Hey Bill! I like your history focused videos like the failure of the bell video phone. Perhaps you could talk about the GUI and Internal internet framework yhat Palo Alto was using with coaxial cables before Microsoft and Apple got their mitts on them? Or you could talk about the first transatlantic telegraph line laid in about 1850s and it's failure and eventual replacement 12 years later. You can tie in fiber optics as a "see also" because we couldn't pull off international phone calls without fiber, indeed, ATT helped launch the first communications satellites before adapting Bells photo phone patent into fiber optic and laying oceanic cables in the 70s.

The candle series is great but I think your absolute best video is The one about aluminum cans. thanks for all your work!

Hi Bill! How about explaining the history of PID controller and its usage for today technology.

I love your videos- informative, experiential, clear and short.
I would like to see more historical focus on products of transportation: bicycle, auto engines (different parts), trains and airplanes.
I realize the broad fields, but any focus would be helpful.
Thank you Michele McFaull

How does cruise control in an automobile work?

Light Field (Plenoptic) Imaging
Hey Bill - love your videos - having withdrawl symptoms, need more! Would love to see a video on Light Field Imaging!!

Thanks, Clint C.
How do Relays Work?

Hi Bill!

I have to tell you that your work is amazing! Reminds me of the James Burke Connections TV series in some aspects. Your work would be GREAT to share with students who are studying Technoogy & Engineering Education through the ITEEA Standards for TEchnological and Engineering Lietracy and also for students who participate in the Technology Student Association! I have been watching yuor videos and i have to tell you that the topics you are covering closely reflect the topics and projects that are in several of the textbooks I used when ui was teaching middle school and high school. You are doing amazing work!

My topic I am suggesting is relays. I am building a model ROV like Robert Ballard used, or also like what I saw was sued to day to find the missing Apollo rocket motors that were found in the sea bed that I saw on TV this morning. I am using DPDT relays to make H-bridges for motor control right now and I am suddenly facinated on the operation of this old, but very beneficial technology that continues to help us in automation, manufacturing and telecommunications.

How do speakers work? I admire your work. Thank you.
-Ondřej R,

How do optical mice work?

How do space ships (space probes, space shuttle, ISS, etc) communicate to earth, and vice-versa. Specially the ones that are really far away like the Vogayers. Maybe you can merge it up with the antennas and wireless transmition ideas that are already posted. Good Luck.
-Leonardo R. [Interestingly we have been reading about Voyager and this problem for our fourier series. Not sure it will make it in there, but the transmission of images is fascinating.]

How do fridges work?
-Josh V.

How do holographs work?

-Alex A.

Maybe a video discussing how developing mathematics unlocked new possibilities in engineering. Not really a math lesson, but more-so highlight any discoveries or techniques that weren't possible before advanced mathematics had existed. There must be some interesting thing in this area.
-Stephen J.

What do we currently know about dark energy and dark matter?

- George S.

I would be very interested to find out how nanoparticles are made. Whether used in paints, biological assays or development of new materials, how were the initial particles developed and how are the produced now?

-Jake H.

How your basic inkjet nozzel works. a simple eletric film allows ink to passthru. HOW!?!?!?!

Carlos Pineiro @cashe18

clear understanding of nano sensors

I want to know how motion sensor woks (See smart phone accelerometer video)

Want to know how solar panel works. thanks

I am interested in process and machine control in the real world.

For example, I have heard that the reason why the Wright Brothers were successful is they solved the control issue. A bicycle is an unstable process with the human as the controller. The same was true for the Wright Flyer. Hence the reason where the bicycle designers fit in.

Other control items might be interesting like thermostats (on, off control) and why turning the temperature up past your desired temperature, does not heat the house faster.

I will try to think of some other real life control items.

-Matt of Green Bay (UIUC ChemE 2000)

There's no way to vote for ideas? That would probably contribute a lot to the speed and range of your idea feedback.

