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# Physics Experiments To Inspire Undergraduates?

#### kdawson posted more than 5 years ago | from the describe-the-universe-and-give-two-examples dept.

249

PShardlow writes "I have recently been asked to propose two projects for a 1st year undergraduate teaching laboratory in the summer term this year. These are projects that a pair of students will spend 36 hours working on, and as such can be quite in-depth. A good project would include something they can build, something they can measure, and something they can calculate. Previous projects have included cloud chambers, a Jacobs ladder, a laser Doppler speed camera, laser sound detection, smoke rings, and physical random number generators. This is an opportunity to really inspire students into the joy that can be experimental physics — but it only works if we demonstrators propose interesting projects. So I ask the Slashdot community for suggestions of fascinating projects to do, things that are relevant to today's physics problems but could feasibly be completed by a pair of first-year undergraduates in 72 man hours."

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### Coil Guns (5, Interesting)

#### paultag (1284116) | more than 5 years ago | (#26882459)

Coil Guns rock. Inspired me to get into electronics. One that shoots Fist sized slugs would be enough for any of us :)

### Terrible News! Please read! (-1, Offtopic)

#### Anonymous Coward | more than 5 years ago | (#26882535)

At 10:28pm EST Rob Malda was rushed to the emergency room and was found to have a microscopic penis. Yes, folks, Rob "CmdrTaco" Malda, hero to many millions of slashdot nerds around the world, is hung like a 3 year old Asian boy.

### Re:Terrible News! Please read! (0, Offtopic)

#### JustShootMe (122551) | more than 5 years ago | (#26882645)

And how would you know how a 3 year old asian boy is hung?

Something to think about.

### Re:Terrible News! Please read! (0, Offtopic)

#### genner (694963) | more than 5 years ago | (#26882683)

And how would you know how a 3 year old asian boy is hung?

Something to think about.

Don't jump to conclusions. He probably saw it in the mirror.

### Re:Coil Guns (5, Interesting)

#### phantomfive (622387) | more than 5 years ago | (#26882737)

Indeed, anything that blows things up or is destructive is always a good idea.

I had one idea last fourth of July to separate di-hydrogen-monoxide with some electrodes into a floating pillar of its component parts hydrogen and oxygen, then reassembling it very quickly.

I saw another guy install a switch in a baseball bat, and connect it to a camera. Then use it to take pictures at very interesting moments. On the watermelon, on the egg, , on the soda can.

Another idea might be some kind of musical instrument. Put a microphone next to almost anything that vibrates or beats and it can make interesting musical noise. You can investigate variations in length, density, etc, and how that varies the tone and pitch.

Maybe build a trebuchet?

I still say let 'em blow something up.

### Re:Coil Guns (2, Interesting)

#### sakusha (441986) | more than 5 years ago | (#26883315)

Anything that blows up is probably a Chemistry experiment, not a Physics experiment. Electrolytic decomposition of water into hydrogen and oxygen is a chemistry experiment.

The only thing like that I can truly put in the category of Physics is the "Ice Bomb" experiment, which is extremely hazardous. Somewhere on the internet, through some professional Physics & Chemistry website, I saw the best video of that experiment ever. They got a cast iron sphere about 2 inches thick and about 4 inches in diameter, it had an huge cap with threads about an inch deep. They filled it with water and sealed it up, it was truly a 4 inch cannonball with solid iron walls 2 inches thick in all directions. Then they dropped it into a big vat of slushy water ice and dry ice. All that was surrounded by piles of sandbags and plexiglass shields. After a few minutes, the ice bomb exploded, flinging shrapnel everywhere, ripping apart the sandbags and the protective plexiglass shields. They retrieved the pieces of the metal sphere, it was ripped into pieces. Wow you should have seen that explosion.

Nowadays, people do this experiment with pop bottles, it's lame. Find a good Physics supplies shop that is focused on educational demonstrations, they have loads of great gear for doing experiments like this. You can't beat the classic demonstrations, although it may be expensive to arrange the really good equipment (especially if you're going to destroy it).

### Re:Coil Guns (0)

#### Anonymous Coward | more than 5 years ago | (#26882777)

You could also create a makeshift GPS system with weather balloons.

### Re:Coil Guns (1)

#### cong06 (1000177) | more than 5 years ago | (#26883179)

In Electronics, I was greatly inspired when I created an autonomous Remote Control car.
It was mostly fun because it went really fast.
I'm sure that Electronics projects require more then just simple training, but destruction isn't the only fun project.

In general, with the projects suggested so far I could see them not quite fiting what PShardlow is looking for:

things that are relevant to today's physics problems but could feasibly be completed by a pair of first-year undergraduates in 72 man hours.

The easy solution for interesting is always Classical Physics, but for something more "relevant" lasers might be fun...
The main thing that turned me away from projects were the long write ups, the sitting and waiting for data, experiments that take longer to set up then run. It might just be me, but I feel like if you avoid these, and let them choose a topic, then they might enjoy it more.

### Re:Coil Guns (3, Funny)

#### Anonymous Coward | more than 5 years ago | (#26883329)

In Electronics, I was greatly inspired when I created an autonomous Remote Control car.

Wow, you created an oxymoron on wheels! That IS inspiring.

### Re:Coil Guns (1)

#### shawb (16347) | more than 5 years ago | (#26883369)

That's a car that receives instructions remotely, but makes up it's own mind on where to go.

### WTF?!?! (-1, Offtopic)

#### Who Is The Drizzle (1470385) | more than 5 years ago | (#26882461)

Linux just isn't ready for the desktop yet. It may be ready for the web servers that you nerds use to distribute your TRON fanzines and personal Dungeons and Dragons web-sights across the world wide web, but the average computer user isn't going to spend months learning how to use a CLI and then hours compiling packages so that they can get a workable graphic interface to check their mail with, especially not when they already have a Windows machine that does its job perfectly well and is backed by a major corporation, as opposed to Linux which is only supported by a few unemployed nerds living in their mother's basement somewhere. The last thing I want is a level 5 dwarf (haha) providing me my OS.

### Re:WTF?!?! (3, Funny)

#### JustShootMe (122551) | more than 5 years ago | (#26882497)

That's a great idea. Have them try to figure out which post this was actually meant for. That oughta take about 72 man hours, give or take.

### Re:WTF?!?! (0)

#### Anonymous Coward | more than 5 years ago | (#26883065)

Hmmm... it looks like the post anonymously button is working today. You must just be an idiot.

### LHC (4, Funny)

#### Anonymous Coward | more than 5 years ago | (#26882493)

Accelerate small particles to high speeds, create mini black holes, destroy the planet. Quite fascinating IMO.

### The Amateur Scientist (5, Informative)

#### Anonymous Coward | more than 5 years ago | (#26882507)

Perhaps a collection of "The Amateur Scientist" columns from Scientific American would be a good source of ideas? A CD [amazon.com] of the columns has been published.

### Re:The Amateur Scientist (-1, Troll)

#### Anonymous Coward | more than 5 years ago | (#26882679)

The latest issue of SciAm has a good one:

First, roll up a shitwagon with a few buzzards sitting on its bedsides.

