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 »



Woah!! This is so cool! I love these videos.
How did they make the robot but have it so small and still be able to fit the coding and info?
The technology spotlight was really interesting today!!
I love guitars too.
Morse Code is interesting to learn about
dang, I thought the robot was gonna be as small as the human finger or something NOT smaller than a grain of sand, bro that’s crazy.
I’ve always wondered why the light bulb had those coils inside them. Now I know!
What is the tiny robot capable of doing for something so small?
I can’t believe there are robots that small!
What is an Airospace Engineer?
Yay for Science Live being back from break! Excited to watch!!
What is the vacuum tube diode?
What was the first technology using signals?
I was shocked that they can make a robot that small.
I’ve heard of rectifiers before, converting AC to DC is very useful tool.
Amazing how one of the most important languages, widely used in the army, was invented
Vacuum tubes are so interesting
How long would it have taken to think of a new way to swim for that tiny machine, and then make the machine able to ‘swim’? How wonderful.
I would’ve never guessed Morse code was invented by a artist.
Learning how to make circuits is one of the most impressive things you can do in my opinion, there are countless things you can make, for example one of my favorites is the Tesla coil with its wireless power it produces.
That truly is the smallest robot!
i love these videos there so entertaining!!
it’s interesting how – is attracted to +
I’m looking to buy a Morse code tool so I can learn it. good to know just in case
i love learning something new every time from this!
This is so cool! thank you for the amazing video!
hello from kentucky!
That was a great episode
I love science live!!!
Amazing video I can’t wait for the next one
I loved Anastasias story very inspiering
I think its important to learn morse code because you never know when you may need it or may have to understand it.
drones are so cool!
Hi from Tennessee
this is so fun to learn
love accellus
I had no idea that’s how Morse code was invented. That was very interesting!
It was really cool to see how morse code was invented. I never really thought about the process of creating it.
loved the robot
hooray for science live
How is that robot so small? Not at all what I imagine when I think about what a robot looks like!
Thank you for the video! Always excited for these!
I really do love how the jokes are at the beginning of the episode. Keep it going!
I wonder how small we can get a computer to be?
The robot was so cute.
Always looking forward to these!!
you guys never fail to teach me something new
So glad to be back from holidays. looking forward to a new session.
Thank you Science Live!
We vote for David, but both were very good!
The circuits were cool!
computer chips have always interested me
technology spotlight is my favorite part of science live. I look forward to it every week. Thanks!
Thank you for making these videos and getting to learn new stuff!
“definitely not Caleb” got me laughing 🙂
Great to meet Mr. Billings family in this episode.
Awesome video they made it very interesting to stay focused and understand the material. I liked there graphics explaining all the terms.
I enjoy breakthrough moments in science!
Morse code should be taught in schools like cursive!
Plants breath through tiny holes in there leaves
Amazing video supper interesting!!!
the small robot is really cool!!!
AC and DC are interesting!
This is so awesome, great stuff!
Loved todays video can’t wait till next week! Thank you Acellus!
How expensive is it to make a large computer
i actually enjoy these videos a lot more than i thought i would
I’m enjoy science live
I enjoyed seeing your family!
If I practiced enough I would be able to decode the clicking sounds, cool.
What year was the worlds largest computer made in.
Thank you so much for the amazing information! I’m so excited to learn more!
thank you so much for taking the time to make the amazing videos for us.
i love these alot.
David and caleb are so funny together
Thanks for teaching us about morse code!
I love history.
I enjoyed learning about the nanorobot and the Morse code
I love science live!!!!!!!!
Gotta start the new year on the right foot.
is there a class for Morse code?
I love these new facts that i just learned!
morse code is so cool !
I wonder what the biggest computer would look like.
I love science live i always learn new things!!!!!!
I find robots to be fun and helpful in certain things!
Great Science Live! It’s so great to hear about how AP-level and Honors-level courses can help students become accepted into universities!
It was interesting learning about how Morse code and the telegraph was invented thanks to Dr. Tobias!
do you think people could ride on drones one day?
Love technology and science live
I am learning more and more about science every live. Thank you for these,
Thank you Caleb and David!!
I really love the r51!
I learned that robots can be really small like salt, that have memory and can swim.
Thanks for making learning fun.
Does the vacuum tube diode remove the waste of electrons in the circuit via the plate of metal?
WOW I love science live so much
I think it was really weird that the robots were smaller than a grain of rice.
I had heard of that agency that helps recover online reputations!
On the right foot! XD
When was the largest computer made, and how big was it?
This video was really fun, I wasn’t expecting any new people to come, so this was cool.
i want to vote for both .
That’s crazy the little robots are so cheap!
This episode was good.
Morse code is really cool to me. When they used it in WWII to communicate was really cool as well.
Drones are sooo cool
the nanorobot was cool, how it was developed.
Here from alaska!
this was a cool episode
I really enjoyed this episode! Can’t wait for the next one. Thanks Science Live!
these are so fun to watch
Drones are so cool
What is the largest computer ever made?