Someone already said it, but a video about vacuum tubes and their applications (logic, memory, amplification, radar, etc) would be great.

Explain an EMP and what can be done to protect something from its effects.
- Craig


I REALLY miss the humor. The person coming back looking for where the copier went off to, and Bill standing there with the hammer! /lol. Please bring the quirky humor back please!
- David Mcanulty

I think the bicycle is a great invention that lead to many other inventions. So many things that are creative, like spokes, chains, derailleurs. Most used and most efficient vehicle in world. Also, humor is great! Rick

I really liked your video about how an LCD screen works, and wanted to suggest maybe a video on Cathode ray tube (CRT) screens. and maybe what makes them unique to other screen technologies like OLED or LCDs - Frank

Please explain how radio antenna receives EM signal, thanks.
- Charon77 Charon77 Jun 27, 2012

I have always wanted to have an understanding of auto focus in a SLR camera. How does the process in the camera body work in concert with the cameras lens?
Also, why can't we have a lens that is wide angle all the way through to high zoom in an SLR? ie 18 - 400 mm. Is there a limitation in the optical material?

Kindest regards and most grateful appreciation for your time and effort in creating so many informative and fascinating videos.
- Wally Sorich

It would be interesting to see a video explaining how a Scanning Electron Microscope (SEM) or Atomic Force Microscope (AFM) opperate.


Lenny Briscoe

MORE TECH STUFF! How central processors work in computers!!!!!!!
How a car's ECU works - RC

Great series of videos, Bill, I really liked them all

I think it would be very interesting to make a series around the principle of the working of heat pumps and all the derivative technologies. The emphasis can be put on explaining that one cannot create cold but only move heat from one place to another. Of cource, the heat pumps come in so many flavours, can be mechanical or semiconductor and work even on a molecular and quantum levels, but the principle is the same - moving heat from one place to another with the resultant effect.

Best regards


I would love to see a video on how touch screens work since we use them so much now-a-days and i know there are many different type of touch screens. Love your show by the way!

I second this. I understand a little of the resistive screens, but have no clue on the capacitive ones.

Love the videos! When will new ones come out? I'm not sure if anyone has suggested, satellite tv, computers (buss speed, instructions per second versus memory and the laser printer), modern engines (jets, automotive), the ball point pen, the dyson motor less fan, fire suppression sprinkler, gyros, circuit boards, microchips, an automatic teller machine, door lock or glass. Sorry for the random blast of ideas.

Thanks for the knowledge and videos. Is there a donation page to help support more videos?


How about optoelectronic devices (i.e. LEDs, diode lasers, etc.) and the photoelectric or photovoltaic effects operating in them. As well, maybe an episode describing current commercial solar cells and the engineering challenges which still exist for this technology.

Also, there have been several episodes about the first transistors and MOSFETs, but what about the planar micofabrication protocols which have allowed for the integration of billions of these devices on a single silicon chip. The development of optical lithography by companies such as ASML is an impressive feat of engineering.

Thanks for the great videos!


I would love to see something on Wireless transmission of audio or data. FM Radio, Cell Phones, Wireless Internet, Ect.

P.S. I really love this series!


build a vacuum tube and explain how it works please

Medical / bioengineering such as how artificial limbs are developed, how an MRI works.
Also very useful to this grade 8 science teacher, hydraulics and pneumatics in everyday devices, water treatment systems.

how does a simple circuit, such as the Fuzz Face (see http://www.geofex.com/article_folders/fuzzface/fffram.htm), use electricity to modify sound waves in a musical way. Or, more generally, how do electricty and sound interact?


how about cyclonic separation as used in the Dyson vacuum cleaners
- rich


The LCD Monitor Teardown is a fantastic video, although a little fast paced for the average user/consumer. Could there be a video also discussing LED tv's/monitors, perhaps also LED versus LCD tv's/monitors? It would help users/consumers understand what it is they specifically want and what to buy. -- good suggestion ... the pace is on purpose. We've found that people will stop start and rewind, so better to err on side of fast with subtitles ... bill-engineerguy

Digital camera - how they work and the ergonomics

Toner Printers, i.e. how toner works with a fuser.

ion propulsion?

