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 »



Mose code is so interesting!
It’s very interesting to see how science and all aspects of it evolve over time!
Happy New Year!
What is that painting of paintings called? That looks cool
Comment What are the names of those paintings?
hi
Hi from Virginia!
wow that is crazy
Hello from Nevada!
cool stuff!!
this is cool
Hello 👋
Hello, how was Christmas break. I had so much fun!
Happy new year everyone!
so cool
How do you Build that small of a robot?
Happy New Years everyone!
thats smart
the robot was so small
I love that painting!
Hello! From Virginia!
is this how they started morse code?
hi science is so cool
Comment: the painting looks pretty cool and so does the tiny robot
Hello From Arkansas
What is that painting of paintings called? That looks cool
hello
Hi, from Florida.
I love paintings!
Could the microbots target infections in the human body?
Hello from Kentucky!
Hello from Ohio!!!!
I want to paint like that because its so cool!
Hi from South Dakota!!
The tiny robot is so cool and its a great idea.
that’s actually really cool
Samuel Morse was a artist before becoming a scientist
cool
How interesting!
HIIIII from NCCCC
I finally got to see it live for the first time 🎉
Hello from Nebraska.
That is so sad that he didn’t find out until a few days later that his wife died.
Hello, from Long Beach, this is cool!
cant wait for next live
happy new years
It’s so interesting to see how far tech as come
Hey, from South Carolina
That’s a very cool painting
that’s so cool! very inspiring.
Hey From Kansas!
That’s cool I didn’t know that robots can be that small
what time period was Samuel in when he received the letter?
i learned about the pony express today!
I love science!
I think a lot of ideas and inventions are motivated by drastic circumstances.
Hello there!
thanks
this is ivy from Cheny WA
How many paintings did this person create, sorry I do not remember the name
Samuel Morse was a artist before becoming a scientist.
Samuel Morse has always interested me. His invention of morse code is incredible and changed the lives of so many people.
hi from mississippi
Wow!
hi from florida
I wonder how those robots will be used in the future with building?
great I love it!!!!!!!!!!!!!!!!
Really interseting robots but the concept is pretty cool!
this is cool
telegraph?
I love this info
Hello from VA
Hi everyone!
Love science live!
I think it is cool that you can make a robot. That’s super cool.
That is so cool!
super cool!!
hi i’m watching
happy new year.
i love science live
I am wondering how can the self portraits come out good?
Books are cool
How long does it take to make these these microscopic robots?
I love this stuff
the robot is so small, but is there a way to make it even smaller?
Dr. John’s presentation about the tiny robot was awesome!
Hope 2026 is awesome for everyone!
Happy 2026 everyone!
Beautiful paintings.
When I heard about the smallest robot in the world the thought it was at least five inches, but it was about as small as a grain of sand, and it can swim!
Hii! Watching from Mississippi!
I vote for Caleb
I did not know there was tornados in philadelphia
Glad science Iive is back
Happy late New Year from Mississippi!!
hi
wow I love all the new things I learn on Wednesdays!!
Hello from Tampa/Florida
Welcome back! Happy New Year to everyone!
My dad is always saying he’s going to change things in January! He also told me about Morse code before! Its really cool!
hi science live
Comment how does the robot move
Nice to be here
Hi from Illinois!
Hope everyone had a great New year plus Christmas!
Hi
Hello from Georgia!!
Love these episodes 👍
What other outputs could be added to improve the capabilities of these microscopic robots?
That’s so interesting how the robot is so small
I wonder how those robots will be used in the future with building things.
Happy new years
If it’s that small how do you charge them and make them if it’s that small
robots are getting smarter
wow interesting
Thank you for this lecture today.
How do you even make it? Like is there special tools you need to fit in that little space? how do you not break it?
That’s interesting; who would have thought a robot could be smaller than a grain of salt, much less be that powerful for its size
How do they make the robots.
Happy New Years, Science Live!!
Could those microscopic robots be sent to the moon to cheaply and efficiently build moon bases?
science live is my favorite time of the day!!!
welcome back, everyone 😀
How will the robots be used to help people
Anastasia is inspiring 🙂
Hello!
Science fiction is the perfect description for what I was thinking! What if these robots aided with planetary exploration? Even though I’m interested in the medical and veterinary field, breakthroughs in medicine was not something I had in mind, haha!
Happy new year from Alabama!!
hello
hi, happy new years from virgina
Hi! Loving todays live.
wow i learned a lot about computer chips
Hi from Michigan
it is so cool that the robot is the size of a grain of sand
wow thats so interesting!
I love science! thanks for the live!
i love science
hi from Maine
wow the tiny robot is very interesting :O
hello! from Texas the big rock 07
Hi from Rochester ,ny
that is so crazy that you can program a piece of metal that costs a penny technology is getting so crazy!
That’s insane that people made a robot that small
How long did it take to design the little robots?
HEY FROM NC
Happy 2026! Will the robots be able to be used for transportation of small objects?
Science Live is back!
there is so much technology that mimics living things!! very cool
Tornados are both dangerous in some ways and amazing in others. I’m glad they made a device to track tornados down.
That is so cool that the computer chips can be smaller than a grain of salt! I would have though they couldn’t be that small! Also its so weird about the price, I thought it would have had to be thousands of dollars. Not one penny!
It honestly it reminds me of the movie ” Big Hero 6″
Wow!! That’s amazing!!
these are some cool robots
i didnt know things could function so tiny!
Hi from Tennessee
That’s so cool !
Nice
Love it!
Happy new years everyone!
Welcome back all !!:)
Something about the idea of tiny robots wiggling to communicate like bees is kind of cute.
I love Science Live!
Hi from St Louis
hi from hawaii
im so excited for tonight!!!
so cool! hope yall are having a great year so far!!
nano bots are cool
I love science, I’ve learned so many new things. And the tiny robot is AMAZING, honestly it pretty awesome how people can invent something that tiny, and it also can swim!
How is it possible to create a tiny robot that is even smaller than a single grain of salt? 🤏🏾🧂🤔
you need SUPER DUPER tiny parts i guess?
And machines with super perfect movement.
How is it possible that a robot can be smaller than a grain of salt???
This is so interesting to learn,I didn’t know they could be that small.
That is so cool!
How do batteries work?
hello happy new year
My day is going great
What kind of use case would those tiny robots come in handy?
Happy late new year!
hello from wyoming!
Hii from georgia! Saw your recent post about releasing more history lessons on conspiracy theories ! i’m excited and can’t wait.
Same. From Georgia and excited for the Conspiracy Theories course as well.
Hi im from georgia too!!
Hello from nc