The Vacuum Tube Diode
January 7, 2026 • EPISODE 292
What invention helped spark the age of electronics? In this episode of Science LIVE, Dr. Roger Billings and the Protégés break down the vacuum tube diode—one of the earliest electronic components that made controlling the flow of electrons possible. Learn how this simple device works, why it was so important in early radios and computers, and how it laid the groundwork for modern electronic technology. Join us for a clear, engaging look at a key milestone in the history of electronics.

About DrB
Dr. Roger Billings is a visionary innovator whose work has touched the lives of millions of students and transformed the landscape of education. Widely known as “DrB” to the countless kids who benefit from his groundbreaking Acellus learning system, Dr. Billings has dedicated his life to advancing education through technology.
As part of DrB’s lifelong commitment to supporting education, Science LIVE was launched as a way to “give back” by mentoring students in conjunction with the Roger Billings Scholarship Program.
Read more about DrB »
About the Roger Billings Scholarship Program »



1. I vote for both
2. Can’t wait to learn more about the honors classes
3. R-51 son and grandson was funny
way to go Anastaisa!! thr drone ideal was such a great ideal!!!
Great video!! Can’t wait for a new episode of Science Life!! 🙂
Robots that tiny could go into almost anything
I vote for both!
I always like watching R-51 section at the end!
I cannot pick between David and Caleb. I think both did a great job. No worries, Caleb. I cannot pronounce that guy’s name either.
David – yes
Caleb – yes
They both have my vote!
I really enjoyed the segment in R51 when you made a son and grandson. I also really liked both protégé David and Caleb. They did a great job explaining how to rectify the wave. Awesome science live this week!
Another amazing episode to kick off 2026! Thank you for always making science fun and interesting!
The first science live of the year was awesome!
Abilities to take AP classes are a real gold standard! I am loving this capability & thank you for letting us know!
I will vote for both!
Merry Christmas, Happy New Year Acellus! Thank you for teaching us about electronics, and so many more amazing things! Have a blessed day! 💗
I vote for both!
great video, i vote for Caleb!
I vote for David!!! Happy New Year, 1st Science Live since 2025!!
I’ve never heard of Samuel Morris, that was neat to learn he was a painter to! Great week 👍🏻
First week in Acellus! Thank you!
I vote for Caleb
I vote for both!
I vote for David!
Both!
I vote for David
Both boys did great!
I vote for both David and Caleb. They did an amazing job!
i vote for both! Another great episode
Hi from Maryland i vote for both of them.
It’s crazy how small those robots are!!
I VOTE BOTH!!!
why don’t we just use plants to breathe underwater? If we exhale carbon dioxide, and they exhale oxygen, can’t you just breathe as long as you and the plant are alive?
I vote for both!
I vote for Caleb. I hope he becomes a successful actor. And he and his band do great with the music too. And David, I’m glad he enjoys sports. Great for body. Thanks for the explanations too
Congrats Anastasia for college. and thanks for the vid. Happy New Year
Is it possible to make the micro robots even smaller?
I like both Caleb and David, but I really love Caleb’s jokes that he made throughout this live lol.
As always these science live videos teach me something new and interesting! I vote for david
Hello from Mississippi!
Both have my vote!
I vote both!!!
DEFINITELY BOTH!!!
I’d vote for David but don’t want to leave Caleb out so I’d say both!
I vote both!!
I love this! Science Rocks!!!!
I now the teeny tiny microchip takes sunlight to move, but how does it actually move?
I vote both!
I vote both of them!
I vote for both! They are so amazing at what they do and it sounds cool with everything they do. I think they explained it very well and would be exceptional.
i vote for both i cant choooosee.
Both!
I vote for both. I liked having them on the video.
I love learning with acellus!
I vote for both!
oh I’m definitely voting for Caleb
Both of them have my vote
This was my favorite science live episode, I vote for both!
I vote both and I am so proud Anastasia for getting into the college and I am so proud of the work she had done and everything that she was apart of.
I vote for David as well!
When did scientist first discover that plants “breathe”?
This was my favorite science live episode! I vote for both!
Both!!!
Can we learn about how a piano works?
I vote BOTH!
I like how they both explain. Meaning the vaccum prevents electron collision with gas molecules. The diode conducts in only one direction.
I vote for both, they are both winners.
I really liked that video!
The Vacuum Tube Diode was important for electronics and radios.
I VOTE BOTH!!
Can we learn how to make basic generators?
I never knew morse code was developed using magnets to control a pendulum system.
I vote for both! They both are amazing!
I think both Caleb and David should get to be proteges.
How does the glass over the bulb not break from overheating???
LOVE IT!!
Who discovered the magnetic pull of Earth?
Would a transistor keep the electrons flowing in one direction?
happy new year! i pick both! and anastisias idea is so cool, thats awesome!
I liked how this episode showed how a simple invention like the vacuum tube diode led to radios, computers, and modern electronics.
I vote Calab!! 100%.
I vote for Caleb
Im voting for David!
both have my vote!!!
I vote for both they are both so good.
Still love Dr. Tobias’ section.
My vote is David!
science is the best
It is so crazy that a robot can be the size of a grain of rice.
David and Caleb’s video was fun to watch.
I always wondered how Morse Code came about, good to know now!