Next, have each student measure the time it takes a bird to fall off the truck as well as the distance from the truck where the bird hit the ground after losing consciousness from a whiff of the stinky Indian students.

After that, get the height of the truck and do the parabolic-arc equations which describe how high the birds were, how long it took them to hit the ground, and how far away they were when they hit the ground. Compare the gathered data to the calculated data and discuss.

Optional: Send the stinky Indians over to the biology lab to be swabbed for bacillus stinkius and then put into the autoclave.

### Re:The Amateur Scientist (1)

#### srothroc (733160) | more than 5 years ago | (#26882849)

Along those lines, I'm sure Mr. Wizard has done something interesting that you could draw inspiration from, too.

### Re:The Amateur Scientist (3, Informative)

#### TapeCutter (624760) | more than 5 years ago | (#26883157)

Let's not forget the late great Prof. Julius Sumner Miller [abc.net.au] . The clip from episode 11 will take a bit of explaining.

### Re:The Amateur Scientist (0)

#### Anonymous Coward | more than 5 years ago | (#26883071)

'Sci-Am'?? They're physics undergrads, not arts students.

### Gas turbine engine. (3, Interesting)

#### JustShootMe (122551) | more than 5 years ago | (#26882515)

Build a gas turbine engine out of an old turbocharger.

Or if you want to go all out, have them fire up a GE90-115B. ;-)

### Remote sampler (1)

#### camperdave (969942) | more than 5 years ago | (#26882979)

Build a gas turbine engine out of an old turbocharger.

I just had a Junkyard Wars [wikipedia.org] flashback.

Perhaps you could get them to build some sort of remote sampling device, like a simulated Mars probe/rover or something.

### Re:Gas turbine engine. (1)

#### TheTurtlesMoves (1442727) | more than 5 years ago | (#26883629)

Thats takes quite a bit more time than 36 hours. And cost of materials for this sort of thing also needs to be considered. A normal experimental can be repeated with minimal part replacement.

### Smoke rings (1)

#### iteyoidar (972700) | more than 5 years ago | (#26882521)

You can do some totally awesome things with smoke rings if you rig up a smoke ring maker to a signal generator or a computer and then define various smoke ring generating waveforms/pulses. You end up mixing fluids and electrical/circuits and smoking into one project.

I have no idea what smoke rings are relevant to however.

### Effects of microgravity on human breasts (4, Funny)

#### jollyreaper (513215) | more than 5 years ago | (#26882525)

Securing time on the ISS might prove expensive so I have prepared this simulator out of a trampoline and high-speed camera. I'm not sure exactly what we're trying to prove here but rest assured, the undergrads will be inspired.

### Re:Effects of microgravity on human breasts (0)

#### JustShootMe (122551) | more than 5 years ago | (#26882635)

And then they can measure the average amount of sperm created by the average human male.

The females can be the test subjects...

Now that's an inspiring project!

### Theremin (2, Interesting)

#### blargfellow (948805) | more than 5 years ago | (#26882583)

A Theremin [wikipedia.org] makes a good project for undergrads. We probably put ours together in about a day once we got the parts.

### Water "Bottle" Rockets (4, Interesting)

#### Teancum (67324) | more than 5 years ago | (#26882613)

In terms of physics experiments, I can't imagine something that would both capture the interest of the students, be cheap enough to have a school with a limited budget be able to afford, and allows for multiple variable parameters to be adjusted. It is also a great summer time project.

Yes, this is sending up a 2 liter plastic bottle (or whatever is handy) by filling it up with water and pressurizing it with compressed air to see how high it can go.

There are all kinds of things that you can measure and document, including thrust (including ISP if you want to get that technical), altitude, learning about trigonometry (to measure altitude), payload mass, and even learning about the basics of the laws of motion through a hands-on experiment. Knowing the altitude and how long it takes to fall from the apogee, you can also calculate the local acceleration factor due to gravity (which can vary from one place to another).

There are also a number of variables that can be adjusted in a controlled manner, such as water volume, air pressure, atmospheric conditions (do rockets fly higher in cooler weather vs. hot weather?), rocket shape, nozzle shape, and rocket size (2 liter vs. 1 liter bottles). You can observe conditions, develop formulas from experimental data, and make predictive theories for what happens when you adjust the variables.

For the really ambitious, there are some 2-stage rocket plans available if you dig up using search engines, but a simple rocket is comparatively easy to build. Be careful with the multi-stage rockets, as you can get enough altitude that you may need to file a flight plan with your local airport under experimental rocketry procedures.

### Re:Water "Bottle" Rockets (1)

#### TheTurtlesMoves (1442727) | more than 5 years ago | (#26883765)

In fact model rocketry is a good one too. However 1st years shouldn't be too basic. A good one is calculating the expected performance. Water rockets have some nice dynamics. You are pushing a fluid through a small orifice and you have a compressed gas providing the energy.

If this is done on a test stand with a strain gauge you can get into some nice data gathering and analysis. Water can make a mess but you could leave that out and use compressed air.

For even more fun, if you have some budget to get something made in the workshop (I did), steam rockets offer even more physics (state changes) and more performance. But now safety is something that has to be considered and I would tend to leave this as a test stand experiment. Noise can also be a big deal for something like this.

### Muon Lifetime (4, Interesting)

#### physicsmichael (1294958) | more than 5 years ago | (#26882617)

Once upon a time I did a lab were we used a very simple scintillator and an old photomultiplier tube to detect muons and estimate their lifetime. If you have the parts (including the electronics), it is fun. Exciting? Well depends on the student.

### Ripple tanks (3, Interesting)

#### Anonymous Coward | more than 5 years ago | (#26882643)

When I was in High School (in 1964!) we had a physics curriculum called PSSC. If you can find an original textbook it is full of ideas. It was largely an experimental approach, which was perfect for me at the time. The most fun I had was building a ripple tank. You could add high-tech challenges like digital control of the wave generators (I suggest 2 for point source and 1 for line waves)to look at effects of phase variation and interactions of different wavelengths.

### Re:Ripple tanks (0)

#### Anonymous Coward | more than 5 years ago | (#26882733)

I too took PSSC physics and it might be very possible to update some of its experiments. For example, take the ripple tank suggestion above and add a digital camera. I suspect one could take some photos, then do some image processing to yield interesting results.

### Re:Ripple tanks (1)

#### dov_0 (1438253) | more than 5 years ago | (#26883487)

Add the human breasts from a few posts up with the ripple tank and the high speed camera and you have a winner I think.

### Chaotic Laser Synchronization (1)

#### kasmq1 (1275330) | more than 5 years ago | (#26883621)

working with chaotic lasers is much fun, and considering that chaos is the last revolution in physics ( some say ) it would be quite interesting

### also encourage presentation... (1)

#### hort_wort (1401963) | more than 5 years ago | (#26882647)

In my undergrad days, we chose from a series of things to do. This gave us all a chance to choose something we were interested in. Most of the grade came from presentation and analysis though. It took us all a long time to figure out how to attach an importance to error analysis, and how to present our results in an interesting way. We ended up all designing websites with our results using the university's servers. I got more out of designing my own experiment and report than I ever would have gotten out of a pre-conceived lab.

