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 »



I vote for caleb
Good video! I think I prefer David by the way.
I vote for both, love science live
I vote for both Caleb and David.
I really like both but I voted for David!
I like learning about tornadoes
Caleb for me!
I think Edison is cool! Also I prefer David
I love 💕 morse code.👩💻
i vote for both too!
I voted for David.
I loved the new segment!
I vote for caleb.
Proud to be a certified nerd!!!
I’m gonna go David tbh
I voted for David
I vote both!
I really like today’s science live, and I vote for David.
I VOTE DAVID
I voted both, but if I had to choose one I would go with Caleb.
And I vote for Caleb
Definitely the favorite.
Why can’t we have co-proteges? They seem to work well together. They have good chemistry! Punny!!
Now that was a lot of fun 🤩
We’re going with David
i vote for both too
I honestly have to go with both David and Caleb because they both have different interests and that’s how team is started and I think they would make a great team!!
so how long will it take for those robots to get the medicine to the right place
both of them remind me of the big r
I had to vote for David.
I voted for r51’
I vote for both of them!!
I vote Caleb!!!!
I thot it is fascinating how the universe of Pennsylvania made a very small robot.
David and Kaleb both did very well explaining and teaching so they both did very well.
I really like the mini chips from the technology spotlight. Considering how small it is, it actually turns out to be very valuable. Appreiciate the Science Live every week.
It was cool to learn that if you take higher level classes you can have a better chance to get into universities and learning about the drone going into the tornados The worlds smallest robot is so cool
I vote for both. This episode was hilarious!
I vote for Both
I vote for Caleb!!!
My vote is for Caleb!!!
I vote for both!
I vote David!
I think I like them both so I vote for both of them (:
I vote for both of them!!!
I can’t choose! I vote for both Caleb and David.
I like how Caleb and David explained the steps to the vacuum tube
I like Caleb and David
Is there a way to convert DC currents to AC? Also, I vote for both David and Caleb.
It’s great that you’re taking on proteges! Will they be at the next episode in Science Live?
I vote for both. And I have a question for Dr Roger Billings. Can you explain how does a personal hydrogen generator work? Thank you.
Happy New Year from Texas! I vote for both!
I vote for Caleb
The way that morse code is organized based on letter frequency is very interesting, I had no idea.”
Davvvvviiiidddd
heehee both! 🙂
Science live!
I love watching these Science Live videos!!!!❤️🔥❤️😇
My biggest question is about the microscopic robot, does the microscopic robot swim on top of the surface of the water or under the surface of the water? Its kinda hard to tell by the video.
I liked to hear about how they used Morse code to communicate from miles away!
i think I will have to vote for both. It’s pretty tied up.
YES DAVID
what grade do you have to be to take AP classes
David and Caleb both seem like they could teach well so it’s just a matter of opinion, or maybe it can be Acellus’ fist dual teacher class?
Thank you for the science live!!
I love the blue guitar.
I honestly say that I vote for Both David and Caleb
David and Caleb happy new year everyone!!!!!!!!!!!!!!!!!!!!!
I vote for Caleb
I vote for both!!
it was so funny. He said he he started the year off on his right foot.
I vote for Caleb
Science live is the best💗
I vote for both. I like them for different reasons
team Dave for sure
I always find Science Live very interesting! I would give both of them my vote!
I vote for David.
Thank you for science live, I voted for both!!
It was very interesting learning about the vacuum tube diode. Can’t wait to learn more next week
Both!
I vote for David he is great.
vote for both honestly
I would vote for both
The hydrogen drone is amazing because it can go into a supercell!
Both David and Caleb would be great.
I vote for Caleb
I vote for Caleb!
Why do I have to choose? I pick David.
Science rulesss
I vote for Caleb!
I vote for David and Caleb both are great
I vote for both!!
David and Caleb !
I vote for both David and Caleb
I vote Caleb, he explains things good and he is funny
I vote for David
I vote for david! He had the best one.
I vote for David an Caleb and David was really serious with it
i personally vote both of them
this video was great i vote both david and caleb because they are both intelligent and great
I prefer both Caleb and David they both did a great job
Hey its Chloe!!! I would probably have to say both. They did an AMAZING job.
I voted for Caleb!!!!!
I vote for David and Caleb
I love accellus academy!! Thank you guys for the lesson
It was fun to see David and Caleb. I loved R51’s show.
honestly vote both
Hello,I vote for David.
Hello, This is Emily! I’m new to Acellus.
I liked the R51 part and I liked how we learned about oxygen and how plants breath. That was fun, I like online school.
I vote for David!
Glad to be back! My vote is for Caleb! All the way
R51 Is Amazing!!!!
They both seem very intelligent and cool!
I honestly vote for both thank you for this
I like the way David and Caleb worked together.
I voted for David but both of them explained things really well
I am on the American Revolution in AP United States History. I love the class so much and can’t wait for Conspiracy Theories.
I vote Caleb
I vote for both!!!!!!!!!!!!!!!!!!!!!!
I’m wondering if, with that small of a robot, we could get closer to robots being able to get inside the human body and fight infections. Also I vote for both Caleb and David. Caleb seems to excel in the arts while David seems more calculated.
So interesting!! I voted David
Back from break! Can’t wait!
Can’t wait for the next episode I vote David!
Great video !!!! But I gotta go with David now I’m already waiting for the next episode
I vote for David!
David 100%
I vote for both!
I love this so very much 🥹
I think both Caleb and David are fun!
Lol, R-51 got me 😂 he is so funny. Thanks Science Live
I vote of both Caleb and David
both. They are both lit
Voting for David!
Vote for both of them!
I vote for both. cool episode!
how was the new years party? Mine was great. Happy 2026!!!!!!
Happy New Year from Illinois! I would vote for both they were both great!!
Robots can be smaller than a piece of salt!
I ❤️Acellus
I loved learning about the Vacuum Tube Diode!!
I vote for David.
I vote for Caleb!
I can’t chose one I vote for both happy new year! this video was fun
I vote for both
Anastasia is amazing! Congrats to her! I voted for David because he is more serious and mature! Both are great though! Such a great live!
I vote for both!!!
David gets my vote.
I rate this science live a 10/10 !!!!
Love this episode. They all did a great job.
I vote for David and Caleb
i vote caleb and david
I vote for both
I vote for both david and Caleb lol there both great
science live is my favorite part of the week.
I vote for david
I vote for both Caleb and David!
Dr. Billings, I think David and Caleb are both qualified to continue! They each bring something different to the presentation.
I vote for David. He is just so good!
I vote for DAVID and CALEB
Dr. Tobias, what did the other person reply to Samuel Morse’s first message?
Dr. John, could these robots cure or at least help with diabetes?
Happy New Year! I am excited to be back! I can’t pick, so I say both!
I can’t choose between David and Caleb 😭
I would have to pick both as well. I think science is just awesome and there is just so much to learn and do.
Dr. Billings, I like both Caleb and David! They are good together, so we should keep them both.
Dr. Tobias, I wonder how hard it was at first to translate the messages without paper.
Dr. John, maybe those robots could build more of the same type of robot on that micro scale?
How many drones are you thinking to deploy? I was thinking about having stations like police stations and fire departments
I would pick both of them to be honest. They’re both good candidates and great explainers.
David is number one for me.
I thought it was funny when R 51 made his son and grandson appear, it
made me laugh
I vote for both David and Caleb !
I vote for both, awesome episode!
I vote for both