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 »



Thank you so much Acellus Live for all you do! I look forward to it every week.
It is so cool that we can watch plants breathe and with this knowledge we can make new plants!
It is amazing that we can track tornadoes in areas that don’t have good radars!
I can’t believe that there is a robot that is smaller than a grain of sand!
I think Morse code should be taught more. Please make a Morse code activity for Accellus! It would be fun and educational.
Thank you for sharing this information.
I love watching Dr billings
I find the swimming tiny robots very interesting! I love learning about this kind of technology.
i learn something new every time I watch science lives
Drones are so interesting!
Great Episode! The Billings family are very funny!
i love it! it was Awesome video!
Morse code is so cool, I’m really tempted to learn it!
That small robot is really cool!
Always entertained with science live!
I think this weeks video is very interesting.
I think Caleb and David make a great team
How long did it take to finish Morse code 🤔??
Roger billings made the first hydrogen cars while everyone else is waiting for them
I wished more people talked about morse code…this was a great live!
Loved this thank you
Science live is awesome!!
David and Kaleb both did really well. I vote for Kaleb because he explained the things really well and made it fun!
I really enjoyed the live session this week! Both contestants definitely have my support!
My famiy and I plant flowers and vegetables each year in the Spring, but we keep coming to find out that living in Illinois, the weather is not the same so we learn something new each year.
That was cool, thanks!
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I feel inspired to learn morse code now.
I never would have guessed that plants could breathe! I guess if they have holes in their leaves to breathe that would me all plants have holes in their leaves.
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This science live was so cool
thank you. Learned so much.
Drones are my favorite
David and Caleb are so funny! I love the way they explain the Edison effect and how it helps create a vacuum tube using a light bulb and a AC Generator! It blows my mind how these things work!
hi from Kentucky
That is astonishing that they could even make a robot that small, and having that microscopic spec actually move by commands is actually insane.
What is the Vacuum Tube Diode?
y they explain how the edison effect helps create a vaccuum tube to rectify a wave. It blows my mind how these things work!
This is so interesting but I have a hard time following the electrical current.
I’m excited for another whole year of science live.
My favorite R-51 segment yet.
Morse code is so awesome. Thank you for the info!!!!
Wow its so crazy how Morse created his own zigzag langauge and later Morse code!! Thanks for this video!
Computers are so useful.
love love love Science live thank you for everthing we get to learn!!!!!
I love how funny David and Caleb are! I also love the wa
Wow that was very interesting.
whats the smallest computer ever made?
Id love to help them in their workshop.
Absolutely loving this, keep it up
I love that everytime i watch i learn something new
Why isn’t Morse code thought more to people?
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Amazing !🤩 I love science live!
What is the main function of a vacuum tube diode?
Morse code Is so interesting.
How is morse code used in the present day?
How often do plants breathe?
Plants give us oxygen, good to know.
Hello from North Carolina!!
Drone are like so cool
this is my favorite episodes of science live?
I look forward every week to these science videos and I kept checking in during the holidays for new ones forgetting that those two weeks we were “off.” I watched other ones and am interested in watching many more. I want to be a lineman someday so I am particularly interested in the electricity and engineering videos. Thank You for making these so user friendly and not boring.
Exciting news about the new AP courses!
What is the oldest computer ever made?
I love the paintings they are all so intricate and pretty!
Love watching these lives every week!
Sammuel Morse in the early 1800s started out as apainter in France. He started thinking of a way to get messages quicker after he recieved bad news about his wife. He worked on what became the telegragh.
hi from georgia
These weekly videos are extremely insightful.
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LOVED THE VIDEO!!!
Love this!! I want my own drone now 😂
Superb recording! I specifically enjoyed the insight shared by Dr. Tobias when he stated that we might one day be entering the Hydrogen-punk era.
Considering I have only known cyber-punk era, I believe this change is much needed since we have innovated a lot since the 1990’s.
I am very excited for this era since green-house gas emmissions will be under control, energy efficiency will sky-rocket, and many more pro’s for us as a people.
How is the largest computer used
Thank you for producing such insightful science lives!
It is astounding how they can make robots so small and able to swim.
I love that part where they drank some coffee in the middle of the project!
The Morse code segment was super cool!
Morse code should definitely be taught more.
