27 July 2010

3-D without glasses: Class 1 of 3 on autostereoscopic displays (free, YouTube)

Hi -

Stereoscopic cinema looks wonderful, in my opinion, and it was built on about 150 years of technology to bring it to where it is today. Regardless, some folks ask "when will we have 3-D without glasses?" Picky, picky!

Autostereoscopic 3-D displays allow you to perceive 3-D images without additional eyewear, a topic I've studied since 1988 (shudder!). Want to learn more about that? I worked with my employer, Optics for Hire (OFH, Arlington, Mass.) to create a three-course series on YouTube (in 10-minute segments) and authorSTREAM (in their entirety):

  1. (available now) The fundamentals of "seeing in 3-D," including monoscopic and stereoscopic depth cues. What's physically possible today, and what's definite trickery? How much underlying electro-optical oomph is needed for 3-D?

  2. Definitions of autostereoscopic. Broad overview of many autostereoscopic displays, from parallax barrier systems (like the Nintendo 3DS) to volumetric and holographic displays.

  3. Lightfield displays using whole-view scanning and piecemeal lightfield reconstruction.

OFH is releasing the classes over a period of several months to our friends (we like to educate our customers and prospects rather than inundate them with junk mailers).

Class 1 is available whole (authorSTREAM), or Class 1a, 1b, and 1c (YouTube).

I'm looking forward to announcing classes 2 and 3 because they have a lot more meat, but some of the stuff in class 1 might strike you as new and surprising.



ps Like optics? Check out these other free instructional videos about designing LED optics...

06 July 2010

Short science projects for inquisitive young kids

Hi -

A friend asked me if I have ideas for science "experiments" or book suggestions for 2.5 and 5 year-olds. What a compliment to be asked that! I am actually short on ideas, but here is a start.

Please, readers, chime in!

General note: I like stuff that has almost no set-up (so they don't have to wait), is open-ended (because the project usually veers quickly in the direction of their interest), and whose elements are inexpensive or instantly gifted (e.g., yep, it's your magnifying glass now).

Science ideas: 2.5 yr-olds and 5 yr-olds (it's up to you what you think is a good fit for your kid)

  • Get several inexpensive magnifying glasses of different kinds from the 5-and-10. Get the ones that are actual convex lenses, not the flat-circle-ridgey "Fresnel lenses," since for some reason a lot of people don't realize that the Fresnel lenses are just as dangerously capable of focusing sunlight.
  • Make things look bigger! (newspaper, bugs, a veiny leaf)
  • Help your child make a picture of the room-light on a tabletop by finding just the right height for the lens, between the two
  • ....or try it with your glasses, if you're farsighted
  • I'd avoid the "burn stuff with a lens" trick at this age. Make sure they don't look at the sun, either. It's up to you if you TELL them this or not, because it might plant the ideas in their head.
  • Advanced: camera obscura! Go to a room with a window, during the day. Turn the lights out. Hold the lens near a wall - can you focus an upside-down image of the window onto the wall? Can you move the lens a little and make a picture of the house across the street?
  • Make rainbows on the wall by helping them to aim a prism (or the edge of something sharp and transparent) with a shaft of sunlight
  • Let them play with a CD and look at the rainbows (diffraction bends red light more than blue light)
  • Shadows
  • The OSA's Optics for Kids
  • Fill little containers - little clear cups, tiny Tupperware, ice-cube trays - with water, and drop Cheerios (or whatever) inside. Put in the freezer. How long will it take to freeze?
  • Drop food coloring droplets into water-cups
  • Supervise them as they play with cups and measuring-devices at a sink

  • There's actually an Elmo-branded seedling kit that comes with little cups and seeds in a thin plastic greenhouse. The tomato ones worked pretty well for us.

  • Depending on your comfort level, and your willingness to judge electrical or mechanical safety, we've gotten a lot of learning out of disassembling stuff around the house. A broken cordless phone, with the power-adapter UNPLUGGED, is a great source of stuff. You can point out "computer chips" and electronic components and red LEDs (ell-ee-dees). We took it a step farther and got a battery connector from Radio Shack (this) and put an AA battery in it and made the LEDs light up and the speaker make crackly noises.
  • Explain how the speaker makes crackly noises. (Most speakers have a magnet inside, and nearby, a coil of wire taped to a paper cone. If the cone moves, it moves the air, and your eardrum moves, and you hear sounds! But how does the cone move? If you pass electricity along the wire, it will become a magnet, and it will move towards or away from the permanent magnet... Why does electricity through a wire make a magnet? No one really knows, I don't think. They have fancy words for it, but I don't think anyone has the true answer.)
  • Take apart an old VCR, if you're confident it's been unplugged for several days. On second thought, don't do that unless you know how to safely discharge the power capacitor for a big spark. Never mind.
  • Watch bulldozers.
  • Make a paper airplane.
  • Buy them a good kid's camera. We liked this, but the reviewers didn't. [amazon]