Ideas (general)

More Videos on computer components and computer technologies would be awesomely great

all houshold appliances (and what is hidden inside them and why)
any very rare elements that any one country might have a monopoly on (and what it is used for, and how much it costs and how it is mined or whatever way they get it)
what hydrogen can be used for
some basics (atoms - molecules - what is the smallest part you can get at with what method)

This wiki isn't allowing unregistered guests to make pages, but they can edit as they wish. So if you have an idea for a new page, don't wish to register just put it here and we'll make a new page, or someone who has registered can move it a page.

removing my post of using a circuit simulator since that was for another wiki.. sorry! :-)

How about
  • LiPo batteries?
  • How a laser printer works (or did you do that already?)
  • For that matter how an inkjet printer works
  • Flash memory (Like SD cards)
  • SIM cards
Thanks - cant wait for more videos, Mark

Hello Bill,
These ideas could work:
  • Coffee machines and devices might be interesting in the sense that there are so many different devices that have all taken different approaches to solving the same problem. In particular, the manual (stove-top) espresso pot, the Cona vacuum pot, french press and modern espresso machines could be compared and examined.

  • Induction cooking hobs or comparing how different hobs work (Ceramic, induction and the old fashioned coil ones). This would work in the same sense as the above suggestion, in that they are all different ways of tackling the same problem.

Thanks for your wonderful videos, Jim, Hobart Tasmania

Some random thoughts:
  • how was the particle accelerator constructed? if it isn't "classified" info.
  • gps - [we are going to touch on this in series #4 when we talk about atomic clocks, not sure whether in video or only in companion book ...bill-engineerguy]
    • [The now pervasive nature of this, from its military targetting beginnings to commercial navigation, synchronisation of comms networks, mobile phone localisation etc. We will only appreciate how far it has crept into life when someone switches it off! ... ArtfulBodger ] [Indeed! In working on this section of the book and on the video I was always amazing it how pervasive GPS has become. I agree with ArtfulBodger ... billengineerguy]
  • refrigerators (bonus points for the einstein-szilard one)
  • physics of tippy-tops
  • linkages (e.g. reciprocating straight-line, etc), possibly related to the use of steam power [I'm fascinated by mechanical thinks: Am trying to get a organzing "conceit" for discussing such motion. There is a page here on the most important mechanical motions. billengineerguy]
  • digital cameras [The ccd is coming up in series #4: What a fascinating thing! billengineerguy]
  • thermal expansion - as seen in steel/concrete building, use in clock pendulums (especially Harrison's)
  • electronics-based storage, from ancient (phosphor tube memory!) to modern (floating-gate NOR flash)
In general, my favorite episodes have been the ones where they've shown concrete examples of theory - e.g. the fibre optic internal reflection/water bucket one, the xerox machine, and the pop cans.
-- moof

Suggestions from your biggest fan:
  • My favorite episode was the Hard Drive video!
  • I think you should make a Bose-Einstein condensate and a superfluid for your next video.
  • More computer-related stuff.
  • Heat pipe cooling
  • SLR / DSLR cameras & film-vs-digital
  • Manual-winding watches/timepieces
  • 4chan memes

tim: how work a MEMS gyroscope ? [We will have the MEMS accelerometer up in series #4, related in a way; I've looked into gyroscopes: Looked at Sperry's work. Interesting stuff]

How about how touchscreen devices work? or how tv works (in terms of analog and digital signals from your service provider)?



Player Pianos (or Punch Card computing, like I suggested in the mech motions page)
does the shape of the musical instrument have influence in the quality of the sound? is it possible to construct a single instrument with wide range of frequency but produces only single frequency.

