Saturday, April 10, 2021

James Lincoln's video is about to hit 1 Million Views


Great News!

We are about to hit 1 Million Views with this video:  

Thanks everyone for your support!

Please click to watch it!

- James

Friday, October 25, 2019

James Lincoln to Portray Richard Feynman

As part of PhysicsCon 2020 - Celebration of Physics, James Lincoln (AAPTFilms) will portray Richard Feynman, accent and all, and give a 1 hour lecture on physics – with questions. The lecture will take place in the same Caltech lecture hall that Richard Feynman delivered his famous lectures in 1962-63. Richard Feynman (1918-1988) is often regarded as the greatest teacher of physics and brought colorful stories and eccentricities along with his enthusiastic instruction. In this lecture, Lincoln celebrates the mannerisms, energy, charisma, and gusto of the Nobel-Prize-winning professor as he might have been when he stood in the same place all those years ago.

Where did you get the idea to do this?

            “I didn’t set out to set out to impersonate Richard Feynman, but I have been studying his work for a long time,” says Lincoln. “As I became a teacher myself, I learned more about Feynman the man, and I was intrigued by his work on the Challenger Investigation; an event I remember. But my favorite aspect has always been these lectures, and I wanted to actually watch one to know more about how they were made.”

How did you prepare for this lecture?

            “I already had listened to all of the original audio recordings of The Feynman Lectures on Physics, which are available on CDs, and I got at my local library. These helped me understand what it was like to attend these lectures, but also I became very familiar with the teaching style of Richard Feynman. I was always impressed by Feynman’s enthusiasm for physics and in the recordings, there are a lot of ‘Feynmanisms’ – quirks, tricks, and untold stories - that didn’t make it into the three red books. I shared some of these at a national AAPT meeting [American Association of Physics Teachers].”

What makes you think you can pull this impersonation?

“Well, during my presentation I would often have to quote him [Feynman] and I found I was able to imitate his voice and word choice quite easily. I have always done voices and impressions, and I also did plays in high school, and of course I make films. But Richard Feynman is a unique character to play because he was also a great physicist. I think it might take a physicist to get this part right. Hopefully, people will learn some physics as well as get a chance to experience one of these historic lectures. I suppose that I am mostly doing this for the fun of it, which is very much in the spirit of Feynman, and probably the only reason he might approve of such a performance.”

PhysicsCon 2020 is set to take place in the Feynman Lecture Hall of Caltech and features demo shows, workshops, and other talks on physics. 

Register to attend at

Wednesday, November 14, 2018


There are many demonstrations on how and why the sky is blue.  But this one might be the simplest.  In this video, Anna Spitz shows how to create a blue sky effect with just a glass of water and a drop of milk.  It is called Rayleigh Scattering.

The AAPT Films Video: Blue Sky in a Cup - Starring Anna Spitz.  Written and Directed by James Lincoln.

Of course, Anna Spitz has already hosted a video about the blue sky in this video from Arbor Scientific:

Check out more videos like these at

Friday, January 27, 2017

See Inside Your Own Eye and Hear Your Own Muscles


The human eye is not without its flaws.  Some of these include the blind spot, poor peripheral vision, and the fact that our retina is covered by blood vessels!  Normally, these arteries are invisible to us, but they can be made visible with only a cell phone flashlight.

In this video Anna Spitz explains how to use a flashlight to see your own retina.

The experimental set up – only a gently closed eyelid and flashlight are needed.

All human skin is partially transparent to light, especially red light, and we can use this to see through our own eyelids.  (This experiment works, no matter what skin color you have!). 

To perform the experiment, turn a flashlight on and hold it DIRECTLY UPON your gently closed eyelid.  Then wiggle the light as you look around with your eyes closed.  It seems to work best when the light is near the nose.

  A simulated image similar of what you will see on the surface of your retina.

When you succeed you will see several arteries emerging from a single location.  This is the optic nerve.  You might also notice a dark or grainy spot in the center of the retina that has very few arteries near it.  This spot is called the Fovea, the most sensitive part of your eye.

A view of the author’s retina from a recent visit to the eye doctor.  Notice there are very few arteries on the fovea, thereby not interfering with this most-sensitive part of the eye.

The optic nerve obstructs a small part of the retina from seeing.  This location is known as the blind spot.  Our brains hallucinate a patch over this blind spot so that we generally do not notice it.

The fovea is darker because it absorbs more light, being the most sensitive part of the eye.  It is also the part you use to read and see color.  Generally, light that is not landing on the fovea is quite blurry and the color vision is poor peripherally.  You can notice this by looking at the wall and trying to read what is on the computer screen.  YOU CAN’T DO IT!  Even though you know there are words, they aren’t legible.  Also, at night, your color vision is very poor so the fovea isn’t much help and your peripheral vision is just as good as your central vision. 

As a final note, everyone’s retinas are different as you will easily see by comparing these pictures, or any picture of a retina to your own.  Thus, you can use retinal scans as an alternative to finger print identification. 

If you are surprised that you have arteries in your eye and have been looking at them your whole life but haven’t noticed, then consider this test.  Are you wearing a shirt?  You didn’t notice until you were asked because you are used to it.  Similarly, we don’t notice we have arteries on our retina until a light hits them at an angle to which we are unaccustomed. 


Another experiment you can do with almost no equipment is to hear your muscles.  By simply putting your fingers in your ears.