Just to show how fun it could be to have them design a website, check this one out:
http://ratphysics.com/ [ratphysics.com]
(This is not mine...)

### Magnetohydrodynamic drive (0)

#### Anonymous Coward | more than 5 years ago | (#26882665)

I always wanted to build a magnetohydrodynamic drive - simply put, generate an electric field which causes ions in salt water to move in the field, and then put a magnetic field 90 degs to that and now you have charged particles moving in an electric field. Guess what, the right hand rule says they will now be pushed "out the back" propelling the ship forward. http://en.wikipedia.org/wiki/Magnetohydrodynamic_drive

### Standing Wave... of Fire! (5, Interesting)

#### artor3 (1344997) | more than 5 years ago | (#26882673)

One of the projects I got to work in my first year of undergrad was a flaming standing wave generator. While Jacob's ladders and Theremins are cool, you can't actually *see* what's going on... not so with the flaming standing wave!

The actual name is the Ruben Tube (not be confused with a Rubix Cube), and it's a fairly simple design, too. Just a hollow tube with holes along the top. One side has a hard cap with a place to attach a gas tube, as with a Bunsen burner. The other side has flexible cap, with a speaker pointing at it.

Turn on the gas, light the tube, and play a constant frequency over the speaker. It sets up a standing, longitudinal wave in the tube, which means compressed and sparse areas of the gas. This lets the students see the wave in the flames, and makes it look like the much-easier-to-visualize transverse wave.

It's easy, it's cool, it's visual, and it helps students wrap their minds around an important aspect of physics. All in all, a great experiment.

### Re:Standing Wave... of Fire! (2, Interesting)

#### forkazoo (138186) | more than 5 years ago | (#26882887)

One of the projects I got to work in my first year of undergrad was a flaming standing wave generator. While Jacob's ladders and Theremins are cool, you can't actually *see* what's going on... not so with the flaming standing wave!

The actual name is the Ruben Tube (not be confused with a Rubix Cube), and it's a fairly simple design, too. Just a hollow tube with holes along the top. One side has a hard cap with a place to attach a gas tube, as with a Bunsen burner. The other side has flexible cap, with a speaker pointing at it.

Holy crap, that's awesome. It's absolutely simple enough for a first year undergrad, and it involves fun with fire, so it'll certainly inspire some of them. Sadly, I'd never even heard of this thing until you mentioned it. Though, now that I know it exists, I can't help but think a few bands I know may be getting a suggestion for their live shows...

### Bell's Inequality and entanglement (4, Informative)

#### xPsi (851544) | more than 5 years ago | (#26882685)

Here are a doublet of papers for an undergraduate laboratory demonstrating Bell's Inequality and and entangled photons. The whole apparatus (detailed in the second paper) is estimated to cost USD 15k circa 2002, so the optical elements have probably come down in price since then.

1. Entangled photons, nonlocality, and Bell inequalities in the undergraduate laboratory. [American Journal of Physics 70, 903 (2002)], Dietrich Dehlinger, MW Mitchell. http://arxiv.org/abs/quant-ph/0205171/ [arxiv.org]

2. Entangled photon apparatus for the undergraduate laboratory. [American Journal of Physics 70, 898 (2002)], Dietrich Dehlinger, MW Mitchell. http://arxiv.org/abs/quant-ph/0205172/ [arxiv.org]

### Re:Polish cannon (1)

#### hamburgler007 (1420537) | more than 5 years ago | (#26882897)

How about a polish submarine to demonstrate buoyancy?

### Re:Polish cannon (0)

#### Anonymous Coward | more than 5 years ago | (#26883213)

Complete with flyscreen windows, I take it?

### Some ideas... (5, Interesting)

#### Dr. Zowie (109983) | more than 5 years ago | (#26882707)

Ultrasonic tape measure / speed of sound experiment. Ultrasonic transducers are easy to come by; students should send some pulses out one, and then sense the return pulse, giving either a numeric indicator or a voltage level that corresponds to the delay time. A little electronics heavy, but if they have had a background in electronics it should be pretty fun. Proof of concept: ultrasonic tape measures at Home Depot for $15. (Trick: you have to build some kind of ultrasonic horn to channel the pulse and collect the return pulse -- otherwise it diffuses too much) Lunar range finder. Get a green laser pointer and modulate it with a digital stream. Mount a beamsplitter on a little telescope and point it at one of the Apollo landing sites. Send the laser pointer beam out the telescope, pick up the return signal with a photodiode at the eyepiece. With digital correlation, you can measure the distance to the Moon in only a few minutes of integration. This may be a little ambitious for a 36 hour project, but it makes a dandy six-week independent project. As a side bonus, have them calculate the strength of the return signal. It turns out that the experiment wouldn't work without the retroreflectors planted there by the astronauts. Million-volt van de graaf generator. Given a length of acrylic tubing, a long rubber band, a couple of brushes, a motor, and a big metal ball you too can make sparks that leap halfway across the room. If you really do get a megavolt, you can put a Geiger counter nearby and look for gamma rays(!) Barometer. Make a barometer that can measure the height of your building. Pretty simple to do - just requires mercury, a glass tube, and care, or (for a more sensitive one, but harder to calibrate) an columnn of vacuum oil with a sealed partial vacuum at the top - but very moving: you can demonstrate the mass of air with remarkably simple equipment. Pipe organ. Have them cut the tubes to length to create a scale. Spectroscope. Stanford used to give out posters that could be folded up to make a little spectroscope, with a$0.10 transmission grating slide as a dispersive element. I handed them out to my CU students and asked them to do "something interesting" with them. One of them taped over the slit. Another one used razor blades and sketched the Fraunhofer spectrum of the Sun. Yet another used it to debug a sputtering apparatus for his work/study job. You probably don't want to be that open-ended, but you can certainly ask them to make one and calibrate it using fluorescent lights. Everyone but tape-boy really felt inspired by actually *seeing* spectral absorption and emission lines.

Doppler radar. Not as hard as it once was, this may still be on the ambitious side. Edmund Scientific has microwave transmitters that will serve. Heterodyne the signal with the return pulses, the output frequency gives you the speed.

Measure the curvature of the Earth using a car's odometer and a sextant. Cheap but effective can be had for $25-$30 at sailing supply stores. Have the students travel about 60-100 miles north or south and measure the altitude of a celestial object at both places at the same time of day. Students can "shoot the Sun" at true noon on successive days (compensating for the analemma) or "shoot Polaris" on successive nights at the same time. (Even Polaris is about a degree off the pole, so you can't shoot Polaris at different times on the same night without compensating for that...)

### Re:Some ideas... (1)

#### tlhIngan (30335) | more than 5 years ago | (#26883023)

Lunar range finder. Get a green laser pointer and modulate it with a digital stream. Mount a beamsplitter on a little telescope and point it at one of the Apollo landing sites. Send the laser pointer beam out the telescope, pick up the return signal with a photodiode at the eyepiece. With digital correlation, you can measure the distance to the Moon in only a few minutes of integration. This may be a little ambitious for a 36 hour project, but it makes a dandy six-week independent project. As a side bonus, have them calculate the strength of the return signal. It turns out that the experiment wouldn't work without the retroreflectors planted there by the astronauts.