How cloud computing works
You can explain the details regarding
  • Reliability
  • Security & Trust
  • Computing Power
  • Options available
  • How dependent we are on Cloud services etc etc

I understand how traditional transformers and voltage regulators work, but that doesn't seem to be how the tiny power adapters used by iPods work -- for one, they automatically adapt to different international voltages; for another, they're too small! A session explaining those would be cool. [Interesting idea: I never thought of such a thing ... thx for posting this ... bill-engineerguy]

I second this - came and found the wiki after thinking about it for awhile. Years ago we had these huge "wall wart" adapters that came with everything, anything, that needed DC power. Now, the power supply for my kindle is about the size of my thumb. What changed and made that possible? Are they cheaper? And cheaper for whom? To make, or to operate, or both?

It turns on and off really fast, can be implemented with one semiconductor and one capacitor which does cost less and is lighter than a bale of copper wire. Power semiconductors that can switch many watts used to be expensive but not anymore.

  • If you cover this one, be sure to at least mention the difference between linear and switching voltage regulators ~jstapels

Capacitors and super capacitors could be quite interesting.


I Agree with Jon, capacitors would be very interesting.

feature about the largest capacitor ever made!

I just heard about a fly ball governor in my control system class.
Maybe an episode about early control systems like Ctesibus' water clock, Hero's self-leveling bowl, etc?

How about how engineers use quantum properties to solve different series of problems, like for example quantum computer or how using proton in transitors can make computer a lot faster and powerful.

How nice it will be if you show about super conductors,how does a remote control works,how does a WI-FI modem works.

how do they make superconductors?

How about:
- The swashplates/rotor system on helicopters with one and two rotors.
- Manual and Automatic gearboxes
- Tesla coils and Jacob's Ladders
- Various lock mechanisms (padlocks, doors, safes etc.)


I would really like to see how engineers come up and test ideas to build structures designed for strength. An example might be bridges.

Not a specific proposal, but in general I see nothing more important to the current generation than basic concepts of energy. It would be interesting to see an entire series with episodes tied together with the theme of energy. Why has petroleum been so critical to humans? What did we do before petroleum? Do solar panels produce more energy than they use, from manufacture, installation, removal, and disposal? If we spent every drop of remaining oil on manufacturing alternatives (wind turbines, solar panels, tidal plants), would humans have as much energy as we did at the peak of petroleum? --uiuctodd

I think that inner workings of a tone-wheel organ will be an interesting topic because of the hardcore mechanics involved into making the tones. Or maybe analog synthesizers.
- Goran B [I've always wanted to do a series on music - how its produced mechanically and electronically, how its encoding on old-fashioned records and in digital formats .... bill-engineerguy]

How about magnets, types, uses, etc.

Car radiators - or radiators in general, would be interesting. There are lots of different types.
Cooling towers for building scale air conditioners (I suspect the budget wouldn't cover Bill's normal approach to that, however)
Air conditioning or refrigeration compressors - or the refrigeration cycle in general
Noise suppression - particularly for cell phones and other devices that are trying to do voice recognition.
Spark plugs or tires - both have developed a lot from what they were 30 or 40 years ago, to the point most people never think about them.

Idea: Old style slot machines (springs, gears, and timing). New slot machines are steppers and microprocessors (or just video), and aren't as interesting, but the old machines are things of beauty. Related: Electromechanical pinball machines (1960-1970's), or even the old electromechanical Bingo machines (1950's).

  • Chromatic and spherical aberration and it's correction
  • telescope, microscope
  • how do astronomers measure distance of celestial objects?
  • antireflection coating

--Vladimir [Interesting ideas. We are planning a series - its in the early stages - on the Fourier Transform - which has a lot of optics in it. ..bill-engineerguy]

more ideas
  • Magnetic resonance imaging
  • Absorption spectroscopy

How about a tear-down and explanation on how a heads-up display work, such as the ones used by fighter pilots; also used in some fancy cars now. The latest use I've seen is with Google's Glasses! I think it would be interesting to see how they get the images to show up on or where there is a transparent surface that you can also see through.


