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 »
Here from Missouri. I am almost finished with all my classes for graduation and a little sad that I will not know what to do without having these classes every week. I am off to technology college after graduation and thanks to Accellus, I know I will be successful. I will be on my way to become a electrician. Nervous and excited all at the same time.
yes Caleb yes David. Hope you had a Amazing New Year!
Happy New Year, science Live!!!
I vote for both David and Caleb. I really liked the presentation
I loved the segment about Samuel Morse!
Thanks for such a wonderful topic, vacuum tube Diode. I vote for David.
Wow I didn’t know plants breathe.
I’m so happy that SCIENCE LIVE IS Back!
i vote for both Caleb and David
Happy Belated New Year Science Live! I vote for both David & Caleb!
David and Caleb did so good. We really enjoyed seeing them and learning from them. It was so funny when Area-51 appeared at the end.
I knew plants took in carbon, but I didn’t know they breathed it.
I love how it shows you to never give up.
I definitely vote yes for David and Caleb! Have a good New Year, everyone!
This live was amazing!
Anastasia is so amazing that she can make a new way to find out if tornados are forming.
I love these videos
plants breathe? crazy!
They were both great but I vote Caleb.
Yeah! That is how they survive. If they had no air they would not be able to live.
It’s so cool that plants breathe!
Science live is so fun to watch I cant wait for next week to watch another one.
how small can the robots get
Such a hard decision between David and Caleb. Can we vote for both lol? This may have been the best science live yet! Happy New Year everyone.
I love science live.
Happy New Year!!
The writing program looks fun! I vote for both Caleb and David.
It’s hard to choose. David-yes, but Caleb…also yes 👍! Anyway, HAPPY NEW YEAR🎊!
How do you program the worlds smallest robot to swim?
its programed while its made.
This is the best one yet!!!!!!!!!!!!!!!!!!!!!
yes I agree!
Happy new year!
Watched from Alabama.
Hey wait a minute, I was raised in Alabama!
Happy New year!
I love science live!!!!
Both are very good! Had to go with David though haha!
David and Caleb are funny
Pick both!
I like how he talks about Morse’s code was being made and the process of what inspired him.
David and Caleb are both good candidates.
Happy New year from Seymour, Tennessee
Why does the little robots need light?
I like both of them. They make a great team! I really like how they explain and show it.
I vote for both. And happy new year!!!! 🎊🎊🎊
Caleb
This is cool!
Comment
I am really happy both David and Caleb will be teaching us more in the future. They are really funny.
That was really good!!! I enjoyed the class.
Science is awesome!
I liked David and Kaleb’s video a lot. They have to make more like that!
I love acellus
amazing stuff like always!!!!!
I love playing basketball!
Happy New Year ! who was the first person to invent the vacuum tube and what year was that?
is AP literature a new class? If so, I would love to take it and love David. And science live. And happy new year 🙂
son and grandson, R51 is so funny
Happy new year everyone! Have a great 2026!
How do the little robots swim?
Yes Kaleb yes David
Science live is the best!
That’s so cool she used drones to help people stay safe during tornados.
I think David and Caleb should be working together as a protégé team!
If its not to late to vote, I vote for David. 🙂
I enjoyed watching this. Happy New Year!
I really like watching Science Live.
I liked the part where the origin of telagraph was explained. also, happy new year!
I like both!
I enjoyed the video today!
Wait a minite there is a town in Montana named billings is it named after you?
HAPPY NEW YEAR!!!!
This is my first science live and love it.☺️
I love science live!!!!!!!!!!!! Happy new year!!!!!!!!!!!!!!!!!!!!!!!
I LOVE THE LIVES SO MUCH SO THANK YOU.
Cannot believe how small those robot chips are! and able to swim haha. Happy New Year!
The Vacuum Diode and seeing how the waves of electricity work was very interesting.
not David or Caleb i think it should be R51
Science is so cool!
Hello from Maryland. Happy New Years to all. I love to get lost in a book, too!!
Happy new year!
And I like both but I favour Caleb
BOTH!!! AND HAPPY NEW YEAR!!!!
The 30 second montage was really funny. they’re both really good but I like David better.
Science is so amazing!
Happy New Year to everybody!
First science live of 2026!! Happy new year everyone!
