The Relay
December 10, 2025 • EPISODE 290
How does a simple relay help us understand electricity and circuits? In this episode of Science LIVE, Roger Billings breaks down the science behind the relay—the clever electromagnetic switch that makes it possible to control circuits with precision. Learn how relays work, why they’re essential in everyday electronics, and how this simple idea became a building block for modern technology. A clear, hands-on look at one of engineering’s most important tools.

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 »



Is a battery kinda like the coeher you showed us?
I liked learning how a relay works
I like learning how a relay works
Watching from Texas!
I never heard about a transistor before, thanks for the information.
R51! You can’t steal big R’s stuff!
Comment My grandma uses WD – 40 around the house. She said it’s great.
Evening from FL!
I did not know DNA could have memory!
i love Acellus
Great video, learned a lot of new things.
I really liked the part where we learned about DNA
this really taught me a lot about science i really enjoyed thanks see you next time :3
Man r51 is pretty funny at the end of each live.
I thought r51 was hilarious!
thank you!! this was great😊
The WD40 thing is awesome!! Can’t believe it took 40 tries to make it!!
Dose r51 use DNA to store Data?
I look forward to these videos every week!
I was not expecting the lighting at the end of the video.
Thank you Mr. Billings that’s a lot of cool information.
Failure brings you closer to your goal!
Watching from Texas
I always learn something new when I watch Science Live.
I think it would be amazing to store very large amount of data as “DNA powder” for a very long time.
R-51 sounds like a droid’s name from Star Wars.
I always look forward to R51, he makes me laugh!
It’s awesome how much you can learn from science live I would never guess thats why its called WD40 so coolll!!!!
This one was interesting
WD40 today is used for so many things!
“Fun Fact”
Did you know that when you put WD40 on a horse’s hoof it helps prevent cracks and when they do have cracks it
heals them? This is very true!
These are always so incredibly interesting!
The WD-40 history teaches an important lesson to never give up, even if it takes forty tries.
SOOOOO COOOOOLLLL I LOVE SCIENCE LIVEEEE!!!!!!!
How long did the process of creating radio take?
Wd-40 is what my dad always used!
Your video this week was interesting and correlated with my Physics class this week.
How far in advance should you buy tickets for graduation? Is there a possibility that it will sell out ?
My dad would love the WD40 backstory! Another great science live thank you!
Love it!
I love watching science live! These episodes are so interesting and enjoyable! 😁😁😁😁
Science live is amazing.
I’ve seen relays before but never really knew how they worked so that was interesting
I didn’t know that you could store data through human DNA!
DNA is so amazing! I’ve been learning about it in biology!
I never realized w-d 40 had so many uses!
Science live is the best!!!!!
I love science live!!!!
Wow, that’s cool Dr. Billings!
Radio waves are such an interesting phenomena! I’ve always been curious as to how something so seemly insignificant and even invisible can be so useful! Thanks for explaining these older technological concepts to us so we can see where modern communication came from!
Nice to learn about Marconi invention, long distance radio waves.
How they worked. The bell , awesome. Thanks R51
Nice to see how the bell works and the long distance radio waves invention. R51 great.
Thank you Dr. Billings!
WD 40 is very cool
The ringer on the bell was a great idea!
Relays are so cool!!
favtimeoftheweek
poor R-51
I absolutely loved this, every live just keeps getting better and better!
I think it would be a fun idea to have a create your own robot station at Acellus World. Maybe R-51 could help us create them!
Mr. Billings is so cool!
It is crazy how WD-40 is used in 2000 ways.
Love this class
The Relay is so COOOOOL
This was very inspiring! Thank you Dr. Billings!
Hi fellow science lovers!
Thank you so much! Science is so interesting!
The end was hilarious, thanks.
Can you ring the bell far away with the lighter
wow I learned so much about WD40!
The Science behind DNA is fascinating to me!
Thank you Mr. Billings
Learning about radio waves in detail is great.
Another exciting session today! The whole topic on radio waves was really intriguing, but honestly, getting to see R-51 (I hope he’s doing okay!) is always key. It makes me laugh every time. My family and I love watching Science Live together, and Dr. Billings always makes science so interesting every week!
Always learn something interesting!!
I loved the back story about WD-40, Really Cool!
WD 40 is awesome!
Today’s session was so exciting! Learning about radio waves was really intriguing, and I especially loved hearing that the name WD-40 came from the 40th Water Displacement trial—that’s a super interesting fact! My family and I love watching Science Live together. Thanks, Dr. Billings, for keeping it so interesting every week!
This episode was so cool!💙
i love R51
Dr. Billings is amazing!!
Always interesting to learn about how everyday items like WD40 came to be!
Is r 51 going to be at Acellus world in 2026?
Very cool!
It was interesting to hear how WD40 was invented.
Dr. Roger Billings is amazing
WD 40 has gotta be one of the coolest origen story’s ever
I have used WD-40 for my legos, and it works really well!
I did not know that WD 40 was used for so many things and I like since they test it 40 times they named it WD 40. Maybe i will do more research about it too.
I always Love Dr Billings Science Live it’s one of my favorite in acellus.
I LOVED THIS!! R51’s always been my favorite :p
Learning about circuits both in my Acellus Science course and in Science Live has been very interesting!