I believe that is quite out of reach for a first-year physics undergrad - mostly because the laser power needed is extremely high (I've heard easily in the kW range, or 10's of kW), and the amount of photons you get back, literally, is countable by hand (on the order of hundreds of photons), and that's by hitting the retroreflectors. If you aimed elsewhere, the photons you get back can be counted on one hand.

Perhaps a good idea is, if you have s ham handy, is to build from components (resistors, diodes, capacitors, inductors, etc.) a VHF radio rig and use that to talk to the ISS. 36 hours is enough for a small group of people to research the necessary basics (radio plans are common - adapt them as necessary), build it and associated equipment (antennas...), and test. There's nothing complex about it, but it's an interesting project. And a reasonably equipped physics lab has all the necessary equipment for testing. The good part is that it can be scaled easily - if VHF seems too daunting, go for a simple QRP CW rig and try to contact someone on another continent. If that's too easy, go for a SSB design and slightly more power, and do phone. Or if VHF is doable, but the ISS seems daunting, contact a local VHF repeater.

### Re:Some ideas... (1)

#### sakusha (441986) | more than 5 years ago | (#26883365)

The Lunar Laser Ranging Experiment is a great demonstration, but laser power isn't really the problem. I've watched someone demonstrate this experiment on a modest 40 inch reflecting telescope (modest by university observatory standards). The problem is not sending enough power, or getting enough photons back. The problem is hitting the damn LRRR. It is not as easy as it sounds. The guy that demonstrated it was well practiced at hitting the target, he used to demonstrate it every semester and knew from long, tedious practice where to aim. Even then, it seemed to be more aim by gut instinct than by any precision pointing.

### Re:Some ideas... (1)

#### TheTurtlesMoves (1442727) | more than 5 years ago | (#26883713)

There was an article about this on /. a while ago. They are *counting* [wikipedia.org] photons. From the wiki:

..under good conditions, one photon will be received every few seconds.

This makes a difficult experiment for 1st years. Also you may find getting the telescope time hard unless you have one on campus (can anyone say light pollution).

### Chaotic bathtub faucet (1)

#### Weaselmancer (533834) | more than 5 years ago | (#26882741)

It's from James Gleick's Chaos. [around.com]

It's an example of order in chaos. What you do is to take a bathtub faucet and hook it up to a water source. Then turn it down to a trickle. Eventually you'll get to the nonlinear bit, where the oscillations from the last drop affect when the current drop falls.

Hook up a light beam to time when each drop falls and plot the result.

Then do a sort of second-order plot. With the delta time between drops 1 and 2 on the X axis, and the time between drops 2 and 3 on the Y axis.

It will create a sort of phase space portrait of the system. You'll see attractors form.

If I had the time I'd do it myself. Sounded pretty magical when I read it the first time.

### Precision Laser Measurement (1)

#### mookerji (1412833) | more than 5 years ago | (#26882753)

A laser measurement experiment could cover a number of interesting theoretical subject areas: optics (diffraction), solid-state physics, and atomic level structure. Experimental areas such as error analysis, linear/nonlinear fitting, lab safety, etc. would definitely be applicable.

One measurement that immediately comes to mind is using single/double-slit diffraction to measure the width of a narrow object, such as a hair or a thin wire. You can place a strand of hair in the light's path and then use the measured distance between the interference fringes to interpolate the width of the hair.

In retrospect, I think this might be a bit basic, and might best be suited as an introductory experiment. You certainly wouldn't have to build anything, if that's what you're aiming for. I personally think that constructing an experiment, unless carefully designed to be robust, would certainly take more than 72 hours.

A few other sources come to mind for me. The American Journal of Physics, which is an pseudo-educational physics magazine, might be useful when looking for new experimental ideas. The lab class I took last year had a bunch of great experiments, some of which are/were fairly cheap to implement:
http://web.mit.edu/8.13/www/experiments.shtml [mit.edu]

### Quake III Railgun (1)

#### cosm (1072588) | more than 5 years ago | (#26882765)

Ok, the title is just supposed to be catchy.

In my high school AP Physics B/C class, we built a 'railgun' per se to accelerate a metal object down two rails of alternating flow of current (DC current just in opposite directions on each rail). Using the right hand rule or some other memory trick will reveal the forces acting on the projectile, or just look on wikipedia.

Good project to study electricity, magnetic field strength, velocity and acceleration in a 3D plane over a period of time, wind resistance, and most of all shocking the living shit out of yourself with a homemade 3F - 259KV Max Capacitor made of materials used for cooking.

### Experiments vs. Replicating Cool Projects (4, Insightful)

#### billstewart (78916) | more than 5 years ago | (#26882767)

I've always found it frustrating that so many projects described as "experiments" aren't experiments - they're (optionally cool) projects replicating somebody else's work, but you're not learning anything new, you're just validating what somebody else already learned. That can still be fun - hands-on experience is different than book learning for most people, and blowing things up is always a good time - but it's not an experiment.

I've seen lots of freshman engineering / design projects that are at least not just replication - building bridges with toothpicks, making eggs survive dropping from high windows, etc., but even those are often not done with actual science in the process, just empirical engineering.

Some of the typical blowing-things-up projects can also be experimental - make your potato cannon, figure out something about the amount of energy you're getting from the fuel and how far the potato goes and therefore conclude something about your gun's efficiency. (You already knew you needed to point it at a 45 degree angle for maximum distance, and probably even why...) Can you find other ways to learn something new from your projects, even if it's less interesting that the fun of doing the project?

### Trebuchet (2, Interesting)

#### CaptainPatent (1087643) | more than 5 years ago | (#26882781)

Back in AP Physics in high school my teacher didn't quite have a full agenda for us so we had about two spare weeks to kill at the end of the semester. He wanted to do a project similar to what you're describing and he came up with the idea to build a trebuchet.

There was plenty to build and measure, but there is a ton to calibrate which is the important part. In order to see how far we were from the ideal launch many of us (on our own) were calculating the theoretical maximum lanch distance using the weight we had loaded, the weight of our "ammo" (a tennis ball) the length of the arm and attached string, and quite a few more factors.

The best part about this is you have a very wide variety of math you can accompany with it because a lot of the more negligable forces can be ignored or simplified. If you want you can just do some basic angular momentum / vector acceleration equations and get pretty close to the correct efficiency or you can go as in-depth as calculating frictional forces, properly describe the launch cord motion as a differential equation, etc.

Honestly the experience was probably the most inspirational experience I had not just in physics class, but in school. I'd compare it to a good episode of mythbusters because not only did we get to build something cool and do some calculations, but we got to launch things across our school's front lawn.

### Why not an automated defense turret? (2, Funny)

#### zippoiii (887540) | more than 5 years ago | (#26882787)

Start with a battery powered watergun. Add a couple of small motors to pan back and forth, and to adjust angle up and down. Next, you'll need a ultrasonic rangefinder. Hook that all together, and write a piece of software for a control computer to watch for differences in the distance that it thinks things are at. Scan back and forth, and look for things that are different, then hose them down. We almost got to build one of these, until we mentioned to the prof that we wanted to fill it with naptha, and add a sparker in front of the nozzle of the squirt gun...

