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 »
R51 did it
Happy late New Years! I vote for Caleb!
This Science Live was so interesting!
This was so fun to watch! Thank you Acellus!
merry Christmas and a happy new year everyone.
I vote for both david and Caleb.
Best part of my week!
So cool! Enjoyed watching this one
I love science live !!
Congrats to both David and Caleb amazing
Science live is hecking awesome!
Congratulations on the new AP and literature course! It was really cool hearing more about Morse Code history. That was a great video about David and Caleb and how they solve problems. Happy New Year!
Happy New Year to everyone at the Science lives!
I vote for David ! Happy New Year!!! Great live !
It’s cool how plants breathe carbon dioxide and not oxygen.
The possibilities are almost endless with theses robots when become advanced.
I think its crazy that the smallest robot in the world can do so much, while being smaller than a grain of salt.
Vote for both!
i love drones! it’s interesting how they use them to keep people safe from tornadoes!! 😀
It’s incredible how engineers can create microscopic robots, SMALLER THAN A GRAIN OF SALT! I vote yes for David and Caleb. Great demonstration of AC and DC current.
This live was very fun to watch, and I learned a lot of cool new facts.
this was very interesting r51 having a son and a grandson was so funny
cant decide they are both so funny though!
Absolutely both David and Caleb!
i vote for david and caleb!!!
Caleb
Science live was great and even more educational. I’m excited to be back, and happy belated new year!
Caleb has the coolest job. I hope he gets to become an actor!!
i love that drones keep people safe from tornados
I vote for David and Caleb!
I thought both David and Caleb were very entertaining to watch but I vote Caleb because he was hilarious.
David and Caleb both seem really cool. I would like to see them both come back if possible. Also Happy New Year!
Thank you for explaining HOW the dots and dits of Morse Code were assigned! I always wondered!
greetings from wyoming. thanks for the live
I really enjoyed the latest edition of science live. I vote for both David and Caleb.
I’m just amazed at the fact that Fleming worked for both Edison and Marconi, and was the person who used the Edison effect to create the first Vacuum Diode.
Both Caleb and David I like. but Caleb I like more.
Happy New Year! I love hunting too!
David and Caleb!
I vote for both
I don’t think I am a good enough listener to have been an operator for Morse code!
Always love tuning in.
I liked them BOTH. They explained it so well and, they made it interesting too. I have only been in Acellus for a week but, I LOVE IT SO MUCH !!!!! Reply if you love it !!!
I love science live stay blessed, David was super funny
its really cool how they take the time to give us so much knowledge about various topics
I liked learning about how plants breathe through their leaves because they have tiny holes. They breathe in carbon dioxide and breathe out oxygen.
My favorite quote from this episode: “Here at Acellus, we’re having a lot of fun!” So true and I tell my friends this all the time.
I am also learning how to play the guitar.
Love this one! Hello from Florida!
Happy belated New Year!
Wow! This was very encouraging for students who don’t believe they can be inventors!
I vote for David and Caleb good luck to both!
They are both very good, but I have to go with Caleb.
I learned so much from this and it was such a great start to the new year thank you.
I can’t pick between caleb or David
I enjoyed watching the video that David and Caleb made.
WAIT A MINUTE R-51 HAS KIDS NOW!?
Happy New Year! I would probably vote for David.
Thank you Dr. Billings
Happy New years I enjoyed todays live! Vote for Both David & Caleb!
Both are amazing… but I will go with David.
I Love this science Live and I vote for David &Caleb
Happy new year!!!!!!!!!🎊
Both are good but I think David!
They’re both wonderful candidates. I would but both if I was able to but Caleb seems better.
I loooooooooove robots!
This video was so interesting and educational! I love it!
They are both wonderful candidates, but I think I would choose Caleb over David. They make a good team though. If I was able to, I would vote both.
That is cool how a robot can be that small but how is it classified as a robot if it looks like a chip?
Loved the live! It is so hard to choose who to vote for! I really liked both of them!
wow that’s crazy how much robots can do !
welcome everyone and welcome to a new year! And I’ve voted for david!!!!!!
I can’t believe it’s already 2026!!!
That drone looks so cool! Would love to see the statistics of the tornados when done
Happy new year!!!🎊
HAPPY NEW YEAR
Really liked this episode, that robot was SO tiny it’s crazy, and I think I would pick David but I do like them both
I liked how Dr. John was talking about the smallest robot that was ever created. Dr. John had also explained that this robot is so small it smaller than a gram of salt and that it can swim even though it’s size. Dr. John had also said that the hardest challenge was making sure to create it to swim since it’s such a tiny robot.
How did we discover brain waves?
This video was great! I vote David and Caleb! Also didn’t know that plants could breathe.
I love science weekly! I always look forward to it every week!
Hi from Canada, love the video.
I like David because he hunts and plays foot ball and i do the same as him.
I like how both Caleb and David work and i think they should be partners, so I voted both!
How did they make that robot so tiny?
HAPPY NEW YEAR! I can’t wait for the new AP LITERATURE AND COMPOSITION CLASS!!!! I hope ya’ll have a great day, and keep on working!
happy new years from Massachusetts hope you all had a good break
David and Caleb are funny!
Happy New Year! So glad Science Live is back!!!! Happy 2026 y’all!
Amazing Science Live! Happy new year!
