- Hammer and steel slug attached to vertical tubes.
- Happy/sad balls
- Astro blaster
- Bag of sand
- Spring loaded hopper thingy
- Dropper Popper
Explore the physical properties that contribute to an object’s bounciness.
Demos in this set include:
How to measure Planck’s constant using an LED
Wire balances on top of battery and is free to rotate. Top of wire touches positive terminal; bottom of wire touches magnet connected to negative terminal. Wire completes circuit and current travels through wire. Direction of magnetic field creates a Lorentz force that causes wire to turn.
Historical significance: First electric motor. First successful model devised by Michael Faraday. See: https://en.wikipedia.org/wiki/Homopolar_motor
Developed by NASA Scientist Steve Papell in the 1960’s, Ferrofluid is a colloidal liquid made of paramagnetic nano particles. When subjected to a magnetic field, the nanoparticles form regular patterns of peaks and valleys.
For an interesting list of modern applications see:https://en.wikipedia.org/wiki/Ferrofluid
Beads change color, temporarily, from white to blue, purple, or red when illuminated by UV light. Use with UV flashlight, or direct sunlight.
See physics here: http://www.arborsci.com/uv-beads-package-of-1000
Flashlight emits UV light, of wavelength 385nm. Contains filter to block white light. Use also on minerals, florescent dyes, scorpions, etc.
Appearance of egg mimics that of the sky.
Glass egg is translucent, milky white, and contains no pigment- only microscopic particles that scatter light. Short wavelengths of light (blue) have a tendency to scatter off the microscopic particles in the glass; while long wavelengths of light (red and yellow) tend to pass through. The egg therefore appears yellowish red when held in front of a light source, and blue when held in your hand.
Charge teflon rod with fake fur (shown in above photo) by rubbing together.
When charged rod is brought into the proximity of water stream, attraction between water and charged rod will cause stream to deflect.
Copper pipes chime when hit (hang by loop and tap with hard object). Pipes are identical in size and composition, and are therefore identical in pitch.
To see how temperature affects pitch, dip one pipe in liquid nitrogen and cool for 1 minute. Tap both pipes to hear differences in pitch. Caution: DO NOT TOUCH COLD PIPE WITH BARE HANDS. USE CRYO GLOVES.
Pipes located in L02, section C-1. Ask for assistance with LN2.
Is the mask in the above image concave or convex? Strangely, it appears convex (sticking out towards you) even when viewed from the concave side. Even more strange: the face appears to turn and follow you as you view it from different angles.
Below is a profile view of the mask.
Illusion works best when mask is illuminated from behind.
In a Big Bang universe, the shape of our past light cone is not strictly conical, but tear-drop shaped. The moment of now is located at the pinnacle of the drop, the moment of the Big-Bang is located at the very base.
To understand why our past light cone has this shape, recall that the distance from a light cone’s surface to its time axis is the photon’s emission distance. All of the photons we see today- from the very early universe- were emitted from regions of space that were, at the time, very close to us. (Spatial expansion caused these regions to separate very rapidly.) So, photons emitted very early in the universe’s history, and photons emitted very recently have small emission distances.
The slope of the light cone represents the recessional velocity of light with respect to our region of space. The fattest part of the light cone corresponds to the moment in time when the photons we are currently seeing, from the Big Bang, first began to approach us.
The model shown above is actually the light cone for a linearly expanding universe (expansion at a constant rate- i.e., recessional velocities do not change with time). The most accurate model for spatial expansion- lambda cdm- is actually very close to this in shape.
When droplet of olive oil (oleic acid) is placed on water, oil spreads out until oil layer is 1 molecule high.
If the oil “spill” radius and the size of the original droplet can be measured, one can estimate the length of the oil molecule.
Volume of original droplet = volume of oil spill pancake.
Use wire loop (diameter~1mm), to estimate volume of droplet (assume droplet is wafer, not sphere). Use calipers to measure.
Dip loop in olive oil.
Remove excess oil using paper towel.
Dust surface of water with lycopodium powder. This allows you to see clearly the final diameter of the spill. The larger the container the better.
Dip tip of wire loop into water. Oil immediately spreads out to form circle (very cool to watch!).
Should get order-of-magnitude accuracy.
Heat of friction causes ink in “Frixion” erasable pens to disappear.
Ink reappears when exposed to cold temperatures.
Use lighter for high temp. (Be careful not to burn paper. Just wave flame in front of paper until ink disappears)
Use liquid from compressed air to achieve cold temperatures. (Invert can and spray. Be careful not to get liquid on skin. Extremely cold.)
Heat aluminum blocks to 350 degrees C using adjustable hot plate shown in photo.
Use water dropper (with demo) to place droplets of water onto surface of hot aluminum blocks. Leydenfrost effect causes droplets to hover, and prevents them from evaporating immediately.
Droplets on the ridged block are propelled along the surface- from right to left in above photo.
Raise one edge of the hot plate slightly, so that droplets on smooth surface slide down while droplets on the ridged surface climb up.
See more about this here: http://www.wimp.com/when-water-flows-uphill-the-leidenfrost-effect/
Located in L35: Below, and to the right, of the sink.
Accessories (black plastic bag, aluminum sheet, transparent plastic sheet) located in cabinet with camera.
For information about exciting and interesting IR technologies and applications see: http://coolcosmos.ipac.caltech.edu/infrared_world
Few demos are as simple and surprising as this one.
Located in L02, section B-3.
Solenoids: L01, section B-2
Galvanometer: L35, section F-3
Power supply: L35, section F-1
Some ideas for experiments beyond the typical shock-myself-and-my-students:
Located in L35, section H-3.
Very nice (and expensive) demo. Please handle with care.
For detailed operation instructions see Instructions booklets-
one for fuel cell stack, and one for electrolyzer.
For Demo and Lab ideas see “Fuel Cell Technology for Classroom