### Re:Why not an automated defense turret? (0)

#### Anonymous Coward | more than 5 years ago | (#26882967)

You mean... like this USB-controlled servo squirter [nerdkits.com] ?

### Interferometers, Astronomy, Books and Web Sites (4, Interesting)

#### syousef (465911) | more than 5 years ago | (#26882803)

Here's a simplified Michelson-Morley interferometer experiment
http://tonic.physics.sunysb.edu/~dteaney/F07_modern/lectures/mlab1_michelson.pdf [sunysb.edu]

For that matter you could get them to build their own Dobsonian although the physics there isn't too hard (basic optics), especially if you don't hand figure the mirror. There's also a large metalwork or woodwork component that might not be considered relevant.

Here are some really good astronomy tutorials (though the prac work is done with simulated software). You might be able to modify them to something more practical
http://www3.gettysburg.edu/~marschal/clea/CLEAhome.html [gettysburg.edu]

Some of the topics covered by the above
Radio Astronomy of Pulsars
Astrometry of Asteroids
The Revolution of the Moons of Jupiter
The Rotation of Mercury by The Doppler Effect
Photoelectric Photometry of the Pleiades
Spectral Classification of Stars
The Hubble RedShift-Distance Relation
The Flow of Energy Out of the Sun
The Quest for Object X
Jupiter's Moons and the Speed of Light: The Classic Roemer Experiment

There are books and web pages out there....many tend to be geared to highschool, then there are some that would require you to up your insurance...so you'll have to sift through them

### Theremin, the coolest physics musical instrument (1)

#### ParadoxDruid (602583) | more than 5 years ago | (#26882811)

I recommend having them build a Theremin ( http://en.wikipedia.org/wiki/Theremin [wikipedia.org] ). Several students did this at CU Boulder, and the results were both informative and amusing.

### Physics projects relating to the real world... (1)

#### sfm (195458) | more than 5 years ago | (#26882831)

Disassociate H2 and O2 from water, measure the energy. Evaluate how much you get back in 35% efficient burning

Why do windmills have 3 blades. Why not 50? Why not 1 ? Why not 2 ?

Expose film with active radioactive element (Americium) from a smoke detector

Millikans oil drop experiment (I always loved that one)

These are just the ones that come to mind at 10:00 on a Monday night. I'm sure there are many MANY more.

### Tesla Coils (1)

#### Dodder (1410959) | more than 5 years ago | (#26882847)

Tesla Coils are very cool. And I've seen a lot of renewed interest lately in their applications for wireless power distribution.

### Physics. (1)

#### Ostracus (1354233) | more than 5 years ago | (#26882857)

Some simple experiments [umd.edu] .

### Double Slit Experiment..... (1)

#### Desmoden (221564) | more than 5 years ago | (#26882873)

Nothing is cooler, and nothing is such a opening to the amazing magic of physics

### Re:Double Slit Experiment..... (1)

#### aquabat (724032) | more than 5 years ago | (#26883523)

Nothing is cooler, and nothing is such a opening to the amazing magic of physics

with an electron gun, slowed down to emit a single electron every couple of seconds or so, aimed at a photographic plate, so they can see the interference pattern form, one dot at a time.

### Re:Double Slit Experiment..... (1)

#### TheTurtlesMoves (1442727) | more than 5 years ago | (#26883723)

We did this as a 3 hour experiment. Its not really a 36 hour project.....

### BOOOOOM!!! (1)

#### slagheap (734182) | more than 5 years ago | (#26882953)

Fill an enormous balloon with hydrogen and oxygen, then hold a candle up to it.

My freshman undergrad chemistry professor did that in a big lecture hall. I can't say I was inspired by it, but it is the only thing I remember from that class.

### Build memory - Store bits in a piece of cable... (1)

#### GrpA (691294) | more than 5 years ago | (#26882963)

Take a long length of cable (or fiber, but cable is fine) and turn it into memory...

Give them an appreciation for how much of an ethernet frame is actually in transit over 100m of ethernet at any one time. (about 33 bits). Teach them to take Ethernet cards apart and use the circuits in them to build a complete memory unit.

Make them develop their own memory - enough to store their name, using common components, eg, using sound waves or similar to store data. You can even store data as mechanical waves in a spring with transducers.

Use high frequency programmable pulse generators to gate image tubes so you can use light to build a three dimensional image (like LIDAR) with a camera. (You can build LIDARs too, but that usually requires complex mechanical components).

Having a concept of how dynamic things can be can be useful. Most people tend to have static minds - eg, we see things in a fixed state.

Thinking of things as dynamic can be a useful skill to gain.

Also, don't forget practical recreation of physics experiments, such as measuring the speed of light with rotating mirrors and lasers (or even a candle)....

Reproducing an old experiment can also be incredibly valuable. Or better still, use modern technology to improve such an experiment to make it "classroom" sized.

GrpA

### Bubble Fusion (2, Interesting)

#### GravitonMan (1145905) | more than 5 years ago | (#26882977)

In undergrad we spent a few weeks attempting to reproduce Dr. Taleyarkhan work on sonic cavitation experiments in deuterated acetone. While there is much controversy surrounding the this type of fusion, it is an interesting and simple experiment, but hard to get reliable results.
http://www.absoluteastronomy.com/topics/Bubble_fusion

For students it is be exciting to be apart of the human quest for fusion power. And is useful as a teaching tool for all methods of fusion. Taking part in a controversial research project can be very stimulating.

The experiment can be attempted using a pyrex 100mL flask and placed piezoelectric speakers at key locations. The flask is filled with deuterated acetone and the speakers are modulated at different frequencies until cavitation and sonoluminescence is achieved. Their are several types of neutron detectors that can be used. Some of them cheaper than others but less sensitive.

Anyways, just an idea. Alternatively, you can also build a fusor, which is a bit more involved but with the right setup could also work for a short term project, would require you todo some pre-building. http://www.fusor.net/ [fusor.net]
-alot cheaper than ITER or Lawrence Livermore laser confinement...

### Standing wave flame tube (1)

#### fragMasterFlash (989911) | more than 5 years ago | (#26882983)

Every undergraduate should play with fire at least once. Have your students build a Ruben's tube [wikipedia.org] to demonstrate standing waves. Bonus points if they can predict the the frequencies which will produce sinusoidal flame patterns prior to lighting it.

### Ionocrafts (aka lifters) (0)

#### Anonymous Coward | more than 5 years ago | (#26882993)

Ionocrafts (ion propelled aircrafts, also known as lifters) are definitely a first pick. Hook up your old monitor to an aluminum foiled balsa structure and... you just created an UFO. Wikipedia has a few links on the subject.

#### cowtamer (311087) | more than 5 years ago | (#26883053)

For ideas:

http://sprott.physics.wisc.edu/wop.htm [wisc.edu]

(He had our attention when he rolled into the lecture hall on a liquid-nitrogen propelled tricycle..)