Happy New Year! So glad to have Science Live back
In a half-wave rectifier circuit using a vacuum diode, what is the state of the diode during the negative half-cycle of the AC input?
In a vacuum diode, why does current only flow from the cathode to the anode and not in the reverse direction?
Both of them! Thanks!
Caleb was great, but I prefer David for sure, MORSE CODE IS SO COOL!!!!! Happy New Year!
It is cool I agree with you
Why did Dr. Roger billings create Acellus.
Because he wants to help us learn.
R-51 is so funny 😂
Dr. John mentioned that every robot has its own personal ID. What if the ID’s are mixed up? Would the robots still work?
Happy New Year to everybody!
YAASSS, Acellus is NUMBER 1 on my favorite school program list. Reply if you love Acellus, if you don’t, it’s okay, I’m not pushing. BUT PLEASE!!!!!
I loved this episode. It was fun learning about the tiny computers and seeing Dr billings son and grandson give a lesson as well.
I love science live!
I love dr John!
Both!!
loved learning today!
I think science live was funny and inspiring I also think that both of them should get picked
and I’m so excited to continue with Acellus
I like both but i like Caleb more!
Great stuff as always!
Hi r51. I love you
Both for sure!
David and Caleb are both great choices. I liked this video and I loved learning about Morse code too.
Science is fun!
I choose both!! I love the science live!!
david for sure!
Great to be back! Happy new year!
Science live is so interesting!
I love 💕 science and Morse code.👩💻
Both for sure!
Happy New Years! I am excited for the science lives to start again!!
I pick David. Happy new year!
I like both of them.
Science live is so cool.
Happy new year everyone!
Love watching these on Wednesdays!
Science live is the best!!!!!
this is a great show
I love reading. I choose David.
David and Caleb are both good choices. I liked this video and I liked learning about Morse code too.
Happy New Year!! I like David and Caleb both
Happy New Year!
I VOTE✋ grand son
I also think both! I love science live!!!!!!
Hello from wisconsin!
Happy New Year!
I love science lives. Here, from Wisconsin.
I love science live!!!
I vote David.
Both
Both, for sure.
both!
I Love Science Live !! Happy New Year 2026!!
Happy new years! I had an amazing time watching this week’s science live!
Happy new year!! l love how much I learn on science live
I am actually feeling joy from this
Definitely both!!!
Science live is so cool!!
both of them, happy new year! Love these episodes
So inspiring!!!
I love Pajet MONET,s shirt so much!
I love Acellus!!!!!
This weeks science live video has been very interesting and fun. Over the past two weeks I have been waiting for the next science live video to air. I have also wondered why Dr, Roger billings has not made a car company for hydrogen cars.
Dr. billings is the best!
I love science💕🩵💙
I like both David and Caleb’s videos.
i just started Acellus!
Both!
Happy new year it’s been great being here!
Science live is the best and I vote for David and Caleb. Also, Happy new years everyone!
I pick both DEFINITELY!!!! :3
Awesome Science Live! Acellus is so much fun! Super cool session tonight!
I like both a lot. So my answer is both!
Both for sure!!
Both but like Caleb more *
Both or Caleb!!!😍✨☺️
I would like to have both David and Caleb.
Both of them are a good duo
I think they’re both great! They showed a lot of interesting things with electricity.
First time watching! Just started Acellus this week. So far, I enjoy it! Enjoyed this live!
BOTHH
Both!! 2026 has been a great year so far!
I choose them both! I love studying science!
I pick both!!
Very cool!
I say both!!
I understand more why reading is important, and why it is worthwhile to do for my future endeavors!
Learning about the past and current events is my favorite thing to learn about that’s why I love science live thank you so much for doing science live
R 51 is fuuny!!!!!!!!!!!!!!!!!!!!!!!!!!!
Both please
100% both
I vote David
both!!
Do both of them!
I vote both!
I love you roger billings
hi from Viet nam, I love r51 Happy new year !🎆
science live all 2026!
I vote David!
Science is the best!!!
I pick David!
Hello from Wyoming!
I vote for David. Science live is awesome!!
2026 is here the science live is still the best
100% both
I would say both of them.
Both!
I loved tonights science live! Cant wait for the next one!
I VOTE BOTH
I love Morse code!
I vote David, but both are great.