Plants breathe carbon dioxide
I loved the morse code segment, always fun to watch!!
Great show!
I wonder how someone thought to make a drone… they are awesome!
The freshman student who took all those college level classes and now does research for nasa definitely gave me motivation!!
Awesome video!! Thank you so much for the amazing video<33
I love science see
What computer has the most amount of buttons?
Absolutely loving this!😀
I love science live😁😁
i want to learn morse code!
That is a cool acccomplishment.
technology spotlight never fails to teach me something new
I vote R51
The tech is so interesting!!
Drones are awesome
The technology centered livelessons are my favorite type so far. I think they’re really fun and the most interesting.
Plants breathe carbon dioxide
I wonder what the alphabet is in morse code.
I VOTE R51!!!!!!!!!!!!!!!
The radar systems remind me of the movie “Twister.”
I enjoyed this live! Technology is so cool!
Same
the robot was so cute 😍.
really enjoyed the morse code segment, thank you for the great episode!
I really enjoyed the morse code segment, thank you for the great episode!
Morse code is crazy because it is like a language for technology
I like when Calob and David explain how to build that invention in 30 seconds and in the middle when they stop for drinks because it is really funny.
Happy new year and hi from Georgia!
Morse code should be taught more *
Morse code is cool.
Morse Code is so interesting, it’s not talked about enough
I LOVE drones
What was the original purpose of Morse code and do you think the idea of Morse code or the purpose of Morse code has changed over the years?
I think I can help you! Morse code back in the day was used as a more efficient way to get a message from one place to the other in a short period of time, since any other way would take weeks to a month at minimum
The microscopic robot was really cool
David and Caleb are hilarious
Samuel Morse was a very talented person.
Happy new year science live!!
happy new year to you
Where do you do Science Live
they do it in kansas city missouri
Loved loved loved the video!
Hello from Baltimore, MD. I enjoyed this episode!
This live was my favorite so far!
I say keep Caleb and David!They made the concepts engaging and seem to work well with each other and both seem super intelligent.Hope to see them more.
Caleb and David are the science live dream team!!
How can a vacuum tube help the quality of sound?
I thought making robots so tiny would be more exspensive
I vote R51
I like both David and Caleb. I cannot choose a favorite! They work well together.
I vote R51!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Happy New Year! I love science live!
I didn’t know that plants could breathe that is so cool!
how do they fit the stuff a robot needs in a robot the size of a salt grain?
Hi from Germany!
I really liked this concept and how the vacuum tube diode helped launch the age of electronics. This was a great Science Live.
This video was really fun. The more I find about Morse code’s history, the more excited I am to learn it. Although the part about micro robots was definitely my favorite, and I find it really interesting. It’s crazy to think about how much technology has progressed.
We are in Surrey, England, and most of the buses we see on the road are powered by Hydrogen. (Surrey has the UK’s largest zero-emission hydrogen bus fleet with over 34 buses. ) Sometimes, when it’s especially cold and dark outside, we can see a big cloud of steam come out of the bus. It’s so nice to know that it’s not a big cloud of harmful pollutants! Yay Hydrogen. Always makes us think of Dr. Billings.
Both were great, I think both deserve a vote!
Wow, the robot is so small! Amazing!
Science Live after a long week is the best.
I can’t believe how small that robot was! It’s amazing what technology can do!! Technology has come so far… 📻 >📡 💾 > 💿 📺 > 🖥 ☎️ >📱 📼 > 💻 🤖🤖🤖🤖🤖🤖🤖🤖🤖
I really hope the tornado drone works!
Glad the show is back! Learning about the Vacuum Tube Diode was really fun! Good show as always.
Tornado drone is an amazing idea.
The microscopic robot was so awesome!
As someone who loves to learn about Morse Code, this fascinated me! Wow!
I loved Dr Tobias and Samuel Morse’s painting!
David and Caleb are both really cool. I like drone I think they are cool. I hope it works for the*the tornadoes.
A tornado drone invention is incredible.
Both young men were very engaging in their explanation of the query they had to breakdown for the audience. I feel they both did a wonderful job in capturing the attention of the students. Keep both!!
I couldn’t believe typing an email with morse code, that would take forever.
I love this show!
I like how Caleb and David made it so interesting. I also liked learning about the telegraph.
Samuel Morse creating the morse code is so fascinating and respectable because not only did he do it because of what happened with his wife, but he also had to go through multiple designs and make up a whole new language for it.
Science is awesome!
I can’t believe that people have made a microscopic robot that swims. I thought that it was really cool.
It’s cool how plants can breathe.
Hi R51. By the way that is not how son and grandson work. Son and grandson are people. A sun is a star in space.
Both! They work well together! I enjoyed this Science Live!
I really thought it was cool that Caleb was an Acellus Academy graduate. Inspiring.
Its CRAZY how one of those tiny robots costs 1 PENNY!
This is my first time watching the science live video and I like it. I learned a lot.
Science live rocks I hope everyone will have a great year
Can you add a Korean Language class ?