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 »

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5,107 Comments

  1. Arya

    R 51 is hilarious😂😂😂

    Reply
  2. Waylon

    Ive been really liking the episodes on radio waves. This lesson on relays was really good. I cant wait for the next science live.

    Reply
  3. Kameron

    So much fun learning about DNA thank you!

    Reply
  4. Irelynd

    I never knew it to 40 try’s to make WD40!! I liked learning about the DNA facts as well. Dr. Billings is so smart. 😀

    Reply
  5. Mattox

    That’s so cool to learn about WD40!

    Reply
  6. Kalliope

    I liked hearing about how WD-40 was invented and proving to never give up!

    Reply
  7. Genevieve

    This episode is great. Thanks, Acellus!

    Reply
  8. Layne

    Science live episodes are so interesting!

    Reply
  9. Luci

    whoa! I didn’t know that we found a way to store data in dna.

    Reply
  10. Bailey

    WD-40 is actually something that cool to use!!!

    Reply
  11. Aidan

    I will be trying wd 40 on lego!

    Reply
  12. Maya

    I really liked to learn about WD40!

    Reply
  13. Maya

    I love science live!!!

    Reply
  14. Alexis

    I told my dad I was learning about WD-40. He thought that was pretty cool.

    Reply
  15. Oliver

    Thank you very much for making these videos. I love Science Live!

    Reply
  16. Reagan

    This was great I did not know that it took 40 try’s to make WD40!

    Reply
  17. Emma

    Thank you Dr Billings! I loved learning about the DNA and WD40!! 🙂

    Reply
  18. Hunter

    Are radio waves the same thing as WiFi?

    Reply
  19. Hannah

    The story about coating the NASA rockets was interesting.

    Reply
  20. Karly

    It’s neat how those little balls make electricity.

    Reply
  21. Cory

    watching from Ohio! theres so many things you can do with WD40!

    Reply
  22. Victoria

    its crazy how they came up with WD40!

    Reply
  23. Brody

    Thank you for another week of education

    Reply
  24. Emma

    Thank you for this video Mr. Billings!

    Reply
  25. Luke

    Science live is so interesting!!!!!!!!

    Reply
  26. Tripp

    I can’t believe how small DNA is.

    Reply
  27. Arianna

    I never knew what WD-40 stood for, or how it was invented. That’s so interesting.

    Reply
  28. Lily

    That’s so cool to learn about how WD-40 was created!

    Reply
  29. Zara

    I love Acellus!

    Reply
  30. Eriksen

    DNA for storage? Wow that’s certainly something. With that kind of storage I can collect memes ‘till my heart’s content.

    Reply
  31. Maddison

    I love the WD 40 story!!

    Reply
  32. Kenzie

    Being able to spot something so far away is truly amazing

    Reply
  33. Micah

    Wd40!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

    Reply
  34. Parker

    wow! my family uses WD40 all the time! I didn’t know that was its original name!

    Reply
  35. Kaleb

    Thank you for the weekly science live Mr. Blillings!

    Reply
  36. Evelyn

    Dr. billings so cool and smart😁

    Reply
  37. Grayson

    I love r51 he is so funny

    Reply
  38. Austin

    I didn’t know that you could use DNA to store data.

    Reply
  39. Rebekah

    My dad uses WD40 a lot.

    Reply
  40. Sharlotte

    I like what they said that if you want to succeed try one more time*

    Reply
  41. Hensley

    i like R51. I didnt know all the uses for WD40 like learning about it. Thank you.

    Reply
  42. Faten

    I didn’t know that WD-40 was that useful!

    Reply
  43. Allie

    I didn’t know that wd 40 was originally made for NASA or that it can be used for so many things. Super cool. I’m going to try using it to get the marker stains off my dry erase board. Thanks!

    Reply
  44. Vanessa

    Wow super cool about the WD-40!

    Reply
  45. Julia

    I can’t wait for graduation at Acellus World!

