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 and David.
Does the microscopic robot swim on top of the surface of the water or under the surface of the water.
R51 is the best!!!!
Happy new year from Utah!
I think that Kalub should have their own film class.
love it! I vote for both
I vote for both of them. also plants breathing does not make sense
The painting Samual made of famous paintings is really cool !
I vote for David and Caleb, they make a good team and they are funny.
Great show today!!
I think both are great!
I vote for caleb
I live in Arkansas and tornado season is the WORST out here 🙁
Hi from Mississippi great show, I vote for both!
I didn’t know robots could be so small.
R51 is so funny everytime he comes on I start laughing
HAPPY NEW YEAR from Alabama!!!!!
Happy new year I vote for both
I cannot choose between these two guys, they’re both awesome.
I vote for David and also happy new years
Happy New Year. David and Caleb are funny
I loved this science live possibly one of my favorites!
Making a self portrait is pretty impressive.
I vote for both.
One of my favorite ones yet i love it!
Hi from Japan♡☀︎
my family is from japan too 🙂
Great news to hear about Anastasia’s success.
R51 is so funny, also Happy New Year from Georgia!
I liked the parts about Morse code. I thought that Caleb and David both did a good job.
i love roger billing its my fav part of the week
I love how Acellus is creating a new English program
one of my favorite lives yet!!
i love roger billings i learn sm every week
Let’s get this party started!!!!!!
I love science live it’s the best.
It is hard because I like both of them. Probably Caleb I also like David too. Happy Late New Years!
daviiiiiiid!!!!!!!
they are both so good.
I love SCIENCE!!!!!!
👍👍👍👍👍👍👍
I think it is crazy that robots are getting smarter but smaller.
R51 is my favorite. I love the tiny robot. I vote for David!
You can definitely tell where Caleb gets his sense of humor from haha. I vote for both Caleb and David!
First science live down, and I vote for Caleb !!!
Happy New Year! also i vote for David & Caleb.
Happy birthday Dr. Billings
Yay science live!
I’m so glad that both David and Caleb will be teaching us more.
Happy New years, I vote for Caleb.
WOW!
It was thrilling to see Roger Billings son, and it’s very interesting that robot’s can get so small. Someone should make a army of tiny robots.
Science live teaches me something new every episode.
Happy late new year, hope it brings good luck!
How amazing is it that Dr. Billings has a son just as smart as he is?! I vote both gentlemen, they both seem to be headed in a an awesome direction to a very bright future. Congratulations to Anastasia, just WOW!
Science live is the best!
I vote david, and happy late new year! I loved this Science LIVE by the way.
Happy new year y’all!
how deep can the tiny robots swim around in water and would they be able to swim around in the ocean?
David and Caleb definitely!
Happy new year everyone!!! 🎉🎉🎉 I really liked this science live! My favorite part was when Caleb and David explained vacuum tube diodes also the 30 sec build montage was funny! the ☕ break was funny
I think that this science live was incredible.
This Science Live was my favorite! 100% both CALEB & DAVID!!!!
Thank you Acellus team! David and Caleb were both great, and I loved how genuine their relationship was. Also it was so neat learning about morse code, I think it is so fascinating how it works! I make morse code bracelets with encrypted messages on them for my friends and family! Looking forward to next week!
I love reading books!
I vote for both, David and Caleb😍
I love watching these!
It’s very interesting to see how the vacuum diode has changed over the years.
This science live was fascinating plants breath yes we know that but you explained how and why :D.
Happy New Year. I didn’t know plants breathed either.
science live is so fun to watch!
100% CALEB & DAVID FOR THE WIN!!!
I vote for Caleb & David I also try to play the guitar.
Greetings from Kennewick, Wa!
Happy New Years! Can’t wait to enter 2026 with Acellus and learn so many new things! 🙂
(btw, loved the science live today!)
Happy New Year! Good job Caleb and David!
Excellent science live to start of 2026, I look forward to all of the inventions that will be shown in these upcoming science lives.
I love r.51 he is so funny I love the videos
It’s crazy how planets breathe!
How do those tiny robots swim?
Dr. Tobias is so silly and inspiring, he’s my favorite! I loved the montages of Caleb and David, they are very charming and definitely have what it takes! (I’m expecting to see Caleb in a TV Show 🙂 )
I vote for david
Happy New Year from Kentucky!
Happy New Year from Wyoming!
Watching this got me inspired.
I choose David and Caleb! Hi from IL – Kimry
What is the process that will enable these plants to use water more efficiently? Also, with this new development, what else can we change about these plants to make them more efficient?
Its crazy how it is 2026 already.
what’s the most difficult situation you’ve ever been in roger?
Happy New Year 2026! Amazing Science Live video!