I really love your videos, how about a video on how the internet works, how the websites interact. I always find it difficult envisioning internet operation

-- MIke

How about explaining that how our data in disk drive or any other storage get transformed from bits & displayed on screen or audible through speakers. Its good to explain the whole journey of data from user to device(computer,tablet,smart phones) & again back to user.


Gyro's make no sense to me. Try this:
1. Weigh a stopped gyro with its pedestal.
2. Set the gyro axis horizontal, spin the gyro, then set it on the pedestal and weigh it again while the gyro precesses around and around the pedestal.
3. Compare the two weights. Are they really the same weight?

How does a wind powered vehicle go faster then the wind? See
http://www.fasterthanthewind.org/ for an example. I have seen it baffle smart people to no end. Also, since it is going faster then the wind why couldn't it drive into a headwind?
-Mark K

Hi Bill,
Greetings from India.
I am very much impressed by your quartz crystal video. It would be fun if you include videos of working and constructions of internal combustion auto engines. Since these are the mysterious things that populate the world next to humans, a video about the IC engines would be awesome.

-Anish K


How about Aerodynamics, I heard roughly 300 Hp to drive a car to 150 MPH, but beyond that it takes 700 more HP to get the car to more than double the speed.

Capacitors would be part of your Battery video.

Solar Panels

"Bonding" Screws vs Nails... As well as glues..

Tape Cassette compared to CDs DVDs Blue Ray

Film they are going to higher frame rate, why higher is better.

Pyrite glass, I heard the formula changed, but the idea doesn't crack, hot and cold etc...

Why water seeps up celery veins with out effort.

I always enjoy the videos and your book. Keep it coming..

Richard R


Hi Bill,

Love watching the videos

can you explain How Touch screen Works in one of ur videos
the three basic systems that are used to recognize a person's touch:
  • Resistive
  • Capacitive
  • Surface acoustic wave

All the best

Rishi 09-03-2013

Hi Bill, New viewer here, really learning a lot from your video's... I haven't really seen all that much of your work yet, as such you may have already answered these previously.

Can you explain how:

Digital image compression works, How can a High res 100mb PNG image be compressed to an insanely small size, such as a typical jpeg and yet keep the size and resolution almost the same, with very little loss in quality.

How do optical storage devices, such as CDs DVDs and blue-ray discs work. And is there a theoretical limit to the amount of data stored in this way?... It seems, as light has a wavelength, we will soon reach a point when it would be impossible to fit any more data on a disc, keeping things like error correction in mind.

Lee G, - UK 25-4-13

  • How does transmembranic ionic pump work?
  • How do movement sensors work and how can you cheat with it if you are robber?
  • what's difference with resist- and capacity- based touchscreens and how do they work? how does touchpad work?
  • how fried potato can be cooked in a desert using infrared waves?
  • how do brewers yeast work, what's difference between different types of yeast and how they can be forced to produce alcohol instead of vinegar etc?
  • how does printer works? i mean how do colors form from just 3 or 5 types of ink, and how does raster in newspaper work?
  • How does router work and is it better than cascade of switches?
  • How does human eye work and what does it really detect?how many types of saccades there really are?
  • How do LED work, what's the difference between standard LED and OLED? why are they so "power-saving" ones and how can resistor volume can be calculated to connect a LED directly(with this resistor) to a battery?
  • How do tenso-resistors in general and electric scales particulary work?
  • How does BAC work and how could it detect that damned boson?
  • How does ionic thrust engine work in theory?
Dov Mashleh, RF, 09.05.2013

View it Here

30 Jan 2014
I would like to see a discussion of lubrication. Why are some molecules slippery? Are there significant differences between the operation of natural and synthetic lubricants? Is Teflon slipperiness from the same mechanism as olive oil slipperiness?

Also, I would like to see the same kind of discussion for adhesives.

This is interesting: Tribology is an area of interest to me. Bill-engineerguy