I like David and Kaleb.
did you know that when you “smell the rain” you are actually smelling the chemicals and oils the plants release when they get wet? Always a fact that never ceases to amaze me!! ;3
This science live was fantastic!
Honestly one of the BEST episodes I ever saw what a great way to start the year! Happy new year and I vote for both David & Caleb!!!
I really enjoy learning about radio waves
SCIENCE LIVE IS GREAT
Hi from Canada! This live was amazing! Can’t wait to watch more.
I vote for both Caleb and David. Happy Belated New Year!
Happy New year everyone. Both Caleb and David did a great job.
Can I vote both?
Really exctited for a whole new year of science live! Cant wait to see whats in store for 2026.
Happy new year Dr. R! Love this Science Live episode!
how do the vacuum tubes effect our life today?
Thank you for the Science Live video this week. It was very interesting.
HAPPY NEW YEARS!!!!!
Amazing video! I vote Caleb.
I say both David and & Caleb because they’re a perfect team when working together .
I watched this in Idaho
I think David and Caleb both explained things properly and was super easy to understand!
Happy New Year! 2026 is gonna be a great year!
I voted Caleb
Science is fun
I vote Caleb and David.
happy belated new year!!!!! i vote for david.
I think David and Caleb are both good proteges.
It is really cool how people can make a robot small.
I vote Caleb and Happy New Years Acellus
Thank you Acellus live it was great. I like them both
This was a fun Science Live!
caleb is good
It’s true when you find the right book, you enjoy reading them
Today on Science Live, I learned about the vacuum tube diode and Sir John Franklin. The vacuum tube diode, also known as the Fleming valve, was invented in 1904 and is used to control the flow of electricity. I also learned that Sir John Franklin was a British Royal Navy officer who served in the Napoleonic Wars and the War of 1812.
Never thought I would enjoy learning.
How cool would it be if they started teaching Morse code in schools? Keep rocking, Acellus! This live was great!
I going to vote for Caleb because I love music and I love editing too.
awesome wisdom from the one and only roger billings!
Awesome video! I voted for Caleb!
so cool and i vote for David
GREAT VIDEO! this is like the highlitght of my week y’all. Thank you so much for doing these!
I love my ASL teacher
What is a diode?
I love science. Yes vote for Caleb and David.
I loved this one!
I think both David and Caleb are great candidates!
i love science live! i vote for both guys.
I think David and Caleb both would be awesome!!!!
Happy New Year!! I vote both!!
Happy New Year! I vote for David and Caleb
Thumbs up Caleb Thumbs up David
Yes. David and Caleb for being proteges.
I love Science Live!! Explaining how plants breath and being able to watch them breath is so cool!!!
I can’t wait till next weeks science live!
Science Live is always intresting!!! I love plants so learning that scientist have a way to watch plants breath is so cool.
I learned that there are two main ways that electricity flows: DC means that the electricity is flowing in one way, and AC means that electricity is flowing back and forth. The video was fun.
that video on the vacuum tube diode was really cool
plants breathing is amazing!!!!!!
Vote for both David and Caleb! Very creative and easy to understand. Enjoyed this episode!
Happy New Year from Arkansas!!!
David : )
I love science so much
That was awesome when they built the wave. The part when Area 51 came was funny.
I vote for both David and Caleb!
Caleb and David yes!!
Love these, keep it up and happy new year!
Im excited for all the new things i will learn with Science Live in the new year!
I never knew that plants can breathe, that’s so cool!
I think this is my favorite episode of science live
I thought the dive into something so foundational in electronics was well made and in depth.
Tumbs up David. Thumbs up Caleb
david is my favorite because hes like hunting
One thing I liked about todays video is learning about how Sir John Ambrose Fleming and Thomas Edison got together and had a plan on how they would be able to create the Vacuum Tube Diode.
Great Science Live video to kick off 2026.
I LOVE ACELLUS!!!!
I really like learning and getting to know people.
It was very hard to pick! I voted for both! Happy new years!!
happy new year science live. i vote for David & caleb
This was such a nice video! I loved the section where they talked about AC and DC (although i’m surprised there were no AC/DC jokes). Also I vote for Caleb not only because his name is awesome but also because guitar is awesome
no David-NOT THE DEER, lol the tree sitting XD love that, both videos were funny, I also like when Caleb says (yeah Caleb is definitely the favorite grandson)
Both were good! But I have to go with Caleb!
Will from Georgia
Both are good i had to go with Caleb though
OH MY GOSH THAT ROBOT IS SO SMALL!!! what a great episode 😁 thank you!!
I like the new dudes and I am glad to still see R51 in 2026.
I vote for both I can’t choose just one!
BOTH!!!!!! Happy New Year!!!!! Watching from Massachusetts!
I liked the fact that Caleb and David broke down the terms in the sentence before they made us think about the question.
Honestly, I’d vote for both Caleb and David. It would be too hard to choose just one!
I never knew plants could actually “breathe” I always thought they could survive just off being watered.
Both Caleb and David are my votes!
Caleb said he loves music and does video editing witch made me smile because I actually love music as well and play several different instruments including Guitar. I’ve played Guitar for a couple years now, so I vote for Caleb.
I vote for both Caleb and David. I like how they have very different personalities but also work together very well. I love how they explain things.