    Reply
  46. William

    Enjoyed learning about the relay!

    Reply
  47. Lisa

    I loved how in depth the relay demonstrations were! Awesome!

    Reply
  48. Taylor

    That was awesome!

    Reply
  49. Logan

    Science live was amazing i enjoyed learning about the relay

    Reply
  50. Delaney

    Science is so cool!

    Reply
  51. Alexandra

    Thank you for the live! R-51 was funny as always. Can’t wait for the next one!

    Reply
  52. Ashlyn

    Always wondered where WD40 came from, great science live!

    Reply
  53. Peter

    Poor r-51 that had to hurt ( take it from a guy who tazed himself)

    Reply
  54. Cerys

    r51 is hilarious!

    Reply
  55. James

    DNA is one of my favorite things about biology! It’d be interesting to use for elec storage

    Reply
  56. Henry

    R-51 always cracks me up. 🤣

    Reply
  57. Annerie

    I learned how a relay can control a circuit by switching it on and off which was cool since it helped me understand how simple electrical parts are used in everyday machines.

    Reply
  58. Zelina

    I really enjoyed learning about WD-40!!!!!!

    Reply
  59. Makenzie

    This was a great video. I love how you can tell how passionate Dr. Billings is about what he teaches.

    Reply
  60. Payson

    Haha my dad will use WD40 to fix everything around here! I’m going to show him the video

    Reply
  61. Carolina

    One last thing, I feel a little bad for poor R-51, ( the poor soul got shocked) tell him that I said get well soon!

    Reply
  62. Carolina

    That bell would make a GREAT ALARM CLOCK, Also I feel like R-51 is’nt a big fan of coffee…
    One more thing for DR. Billings, That is such a cool invention! I love how you made it using a house hold item like a spoon!!! <3

    Reply
  63. William

    R51 is funny!

    Reply
  64. Jaiden

    Mr. billings is cool

    Reply
  65. Teresa

    I really liked the part about being able to laugh at your own mistakes and rebound from them.

    Reply
  66. Addison

    This was great I did not know that it took 40 try’s to make WD40!

    Reply
  67. Ann

    I love science live!!!!!!!!!!!!

    Reply
  68. Brenna

    I had no idea that WD-40 was originally a project for NASA.

    Reply
  69. Blaze

    my dad uses WD-40!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! a lot

    Reply
  70. Nella

    Great episode! R-51 is gonna get it this time lol! Thank you, have a nice day everyone, Happy Hanukkah!

    Reply
  71. Brenna

    I am astounded it took 40 tries to create WD-40. I had no idea it began as a project for NASA.

    Reply
  72. Juliet

    Thanks for the great video, loved it so much. Roger Billings is such a smart guy! Love listening to everyone each week.

    Reply
  73. Camilla

    Acellus World looks like so much fun, I’m excited to go one day!

    Reply
  74. Eden

    R51 is my favorite part of Science Live.

    Reply
  75. Nick

    Loving the science lives Dr.B

    Reply
  76. Matthew

    R-51 is my fav

    Reply
  77. Alyvia

    Science Live always teaches me the coolest facts and I loved learning about WD40!

    Reply
  78. Madison

    wensdays are the best day because of science live. r 51 is so funny

    Reply
  79. Adeline

    This was a awesome Science Live!

    Reply
  80. Adalynn

    DR. Billings is the best! I love Science live.

    Reply
  81. Teagan

    WD40 is actually insane! Your so cool. Thank you Mr. Billings!!

    Reply
  82. Natalee

    This was so fascinating. It’s astonishing to me not know that it took 40 try’s simply to make WD40.

    Reply
  83. Athena

    I never knew all of this about WD40!

    Reply
  84. Kenneth

    Interesting to hear the story of WD-40!

    Reply
  85. Isaiah

    Thank you, I really enjoy science live!

    Reply
  86. Zachariah

    Thank you for this weeks show. I appreciate what you do!