Acellus is great. Love these classes, learning so much
The origin of wd40 was super cool 🤯
I thoroughly enjoyed learning about the of how DNA can be used for technologystorage and kept for many years. Its was also interesting to learn that scientist tried 40 times before they figured out the patent for WD 40. I also learned that its initial intent was to be used on rocket ships and that there are over 2,000 daily uses for it today and that the formula has never been changed.
I never knew this was how WD40 was created. My parents use it all the time. The creators we’re determined to make something work for NASA. 40 tries is a lot.
These Live videos are awesome! Dr. Billings is a great teacher and give us the details clearly to understand. The WD40 info is wild!
I ‘m gonna try to laugh at my mistakes more so I can live longer LOL!!
its amazing how much stuff we get from just a simple flick of a light
I’ve heard the idea of DNA storage somewhere else before. It’s great to learn how a bell works by using electromagnet. I look forward to the next episode about vacuum tubes!
the human mind is so amazing that we can figure these things out, really speaks to a creator in heaven doesn’t it?
-r 51 stole your invention
Dr. Billings is amazing.😊
These rockets are so cool! I went to kennedy space center last year!
Good morning from Illinois!
I love learning about rockets and space!
dr. Billings is the best.
This was so fun to learn! So scientific!
I love science live!
This is my favorite episode. I can’t wait to tell my pappy the WD40 fact I learned!
Could you make a kit to sell that would demonstrate a relay and make a morris code?
i loved the lesson about relays
I love the ending! My dad uses WD40 for everything
thank you Dr Billings for these insightful video
I love Acellus live, it’s very interesting
I wish they would make a science live every day!
I really appreciate the educational value of these science lives! They’re informational, but also fun and interesting! It’s a hard balance to manage, so props to you guys!
The ending segments of these are always so funny!
R-51 is my favorite! Great episode!
The DNA part was my favorite! Can’t wait to amaze my dad again!!!!!!!!
Wait thats why WD 40 is called WD 40!
Love science lives!!!
It’s good to see you again DR.billings i’m a tennis player and i’m from Morocco
It’s interesting to hear that history of WD40! I always like those types of stories.
It’s so cool learning about DNA! Science Live is awesome!
This was so cool! I love Acellus!
R-51 should really be careful when he’s handling that kind of stuff. But other than that, he’s such a comedian! He reminds me of a character from a movie I watched last night.
I love science live!
How long is a light year?
Thank you!
Can you tell me more about how relays work please?
My dad uses WD 40 on rusted bolts and squeaky door hinges, I bet he didn’t know NASA used WD 40 also!
I learned to never give up.
WD-40 has an inspiring story:)
I can’t believe WD40 can be used for so many different things.
I’m always learning something new from science live! I think my favorite part was learning the meaning of WD-40.
I like Dr Joshua.
I feel like you should never give up if something doesn’t go your way. Just like how they tried 40 times before the made WD40.
Thanks for the video. I really liked the aluminim foil experiment.
Thank you for providing these opportunities!!!
This was incredible very interesting. The DNA facts were amazing.
This science live was very interesting!
I did not know the story behind WD-40. It teaches us so much about not giving up. There are so many uses for this great product.
I like Tobias part because, I always love how Tobias is telling everyone a piece of encouragement to everybody when it ends off his talk. I also love Dr.John because, he makes his talks most of the time make you stand up on your tiptoes waiting for what is to be said next. Thank you, Acellus team for providing science live’s.
Watching from Alcalá de Henares!. R-51 is so funny lol I love how he speaks.As always making Science Fun!.
Hailey from North Carolina, watching science live on Saturday!
the Aellus’s school is so cool!
thank you dr billings
I loved about the part about the bell!
This is so incredible.
Funny and smart move by the people that made WD-40 to not patent the formula for it when it’s usually done exactly so it doesn’t get copied. But, at the same time, it’s a shame, because I would love to know how they made it and the science behind it.
I loved everything about this episode!
It was Fasinating learning about WD-40
I never knew what WD40 was until today and it was very interasting to learn about
Dr. Roger Billing is an amazing inventor
The WD-40 was unbelievable and interesting.
It was interesting to see the little spark make the bell ring!
I use WD40 all the time and I never knew that the 40 stood for all the failed attempts.
Comment Aceĺlus graduation event looked very exciting. The report on storing DNA date was interesting. Great story about the origin of WD40 and its uses. Explanation of the switch mechanism was interesting. Thank you
Acellus World looks amazing! I will attend in the future!
Science live is so interesting!
I wonder if a fire alarm works similar to coherer with the bell.
I love Acellus! ^^
It’s cool how one invention creates other inventions. I like inventioneering.
I really liked the relay!
You learn something new every Science Live!
The inventing path we’ve been has been quite interesting, especially Dr.Tobais’s section.
R 51’s reactions always make me laugh!
I love Science Live!!! 😍
Learning about the DNA facts was cool.
Learning about the wd40 was really interesting!
Thank you for sharing about the relay.! Excited to see what next weeks episode is about!!
I can’t wait to continue discovering next week! – LydiAnn
Love science live!!
These lives are always so interesting 😊
I was surprised to find out WD40 works to unstuck legos!
Todays video was amazing, thank you