, no way! On the contrary, it's a sign that you have embarked on an adventure to discover how the world really works, which is beyond what evolution may have imprinted in you DNA in order to survive daily struggles.
> I end up wondering how futile all of it seems because in reality I'll never be able to apply this stuff the way it's being presented.
That's a common misconception by non-physicists: that years of advanced studies can be compared with trivial experience in everyday life, as if the value of a senior software developer could be judged by how fast he can install a new version of Visual Studio.
Funnily, when I was in high-school and made a "trailer" for some programming lectures I was attending, one of the lines in it I meant to sound "epic" was "You must use the new version of Visual Studio!"
I worry when I see movies like Star Wars which preach believe your instincts (aka trust the "force"). In reality vast majority of our instincts are either flatout wrong and works only in very narrow situations. In fact, virtually every scientific law is a statement of how our instinct was so wrong. Does Sun rotates around Earth? Is Earth flat? Can an object move endlessly when applied a force? Can two objects of different mass hit the surface at same time? Science is essentially a bandaid to fix our instincts. Vast majority of people will fail at basic probability questions. This is why there are so few people who finally managed to become quantum physicists. They had to break pretty much every single instinct about how world works. So I've always looked at Star Wars's "May the force be with you" slogan with dose of irony. If force is actually with you, you are probably not using your mammalian instincts :).
> I worry when I see movies like Star Wars which preach believe your instincts (aka trust the "force")
I thought that The Last Jedi was interesting because it very deliberately subverted that -- there are multiple pivotal scenes where people fail or endanger others because they're trusting their instincts. I'm not sure I've ever seen a blockbuster with such a cohesive thematic element.
Consciously or not I suspect that's why some folk didn't like it.
I'm a physicist. I think the way to overcome this hurdle is to get into the lab. These days you could do worse than getting an Arduino and learning to make different kinds of measurements with it. And then finding out how and why there are better things than an Arduino. ;-)
When you make a measurement, think about how and why you believe it, to what degree of accuracy. Build things. Break things. Fail early and often.
In any event, electronic measurements is one of the things you'd have to learn as a physics student. One of my textbooks was The Art of Electronics.
But also, one of the hurdles to learning physics is motivation, and I think somehow engaging with the physical world needs to be part of that motivation. I hate to say that's what makes physics different than engineering, but there are a lot of engineers who like to blackbox things, and I owe a certain portion of my job security to being willing to do things like figuring out if we got a faulty batch.
> I think the way to overcome this hurdle is to get into the lab. These days you could do worse than getting an Arduino and learning to make different kinds of measurements with it.
Last year I took Electronics 101 and 102 at my local community college; validating circuits with a multimeter just became second nature. It was only a small next step to validating them with a SPICE simulator (TI Tina) :-)
Why don't you approach it like this: forget about the real world, and think about building a virtual world with all these theories in place. I get you are a programmer so this shouldn't be too hard.
Now don't go building a real physics engine, that is not the point. The point is to calm down the anxiety in your head by working in this very limited virtual world instead of the real world.
After you figured it out in the virtual world, you can do the next more difficult step of looking how much your application in this virtual world would differ from the real one. Or you could just stay in the virtual world of course :).
If there was some kind of VR physics lab I think it would be fantastic because it would democratize access to all the tools without having to spend money to learn in that setting. In fact you could even simulate large scale things and see how they interact (boulder crashing into car, etc).
Is there educational software like this which is aimed at beginners?
It sounds like you want engineering, not physics. Physics tries to understand why something falls to the ground, and to make any progress on that problem you have to idealise the problem and neglect other factors (i.e. Air resistance) so you can focus on just one aspect. Engineering is all about understanding which things you have to take into account and which things you can ignore, and what level of precision or approximation is necessary to get you a useful answer.
Not sure I understand. If you fire a gun toward the ground from the leaning tower of Pisa, and you drop a bullet at the same time, the bullet that was fired from the gun will reach the ground before the other one. The thing is that the explosion gave the bullet additional momentum toward the ground (and a corresponding inverse momentum to the person holding the gun, more or less, ignoring other factors)
>The other common struggle I face is that so much of the physics you learn at a basic level comes with caveats like "assuming no air resistance" or "in a vaccuum" or "at sea level" and perfect weights and I end up wondering how futile all of it seems because in reality I'll never be able to apply this stuff the way it's being presented. If I have to actually apply it - I'd have to start thinking all the possible ways in which the system can be affected, then measure those ways and add them to my calculation.
That is because otherwise the math would be considerably more difficult than it already is, which is already quite difficult for most people for an introductory or undergrad course. Advanced courses cover such stuff, in which approximation techniques are used to account for less than ideal conditions. Also, adding some conditions such as air resistance or other friction does not make the problems too much more difficult and are good enough approximation to reality for most cases.