So cool that a student at my school invented the drone that flys into tornadoes!
What if these little robots could be swallowed and work with body cells to help cure diseases one day.
I really enjoyed hearing about the hydrogen powered drone Anastasia was involved in creating. It sounds like it really ca be useful in predicting or helping to identify the tornadoes. I also liked learning about how scientists are watching plants breathe.
Wow! I think that the tiny robots have just opened a lot of possibilities for studying living matter, we might be able to use them to get inside blood vessels, collect bacteria, or monitor irregularity in almost any system in the body. I really find it insperational that quite a few great scientists were also artists, like Leonardo da vinci, Hedy Lamarr, and as I learned today, Samuel Morse!
I vote for BOTH!
I vote for both!!! 😂
Dr. Billings grandsons and son are very cool
I vote for both David and Caleb together!
Best of luck to David and Caleb!
How do we manufacture computers that small?
There is a robot the size of a grain of salt!
David is soooooooooooooooo cool!
Its fascinating how the worlds smallest robot is the size of a grain of salt.
I vote for both David and Caleb! The short video they made was both informative and very entertaining overall a very fun way to learn!!
I vote for both! they both worked together to show us how we can create a vacuum tube diode so we can rectify a wave
I vote Caleb!
Could the little robot be used to go inside peoples bodies to look at the affected area? This could be a big use for the medical field.
I like both so they both get my vote.
I just want to say thanks for everything because you guys are wonderful teachers.
I vote both!
I think i was really cool how morse code was made. And i can’t wait for next week.
I loved this video so much. The fact about how leaves breathe through tiny little holes and the new technology being created is very interesting.
And I vote David!!!
Another vote for Caleb
Both get my vote.
I vote Caleb!
Both, I vote for David and Caleb. Both are funny and explain things in a simple and easy to understand way. I can’t pick between them
I want to go into video production and making movies, so seeing what Caleb does is super cool! Caleb has my vote!
Great video! I vote for David.
I enjoyed learning about Samuel Morse.
It was so intriguing learning about the small robot, which is smaller than a grain of salt, that has solar cells for data transmutation! And when the light pulses and get the right speed, they can send them a program to do what they want the robot to do.
Two of them are good.
Both I think they make a good team.
Happy New Year!!! I love Science live!!
One of the reasons I love plants is that they breathe but I did not know that they breathe carbon dioxide.
That is a crazy small robot. Technology is getting better and better.
R 51 is a cute little guy
I vote for BOTH!!!
This is a very tough choice but David for the win!
I vote for both
Happy New Year! Looking forward to another great one!
I’m glad that science live is back, I hope everyone had a great vacation!
i vote both!!! i love science live!!!
I LOVE SCIENCE LIVEE!
I vote for Caleb 😆😁
I vote both!
I vote BOTH!
I vote for David!
I enjoyed the explanation of radio waves and AC/DC
The new class AP Literature and Reading looks good.
How much time would it take to make a vacume tube diode?
My family and I all agree that Caleb and David both did a great job, and we would like to see both continue.
Both! They explained everything so well!
Great video. David and Caleb make a great team.
I love this!!!!! Thank you Acellus!
I enjoyed learning about the telegraph and how to spell my name with the dots and dashes.
I like the fact that you highlighted that not all inventions were made by scientists.
Way to go Anastasia!
I like the fact that you highlighted the fact that Samuel Morse was not a scientist, but yet invented Morse code
Fun fact: I am related to Samuel Morse on my mother’s side of the family!
favorite part was watching David and Caleb show how to convert AC to DC
Voting for both!!
I vote for Caleb & David.
We enjoyed watching both of them, they added something new to science live.
Both guys did a great job. Very entertaining to watch. We loved it.
Both of them!
This is a really neat video. I like Celab.
I vote both!
I did not know that microchips could be made so small.
Happy New Year! I hope to see both David and Caleb
I vote for David
Caleb gets my vote!!
I really enjoyed the live today, I would also like to say my vote is for David.
We really enjoyed learning about the world‘s smallest robot robots. We like both of the potential prodigies and think they would do great.
I vote for both caleb and David
I went to a museum and learned how to spell my name in morse code! I voted for David
Team David here!!!
Caleb all the way!!!
I vote for both of them!
This episode was fun. I really liked the science behind the microchip robots. I also liked learning that Mr. Morse was actually an artist who invented Morse Code. This inspires me as I love art and someone would love to invent a hover car.
I don’t see how I can sign up for AP classes. How can I do that???
I vote for both! I must give credit to both Caleb and David because they explained the vacuum tube diode very well! And I thought the painting that was shown during Tobias’ segment was extraordinary.
I wonder what it would be like to breathe like a plant. Anastasia seems like a very smart and dedicated pupil. Ap literature is very interesting. Who else has a high reading intellectual? How can a robot be so small!? Thank you so much Acellus for keeping on point. All the news you give me is so interesting. I vote for both!
This episode of Science Live was very fun! Both of them explained the vacuum tube diode pretty logically.
R51 is so funny!
I loved the tiny robots
I vote for Caleb. I love him so much, he’s absolutely hilarious🤣🤣
Hello! Joining from the Netherlands!
I enjoyed the video from David and Caleb. They did a good job explaining the Vacuum tube diode. They both did a great job.