Who would have thought a video not about concrete could be so interesting!

I did my MSc thesis on a cosmic ray detection experiment (the JANZOS array) trying to detect cosmic rays created by supernova SN1987A, which was in the Large Magellanic Cloud, and is the nearest known supernova in several hundred years. We used two different detection techniques: scintillator detectors (like yours) and air Cerenkov detectors. (Your shot of fancy science cosmic ray detection was air Cerenkov, but much more sophisticated that what we had.) Our scintillator array had 76 detectors, each 1m^2 or 0.5m^2, spread over about 150m diameter area. Although you describe your device as a muon detector, it will detect any charged particle which is able to penetrate the atmosphere from source to your detector, and penetrate the detector itself. When a very high energy cosmic ray hits the top of the atmosphere, it will interact with an atom to produce several slightly lower energy particles, which in turn interact to produce still more particles, until you have very many particles travelling just short of the speed of light and spread out like a pancake. This is a particle shower. Eventually the particles become low enough energy that interactions with the atmosphere absorb the particles rather than generating new ones, and the shower dies. So it starts small, gets big, the dies away to almost nothing. The big exception is the muons, as they are much more penetrating than the electrons, positrons and gamma rays which make up most of the shower. If you are at low altitude, very few cosmic ray showers will penetrate the atmosphere that far, but the muons that they produce will (and hundreds of metres of rock beyond that.) Our scintillator detector array used detection timings from the detectors to reconstruct the direction of travel of the particle shower, and hence of the initial cosmic ray. Muons are so penetrating that a few floors of parking building concrete should have minimal effect on them. (It is a long time since I worked on this, so I might be wrong here.) I expect that the reduction you saw was rather due to shielding from non-muons in the rare cosmic ray showers which penetrated to your level. Also note that when you get a coincidence detection with your two detectors, it might not be a single particle which travelled through both detectors, but a cosmic ray shower where different particles in the same shower triggered the two detectors. You can also get coincident counts from local radioactivity, so long as the particle can penetrate both detectors. Here are some more experiments for you: If the coincidence counts are from single particles, as you move your detectors further apart, the detection rate will fall, and the decrease in rate is easily calculable from the geometry of the relative placement of the two scintillators. Conversely, the coincident hit rate due to cosmic ray showers will be independent of the relative location of the two detectors (unless the separation is large compared to the size of the shower, which would be at least tens of metres.) (Your side-by-side-detectors measurement might already be a measurement of cosmic ray showers.) So it should be pretty easy to separate these two effects. (You'll need to think about the length of the time window for coincidence counts. To detect showers, your window needs to be at least as large as the light travel time between your two detectors. If your coincidence time window is something like 1ms, this won't be a problem, but if it is 1ns it could be.) Once you've done this to estimate separate rates for showers and for muons, you can start to experiment with how this changes depending on location: * At higher altitude, you should see a higher shower rate, but much the same muon rate. Expect a very large difference in shower rate between sea level and a few thousand metres altitude. (Our experiment was, as I recall, at about 1600m altitude.) * Shielded locations (parking building) should decrease shower rate but have little effect on muon rate * Local radioactivity rate (which would behave like muons, as it its single particle coincidence) should be very dependent on location, such as whether your detectors are sitting on rock or on a thick layer of dirt. (I'm really not sure if this rate will be significant at all.) * If you have your two detectors stacked vertically, counts from local radioactivity are likely to be particles coming from below. Try putting a few cm of lead under your detectors and see if it makes a difference. Did we detect cosmic rays from SN1987A? The Cerenkov detectors gave us a marginal signal (I think it was 3.3 sigma, after correction for multiple testing) for a two day period when other experiments also thought they saw something, but we got nothing significant from the scintillator array. If I remember correctly, our scintillator array detected about one shower a second, but it had much greater collecting area than your little detector, and it was probably at greater altitude, which has a big effect on shower frequency. We'd have loved to have had dedicated muon detectors (basically more scinillator detectors but buried under a few metres of rock) as part of our array. Showers initiated by hadrons (protons and antiprotons) produce lots of muons, the approx 1% of showers initiated by gamma rays or electrons/positrons do not. Because magnetic fields bend the paths of hadrons, the direction of the shower doesn't indicate the direction to the cosmic ray source. If we could have distinguished between hadron initiated showers and gamma/lepton ray initiated showers, it would have improved our signal (gamma ray initiated showers) to noise (anything-else initiated showers) enormously.