    Reply
  87. Audrey

    Dr. Billings sure explained the Wd-40 well. So interestings.

    Reply
  88. Layla

    Amazing! Love learning about DNA.

    Reply
  89. Matthew

    R51 really knows how to carol

    Reply
  90. Brooklynn

    I love WD40! I’m a Diver and we use it on the divingboard to make it easier it adjust!

    Reply
  91. Halimah

    Such an amazing science live!

    Reply
  92. Clate

    I didn’t know cassette tapes were still around. Wonder what people use them for now. My mom said she use to record music from the radio.

    Reply
  93. Noah

    I thought the segment on WD40 was very interesting, and I did NOT know it had so many uses!

    Reply
  94. Jack

    Why would you need to store DNA?

    Reply
  95. Baylee

    I live science live! I learn so much!

    Reply
  96. Jonah

    R 51 is the funniest scientest ever.

    Reply
  97. Gavin

    wow that’s so cool I didn’t know that Dr billings was this smart!

    Reply
  98. Summer

    WD 40 is crazy!

    Reply
  99. Steven

    Science is so cool!!

    Reply
  100. Mason

    Area 51 is my favorite part. It always makes me laugh

    Reply
  101. Aiden

    I always love learning something new every Wednesday

    Reply
  102. Lilah

    Science live is the best!!!!!!!

    Reply
  103. Magdalena

    We take Marconi so for granted every day. Can you imagine a world without his discoveries?

    Reply
  104. Elizabeth

    Who knew the name WD-40 implied 40 tries. That’s so funny.

    Reply
  105. James

    this is so COOL this is what I look forward to watching this every week

    Reply
  106. Hania

    Really excited about the graduation ceremony

    Reply
  107. Taylor

    Thank you Dr. Billings! I hope R51 is okay! 😂

    Reply
  108. Kaden

    learned a lots about WD40

    Reply
  109. Emma

    I love science live!

    Reply
  110. Faith

    Don’t magnetic fields have a negative affect on tape (like cassette) storage?

    Reply
  111. Riley

    mr billings is super smart and cool

    Reply
  112. Zeth

    WD40 has so many uses, I had fun learning about this with my mom!

    Reply
  113. Jordan

    R 51 is so funny.

    Reply
  114. Joseph

    I never know how W-D40 was invented or why they called it that! This was very interesting and educational.

    Reply
  115. Elianah

    i like the way they demonstrate everything in the video!

    Reply
  116. Nguyen

    Thank you very much, Mr. Billings. I find science really interesting.

    Reply
  117. Bryer

    It’s so cool when you do the experiments live for us to see it in action

    Reply
  118. Ava

    This video was very interesting. Learning that it took 40 tries to make WD40 is the highlight of the video.

    Reply
  119. Lana

    MY dad used WD-40 on my bike this summer because the chain was rusted.

    Reply
  120. Ella

    I love how much you all know!!

    Reply
  121. Savannah

    Love learning new things!

    Reply
  122. Samantha

    Science Live was great and I’ll have to use some WD-40 for my legos!

    Reply
  123. Alexander

    History really does repeat itself. It’s fascinating to me that somehow after all this progress, somewhere in the world people are using cassette tapes again.

    Reply
  124. Makealani

    Science live is always so informing and educating I love this extra knowledge every week!!

    Reply
  125. Easton

    R-51 is a very funny guy, I hope he feels better

    Reply
  126. Emma

    I LOVED the story about WD40!!!!!!!!!

    Reply
  127. Killian

    I love building circuits. I have an Arduino kit I build with my dad, and I built a delivery robot last week from a kit I get every month.

    Reply
  128. River

    Science Live has taught me so many random things that I probably wouldn’t have researched, so I’m grateful

    Reply
  129. Ava

    I loved this weeks video!

    Reply
  130. Muthoni

    It’s awesome that they built a bigger building to accommodate the amount of acellus graduates per year!

    Reply
  131. Georgia

    Wow Dr.Billings is the smartest I think.

