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 »
Another one for Caleb
I vote for David
Science, live is the best
I love using Acellus and I just wanna say happy new year
It was very interesting to learn about Samuel Morse and how moris code started.
I voted for Caleb, but both of them seemed very qualified.
Being part of the first telegraph transmission must have felt like magic.
I vote for Caleb 100% but I like David too!
I VOTE DAVID!!!
Thank you for this amazing video. A great start to the new year. I voted both of them!
I vote for both David and Caleb!
I’m so happy I kept on checking for a new Science Live knowing there won’t be one for the holidays but I’m glad there’s one now, anyway I vote for both!
#sciencelover!
Today’s lesson on the vacuum tube diode was very interesting and easy to understand. Both David and Caleb did an excellent job explaining the topic, so it was difficult to choose only one person to vote for.
David’s explanation was very clear direct, and convent. He was clever in ho he presented the information and quickly for to the main point, which made the concept easier to understand.
Caleb, on the other hand, was very well organized and sounded friendly and confident. His explanation was structured clearly, and the information flowed smoothly, which helped me follow the lesson step by step.
Because both presenters explained the topic so well in different ways, I would like to vote for both David and Caleb.
This video was great and I like hearing about the world’s smallest robot that can swim. I vote for both!
My vote is for both!!
Thanks for continuing to make these videos!
Scientists at the University of Pennsylvania, in collaboration with the University of Michigan, have developed the world’s smallest fully programmable and autonomous robots.
These micro-swimmers, about the size of microorganisms (0.2 x 0.3 x 0.05 millimetres), can move independently, sense their environment, and respond to changes, all while costing only a penny each.
Caleb and David both get my vote!
I genuinely did not know that you could make robots that tiny!
great video! Mr. Billings is probably my favorite part of these videos.
I’ve always wanted to work for NASA since I was little.
It’s nice to see someone who went to Acellus follow those dreams, it’s inspiring to me.
It’s cool to see how Morse code was created, just some of those few discoveries really led us to the technology we have today.
Also.
I vote for both 🙂
I vote for both Caleb and David. Can Billings offer a course in morse code. I would like to learn about it and how to communicate and understand the messages coming through by listening to the sounds coming in. I would like to know more information on how the hydrogen drone would work and how it would be deployed?
David is definitely more technical but im Going to go with Caleb his humor makes it more engaging and over all makes me enjoy listening way more.
Both got my vote!!
I vote David to win!!
Its hard to pick, so I say both!
So cool that a robot is capable of being smaller than sand
I vote both!
This was my first and I really enjoyed the video. I vote for both to come back.
Can the robots propel themselves forward when swimming?
Happy New Year! Loved both Caleb and David
I vote for both!
I vote for both. It’s incredible that a robot can be so tiny and still move around!
it was nice to meet some family members of Dr.Billings!!!
CALEB!
Sounds like you had some great mentors!
I enjoy these videos each week. They are very interesting
I want to challenge myself to do great this year!
Cool video. I like the part about telegraph and Morse Code!
I vote both they work amazing together!!!
I think being able to predict tornado’s would totally be extremely beneficial for us, because if you can predict where it is you could evacuate the area before the tornado even gets there.
I never actually knew so much went into Morse code. It’s really interesting.
I vote David!
Yes David and DEFINETELY YES TO CALEB!!! They both make an astounding team and their sense of humor makes it really fun and not one bit boring!!! Mr. Roger Billing’s you have an amazing son and an AMAZING grandson!!!!! Hope to see them on future episodes. And I think you would make a very talented actor one day Caleb!!!
Both get my vote!
R. 51 is funny
That’s really good for her. I’m glad she accomplished her dreams.
happy new years I’m happy the science lives are back
Congratulations Anastasia! 🙂
I love Science lives and starting a new year.
Thank you for making these for us!! They are always so well put together.
both get my vote!
I vote for Caleb
David all the way!!
I love this episode. A lot to learn, Vacuum tube diode, David and Caleb so so great. I vote for both. R51 always nice.
I loved learning about AC and DC currents. I vote for both!
Seeing a robot smaller than a grain of rice, that can swim is pretty cool. Programming robots has evolved so much.
Also, the opening joke was pretty funny.
I vote for… BOTH! They are both funny and smart! I love how they explained to help us understand.
It’s a tie for me! I think they’re both great options!
what do they need a robot so small for
Did Samuel Morse make any money off of his invention?
i vote for caleb
I vote Caleb of course!
I VOTE DAVIDDDDDDDDDDD
I loved both of them
This was absolutly my favorite video so far
This was my first ever Science Live video I’ve watched. Caleb and David explained everything so well. The whole video was very interesting, I can’t wait for the next one!! I love how there was more than one subject; I feel like the video was more entertaining that way. Also, can those type of robots get any smaller?
I vote for David!
Also, this episode is very interesting, I love how both David and Caleb explain very well so, whoever is watching Science live can grasp even more clearly!
I vote Caleb!
I vote for both Caleb and David.
I find it amazing how much I learn from each and every podcast. My vote goes to both! Sorry I can’t just pick one.
