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 love to watch these videos!!
Anthony watching SCIENCE LIVE from Oklahoma
Wow I vote for Caleb
Will humans ever be able to send a probe into the Sun’s atmosphere or core?
Imagine how different our lives would be without electrons 🤯
that joke was cheesy and I loved the video it was awsome and a great thing to watch after new years but for me I lifted my leg so I could start on my left leg now that was a cheesy joke right !!
I love science live.
wow! I loved this episode of science weekly! I cant wait to see what new ideas you come out with next!
Always have fun watching these!
what is the largest computer or electronic ever made
Best science video ever 🙂
it is interesting how a solar cell can transfer data using light
Learning about Morse code and the telegraph was so interesting! Thank you for this video!
I think that my favorite part was when Caleb and David were working together I thought it was funny.
I love plants and watch them grow
happy new years!!!! i love this episode !!!
wow! These micro robots are so cool and amazing! I cant believe somebody made this robot this tiny and small!
how does an ac generator work?
This video was super intersting and intriguing and brought new light onto so many unique things.
I never knew that how things work with electric vaccum
It was cool learning about your son and “favorite” grandson!
i love drones
That robot was so small! It is like a very small version of my hexbot nano toy.
David and Caleb – yes
We should learn more about Morse code
I love watching live science !
I literally always learn something useful new from these videos
We should learn more about Morse code
Hi from WA state
morse code is awesome i want to learn more!
science live is the best, happy new year
We should learn more about Morse code
I vote to keep Caleb and David. Both of them were super funny and explained the concepts well!
Happy Science Live night everyone!
Happy Wednesday From Texas!
Thanks for taking the time to makes these informative videos
I didn’t know Morse was an artist – so interesting!
How did Samuel Morse invention of the telegraph and Morse code change the speed and reliability of long distance communication in the 19th century
Great video!! I liked seeing more behind the scenes than usual and seeing the people who make these videos!
Happy New Year! New science news for 2026!
How long did it take to build the tiny robot?
Learning about morse code is so interesting!
what is the most high tech computer they ever made
Why do plants not breathe oxygen?
Thank you for this episode. I aways enjoyed Science live and I am a little sad that this will be one of the last episodes that I watch before I finish Acellus.
Hello from Louisiana!
I had never heard of the Vacuum Tube Diode before until now, but that is a very important invention and definitely paved the way for many other inventions and help make ac/dc the norm.
I always love Tobias’ part!!
What grade do you have to be in to have AP courses.
If we turn the battery around on the opposite direction, would it go on the opposite direction, where the battery was, or would it stop completely?
hi from Ohio!
Awesome video, excited for the next one!!
Hi from maryland
It was nice to learn about how electricity works.
One cent per micro-robot is impressive.
My favorite part of the science live is R 51
I love the extra things I learn from science live. I never thought about viscosity and smaller objects in water.
My name is Harvey and I’m from Illinois
Hello from North Carolina
What is the main function of a vacuum tube diode?
Awesome video excited for the next one!!
Very cool way to rectify currents, learned a lot!
that was a really cool way to make a vacuum tube diode
I loved learning about the vacuum tube diode, I was soaking in every little bit!
Drone part was my favorite.
i love science live!
Loved learning about morse code part!
It’s very interesting that tiny little solar cells and robot IDs can still function in just one tiny computer chip. I didn’t know how science can make such interesting technology!
My vote goes to David and Caleb. I enjoy watching science live.
Does there only work on solar or can it use the moon light as well?
Science live is awesome
Love Acellus!
so cool to have David join in on the live
I Love science live it always teaches me new things!
how did u know plants breathe and why can they breathe also do they do something for our world
How do they made those very small device that is crazy
Drones are so awesome!!!!!!!
Plants breathe, wow what a interesting fact!
Where is science live done?
Loved the live!
I love science live!
how fast can they produce one of those small robots?
That drone is soo good I would get one of those if I had enough money
Technology never fails to be so impressive
Morse code was something my pawpaw explained to me as a child. It’s cool.
how long does it take to design and buy things for a drone?
I love the Way things are explaind in science live.
you learn so much!
Comment Modern electric technology, is a very interesting invention now!
This is really neat to watch. I am a new student.