[Prof. Sprott -- sorry about the Slashdotting...]

### Acceleration (1)

#### Technician (215283) | more than 5 years ago | (#26883063)

A good engineering challange is building a something launcher. Whether it be eggs, taters, t shirts, etc., the project will provide many reasons to do the engineering. Recently I participated in an engineering challange for high school students to build a t shirt launcher.

Some of the items needed solved were what type of stored energy to use, how to release it quickly and effeciently, and how to transfer the energy with little loss of energy.

Some of the material was beyond HS physics, so some stuff came to measurement, trial and error, and tweaking for best performance.

Here is the web page dedicated to finding out the best diameter and length of a launch tube to match the stored enengy supply in both volume, pressure, and flow rate from the valve.

We measured the acceleration of stuff in the launch tube to find the point where the acceleration dropped off at the peak speed and cut it there.

We won the competition. Arlington HS is the overall winner.

Those guys have me hooked now on competition marshmallow launching. I just built a small version (0.8L tank) of the launcher. From the sound, I think it's supersonic. I'll be getting near a shooting chrono later to find out if I made supersonic.

The t shirt cannon was launching apples in excess of 800 FPS. I'm hoping I'm getting marshmallows in excess of 1100 FPS.

Impact of fruit against 1 L water bottles can be seen here.
https://inteltrailblazerschallenge.wikispaces.com/Photos [wikispaces.com]

Tons of fun. Think safety if you embark on this trial.

### my physics experience (1)

#### GreenCow (201973) | more than 5 years ago | (#26883075)

I recently had my first physics class as a college sophomore, calculus-based mechanics. It was very fun and useful, as a computer programmer. This was my first lab class since high school and I was certainly inspired by each of the ~3 hour labs. The most fun was using a spring cannon to shoot a rubber ball through a ring, using kinematics equations my group of 3 was able to launch the ball precisely through the ring on the first attempt (we were scored by number of attempts).

We spent a total of about 30 hours on 10 labs throughout the semester. I found these to be a good length for keeping our attention and teaching each concept. It was nice to have access to a fairly new lab with laptops which we used to record and analyze sensor data. This all takes place in a very affordable California community college.

I know I haven't answered the question yet, just providing info on my experience for whatever it's worth.

Other interesting labs were: landing a ball in a small cup after rolling off a slope on top of a table. using a car with a fan attached to measure acceleration and velocity. colliding cars of different masses to measure impulse. calculating mass by measuring the velocity of a car being pulled by a mass on a string which was pulled down by gravity.

This class covered only mechanics. I imagine that labs in the fields of electromagnetism, waves and optics must be exciting in different ways. This first physics class left me wanting more, but those will have to wait, as they aren't required in my computer game design major.

One experiment could involve some rockets and landing a delicate payload safely. It has obvious applications. Other useful applications of physics should be sources of inspiration. A student should feel inspired by doing something useful with physics, something that they would use as a professional physicist, something to form the basis for novel applications of physics.

Something involving optics like capturing images of comets using a handmade telescope could be fun.

With the green energy revolution upon us, there could be some home made wind, tidal, and solar energy capture and storage systems to build.

### Exploratorium Cookbooks (2, Informative)

#### shmorhay (781528) | more than 5 years ago | (#26883099)

The San Francisco Exploratorium, an interactive, hands-on science museum, published a three-volume set of instructions for creating useful and educational (and sturdy) projects for children and adults to manipulate and study, although these are now hard to find, and expensive. Search the used books website http://www.abebooks.com/ [abebooks.com] for "Exploratorium Cookbook" (and grab any copies you can) and see also the Exploratorium website at http://www.exploratorium.edu/ [exploratorium.edu] . See also the very recently published book "Laboratory Experiments in College Physics" by C. Bernard and C. Epp, published in December 2008 (ISBN 978-0471002512) available on http://www.amazon.com./ [www.amazon.com]

### Re:Exploratorium Cookbooks (3, Informative)

#### shmorhay (781528) | more than 5 years ago | (#26883421)

To save you some digging, here are the direct links for buying each of the volumes directly from the Exploratorium itself (these show up when you search that website) -- http://store.exploratorium.edu/browse.cfm/4,622.html [exploratorium.edu] and http://store.exploratorium.edu/browse.cfm/4,775.html [exploratorium.edu] and http://store.exploratorium.edu/browse.cfm/4,760.html [exploratorium.edu] and for all three as a [discounted] full set (for \$350) -- http://store.exploratorium.edu/browse.cfm/4,19.html [exploratorium.edu] These may be overkill for your immediate needs, but if you are ever tasked with starting your own hands-on science museum, the Exploratorium folks have very kindly documented their approach.

### Have them build something that *won't* work (1)

#### willoughby (1367773) | more than 5 years ago | (#26883111)

Sci-Fi captures imaginations, so pick something from that - let's say a light-sabre from Star Wars.

Have them build one, explain why it can't be done yet, and demonstrate some current technologies which will probably evolve into the Sci-Fi device. Calculate the battery capacity such a device would require, the power output required to cut through a 2 centimeter thick steel plate, etc.

### Lumen meter? (2, Interesting)

#### thogard (43403) | more than 5 years ago | (#26883139)

Have them build a lumen meter for measuring light bulbs. Its the sort of thing that each year and add to or redesign since it seems simple to get initial results but the problems go much deeper.

### Give topics, let them come up with the spec. (2, Interesting)

#### bronney (638318) | more than 5 years ago | (#26883145)

To engage them, give them broad topics to explore such as conservation of momentum, change of state, magnetism, and illustrate them with they own experiments.

That microgravity on human body thing's good too.

Yes.

Next question.

### 36 Hours!!! (0)

#### Anonymous Coward | more than 5 years ago | (#26883181)

36 Hours!!! Thanks for the laugh. Kinda brings a tear to my eye actually thinking back to all those oh so many more than 36 hours I spent in school working on your typical discipline related projects. Not that I regret it or anything, but 36 hours - that's just plain funny!

### Wah.. ? (0)

#### Anonymous Coward | more than 5 years ago | (#26883187)

...physics experiments in underground lairs, (cough), sure, (cough cough) ? In my time, we conducted all kinds of experiments in underground lairs, (cough cough) - but rarely any physics involved. Science, that is, (cough).

Now get off my lawn !

### Re:Wah.. ? (1)

#### Sparky McGruff (747313) | more than 5 years ago | (#26883465)

Perhaps the poster (and you) could consult with Michael Phelps about the aerodynamics experiments he was working on. Something about acceleration of hot gasses through a water-air interface? The "bong effect", I think it's called. I think such experiments would be very inspiring for many undergraduates.

### Something relevent to current physics problems eh? (3, Funny)

#### deek (22697) | more than 5 years ago | (#26883211)

I hear that the Large Hadron Collider is currently having problems. Maybe your students can build a replacement ... except smaller. Call it the SHC, or even the VTHC.