A video about a civil engineer using electronic equipment to do particle physics, sponsored by Zod from Superman. I think we just broke reality.

This project was designed with funding from the MIT Physics Department to encourage students to pursue careers in science and engineering. I want to help further the educational aspect of what Spencer and his team are doing by giving these detectors (and my leftover spare parts) away. If you are an educator and interested in having a desktop muon detector for your classroom or if you'd like to build one as a class project, shoot me an email at the address in my channel’s “about” page and we’ll give these devices a happy home. Edit: The detectors and spare parts have been spoken for!

Muon detection was used to discover a new hidden chamber in the great pyramid at Giza in 2017 and it is touted as a new approach to 'seeing' inside large dense objects like volcanoes, a technique called muography

Fun fact, those muons don't last long enough on their own to make it through the atmosphere, but they're moving so close to the speed of light that their lifetimes get a boost thanks to time dilation a la special relativity.

When I was like 5 years old, my father explained to me how cosmic rays are constantly shooting through my body all day long. And there was nothing I could do to stop it. Engineers make for trepadatious parents.

Certainly easier than buying a mine and filling it with heavy water and light detectors! The enclosures and overall look of the product is very professional. Good stuff.

It would be interesting if you set this up at the bottom of an alcohol cloud chamber, being able to see the transit of the particle and then gauge whether it's always picked up by the detector.

"I was going to talk about concrete but made a muon detector instead" hahahaha who doesn't?

I’m so thrilled to have stumbled on your channel. I just binge watched all the videos. Amazing and fascinating stuff thank you so so much

Thanks for your venture into subatomic particle detection, processing and readouts. That circuit board was beautifully designed with descriptive labeling. I spent much of my career at the SLAC research facility, as an electronic technician working with particle detectors and beam position monitors.

With increasing size of the szintillator you can quite reduce the necessary measure time. Currently we implement a similar device with a big very thin woven szintillator. This will be put on a drone / weather balloon to measure rate and direction depending on the height. In this case the experiment focused on undergraduate physic students to build this. Additional we will use one of the STM32 boards for its much higher performance and efficiency.

This is a great true random number generator.

A civil engineer building a muon detector. This is a perfect example of the pros of the internet and spread of information!

Just saw this video, and immediately knew it'd be one of my favorites! You didn't disappoint. Thanks!

I love this!! You like science and the arts! Thank you so much for sharing these projects!

You sir are fantastic. I love your videos!

This is one of the most wholesome science/engineering channels on KZfaq, right up there with SmarterEveryDay

omg, even at the start of this video, i can tell this is going to be cool. we have just been covering subatomic particles and their relatives in physics, all the hadrons, leptons, bosons and mesons. its so cool, and i need this in my life now

Something you may enjoy, software defined radios. Can gather radio system capacity (loading) data with them, spectral analysts, see how reinforced concrete affects signal, track ADS-B…all sorts of fun stuff.

You can find void space in volcanoes and pyramids using muons and your last experiment touched on that. If you had more detectors you could even graph empty spaces with enough data points. Thanks for the video!

Keep up the great videos! Love these!

To be honest I don't watch all your videos, I just let them play and like them, I just want to support a fellow engineer, cheers from Syria.

That soldiering job though😅 edit:don't let EEVBlog see this, Dave will have a heart attack.😛

As always, great stuff!!

That's awesome!! I'd love to get one of those!!

I did this for my senior project in physics. It was pretty great.

Awesome video- I'm a bit tempted to build an array of those myself. If I can offer some constructive criticism on soldering- It helps to apply heat to the part and board pad at the same time, then introduce the solder after they're both warm. When done this way, the solder will quickly wick to both. It also shortens the amount of time you have to work with the solder, so you can get the joint done correctly before the flux burns off (which makes the solder unworkable.) You'll also want to make sure that you're touching the solder to the pad and part, and not the iron. Touching it to the iron will burn off the flux before it can do its job.

