Take Care of the Holy Ghost | Ruben’s Tube
What you need:
- 5′ length of Pipe (PVC will work for a couple of times but eventually will get soft and melt… aluminum or steel is the best way to go but it MUCH harder to work with and more expensive. It will last you forever though)
- Aluminum foil tape (ONLY if you are using PVC pipe) – available at Home Depot or Lowe’s
- A propane hose – the one I used can be purchased from Amazon.com at the link below
- A propane tank
- A lighter
- A 2″ speaker (and amplifier if the speaker you use doesn’t have one attached) – – the one I used can be purchased from Amazon.com at the link below
- A drill
- A 1/16″ bit (or several because they will probably break)
- A latex balloon
- Various tools as needed
- Lots of time to fiddle
About the Lesson:
We recently did an experiment in class which I had seen online but never before put into practice. It just seemed so daunting and so labor-intensive to get working but finally I got up the courage to tackle it. I was very glad I did because it turned out to be one of the better lesson we have ever done!
This experiment is called the Ruben’s Tube and if you do a search on the same you will find many instances of people who have put together step-by-step tutorials and who also show the final outcome. My tutorial is going to be much more limited than some of those so if you find any gaps in the steps that I list here, feel free to gather the missing information from the many sources available elsewhere.
The basic idea is that you have a tube approximately 6 feet long with the middle 4 feet section having holes drilled in a line across the top. On one end of the tube propane feeds in and on the other is a speaker matching the diameter of the pipe. Once the tube fills with propane, you light it where it comes out of the little holes and you have a row of tiny flames across the top of the pipe. When you play sound through the speaker the flame reacts to the sound waves and makes quite an incredible demonstration. When you play a simple sound wave you can visibly see the wave form reflected in the flame. Pretty incredible!
Put It Into Practice:
You can see the actual object lesson in the video at the beginning of this article, BUT in class, we lowered the lights and likened the flame to the Holy Ghost that is inside of us using among other verses in the bible, Acts chapter 2 and explained the kids that you have to take care of the precious gift that you have been given. Everything that you allow into yourself through your senses of sight and hearing affects the Holy Ghost that is within you.
At first we just played different frequencies of sound waves to show how directly the flame was correlated to the sound that was fed to it. We then played some classical music which was pretty cool but followed it immediately with a loud, stronger percussion song which cause the flame to react crazily, shooting several feet in the air and actually putting the fire completely out. We told the kids that you have to be very careful with the type of music that you listen to and with what you watch because if you’re not careful you can actually put out the fire of the Holy Ghost that is in you. You can talk about David playing his harp to Saul to drive away the demons that plagued him. We then played soft, pretty gospel music and contrasted the flame’s reaction to this compared to the one previously played.
We ended that the entire lesson with slowly turning off the propane and as the flames got lower and lower we explained that some people don’t cherish the amazing gift of the Holy Ghost and allow it to become more and more dim until eventually it goes out completely. “Imagine being so distant from God that your Holy Ghost is completely extinguished. You are as lost as you have ever been and don’t even realize it.”
The ending was very somber but definitely made an impact on the kids and was a lesson that will likely always remember.
Preparation:
- I purchased a 8 or 10 foot, 2 inch diameter PVC pipe from Home Depot along with an end cap. According to online sources, thin-walled metal irrigation pipe is better but also much more difficult to obtain and work with. I was unable to find it and didn’t want to go through the hassle of ordering it. Metal is better in the sense that it will last much longer and you don’t have to worry about it melting. I tried to prevent the PVC melting by using aluminum foil tape which definitely helped but is not a perfect long-term solution. You will be able to use the PVC version 4 or 5 times but after that you will likely need to replace it.
I cut the pipe down to 6 feet long and then put aluminum foil tape which I also purchased at Home Depot all along the top of the pipe anywhere there was going to be holes drilled. On my first iteration, I only put one piece of tape and I found quickly that this was nowhere near enough as my pipe not only melted quickly but also caught fire (luckily PVC does not burn once the flame is removed so it’s not terribly dangerous but still scared me a bit). On my second iteration, I used nearly the entire roll of aluminum tape covering the top of the pipe in many layers and even going down the sides of the pipe a bit.