### The TeslaTire (1, Interesting)

#### Anonymous Coward | more than 5 years ago | (#26883221)

Magnetic Tires - "the concept of an internal electromagnetic system within a radial tire with applications including but not limited to: use as a braking mechanism; potential replacement of mechanical engines and hence elimination of reliance on fossil fuels; and regeneration of electrical energy from induced current to dynamically recharge the batteryâ

Isaac Lim
isaac.lim@me.com

### Frickin' Lasers (4, Interesting)

#### sakusha (441986) | more than 5 years ago | (#26883253)

What the hell is this with the lasers? These are not projects that are comprehensible on a fundamental physics level, at least not in the construction of the projects you described. And Jacob's Ladder? Seriously? I remember doing that experiment in JUNIOR HIGH school. What has happened to science education today?

I'll give you an example of a laser experiment gone wrong. I remember when I was a junior in high school back in the 1970s, I was taking AP Physics, and lasers were brand new and expensive. But our school just bought one and we were dying to figure out experiments to fiddle with it. One day I read an offhand remark in a physics book that the angle of polarization of a laser beam could be altered by a magnetic field. This seemed impossible to me, sure a laser was an electromagnetic phenomenon, but it was light, how could magnetism affect it? So I figured I could get one of our strongest magnets that weighed about a hundred pounds, run the laser through the gap, and measure deflection with a couple of simple polarizing filters. But no matter what I did, I could not measure any deflection. The teacher suggested I try using a longer beam, maybe hundreds of yards between the source polarizer and the detector. That was a total red herring. My lab partner and I tried all sorts of things to use as long a laser path as possible, a few hundred yards even, but even a car driving by the building would make the whole rig vibrate enough to make it impossible to hit the target, let alone measure the polarization. After a week of fiddling around, we finally went back to the physics teacher and admitted defeat. The teacher burst out laughing, and said, "oh of course, what you were trying to do is impossible, and the length of the beam is irrelevant. It would take massive magnets the size of a house to cause any measurable deflection. I just wanted to see what lengths you'd go to to try to measure it." Oh was I pissed.

Well anyway, I have a dim view of the sort of example physics experiments you described (other than the cloud chamber). We did much tougher experiments in high school. Try giving your students the classics, experiments they'll really learn the FUNDAMENTALS of physics from. I have fond memories of doing the Miliken Oil Drop Experiment in high school, it was so much fun I did it over and over to get more accurate results. Or give your students old school equipment like oscilloscopes. You little kiddies DO know what an oscilloscope is, don't you? We did experiments like setting up two microwave emitters side by side to generate an interference pattern, then hooking up an oscilloscope to a detector, then moved the detector around to measure the high and low energy points of the pattern, then plotted the positions of the detector over graph paper. The teacher didn't tell us the frequency of the emitters so we had to work that out for ourselves from the interference pattern. There are loads of classic physics experiments using oscilloscopes, but they are largely forgotten today because the teachers never learned to use them properly when they were undergrads. Maybe it's time for YOU to learn about them.

If you can't get freshmen physics students motivated by the classic experiments showing the most fundamental aspects of physics, experiments that once were so difficult that they were only done in the greatest labs of Nobel Prizewinning physicists, but now are easily performed in any school lab, you will fail as a physics teacher, and at the goal of teaching physics. Flashy gadgets with frickin' lasers are no substitute for the beauty of the simplest physical phenomenon. If you can't get students to see that through your labs, it will be your failure, not theirs.

### Re:Frickin' Lasers (1)

#### TheTurtlesMoves (1442727) | more than 5 years ago | (#26883755)

I also did most of the experiments you describe in high school. But we did them again in 1st year. But we only have 3 hours for each one, and we had to hand in the lab report at the end of the session. 36 hours is a lot of time, and you could get quite a lot done.

### Let them be inspired by their own ideas (1)

#### ImNotAtWork (1375933) | more than 5 years ago | (#26883271)

Have them pick the project they want to do subject to your approval. If it's too expensive see if they can drum up sponsorship... might be a little tough with how the economy is doing these days.

### Tesla coil (1)

#### goodmanj (234846) | more than 5 years ago | (#26883281)

This is a *perfect* excuse to build a Tesla coil.

### I taught first year physics lab classes... (3, Insightful)

#### kybur (1002682) | more than 5 years ago | (#26883301)

...When I was in grad school for physics, and I remember what inspired me when I was an undergraduate.

Forget about all these complicated electrical experiments that the students will feel like they only vaguely understand. First years have no idea what Maxwell's equations are and are probably still very shaky on Kirchhoff. Anything else in Modern Physics, forget it. Many will be overwhelmed because they have no possible way of understanding all the assumptions that went into setting up the experiment. (And you really don't want people questioning whether a meaningful solution can actually be attained).

Have them do something with mechanics. There are plenty of really neat demos that can be done in mechanics that can also be explained to a very high degree without calculus. Something along the lines of the ventomobil, for example. This is cutting edge engineering rather than cutting edge physics, but this is the type of thing that they can understand just by looking at it, and they will have fun pondering questions like: "can it go directly into the wind?" and "can it ever exceed the wind speed?". When you have an intrinsic idea of how things work, exploring the details of something neat will be much more interesting.

The biggest factors here are your enthusiasm, and how well you identify the needs of each student. Physics is a touchy subject for many, and if they get started off on the wrong foot, forget it. They will stop trying. Take your time (really take your time) at the beginning so that no one gets lost, and your students will have lots of fun.

### Stirling engine run forward/backward (0)

#### Anonymous Coward | more than 5 years ago | (#26883309)

How about a Stirling engine run both as a heat engine and backwards with supplied external work to serve as a refrigerator? Can really do some good thermodynamic/calorimetry experiments, especially if you have some thermocouples to measure temperatures.

### What kind of resources do you have? (1)

#### Dahamma (304068) | more than 5 years ago | (#26883359)

I was always impressed hearing a friend describe her low-temperature physics class, where they were always cooling things to 3 degrees Kelvin and then doing various interesting experiments. I'd imagine that takes a fair bit of resources and department expertise, though.

I don't actually remember the specific experiments, because as happens with most research of this kind, building the equipment to cool a chamber down to 3 degrees Kelvin is 95% of the work...

### Tunneling phenomenon, or semiconductor physics (1)

#### onionlee (836083) | more than 5 years ago | (#26883409)

Yeah, quantum tunneling is a great way to explore many different materials. Also, semiconductor physics can be easy to get into but also get truly in depth with. It would be easy to do work with doping of semiconductors, FETs, and many other similar things. If you are ambitious enough, you could also have them explore the quantum Hall effect.

### Dont forget the basics! (1)

#### neanderslob (1207704) | more than 5 years ago | (#26883417)

As a graduate student in physics at RPI, I'm often disappointed by the lack of physical examples and applications of the material that plagues the teaching of our field. While projects on the latest in our field is terribly sexy, I'd encourage you not to forget that the basics of physics holds some great and terribly interesting insights. I've found that in our rush to learn the latest craze in the field, many HIGHLY intelligent students in physics lack a comprehensive understanding of the basics of their field. While I can't come up with any particularly good suggestions in my scotch-induced stupor, might I suggest some sort of clever experimental process to confirm lower level theory that ties together course work that the students have already encountered.