I'm a 3rd year physic student, and this year we exactly that experiment for our Lab lesson. Expect we used 80's or maybe even 70's gear and old NIM logic module. It was pretty fun. And with all the data you mesured, you should be able to make a exponential fit to mesure directly the life time of the Muon.

I enjoyed this little foray into science/physics. Curious to see what else you'll do that is less engineering related.

Built one of these in my senior year of college. Had a much larger scintillator, and much more primitive electronics. Mind you this was nigh on to thirty years ago. Worked pretty well. Came up with Muon lifetimes that matched within 0.1% of the expected result

Well done. Interesting stuff!

Love this channel

Love your videos

Underrated channel

Very well done!

I usually come here for the concrete, but this reminds me of my time as a grad student working on a cosmic ray air shower array (I moved on to work on stellar astrophysics since). This is a really cool gadget and now that I know about it, I might get one for my office.

you should follow this up with a video about cloud chambers. you could make a really good one! I saw one at griffith observatory in LA and it blew my mind, i never knew such a thing existed and it's still by far my favorite physics "gadget"

I built one of these in high school for a Senior project. Not really as complex nonetheless paved the way for my love of science. Much love!

I can’t believe the General Zod decided to sponsor this episode 😂 his fight with Superman must’ve gone horribly wrong 🤣

Awesome project!

I came here for engineering, and now I have a complex understanding of astronomy and particle physics. I hope you're happy.

Great education video please do more :)

I'm DEFINITELY getting a couple of those kits! Not only is detecting muons amazing in itself, I want to modify them to output the count rate and intensity as control voltage (CV) to control analog synth equipment. Generating entire compositions from cosmic rays - particularly rhythms - would be really good fun. (Not sure yet how to amplify the differences in intensity so to get a greater range of output voltages ... )

I saw an art exhibition that used an array of these or something very similar. On ever detection, each detector would emit a tone. It was pretty cool and sometimes quite musical, other times it was very random.

I got a few of these for my High School, and we sent them up over 4000ft in a rocket! These muon detectors are super cool

You should set up a cloud chamber, it lets you see the path of and interactions between particles of radiation, both from terestrial and cosmic origins. All you really need to make a crude one is some dry ice, a black cooking pan, a plastic box or terrarium and some alchool.

1:09 GreatScott got triggered

Really cool and interesting

Is there a kit that collects all the necessary parts in one place? A cursory look at the project's website describes everything necessary, but you are left on your own for acquiring everything.

Maybe the difference in muon detections was due to change in altitude rather than amount of concrete above the detector? Would be interesting to see how much concrete it would take to block muons entirely.

great job

I am some research on cosmic rays at cern, whe use bigger detectors that capture around 40-60 traces a second, and are capable of triangulating the trajectory of the rays. I can tell you that the day-night cicle doesn't have an influence, but air pressure maybe has, we are investigating it. Also some rays come from the earth, we don't know if they cross the whole planet or are generated by radioactive decay, the experiments are ongoing!

If you want to learn more about elementary particles and really just the whole universe, I cannot recommend enough David Butler's "How Small Is It" series.

Such an interesting video! How strange it has only so little views, compared to other Practical Engineering videos..

Cool, I have been working on a similar device, but no scintillator. I had known about this device before, but didn't realize that was how they were doing the detection, pretty cool. I guess that removes the need to block other particles and electrons from passing through and exciting the scintillator? Or is that still an issue?

This makes up for jumping trains of thought from concrete to astrophysics. Well played

Hey! Nice video as always! Quick feedback: I’m assuming you have the microphone on the desk? I think it would benefit from resting on another surface or being isolated from the table. Every time you touch the table we can hear a bump in the video. :)

Wow this was an inspirational video, Grady. In short, there is no refuge from Muons.

I'd really like a video or series on rammed earth: history, with/without cement, types of reinforcement, thermal efficiency, weather resistance, etc.

Needs googly eyes.

Impressive for a civil engineer! ;) Cleaver guy!