DAVIID
i vote for caleb
I vote for Caleb AND David! They both seem pretty cool!
I vote for David and Caleb because they are funny
Fun again! Another vote for Caleb!!
Both Caleb and David. But I’ll go with Caleb👍
I hope we see more of Caleb and David they are both talented. I vote David
I LOVE SCENCE!🩷🩷🩷🩷🩷🩷🩷🩷🩷🩷
The nano bots are pretty cool. It’s pretty cool to now know Caleb did the editing for the classes I’ve done and it’s really good, did an amazing job. A great live and both David and Caleb need an applause.
My favorite part of science live is R-51. He is funny.
science lives with acellus are so fun! thank you for sharing all this interesting science information.
Acellus Science Live, came back strong for 2026. I enjoyed listening to all the great topics and excited to see who wins the protégé spot. Both guys work great together.
10/10
The teeny tiny robot that runs on a very small amount of electricity is unbelievable!
I personally vote for David!!
Hope everyone had nice holidays!
I vote for Caleb!
Watching from Southern California!
That’s awesome that we might have a drone that can predict tornadoes.
I vote both. Great live!!
I vote BOTH!! 🙂
The success stories of former ACELLUS students is encouraging. I think a lot of these are a lot for elementary students. Happy New Year!!!!
So inspirational! I vote for David!
I vote for Caleb!!!!!
I vote for David!
Thanks for another great science live! Can’t wait for the next one!
Best episode ever! I liked listening to Dr. B’s son and grandson talk about their work, hobbies, and explain the electric technology.
I SAY BOTH!!!!
Wow the video was so cool! My vote is for David!
i vote Caleb
I VOTE FOR DAVID!!!
I’d say definitely both, because having two people that qualify with different skill sets and hobbies can make one powerful duo. I enjoyed the lecture today, thank you.
I vote for both! They work well together!
I vote for Caleb too!
both get my vote!!!
Happy New year everyone!!! If you did not know if we did not have plants we would die. It is because the plant gives us air.
That was amazing!!
Can’t wait to see what this year science live will offer us!
I’m voting for Caleb!!
I vote for both!
I vote for David!
they both got my vote!
Thank you for these videos Acellus and the time and energy you guys put into it.
Love the video very interesting and great humor.
My vote goes to the both of you!!!
YEAH!!!
Love these videos they are such a great part of Acellus. Also very funny! thank you Acellus for your time making these videos.
I can’t vote for just one! I vote both!
David is the best I vote for him
I vote for Caleb.
i vote caleb
i vote both!
Both are great, but I pick David.
Another amazing stream! Glad to see you guys are back after winter break.
Happy new years everyone!!!!
I vote for both, and happy New Year!
Science live always teaches me so much interesting science.
My favorite part in the video is where Dr. Tobias talks about how the telegraph was invented. I love learning about new things especially new inventions and how they were made!
decisions decisions. Both were great
My father’s name is David, so that influences my vote 🙂
I vote for Caleb!
I thought the little montage was cool like showing little bits of them building it.
Thank you guys for all that you do to educate us! Happy New Year!
I love Acellus!
I really enjoyed both Caleb and David! Vote for each of them.
I love them working and building together.
I vote for both! The new AP English class sounds very exciting me I hope everyone that tries it out enjoys it! Very nice science live, looking forward to the next!
We vote Caleb!
I vote both! I can’t decide
Spectacular live!
I vote David
Does the AC every lose any electricity from being used for long?
Definitely both they are very descriptive about the different topics
I vote for both. It was a really funny and well explained video. I enjoyed it a lot
I vote for David!!
Caleb is totally the favorite grandson dude! LOVED THE EPISODE!!
I vote for David.
I vote for Caleb as well!
The idea of hydrogen cars is fascinating
Both are great choices.
David has my vote, very innovative
I vote for both!
Tough choices so I will happily vote for both!!
That is a TINY robot! I wonder how they made it so small. Good lesson. 👍
The tornado solution was clever.
I’m so glad science live is back after the break!
I vote for David because he hunts but I like Caleb because he plays guitar. I also had a question, can you ask Caleb if he could teach guitar?
Caleb is so funny!
This video was so interesting this week. I also vote for both!
David has my vote!
I vote for both. Both amazing people!
I voted for David!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
I vote for Caleb because he’s cooler
I want both of them
I vote Both. They work and explain think so well together.
what’s everyone’s New Year resolution?
David is honestly very intellectual and advanced with his knowledge and very sharp for what he studies, it can really change the world! Although I am truly so fascinated and admire Caleb’s love for instruments, production, and music as a whole, they are both very talented people to say the least. So I’d say they both deserve a vote.
I LOVE ACELLUS!
Great video! I 100% vote for David
Vote for both
i really loved how clearly the vacuum tube diode allows to flow in only one direction by using a cathode and a positively charged anode, I LOVE THIS CLASS!!!
Morse code is so cool! I vote for both!
I vote for Caleb!!!
I think Caleb would make a great actor. I will keep an eye out for him.
I think science live next week is gonna be awesome