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 believe that robot is the smallest I’ve ever seen! I also vote to keep David & Caleb, they were great! I love watching Science Live!
I vote for both!
I vote for David but caleb has my vote to
it motivated me a lot .
Vote Caleb.
I have to go with Devid he’s lowkey the goat
I vote for Both Caleb and David.
happy new year! I’m voting for both!
It’s amazing to see how small computer chips and robots can get.
i would love to see that hydrogen powered drone.
The tiny robot was very impressive!
David is my pick due to the fact that he has potential dad energy and seems to be already heading in the right direction of being a good influence towards the community
I vote for both of them!
Hi!! Great video. Thanks for the winter break! I honestly like both David and Caleb. I don’t think I could pick one or the other!
I gotta go with both!
They would make a great duo!
Congratulations to Anastasia! her idea sounds pretty cool to me, and i’ve always been invested in tornados and natural disasters, so whenever they do finish the product, i cant wait to see how it comes out! i always give both David and Caleb my vote!
It’s nice to be back to watching these videos! I really missed these!!
I vote Caleb!
I vote for David
David and Caleb yes yes yes!! — Just don’t step down. (just not to much at least.)
I think the tiny robot was interesting and thought it was amazing that Morris was an artist before an inventor, because I also love art. I think Rodger’s kid and grand kid were very good but I don’t want Roger to leave because we would all miss him.
I vote for Caleb
Tobias’ sections are my favorite.
Vote David. Good episode
The morse code story was so cool! I always wondered why the pattern for what letters got what combinations was so random.
I vote for Caleb, I liked his perspective more.
Vote for David 100 percent
Science live is sooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo good 👏👏👍👍👍
I think I prefer David! Hard choice though!
Caleb
That was really fun and educational. That mini robot was so cool :0
:)A :)M :)A :)Z:)I:)N:)G:) 🙂
How does blood circulate
love this show!!
I definitley would vote for both honestly they are both the goat
I vote for Both David and Caleb
I vote for both
I vote for both!
I VOTE FOR BOTH!!!!
Hi from Texas! Thank you for the Science Live!
I vote for Caleb! 👍🏻
The vacuum tube diode was very interesting to learn about. I’m so happy Science Live is back!
I vote for David cuz he’s the BEST!!!
I vote both
How did they find out about positive and negative?
Honestly, I vote for both!
love you guys. Calbe and David did a really good job
I vote both to be honest
Definitely voting for Caleb!
I vote for David he did amazing
I vote both!
I vote both I hope everyone had a nice break
I vote for both son and grandson. They make a great team!
This was my first week of online school and my first Science Live. That was fun. I vote David
I vote for both I had fun watching this with my sister
We vote Caleb
This was a wonderful Science Live! It’s a very close race, but I have to vote for David on this one.
Caleb is my goat gotta vote for him!
I vote for both!
I ❤️ science live!
How do you fly a drone in a tornado? Won’t it just be thrown around.
I liked both David and Caleb.
I honestly liked both David and Caleb as candidates. They both possess different assets that could complement each other if utilized together. I liked learning a bit about each of them personally. Good luck to them both!!
I like caleb the most he’s incredible.
I vote for David
Great teamwork. I also loved learning about morse code.
David and Caleb make a great team.
I honestly vote for both . I really liked this episode . Can’t wait to learn more stuff . Learn something new every day
Comment I liked Caleb and David. I liked the vaccum tube diodes, how interesting. And how about Dr Billings sons just as smart as he is. Absolutely amazing!!!
Happy New Year ! I really enjoyed this science live.
BOTH!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
I like the student spotlight
i loved the mores code part, my dad did that in the military!! these lives are great
Today I learnt that robots can be smaller than a grain of rice and still work perfectly fine.
It is nice to know that there is another AP class being added!
Samuel Moore’s telegraph and code essentially laid the foundation for long-distance communication, something we use daily when calling or texting.
Science is one of my favorites! I honestly am going to vote for both!
I think it’s crazy that scientists could build a robot that is so small! It was a cool and interesting video!
I actually like both Caleb and David. They work well together and make it fun to watch. Also, with the tiny robots, would they be able to make them so they could be injected in a human and help to find medical problems?
I just want to say thank you to lady
Pajet for giving me the confidence to face my fear and putting my shyness behind me so I can make someone who looked down happy and I gave her a flower I made.
I vote both David and Caleb. Also the hydrogen drone advanced warning system drone concept is a brilliant idea from the Acellus graduate.
I LOVE ACELLUS!
Thank you so much lady Pajet Monet and Roger billings for all you all do! I vote for David and Caleb!
I would vote for them both
I really liked this episode
In my opinion the portion that dived into how morse code was invented was the most interesting part of this video.
I vote for David and Caleb, they make a good team and they are funny. Great Live!
How did people discover plants release oxygen?
I LOVE Morse Code. I used to study it in my free time. I had my friends write stuff down just for me to translate it into Morse Code.
The Nanobots are really amazing!
A hi from Vietnam
I love R-51 lol he’s so funny
I love both
I love R51 he’s funny.
The world’s smallest robot is unbelievable! So cool!
I voted both!!!! 😀
Great first Science Live in the new year, hope it continues for years to come!
Thank you for the Science Live
They are both impressive and inspiring.