NIce video. I've been measuring cosmic rays for about 6 months now. I gather data and performe flux, time of flight, and shower studies. There's a lot to learn and it's not easy. I've received a grant from the NASA space weather program to do this research, and i have no idea what it's for. One could say i cant see the forest for the trees yet

Nice video! But you start for work at 6.30? That's way early! And you make all these videos. Kudos man!

A box with a blinking light is one thing. It involves following instructions to assemble a electronic kit containing smd components and so on and when it is done, it is just a blinking light. So you need at least two of them to see if particles go to both of them. The other thing is a cloud chamber. They are relatively easy to build, you need an old aquarium (without fish and water), a method to cool it down at the bottom and heat it up at the top to create a temperature gradient. As a medium to create the clouds you need some isopropyl alcohol that will be heated from the top and cooled at the bottom. Another ingredient is a lightsource from the side just above the bottom. The bottom and the sides should be non-reflective (matte black paint) and it should be closed with a sheet of glass on the top to minimize air-currents in it. (There are many detailed building instructions for cheap cloud-chambers on the internet, some use components of old fridges or cooling boxes, some use dry ice and so on, just search for it). Looking into such a cloud chamber is more impressive than a blinking light. It is more comprehensible, a better tool to teach people about the invisible things around them. They might ask questions how it works and this gives the opportunity to explain ionizing radiation and how it creates a trail of ionized gas which attracts the alcohol and water molecules which then condense into cloudy trails. Of course, a desktop-particle-counter is still a nice device too. ;)

I am more interested in the inner workings and specs of the scintillator than cosmetic rays :) I am fascinated by all kinds of detectors.

You are probably aware that the measurement of muon rate atop mountains compared to sea level was and is a major proof of Einstein's theory of Special Relativity. Since muons decay in 2.2 microseconds, at their speed, most should decay before they reach the sea. However, the rate atop the mountain and at sea level does not show that. The answer is that we observe the muon time to slow down (time dilation) allowing the muons to last longer and reach the sea. From the perspective of the muons, time does not slow down but the distance to the sea shortens (length contraction) and they can traverse it in less time. In the early 1960s, David H. Frisch and James H. Smith measured the rate of detection of muons at the observatory on top of Mount Washington in New Hampshire (elevation 6289 feet) and again at sea level, obtaining agreement with the time-dilation prediction of special relativity. They published their results and made an educational movie. kzfaq.info/get/bejne/aamVhLukrs-roGw.html hyperphysics.phy-astr.gsu.edu/hbase/Relativ/muonex.html

For the experiment where you left the detectors in your car at work, it would have been interesting to have a control, as in another set of detectors, sitting in the exact same spot every day. This would tell you if the change is due to the layers of concrete and not something else.

Can I purchase one of these muon detectors somewhere? From you? I want one!

It's best to use two irons when soldering SMT parts by hand. It's easy once you get the hang of it as the surface tension pulls the part into place.

That XOD thing is giving me feelings of nostalgia for Lego MindStorms.

But was the difference in the garage statistically significant. This is a cool project!!!!

Just popping in to tell you that the chain from Detector->PMT->ADC->(etc) is really common in different fields of process and laboratory analyzer design. Sulfur and nitrogen analyzers, for example, use this chain.

I love/hate this channel because I've been watching for a while but my engineering teacher showed in class and I realized I was a huge nerd

Excellent presentation. Real data. There is a app that uses soft errors in cellphone graphic memory to detect cosmic rays. That may be detecting more neutrons than muons, since the charge transfer is low for ultrarelativistic particles. Soft errors are a concern for modern computation, since it limits the accuracy of calculations. You might want to do a follow up comparing the issues.

I could sure use your help.

Forrest Mims, who wrote a lot of hobby circuits for Radio Shack has a simplified circuit similar to this.

muon is very versatile due to how readily available on the surface. Alot of experiments are device to uses this to detect underground reserve of minerals and other features without physically digging thru the earth. best way to describe it would be a muon been a light source and detector been a camera that captures it.

Thanks for this great video! I wonder if you can elaborate further on why muons cause a light emission but other particles/waves don't? I.e. what protections does the device take against false positives?