I measured in about 12 inches from each side of the pipe. On the middle 4 foot section I marked off every half-inch as a location to drill my holes. It can be a bit difficult to get these perfectly in line so I made a line extending the entire 4 feet to help me keep them all straight.- Using a 1/16 inch drill bit high drilled each mark on my pipe. There will be around 100 holes so this can take a while. Because it is PVC, you will likely need to look into each of the holes after drilling it and make sure it is completely clear. I had to re-drill several of them later as there were shaving stuck in the holes. I used a drill press to make the holes but you can get the same results with a hand-held drill as well.
I purchased a propane tank hose from Amazon.com (CLICK HERE TO ORDER THE ONE I DID) and then had quite a time trying to make it work. The end for the propane tank was okay (make sure you buy one without a regulator) but the other end was much more difficult to connect to the end cap which was going to connect to the main pipe. I ended up having to cut the fitting from the non-propane tank side of the hose off completely and then bought a brass or copper fitting from Home Depot which slipped in from the outside and was secured with a nut on the inside. This left me with a hose nipple on which I slip the cut off end of the propane adapter. This left me with a hose directly from the propane tank which fed into the PVC end cap which I then secured to the end of the PVC pipe. I did not glue this in place as I wasn’t sure if I would need it off again later. Some Teflon tape will keep it from leaking and the friction fit is pretty tight anyway.
I purchased a 2 inch diameters speaker which cost about seven dollars for a pair again from Amazon.com. This speaker fit perfectly within the diameter of the pipe and I was able to push it in and probably could’ve left it as a friction fit (CLICK HERE TO ORDER THE SAME ONE I USED) but ended up securing it with epoxy. I was initially having trouble with the speaker creating too much air inside the pipe and therefore too much reaction on the flame on the end of the pipe closest to the speaker. I tried several things along with cutting the pipe between the holes and the speaker and putting a piece of latex balloon over the end and re-securing it with the coupler (suggested online). The idea was to prevent the produced air from reaching the flames but this did not seem to help. I finally ended up just extending the piece of PVC between my speaker and the nearest whole up to about a foot or a foot and a half and this seemed to fix it nicely (the coupler didn’t seem to hurt anything). You will likely just need to place with this a bit.
At this point I was pretty much done but I found that the pipe wanted to roll around on the table or sawhorses that I had it on so I ended up cutting to small U-shaped pieces out of wood into which the pipes sat. This kept them from rolling about which is a good thing with a pipe that is on fire.- Now it was time to try it out. My little speaker needed an amplifier so I grabbed a piece of stereo equipment that I had sitting around and connect the speaker to one of the rear terminals. I then downloaded a frequency sound generator from the Google place store (literally called “Frequency Sound Generator”) which is free app. I connected my phone to one of the auxiliary inputs on the amplifier, connected my propane tank to the adapter, opened the valve and once the tube was full of propane, lit the holes along the top of the pipe (I basically tried lighting holes over and over and over until it finally caught. I just wasn’t sure when the tube was full otherwise) and watched in awe as my roughly 100 little flames began winking at me gently. I then hit play on my sound generator and had an absolute blast playing with all the frequencies and seeing which ones had what effect on the flames. I found that the 400 to 700 MHz frequencies seem to work the best but you may have different findings.
This lesson is definitely daunting and can be a bit scary. I had people standing at the front of the stage making sure that none of the kids got close and I even had one of our teachers who is a firefighter on standby with a fire extinguisher just should the worst happen. Nothing did and nothing should but I wanted to be careful just in case.
Email me at info@apostolicsundayschool.com if you have questions or just put a comment below.
So, if you want to have a memorable object lesson and are willing to “get out of your box”, this lesson is for YOU! Just try it and let us know how it goes!
Top you can see the first pipe that was not insulated well enough and burned… sigh.