  • Record episodes of DESIGN SQUAD
  • Make a simple catapult (for a 2 year-old, just the act of bending something back and flinging it forward is a surprise, like a tongue depressor or a popsicle stick)
  • Make your own play-dough (Jenn always has a fresh batch on hand... Jenn what's the recipe?)
  • Do some research and find decent kits for making motors or radios or windup-airplanes
  • With them, measure and draw a to-scale floorplan of their room... or the house
  • Make a paper cutout model - in 3-D - of a floor of your house
  • Stomp Rocket Ultra (Best. Toy. Ever.)
  • Anything made by Rufus Seder, like this window-pendant that shows a 6-frame galloping horse. (It's a little hard for me to explain this in a brief bullet point.)
  • Get / borrow a stroboscope and use it to look at a spinning top, or the faucet on slooooow drip.
  • Find something that glows - charge it up in the bathroom light, then shut the light and the door.
  • Triboluminescence: chomp down on a Wintergreen Life Saver while looking in the bathroom mirror with the lights off
  • Lots of projects in Howtoons! Also, a book.
  • Lots of projects on Instructables!
  • Polarizers are fun, but maybe more fun with the help of a science-friend. (A demo we do for kids is: put a big polarizer on a light table. Put: clear gelatin cubes, or a clear Scotch Tape reel on top. Put a little polarizer near your eye. Squeeze the cubes and reel. Cool zebra patterns!)
  • Seek out a holography museum.
  • Ask someone handy to show you how to mix cement.
I am excited to continue this list, but please, other people, chime in. Here are some science areas that I have not provided ideas on:

  • Plant-life
  • Animals (drop of river-water under a decent microscope)
  • A catalog of neat science toys / kits: Edmund Scientific -- order a catalog today!
  • Programming computers in some simple language
  • Math (arithmetic, geometry, how far is it from one corner of a square to the other)
  • Chemicals (volcano experiment)
  • Geology
  • Cool mechanical mechanisms (like near the elevators at the Boston Museum of Science)
  • Space (esp this beautiful book: Moonshot)
  • Various YouTube clips (my 4 yr-old was captivated by this astronaut one)
  • Basic physics-stuff, i.e. diffusion (milk droplets into your coffee), why-is-sky-blue (okay, that's trickier unless you understand it already), inertia (Matchbox car goes around loop-de-loop upside-down)
  • MAGNETS! (But it is critical that they NOT SWALLOW A MAGNET)

I realized soon after I posted these ideas that this is only a portion of the "science culture deliverable-for-kids." For me, at least, the other portion of getting your kids comfortable with science is your narrative. What are your opinions of scientists? Do grown-ups know all the answers? What's still mysterious? Are we "allowed" to figure things out?

I think this is what I am broadcasting at home:
  • Regarding science... The facts you learn in school, in books, and from experts, are (at its best) our understanding of the way things work at that moment in time. It'll change. Not only that, but people like you came up with these observations and predictions and explanations. You can add to this knowledge, if you'd like. And if it's not your thing, that's cool too. No pressure to spend your life with beakers and soldering irons.
  • Regarding math, though... Math is unusual because it is a game - played with very precise rules - designed by people. As long as people agree on the rules (e.g. "in this game, multiplying a number by zero equals zero") and the rules of logic, you should reach the same conclusions. The inventiveness is of a different sort, such as discussing interesting assertions and figuring out if they can be proven within the framework of the rules. Plus, if you're a parent who has some math-phobia, maybe this viewpoint can put you at ease. The answer to "but WHY does this math-symbol act this way?" is either "because someone asked us to accept it as a rule since it seems to be helpful to do so" or "in this particular flavor of algebra, those are just the rules." If you're having a good day, the answer is "good question, maybe Newton was wrong about that, and perhaps you are going to win a cool prize."
  • As Feynman liked to say, there is a difference between knowing things and just knowing the names of things. What's more helpful: telling your kid that the reason your sneakers help you cling to the ground when you walk, and not slip, is "due to friction," or "the little jaggies in the ground fit into the squooshy jaggies in the sneaker, and this is related to something called 'friction'" ?
  • Regarding engineering, it is almost completely true to say that if you can imagine a fanciful invention in great detail, it can be built.
  • After a series of "why?" questions of increasing depth, grown-ups usually have to admit, "I don't know."
  • There are plenty of science-things that no one really understands yet. These include: consciousness ("who" is seeing?), why do things fall when you drop them?, aren't we lucky that the game of mathematics lets us calculate things in the real world?, where did all this stuff come from? I guess the answer to some of these things hinges on one's religious beliefs, but the point is that there will always be new things to learn or figure out or invent. And, furthermore, you are encouraged to figure things out.
  • You can totally do this.
  • You can totally understand this.
  • Hey, a cardboard box! Let's be robots!

Any other ideas?