Now to build a mount so you can test any angle between verticle and horizontal or a waterproof version so you can test attenuation through liquids (or just put them below a fish tank XD)

Very cool 👍

There is a patent and schematics for a muon generator online using these existing detectors. It works like solar cells, but isn't disturbed by Earth's weather.

I am surpriced that muons can still pass thrue concrete slabs that a garage is build of, wow. Didnt know they were so powerfull/energetic.

Very good

6:10 Linking multiple detectors together to sense direction is called a hodoscope.

This is awesome! Thank you for sharing this project with us. I want to build my own now. I have many questions about muons; do muons ever reach us from the side? I would have placed them side-by-side in co-incidence mode just to see what happens. i'm curious about the false triggers. I know the endpoint for an electron; it gets absorbed by an atom eventually. But what is the ultimate fate of a muon? We see that the different levels of concrete affect the muon rate. What is happening to those muons? Thanks again!

2:17 Those dishes look so sci-fi! 😀

Fantastic

Question: What if the detectors were placed underneath a container of water and/or ice with varying thicknesses? I wonder if the shielding properties of concrete would be duplicated to some extent. Just curious. Thanks for posting your awesome videos. They are very enjoyable and informative.

Hello Sir, thanks so much for your video, my friends and I are trying to execute this project but we are facing several conundrums, I wanted to ask you when soldering the SiPM do you have any proceeding recommendation regarding the soldering process, as I read in the manual that it should be soldered at certain temperature and the heat should only be applied for 10 secs which makes me worry if we try to solder it we will ruin it as we have little experience when it comes to soldering, do you recommend anything that we do?

Forgive my ignorance if I am in error but previous reading regarding muon detection illustrated a more fascinating property related to this particle. Am I correct in my understanding that the normal decay process would disallow their physical transit from the site of formation (high in the atmosphere where the collisions occur) to the surface of the earth where they could be detected. They decay before they can reach earth, but due to their velocity - time dilation (their clocks slow down), it extends their existence long enough for them to make the journey. Do I have it right? Thanks for your upload.

more things like this, things we can try at home/ hands-on

Why does sticky tack fail in different ways depending on how fast you pull it? If you pull it really fast, you get a really quick and clean break. If you pull it really slow, you get a really jagged and medium-size break. If you pull it at a medium speed, it stretches and stretches and stretches until it finally gets too thin to support its own weight and snaps.

Hehe, I have that same dodgy DC bench supply in my storeroom. Interesting thing is that here in Australia it's branded "POWERTECH", and that US edition is branded as "TECHPOWER". The only explanation that isn't completely counterintuitive is that "Powertech" was already a trademark in the US prior to those dodgy things being unleashed on the world. ;) (The overcurrent protection sounds like it's going to take off ... or blow up. Hehe.)

Ooo! Inner stellar material. I'm made of that stuff! :-) Or as Bender would have it: I'm 98% star stuff!

Now, is it the density of the concrete that causes the attenuation or is it an effect of the mesh used to re-enforce the slabs? Similar to how a anechoic chamber absorbs reflections. I wonder if the "u" could pass thru a Faraday cage? It might reveal the answer to the re-bar question. Are the "u" at such a wavelength they would still pass thru the screen of the cage.

Hey Grady, this was the first video you used the music at 0:46, but it isn't in any of your video's descriptions. Can you share what it is please?

While this is certainly interesting you don't actually need a device this sophisticated to see cosmic rays. When I was in college I used to participate in some science outreach programs for the local elementary schools. One of the things we did (which admittedly was a bigger hit among the adults than the kids...) was build a cloud chamber for detecting cosmic rays. It's really simple. You just need a clear plastic container, some paper towels, rubbing alcohol, dry ice, and a strong light source from something like an old slide projector. Soak the paper towels with the alcohol and tape them to the bottom of your container. Put the lid on the container, flip it over, and place it on top of the dry ice. The cold from the dry ice should cause a vapor cloud of the alcohol to form near the bottom of the container. Then go into a very dark room and shine the light on that vapor cloud. Then just watch! You should see occasional tracks form in the vapor cloud, and those are being produced by the cosmic rays. It's that simple.

Perhaps you could build your own cloud chamber beside it so you can see the particles before they get detected