R51 is the best.
Do they still use morse code that often today?
Today I learned what a vacume tube diode is. Also that no matter what you are good at you can always learn something new.
wow roger billings is so inspiring
I like when there is history in science live! I like both Caleb and David.
I love this so so much!!!💕
Loving Science Live!
I think as the years goes by the robots will be more advance and doing more things for humans.
I voted for Caleb I love cameras and I have always wanted to be an Acter, and I love editing I edit literally every day. 😀😃😄😁😆☺️😊🙂🙃😉😌😛😝😜
I love science live can’t wait for next week.
I really enjoyed learning how the Morris code was invented. The tiny robots were neat as well. Most of all I liked meeting David and Caleb. Caleb needs to teach us how to play the guitar!
How did Samuel moore creat morse code? I vote for both david & caleb!
This is my first live! I didn’t know plants breathe, but now I do!
My name is timothy and i wonder will we learn more about hydrogen or are those episodes over?
I liked when they were talking about the tiny robot.
Happy New Year Science live!! I voted for both Caleb & David! I love Science Live!!
Great video! I vote for David!
I vote for Caleb and David
I want a tiny robot now!
Happy New Year! I vote yes to both David and Caleb.
Its amazing how they were able to make a robot so small!
Plants are so important to our enviornment!
Two bright minds = Two votes ( David and Caleb)
I really like how every episode it shows a student achieving there goals. Go Anastasia
I pick both! Happy New Year!
I like both of them its hard to choose so i’m going to say both
Happy new year! I vote for both
They make a good duo.
I actually have to vote for both of them.
I like this because this teaches a lot facts I didn’t know.
Happy New year! Science lives on!
I love science live!!!!
Awesome science live as always! Caleb AND David 🙂
Happy new years everyone! its been a great year so far!
This is the greatest show
This live was just great, loved it all.
I vote for Caleb and David! also happy new years again!
Welcome back.
Happy Belated New Year Science Live! I vote for both David & Caleb!
Happy late New Year! It’s surprising that people can make robots so small.
I really enjoyed this Science Live. I would like to see them both because they’re both funny.
I really like Science L!VE. I knew that plants do breathe through holes called stomata, but I didn’t know that Samuel Morse was a really good artist .
I LOVE SCIENCE LIVE AND A HAPPY NEW YEAR!!!
David and Caleb. The video was very funny and they both explained the process very well. 🙂
I loved this episode!
Happy new year!!!! I vote for David
Learning how morse code works was amazing and I vote for Caleb
Happy new years Science live, can’t believe it’s already 2026!
didnt know you could predict tornados forming. so cool!
Happy new year from France
I THINK BOTH
I can’t decide….. I choose them both Caleb and David!!
Welcome back, y’all! Happy 2026!
Anastasia’s story is inspiring. I love how she knew her dream and reached for it, and is using it to help people.
I really love both of them, but I’m going to vote for Caleb. Happy New Year from Kentucky!
It would be really cool to do something for NASA!
I vote for both!!!!!
Happy new years! This science live was amazing I can’t wait for next week science live. I love learning new things and I enjoy watching all the interesting information that science lives bring.
David for the win.
I love the jokes from science live!!
🔥🔥🔥
Todd Edmond is my favorite teacher
I always love R51, he is so funny.
i vote 1 for both David & Caleb!
I think that the worlds smallest robot is really cool because it can swim and it can be reprogrammed with flashing lights. I wonder how long it took to make Morse code? I liked meeting David and Caleb today.
Caleb’s segment was pretty entertaining but David was close
🩷 science 🧬
Plants breath that’s so cool.
Acellus is the best
I vote for Caleb and david both
Eli here watching from Ohio
Also I almost forgot to wish you guys a great new year so here ya go. Happy new year and I hope you fulfill your new year’s resolutions.
Thank you for the video. It was very interesting. David and Caleb were really exciting . I didn’t that plants breathe carbon dioxide.
If Dc current is better in most scenarios then AC what is AC used for?
i choose caleb
My vote is for David!
It was cool to know that wrapping a metal and giving it an electric current can turn it into an electromagnet!
Happy New Year!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Happy New Years! The left foot joke was a good one, happy to be starting my new year trying a different schooling method!!
Another great science live, I always love watching.
Happy late New Year to everyone in Science Live!
GEORGIA, TEXAS, monitoring a tornado is cool and i misses this, happy new years.
I’m still shocked planets breathe.
I love science live, I voted for David, I did not know if you could vote for two people or not.
I vote for David and Caleb!
I vote for David and Caleb. THEY ARE GREAT!
Today’s lesson was pretty good! I vote David and Caleb.
I thought it was cool that the smallest robot is the size of a grain of salt.