This advice might seem too simple, but the solution is to just start doing a ton of physics problems rather than trying to resolve any of these issues. Your heuristics for real world physics will probably change faster than you think, and it's very satisfying to feel like you really understand a common phenomenon in depth.
It does sound more like you want to study engineering from your latter paragraphs, but I'd argue a lot of that stuff is just industry knowledge you'd gather over time actually building things. Physics gives you the ability to do some back of the napkin maths to see if something seems to be the realm of feasibility though.
“ @BrandonEnright Yeah, I have. I agree that the difference in time for the two bullets will be so tiny that it doesn't even really matter. I'm just asking if there would be a tiny difference. – chbaker0 Dec 13 '14 at 2:20”
> I start from a place of extreme skepticism that gnaws at me even as I watch myself being proved wrong.
I had the same kind of issues: I thought that energy should be E=mv, not E=1/2m*v^2. The latter seemed really baroque. I set up a ballistic pendulum trying to demonstrate my idea. I finally got it when I was thinking about how if you accelerate a projectile, the force has to be applied over more distance per unit time to achieve the same acceleration, so the amount of work being done goes up quadratically.
Even then, I was annoyed that "the" kinetic energy wasn't a unique value -- it depends on the velocity, which depends on your frame of reference. I finally got over that one when I realized that the kinetic energy in a collision is uniquely defined b/c of the center-of-mass frame.
In graduate stat mech, I basically got lost at the point where the prof said we're supposed to assume that every point in phase space is equally likely -- how the hell should we know that?!? It wasn't until I read the Bayesian derivation by Jaynes, based on Galilean invariance & entropy maximization as a form of being unbiased, that I finally got it - years after I squeaked by with a B in the class.
Relativity -- same deal, the time dilation / length contraction stuff seemed really contrived with all the little square root factors that drop out at low velocities. I finally started to get it when I saw someone write it all in terms of geometry instead of algebra.
QM -- can't say that I grok it yet, but I think I'm in good company on that front. One thing I worry about is that physicists have gotten so good at accepting initially-counterintuitive concepts, that it's gotten to be a badge of honor. I think it's always better to find a way to make the concepts intuitive. Maybe quantum physics cannot ever be made intuitive, but I think we should keep trying to find better ways to understand it instead of gatekeeping the profession by whether people can stomach the Copenhagen interpretation of QM.
>overwhelmed by all the possible things I would need to factor in.
I experienced that too. I made peace with it eventually, by accepting that it's a trade-off. Often times it doesn't make a big difference in the result, but it does make a big difference in how easy it is to understand what's going on (and to solve the math problems). It's generally better to work with the oversimplified problem first, and then you can test changes afterwards to see if they matter.
When you know the theoretical (perfect world) model, it can still be applied in the real world as long as you're aware that you won't get an exact answer, but it will often be "good enough". One of the few times I was able to apply my physics knowledge in my job, I was able to hack together the relevant equations and constants to give realistic answers (to do with still-air cooling of a mobile phone on a charging pad in a car) and I was able to estimate roughly how accurate the answers were, given the remaining unknowns.
I guess I also struggle with knowing when it's ok to be a little vs a lot imprecise, and what that means in terms of units. If I'm building something at kilogram scale can I be off by a few milligrams?
Theoretical physics is like computer science. You focus on algorithmic complexity, etc and neglect the actual HW architecture, latency, and cache concerns.
Because of how the universe works, if you fire a gun and drop a bullet from the same height they both reach the ground at the same time.
Maybe it's because I have a cartoonish version of physics in my head, my first instinct is "no that can't be right" and I start from a place of extreme skepticism that gnaws at me even as I watch myself being proved wrong.
The other common struggle I face is that so much of the physics you learn at a basic level comes with caveats like "assuming no air resistance" or "in a vaccuum" or "at sea level" and perfect weights and I end up wondering how futile all of it seems because in reality I'll never be able to apply this stuff the way it's being presented. If I have to actually apply it - I'd have to start thinking all the possible ways in which the system can be affected, then measure those ways and add them to my calculation.
Then I feel overwhelmed by all the possible things I would need to factor in. Did I forget friction? Is this surface 100% horizontal? Is it windy right now? Am I really at sea level? I feel like the street I'm on is 30m higher.
Then I start thinking about the practicality of measuring things. Even if I eventually learned all of the physics in theory, if I was one of the last 100 people on Earth and the person with the best physics knowledge, could I use it to build even something as simple as a bridge? How precise would my tools need to be? Is it ok for my execution to be off by 0.1 degree? Is that too much of an error? How would I even know?
With programming I feel like there are more opportunities to blackbox things and focus on building practical solutions, whereas with the material world I would have to worry about whether I got a faulty batch or whether the manufacturer was reputable or whether I should have spent more money on a better manufacturer. By comparison it feels incredibly inaccessible to do anything tangible with.