Anna Spitz demonstrates that by putting your fingers in your ears, you can hear your own muscles.

That low frequency rumbling about 30 Hz is the twitching of the muscle fibers in your arms.  Muscle cells are fibrous bundles that grow and contract.  They are all over the body, but they only do one thing.  PULL.  Muscles pull on tendons.  They are even pulling when you think you are at rest.  They are pulling repeatedly just to hold you in place. 

A microscopic view of muscle cells.  All they ever do is pull.

Watch Anna Spitz explain how to hear your muscles in this video:

 Flexing will increase the loudness of the muscle twitching.

Many people mistakenly believe that this sound is the flowing of blood, but this is not the case.  The twitching sound is not timed with the heartbeat, and if you flex the muscle cells get louder. 
Flexing is when two or more muscle groups pull against each other.  For example, biceps and triceps can pull against each other and the arm will stay in place even through the muscle fibers are pulling and pulling.  The repeated pulling action of muscles we call twitching.  The frequency of this action must be between 20 and 40 Hz because that is the frequency we hear. 

Anna Spitz attempts to listen to other peoples’ muscles.

Check out more videos like these at

Tuesday, April 19, 2016

Physics Video Tuesday - Electric Field Demos!

Physics Video Tuesday    April 19, 2016

Visualizing the Electric Field  by James  Lincoln

For as long as I have been a Physics Teacher, I have been interested in making the Electric Field visible to my students.  This is IMPOSSIBLE because it is literally imaginary.  Despite this challenge, I have researched and demonstrated the best ways to display it.  What follows is a collection of videos I have created to demonstrate and describe the Electric Field. 
Perhaps the best way to demonstrate it is with Potassium Permanganate crystals which dissolve slowly on a damp saline cloth. 

ELECTRIC FIELD Visualized with Crystals

For AAPT Films, I created a two-part documentary on all of the best ways I know to demonstrate the electric field:

Ten Ways to SEE the Electric Field - Part 1

Ten Ways to SEE the Electric Field - Part 2

It is not enough that we simply show the effects of the electric field, but we must also know the rules of how it behaves.  Here are two videos I made for UCLA Physics on the Rules of Drawing Electric Field Lines and Rules regarding the behavior of Conductors:

5 Rules of the Electric Field

5 Rules for Conductors

In my research, I did create an original contribution to these demonstrations that I think makes a classic work much better.  In this video, I have some more of my lettuce seed demonstrations.  I have written an article about making this yourself from a coat hanger and Styrofoam cups:

Lettuce Seed Demonstrations

This demonstration is typically performed using grass seeds:

Grass Seeds Electric Field Demos

Monday, January 25, 2016

Physics Video Tuesday - January 26, 2016

AAPT’S Physics Video Tuesday     January 26, 2016

Sulfur Hexafluoride and Helum – At the Same Time! Explained        by James Lincoln

Sulfur Hexafluoride vs Girl (Anna Spitz)    by James Lincoln and Anna Spitz

These two videos we made to feature some of the demonstrations that can be done with Sulfur Hexafluoride.

The first was made by James Lincoln as part of a video contest and the second was made by James Lincoln and Anna Spitz as part of a video demonstration series.

Sulfur Hexafluoride is available from Flinn Scientific, and should only be inhaled from a balloon, as should helium, and never from the bottle directly.


Sulfur Hexafluoride with Musical Instruments by Kyle Forinash

Using Helium and SF6 in a trombone and a few other instruments.

Sulfur Hexafluoride Deep Voice Gas by Steve Spangler Science

Spangler does the voice demo, and floats a boat on it, as well as show that SF6 prevents sparks.

Related Articles from The Physics Teacher

Helium & Sulfur in Musical Instruments:

Helium Speech - Applied Standing Waves:


To submit a video or make a suggestion email James Lincoln:

Monday, January 18, 2016

Physics Video Tuesday!

AAPT’S Physics Video Tuesday     January 19, 2016

Polarization Physics: AAPT FILMS     by James Lincoln

In this video you will find about 20 physics demos using polarizers and related equipment.  
Also included are explanations and instructions on how to succeed doing them.

      1.     Crossed Polarizers
2.      The Mechanical Polarizer (analogy)
3.       The Construction and Axis of Polarizers
4.       The Triple Polarizer
5.       Light waves as vectors
6.       LCD Screens
7.       Circular Polarization
8.       Stress in Plastics, Glass, & Packaging tape
9.       Prince Rupert’s Drop
10.   Reflected Glare
11.   Glare on surfaces
12.   Polarized Sun Glasses
13.   The Polarized Sky
14.   3d Glasses
15.   Malus’ Law (Angle vs Intensity)
16.   Brewster’s Angle
17.   The Faraday Effect
18.   The Verdet Constant
19.   Microwave & Radio Polarization
20.   Projector Polarization

This video was created as part of the AAPT Films Series.  
The series is written, directed, and hosted by James Lincoln.  
This particular video was funded by the AIP Meggers Grant. 


UCLA Physics: Circular Polarization   by James Lincoln

UCLA Physics: Polarization of Light   by James Lincoln

60 Symbols

Polarization (of Microwaves too!):

Paul Hewitt

Hewitt-Drew-it Polarization:
Polarized Glasses Explained:

Related Articles from The Physics Teacher

Microwave Polarization:
Malus’ Law (using Lasers):
Model of Polarizers:
To submit a video or make a suggestion email James Lincoln:  James[at]