Science live has so many diffrent aspects of it
Best video :3 I love watching the videos<3 keep up the amazing work
That is so interesting about the plants! I like learning about them!
Great Video! looking forward to next weeks!!
thank you for this new and interesting episode!
a vacuum tube diode made early radios work and glow when its on
science live is pretty cool
Video was so fun! I liked the drones and the secret code part the best. The best!
I hope Science Live continues for a long time.
That is a really small robot! It’s so amazing how it can do stuff when it’s so small
How would have technology diverged if we weren’t able to shrink electronics?
Having been able to make a robot so tiny, that it’s smaller then a grain of salt. is amazing!
How does the temp sensor affect the reciever?
telegraphs are always so interesting to me!
Why was the Edison Effect important?
hello from tenneseee
Hydrogen cars are better for the earth than gas cars.
When did technology really start to play a part in our society?
I loved seeing how a complete cercut is created. It is amazing how far we have come with electronics. How small do you think computers will become? How much power does it take to run ai?
I liked this one a lot. Science can be so much fun
The robot was so adorable! Techonogly really is awesome!
This is interesting
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Wow, I have always wondered why it was called Morse code.
I love these videos!
Great video. I love how these videos show me new things and information.
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morse code is cool!!
What are these robots good for?
Watching from NY!
This new science live was so cool! It taught many new things!
Can we see a video of the plants breathing?
Science is so interesting!
I think
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i never knew u could move or nudge a tiny robot by just a simple electric current! so cool!
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how does graduation work? Do we come to you? is there a ceremony?
Morse code has always fascinated me. Great episode!
Radar systems are so cool! I hope I could use one in the future!
What is the largest comet in space?
It’s really cool how our education along with persistence and determination can help us to achieve our life-long goals and dreams.
Thanks for giving me and my family this opportunity! I love these science live’s!
Radar systems are so cool! I hope to use one in the future!
It’s so cool to learn about how to help the environment around you!
that tiny robot is super cool! 🙂
I had no idea that Acellus provided such high level classes!
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I love learning about morse code thanks for that segment!
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I like how the nanobots can swim.
The info here is nice to know, wonder if I’ll ever use it. Hehe!
It is truly amazing how small robots are now and I would love to see the process
When you really think about technology its amazing.Great video!
what is the exact size of the robot?
Morse code is awesome!
Who created the first ac to dc converter?
David and Caleb were awesome and so funny!
edit: *Wait, I thought someone else invented Morse code? Also I kind of like both David and Caleb, please keep them both 🤣, although they’re not as good as R-51’s AI generated son and grandson lol.
Why do you think they change the food pyramid?
What and when was the largest computer made?
I wonder what plants breathing looks like.
it would take over 100 million to fill up a house floor with those tiny robots
science and all of that stuff
that robot is so tiny its cute!
That tornado drone was such a cool idea!
Thank you for the educational episode!
This was a well made video, and I love the part where it talks about the student who got into that amazing college, and built the awesome & fantastic machine!
I love the Area 51 parts at the end
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I like the 2 one I love Guitar I also want to play the guitar.😊
The tiny robot moves surprisingly fast for it’s size.
I liked hearing their explanations and I like hearing what other students have gone on to do after graduation
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This video was really entertaining
The robot was so cute!
With the mini robots could you use them for cancer treatment?
how was the Eiffel tower constructed
I’m going to try the morse code with my friends!!
I think learning Morse code could be interesting.
We learned about the world’s tiniest robot and it only cost a penny.
once again a funny and interesting video!!
Those tiny robots are so cool!
What was the biggest computer ever made???
What would the tiny robot be used for?
I loved Tobias’ bit on morse code, I still have my great grandfathers old telegraph key.
I got some cool ideas from this live!
How would the small robots be extracted from the body if they decide to use them as a drug delivery system?
These lives always teach me something new!
Can’t wait for the next live tonight!
The video explains everything very well!!!
Do all students do AP English?
I would like to learn Morse code.
Loved Caleb’s and David’s video’s!
The story behind how the telegraph and morse code were created is amazing! Thank you for this week’s video!
This science live was so interesting ! Can’t wait for next week
Morse code is so cool!
Morse code is so fascinating!!
Watching from Acworth, GA!!!! Keep up the GREAT work!!