    Reply
  132. Maxx

    I love science LIVE

    Reply
  133. Dominic

    Did Mr. Marconi invent other things too

    Reply
  134. Sara

    Acellus is the best

    Reply
  135. Mary

    My dad loves WD 40.

    Reply
  136. Josslyn

    Hello from Illinois!!

    Reply
  137. Valencia

    r 51 is so funny he made my day with that hair comment he is soo fun

    Reply
  138. Daniel

    The DNA helix looks really complex but amazing at the same time.

    Reply
  139. Luke

    R-51 is absolutely hilarious every time.

    Reply
  140. Brandon

    I had no idea that’s how WD40 was invented and that it was used for rockets first! That was a really cool and interesting fact.

    Reply
  141. Anniston

    I love R5 10 and Roger Billings, Happy Holidays to everyone 🙂

    Reply
  142. Kenna

    Thank you Acellus for science lives!

    Reply
  143. Jake

    40 tries is insane!

    Reply
  144. Luke

    Thank you for the lectures, I really enjoyed Dr. Johns lecture on the Atlas Eon 100 and the storage memory it has. Im looking foward to the next lectures that will be on the science live.

    Reply
  145. Luca

    Thank you Mr.Billings!

    Reply
  146. Erin

    Part of me can’t believe R51 got shocked but the other part of me is like “well that’s totally believable”.

    Reply
  147. Madelyn

    Dr. Billings is so inspiring.

    Reply
  148. Rayden

    I always learn some interesting facts when I watch Science Live.

    Reply
  149. Lauren

    The relay was very interesting to learn about, and I am enjoying learning about inventions.

    Reply
  150. Al-malik

    Edison’s quote is amazing! Try one more time!!!!

    Reply
  151. Savannah

    Acellus World looks like fun

    Reply
  152. Jeremy

    I enjoyed this week science live. I really enjoyed this week‘s demonstration in the lab. It was very informative. Thank you so much!

    Reply
  153. Makenzie

    I’m glad to be warm and cozy watching Science Live, its so cold outside!

    Reply
  154. Proudpitcha.b

    Thank you Mr. Bilings!!!

    Reply
  155. Lazarus

    My son love the academy acellus it’s awesome.

    Reply
  156. Charlotte

    Cool,
    I did not know that about WD-40, I just new it help stop my door hinges from squeaking..LOL!

    Reply
  157. Cash

    Loved this episode! So interesting!

    Reply
  158. Jordan

    The WD40 information was interesting. Thank you and happy holidays. *

    Reply
  159. Jerrik

    I love watching Tobias talk about science in the past!

    Reply
  160. Gage

    My dad uses WD40 for everything! Now I can teach him something about it!

    Reply
  161. Dua

    I love watching scince live!

    Reply
  162. Brinley

    I love learning about DNA!

    Reply
  163. Sarah

    i didn’t know WD-40 was used for rockets that’s really cool!

    Reply
  164. Na’kari

    I enjoyed the live! Very educational!

    Reply
  165. Evan

    Happy Holidays everyone!!

    Reply
  166. Nadab

    Thank you Dr Billings for making science fun!

    Reply
  167. Sophia

    science live is really fun!!

    Reply
  168. Avery

    I love r51

    Reply
  169. Jaxon

    I would have never imagined using DNA as a way to store data. Crazy that it could be stored for a thousand years. Really makes me wonder what technology will be like when I’m my Mom’s age!

    Reply
  170. Rhett

    The way they built the bell was very smart.

    Reply
  171. Emmet

    Science live has a lot of information

    Reply
  172. Louden

    Always enjoy watching from Houston!

    Reply
  173. Alexa

    Thank you Mr billings!! I always look forward to the lives!

    Reply
  174. June

    My dad uses WD40 all the time I didn’t know it took 40 tries to make.

    Reply
  175. Aisley

    I really enjoy getting to learn about science with Dr. Billings. I really learn a lot from it. Thank you for making these.

    Reply

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