Do you find it easy to explain physics?

[Smiles302]

Do you ever get asked to explain concepts of physics in your offline life?

Do you find it difficult or easy to explain topics when the person will not listen to a single piece of maths?

At this stage if anyone with zero background of maths asks me something I have to promise to email them an explanation. Off-hand I will mix up my words trying to not use any numbers. While with an email I can include maths, explain the maths, then delete the maths =D

 

[Pengwuino]

I never use math to explain a physical concept. It gets in the way... just like with my actual research!

If a person doesn't want a mathematical explanation, chances are showing them any math is meaningless.

 

[cristo]

At this stage if anyone with zero background of maths asks me something I have to promise to email them an explanation.

That's a little bit bizarre: wouldn't you rather talk to someone than to send an email? The ability to answer questions in a way that your audience will understand is an incredibly important skill to have.

I often get asked things on a variety of topics by my friends, and would like to think I can convey things in terms non-scientists will understand. After all, didn't Einstein once say that if you can't explain something simply then you don't understand it well enough?

 

[Smiles302]

hence why I delete the maths after

 

[Smiles302]

That's a little bit bizarre: wouldn't you rather talk to someone than to send an email? The ability to answer questions in a way that your audience will understand is an incredibly important skill to have

You don't think a background in maths makes some things far more intuitive than no interest in maths?

I am just an undergraduate, This is my first year of people stopping me and asking random questions.

 

[Pengwuino]

Most of the time people who say they understand something better when you show them equation actually have no idea what the equation is telling them.

This happens with my students, I give them a conceptual understanding of what's going on and they feel they get it. Then when it comes to doing a problem and you're forced to write down the equations governing that idea, they'll say they understand it. However, give them a little time and they'll start asking really weird questions in regards to the equations or make weird conclusions based off the equation or just say things that are so weird that they defy explanation. And I can pin it on the math because they point to the equation and then say weird things that go completely against reality.

 

[Calrid]

It's interesting I see a lot of people explaining things in certain ways, Pengwuino there seems pretty good at this as do most people on this forum. I think it is best to just tailor answers to a level. For example I rely on a lot of pictures at low levels and at high levels, well as high as I get I forgo them and rely either on words or just maths.

I find it is easy enough, but I also find it extremely helpful to explain stuff because it then reinforces your own views and helps you remember this stuff, or if you are wrong on some point highlights your misconceptions. Which tbh is why I am here. No point just being right all the time I'll learn but not as much as being just plain wrong.

Examples explaining special relativity conceptually without any maths is quite hard, explaining it to someone who grasps the maths behind the Lorentz transforms is really much easier.

Explaining in just pictures mostly to someone who doesn't know much basic maths how calculus works, is quite hard, explaining it to someone who has learned all the basics is quite easy.

\frac {d}{dx}\;\; a = 0

Sometimes its nice not to have to say the actual words. It's easy to know why this is correct if you know what a constant looks like on a graph and hence what the gradient is going to be to any limit.

Explaining to a 16 year old why gravity is attractive though, I think a nice analogy is apt, let's face it even if I was an expert on the tensor calculus it's not going to help etc, etc.

If someone doesn't get maths at all then a picture often paints a thousand words.

That's why a circle is equivalent to a wave for example and hence why sin (x) is used.

 

[Smiles302]

Examples explaining special relativity conceptually without any maths is quite hard, explaining it to someone who grasps the maths behind the Lorentz transforms is really much easier.

Ha! That's what pushed me into asking the question.

Classical physics I can handle, well to the extant that I understand it myself. Entropy and adding velocities are fairly easy to picture with eggs smashing and car crashes.

Why space-time can be easily seen by holding c constant, is oddly difficult without a diagram. Putting it into words while balancing not sounding patronising with not using other physics concepts that you'll have to then explain is really testing my creative essay writing skills.

 

[Calrid]

Ha! That's what pushed me into asking the question.

Classical physics I can handle, well to the extant that I understand it myself. Entropy and adding velocities are fairly easy to picture with eggs smashing and car crashes.

Why space-time can be easily seen by holding c constant, is oddly difficult without a diagram. Putting it into words while balancing not sounding patronising with not using other physics concepts that you'll have to then explain is really testing my creative essay writing skills.

well its easy with a Lorentz diagram but the maths behind Lorentz transforms only require basic algebra so unless they are a bit mathematically dense it shouldn't be that hard to explain. a lot of people get hung up on the concept, very few on the maths in my experience, which is ironic as its usually the other way around.

If you set c as the speed limit in the equation then the rest just falls out naturally, a few rotational transforms and its not so esoteric.

 

[I like Serena]

I found that it is very important to interact with the people you want to explain something to.
The reason they come to you, is because they can't follow what a teacher explains to them.

Usually I find that there are certain subsets of knowledge they don't have.
For instance, calculating with fractions.
If you don't understand fractions, it becomes very hard to explain manipulating equations.

So when I explain something, sometimes their faces turn blank, and I know I've hit onto something. That is, I either have to explain it in another way that they can follow (using another subset of knowledge), or I have to take a few steps back, and try to explain what it is that they don't know (for instance fractions).

As for a formula, it takes insight and practice to read them.
If you can, it usually makes things much clearer than any long text.
However, most people who ask for help usually have difficulty understanding abstract formulas, and they need something they can visualise in the real world.

 

[ideasrule]

Explaining to a 16 year old why gravity is attractive though, I think a nice analogy is apt, let's face it even if I was an expert on the tensor calculus it's not going to help etc, etc.

Just curious: how would you explain to a 16 year old why gravity is attractive? I'm around that age, so I'm wondering how you would explain it without tensor calculus.

 

[Calrid]

Just curious: how would you explain to a 16 year old why gravity is attractive? I'm around that age, so I'm wondering how you would explain it without tensor calculus.

[PLAIN]http://preposterousuniverse.com/spacetimeandgeometry/covercrop.jpg

I'd start with the ball on a sheet of rubber analogy, and tell them that the degree to which space-time is curved depends on the mass of the object just as it would a ball on a rubber sheet. Then I'd roll marbles towards the ball to show how mass objects are deflected by the gravitational well of other mass objects. You can also show why planets orbit in the way they do with a decent set up.

If they have a grasp of sin, cos etc ie trigonometry I'd explain this is modeled by a non euclidean type of geometry thusly:

[URL]http://2.bp.blogspot.com/_jfT5ucHXk7Y/RhlnzI8e0PI/AAAAAAAAABE/AaoKRGG8jUI/s400/Euclide_non-Euclidi_geometry.jpg[/URL]

In a curved space the internal angles of shapes like equilateral triangles add up to less or more than 180 degrees. The trig terms for these eliptic and hyperbollic forms of geometry are cosh(x), sinh(x) etc and cose(x), sine(x) etc usually denoted by ce(x), se(x).

These functions have the same sorts of trigonometric identities as the euclidean functions, so they aren't typically harder to manipulate than normal trig functions.

[URL]http://upload.wikimedia.org/math/2/b/3/2b37d38ac7cb45139ab706fbce9de3b1.png[/URL]
[URL]http://upload.wikimedia.org/math/7/9/3/793b5c879da3d6ec140694c054003b50.png[/URL]

 

[Femme_physics]

Depends on who you're explaining it to you...with some easy, with others it's hard and awkward