I think it’s amazing that someone from Acellus could go so far in life, and it gives me hope to do something great!
congrats to that girl.
I loved learning about the drones and Morse code! It’s so interesting!
The electricity in the Light bulb’s are cool.
I never knew robots could swim !!!
First science live video I’ve watched , very cool and interesting. The robot was great
I love seeing these videos everytime ! learning is great.
great video Dr.B love the content keep posting. [:
This video was very informative and helpful
awesome video! I love learning and I love science live! I appreciate everyone who teaches us !!
Vacuum tube diodes, the first practical electronic valves, were born from Edison’s “Edison effect” discovery, called “valves” in the UK.
I am happy thatthe acellus lices have started back!
This video taught me stuff about Acellus I didnt know as I am a new student here.
Science is so cool to learn about
We learned about the world’s smallest robot, which is smaller than a grain of salt, and only costs 1¢ 🪙
I vote for Caleb and I loved this live.
what is the biggest computer ever made?
I loved this video!
Why isn’t there a new video this week for science live?
I love science!
That is very cool!
I love Science Live!
Really Enjoyed the video!!
Happy new year
I really do want to achieve doing AP Course starting my 9th grade level.
I love science live and tech spotlight so much!
Pretty good live I always like learning new science technology.
I like the new course a lot! Because English is my favorite subject! Happy new year❤️I love this!
the vaccum tube diode is really strong and can suck alot of stuff!
I really enjoyed this video! Have a great year everyone!
I wish more schools taught morse code
What’s the smallest computer?
This was really interesting and informational!!
Great video! You explained the science really clearly and made it easy to understand. I liked how organized and confident you were—it kept the video interesting and engaging. Awesome job!
Morse code is cool
Hello everyone today’s live is so fun.
I’m happy Acellus broadcasting is back to give us cool facts about science!
I love the technology spotlight!
What is the simplest electronics made?
Thank you for these cool science lives!
This video is so cool!!!
Computers are my favorite device!
They should have a class for Morse code!
hii from tennessee
Such a great and interesting video
Hi from CT
That was an awesome video either way the tiny robots
I love science live
I think Morse code is so cool!!
I love the way the scientists love to pass on their knowledge. You always hear about it. Thank you for the Science Live.
A vacuum tube diode or Fleming valve is the simplest vacuum tube, invented in 1904 that controls electric current flow in a vacuum between two electrodes a heated cathode electron emitter and an anode collector
hello, from NJ
I love learning science!
I love this you should do more.
My mom and I went on a field trip, last week. We learned about Morse code, at the museum! I learned so much can’t wait to go back again!
We need more on Morse code!
What is the largest computer you have ever made?
I enjoyed hearing about Anastasia and seeing the tiny robot. I liked David and Caleb.
I liked the part about the telegraph
Has morse code changed since it was originally created? If so, could you explain in what ways?
Amazing live! loved this one, it was very interesting.
Hi from Delaware!
Hello from new jersey.
I LOVE SCIENCE
Loved this episode! 🙂
science is my favorite
I vote to Caleb and David!!!!!!!!!!
So cool how many things the vacuum tube diode has helped with
Hello from Texas!
You must be very proud of your boys!
My mom has told me about plants breathing out oxygen and my mom loves plants very much. She has 15 plants in our house. So I would like to show her a plant that can show that it is breathing. I know she would love that.
I really like science live
I love these so much! never wannna miss these
The robot is so cool
does it make the flow of electrons better back then than back then?
So you mentioned the U.S. Mail then what about the mail system that covered the nation by train or horseback? Wasn’t the U.S. Postal Service one of the worlds best considering them going thousands of miles?
I like the story of Samuel Morse how he created long distance communication.
Fun episode! Could one of the next topics be something about photography or video editing?
We all love Acellus!
I liked hearing about Samuel Morse and Morse code.
I knew that plants breath but are the holes they use to breathe ever visible to the naked eye?
I like the tiny robots! I love AI and I hope to have an AI robot someday in my house helping me with homework and cleaning my room.
Cool live this week. I love learning about Morse code!
Great video! Thanks for sharing. Love the technology as always!
Caleb and David are amazing!!!
What kind if machine is small enough to make a tiny computer the size of a grain of salt? How could you fix it if it breaks? Are there tools that small?