### Real Advice, (1)

#### hisperati (1408819) | more than 5 years ago | (#26883423)

I was just a few years ago a physics undergraduate student... I can recommend a few ideas:

~Hologram kit from Integraf [integraf.com] kits are viable. Completing the entire project in less than 72 hours however may take some preparation as the film must dry and the setup can be subtle.

~Experiments with Jupiter's moons: you can actually see changes in their positions in the time of a single night with a plain telescope. Lots of possibilities here.

~Roll balls down a ramp to measure G. ~Look at the spectra of sunlight, identify Balmer lines.

~Get some liquid nitrogen and YBCO [wikipedia.org] and play with superconductivity.

A lot of the physics behind these experiments can be subtle so don't expect students to understand everything.

### Something GREEN (1)

#### Mat Chop (1479581) | more than 5 years ago | (#26883437)

I know this may sound cliche, but why not let future scientists work on something GREEN. By green, i mean projects to help save our planet. Such projects can be "free" energy, ie "free from bills" houses.

### How about proving software patents are invalid? (1)

#### 3seas (184403) | more than 5 years ago | (#26883525)

Abstraction Physics [abstractionphysics.net]

### Two for ya... (0)

#### Anonymous Coward | more than 5 years ago | (#26883633)

1) Random number generator based off of physical phenomena - basically take a can, drill a hole in it, install a webcam, seal off the light and the can. Turn on, and turn the video into data... Check for randomness. Discuss what camera is 'seeing' inside a dark can, and why it's being detected (that's the fun part - the random number generation is just a nice aside)...

2) Laser sound detector - a fairly easy experiment. Actual story: At the school I attended, a lot of students put tin foil over the entire window so it'd block the light - then they could sleep in, toke up, etc... We built a laser sound detector based off of the Radio Electronics article (yep, back in the 80's), and started shining it on everything we could think of... We finally hit upon a window in the girls dorm one night that gave us some very interesting sounds - piped that into a stereo in another room (amazing how thin the walls are behind bulletin boards) and pumped the sound out the window as loud as it would go... At the time (oh 1am), the young lady and her friend heard themselves, and then we heard the young lady saying "What the &(*&*&& do you assholes have a microphone in this room! Shit!"...

They never did figure it out... we laughed our asses off for days... And when our electronics prof heard about it, we got extra credit points for completing the LASER and getting the receiver working.... ... damn I miss college...

### TEA Laser (1)

#### offrdbandit (1331649) | more than 5 years ago | (#26883665)

Cheap. Awesome. Loud noises. Involves simple electronics and interesting EM phenomena.

### Cyclotrons, He, Muon detectors (1)

#### trip11 (160832) | more than 5 years ago | (#26883739)

Build a particle accelerator. Not a big one. I've seen homemade cyclotron on slashdot before: http://science.slashdot.org/article.pl?sid=02/10/20/1626204&tid=134&tid=14/ [slashdot.org] Point it at your cloud chamber when you're done, of course.

Superfluid He is also wickedly cool. If you can build something to house it, and pump on it until it gets cold enough, you should be able to do some cool experiments with it.

Though not as visually appealing as a cloud chamber, building a detector to measure the lifetime of a muon was one of my favorite undergrad experiments. Three scientilators stacked on top of each other wired into a bunch of electronics, along with the right formulas, and you can get a reasonable measurement. My prof gave us a Phys Rev paper describing how it was done years ago, access to the parts we needed, a scope, and a computer that had a labview application set up for counting experiments. We figured out the electronic logic from the paper, used the scope to debug and set all the triggers correctly, then had to figure out how to actually calcuate the lifetime from what we measured (along with systematic + statistical errrors). Hard, yes, but man we learned a good deal about real nuts and bolts experimental physics that quarter.

### Galileo (1)

#### JustSee12 (1369599) | more than 5 years ago | (#26883751)

I think you should try as hard as possible to replicate the process of discovery that the great scientists of the past have undergone, especially in a first exposure to college physics. There is no better way to understand how the concepts (quantities, really) of position, velocity, and acceleration interact than by rolling a metal ball down a ramp and taking measurements with the goal of establishing predictive results. I had to replicate this famous experiment of Galileo's with extremely primitive instruments (i.e. my pulse and pseudo-reliable internal metronome). Of course, you don't want to make it so difficult that it becomes frustrating to your students, but making them digest data and create original (or for those who've been exposed to physics in high school, imitative) models should be the goal.

### As a physics undergraduate.... (1)

#### Landak (798221) | more than 5 years ago | (#26883803)

I just spent 9-5 yesterday underground in our labs, programming a simple processor with one or two byte opcodes, having just wired up a very large number of logic gates (via a patch panel) to its control lines in order to create subtraction and addition functions. Registers are displayed in the form of eight blinking LEDs on the front. The whole thing is about as big as a large modern laptop, and infinitely more simple -- it had a very limited instruction set (jump conditional, add, subtract, jump unconditional, start subroutine, etc) and a selectable clock speed of between 1Hz and 300 Hz. The standard method of debugging is, of course, to step through cycle-by-cycle and check the values of the registers and memory making sure they're what you expect them to be.

After two hours trying to get a program to print out the first 12 fibronanci numbers to work (entered via lots and lots of hex on the 'front panel', compounded by the fact that I hadn't noticed one of the wires had fallen out...), I can tell you that the final sight of this very simple computer working to do something useful was inspiring indeed. I've written some assembly overnight that should act as a 4-bit multiplier, and some more assembly to act as a memory-checker.

Regarding what others have said on the page: Millikan's Oil-Drop hurts your eyes, and doesn't give very good results. I personally hate it. On the other hand, if you first years have done Maxwells equations properly (I learnt them in my first year; and it's not hard to derive c=1/sqrt(\mu_0 \epsilon_0) in free space from them), then it's easy to have equipment that allows you to very, very, accurately measure the speed of light. This I did find cool indeed. Likewise for fourier optics and information theory, along with anything that involved liquid nitrogen ("Introduction to pressure gauges"). Finally, there are a few important QM demonstrations that you might like to consider -- Stern-Gerlach, Zeeman effect, and so on.

Good luck!

### Build Steel Pans (2, Interesting)

#### unkiereamus (1061340) | more than 5 years ago | (#26883883)

Have them build Steel Pans [hotpans.se] 72 Man hours wouldn't be enough for building a complete pan, but they could certainly build a pan with 5 or 6 notes. Lots of things to be calculated, dish size, note size, groove size etc. It was all worked out originally by pure empirical experimentation, so if the calculations are off by a bit, it's there's enough wiggle room that you can adjust things. (What? That note marked C3? Nono, that was a typo, it was supposed to be a F3 all along...) The physics of it are actually quite fascinating, and at the end of it, you have a musical instrument...

### Something Green (0)

#### Anonymous Coward | more than 5 years ago | (#26883885)

I think you should follow the fad here. Lot of them probably got into the field to "find solution of the energy crisis". Why dont build something solar/wind to, I don't know, maybe charge their cellphone/laptop?

### Build an ECG meter (2, Interesting)

#### ChaoticPenguin (580349) | more than 5 years ago | (#26883905)

Build an electrocardiogram. The students get to learn some electronics, some programming, some data analysis, and some biology.
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