My favorite part about the episode was the part about the telegraph, I never knew that it was invented by a painter.
Science is one of my favorite things. Experiments I really enjoy doing.
This is awesome!!!
Samuel was such an incredible painter wow
R-51 is to funny 😆
Happy New Year! I’m ready for a good year in school.
How did they build such a tiny, tiny robot? That’s really awesome.
This is probably unanswerable, but how small could we possibly have computers become? They already are so tiny, but I wonder how much further we could take it.
I liked the robot. As well as the way Caleb and David explained the vacuum diode wave part. I agree and vote for both Caleb and David.
This weeks science live was great! I’m looking forward to next weeks!
Whats the difference between AC and DC?
Welcome back. I hope you had a great holiday!
I loved seeing David bow hunting! That is one of my favorite hobbies.
I love science live yay wahoo!!!
I have to vote for both, they both have their own charm, in their own way
HAPPY NEW year 2026 from: Georgia 🎆🎆🎆🎇🎇🎇🪩
I love Acellus!!!
definitely both!! i’ve also always been intrigued by morse code so im happy that was included! i loved this week’s science live!!
100% Caleb!! 🙂
All this robot stuff is really cool and I would like to learn more about it
I think the vacuum tube diode is really cool because its a very early invention that allows you to control the flow of electrons! it was also nice to see more of Roger Billings family like his sons and grandsons.
how are you R51
Happy 2026, y’all!!
Oh wow I never wondered why it’s called Morse Code!! Great episode!!
I cant wait for todays episode! I love Acellus!
I vote for both David and Caleb. Happy New Year from Nevada!
I love you R-51. Happy new year from Nebraska
The part about Morse Code was very interesting!
Hi Addison from Guam 🇬🇺, I did vote for both of them,
And this episode was amazing 🤩.
That robot from Pennsylvania is so small I didn’t know that it could swim that way and I vote for Caleb and David!
The history of electronics is electrifying! Thank you for sharing!
I think it is so cool that books can help understand the past better I love reading. I also vote for both of them and congratulations to Anastasia!
I LOVED today’s live!
This was a very neat video, I hope you all had a happy new years! 🎉
science live is fun to watch!
I vote for David and Caleb. I love science live!
I recently started looking into morse code but never knew how the dots and dashes came to be. It was fascinating to learn the history behind the language and what inspired it. And I was shocked when I saw those miniscule robots, crazy how small you can make them. This is exactly why I like tuning in to Science Live, I learn something new every week!
I love Science Live! Thank you!
Such a great episode! I vote for David! 😀
Thank you dr billings!
Both protégés are great and humorous, so I can’t choose one yet.
Its good to have science live back!
Celab is a cool guy becasue he do everything i like do to:).
Hearing about Anastasia’s gives me so much motivation!And for the voting, I would choose both!
I would vote for both! It’s also so nice to hear previous students accomplishments! It give me and many others motivation to strive!
R-51 is so funny!
I vote for David and Caleb! This was a great episode!
I think it’s cool that scientists at the University of Illinois have a new way to watch plants breathe.
Caleb, the goat. Nice humor and all the grandchildren say hes the best!
Hello from Alabama!
I vote for David.
I vote for both David and Caleb, its hard to decide because they both have strengths in different areas, but that’s really cool to see! I hope they both get this opportunity!
It was fun to watch the world’s smallest robot.
Why does the vacuum tube diode only let electricity go one way?
How does the rectifier get rid of the bottom part of the AC wave?
Tobias is my favorite person on science live.
I still think that Tobis should be science/history teacher.
Thats honestly exactly what i say when people say “I dont like to read.” You haven’t found the right book yet. I’m so glad thats being implimented
hearing about the robot is also super cool
Truly amazing! I learned a lot from this, I will definitely be back for more!
Vote for Both!!
I vote for both David and Caleb
This is amazing ✨
I agree.
Can vaccuum tubes be used to harvest hydrogen somehow?
Agreed! my vote is for david
I vote for David and Caleb
I love R-51in the science live, he’s so funny!
I gotta go with david, hes just the goat. This episode was amazing
I vote for both!!
Same bro
No Caleb
I can’t disagree he is the goat
I honestly vote for both.
I vote for David!!
I’m going to have to go with David but I love them both
I vote for both!!
Ohio ….voting for David
David has my vote . Amazing live!
I vote for Caleb
Both!
Yes! Team Caleb Vote here!
I’m trying to be in a band to! Speaking from CT.
I think Caleb too!! he’s just so funny!
I voted for Caleb and David they were both amazing
I really liked this episode. I vote for David.
This episode was probably my favorite so far. I gotta go with Caleb!
That was wonderful! I prefer David because he’s more serious (probably because he’s older;). I’m very excited for the new episode!
Hi from Utah! Thank you for the Science Live!
I love science and I personally am voting for both.
Both Daniel and Caleb are great! So happy we’ve made it to the new year and science life is back! Excited for the new English class!
Congrats to Anastasia! that is amazing!
I loved learning about the vacuum tube diode.
Honestly, I vote for both!!!!!
R-51 is so funny and makes my day honestly
My favorite part was when R51 was teaching the big R how to make a grandson with 2 batteries and a sunflower.
Thank you so much for these AMAZING lives!!! Hope everyone has a wonderful blessed year.
I rate this science live a 10/10