We’ve all dreamed of having a mini-greenhouse that we could plug into our computer, but until today it was just that — dreams. But dream no longer. Geeks.com is selling a USB-powered Mini Greenhouse that includes a computer interface which helps you monitor growth rate and that includes a calendar, wallpaper and bookmark settings to aid you in monitoring the growth of your greenhouse. Source: USB: Grow Plants with the USB-Powered Mini-Greenhouse – Gizmodo

What about using this as a great science experiment with your kids?  I’m sure the software is fun and teaches you about plant growth.  Clearly the USB is going to be powering the grow light and giving some feedback (moisture maybe).

Face it, simple plant growth projects are fun and easy.  They can teach kids a lot about science too.

Now I’m going have to hunt one of these down…

Post from: Homely Scientist

No, this is not a goofy free energy thing like I saw at Gnomedex on Saturday (ugh, it still bugs me).  This is real science, real physics, and doesn’t violate the laws of thermodynamics: heck it uses them!

This papercraft engine only needs to sit on a cup of hot coffee to drive its pistons. No, it’s not the precious caffeine that drives the motion, but the Stirling engine design, in which the difference between alternating hot and cold gas pressure is harnessed for power. Source: Cheaper Than Gas: Paper Stirling Engine Runs Off Hot Coffee – Gizmodo

Boing Boing has the best description of what’s going on–but essentially what you’re seeing is the expansion, contraction, and circulation of the air in the little area below the engine will drive it.  This strengthens something I was probably boring people to death with later on Saturday evening, there are hundreds, probably thousands of creative ways we can take current technology and improve it or apply it in creative ways.  That’s freakin’ open sourcing energy man!

Post from: Homely Scientist

Well, worm poop is big business you know.  I’ve seen it on Dirty Jobs (Discovery Channel) and this bit from Business Opportunities:

Tom Szaky is passionate about worm poop. So passionate that he dropped out of Princeton to start Terracycle, a company that sells worm poop. Vermicomposting is the process by which earthworms eat, digest and excrete castings (aka worm poop). Water is mixed with the worm castings to produce a nitrogen rich ‘tea’ prized by gardeners who believe the mixture makes plants grow faster and healthier than chemical fertilizers. Source: Business Opportunities Weblog | Niche Biz: Worm Poop

Terracycle is doing something awesome.  Recycling pop bottles and making organic fertilizer!  What could be better?  Unfortunately the Scotts company (MiracleGrow) is suing them.

If you’re interested in vermiculture a quick Google search will find folks in your area to get supplies.  I’m thinking maybe finding an apartment-sized set up for myself.  Why not.  I can just give the fertilizer away.

Post from: Homely Scientist

There are two key parts to a successful can car.  First is using a bead or nut on the winding end.  That pencil or chop stick can’t be touching the whole lid, in fact I think the less touching the better.

Next is the liquid soap.  I think this is the real magic ingredient.  That little bit of greasing the wheel seems to be directly proportional to the speed and distance of the car.

So there you have it.

Gonna be a little hectic around here over the next little bit … I’m moving so I’m trying to juggle all that stuff and blog.

Post from: Homely Scientist

When I picked the kids up on Friday morning I found out the details.  She had to design and build a device that used two simple machines and would go at least 2 meters (6.5 feet).  Bonus points were given for coming back and/or carrying something.  Oh and once she let go or gave the device its initially energy, she couldn’t touch it.

No sweat.  I knew what to build in seconds.  The Can Car.  This is a super easy project and would be great for rainy day races.  Before I get into the Can Car, and the fun I had with the project (because it didn’t work the first time), let’s talk simple machines.

From Wikipedia a simple machine is:

In physics, a simple machine is any device that only requires the application of a single force to work. Work is done when a force is applied and results in movement over a set distance. The work done is the product of the force and the distance. The amount of work required to achieve a set objective is constant, however the force required to do this can be reduced provided the lesser force is applied over a longer distance. Increase the distance and reduce the force. The ratio between the two is the mechanical advantage.

What are the simple machines?  Here’s the list:

• The inclined plane
• The wheel and axle
• The lever
• The pulley
• The wedge
• The screw

 When I took physics I think the screw was considered an inclined plane, no matter A was using the same list …

For the can car you see that the wheel and axle are there, but what is the second one?  That was something I was pondering too, and wanted to make sure I was on solid footing if challenged by a teacher (sorry a grade 4 teacher isn’t a science authority in my book, but I wanted to have a good argument in case A got dinged on the project).  If you look at the PBS site there is a pencil used to wind up the rubber band to provide power.  I’m calling it a lever.  To me it is the same as the crank on a bike or winch.  The lever lets you transfer energy.  Works for me.

Okay making it was fun.  Had some challenges like a poor supply of rubber bands (I wound up using an elastic from an old conference nametag holder–good thing I’m a packrat!) and a few other improvisations.  And the biggest challenge was the first couple versions didn’t work.

See our initial design was based on a spool racer.  Which uses all the same principles of physics, but the major difference is that a spool is the wheel, not a can.  Oh and at the lever end, it’s a washer not a bead.  These two things combined made for a very frustrating first try.

See I used an improvised washer and a very strong rubber band (broccoli bands rock).  The tension was too much.  The chop stick couldn’t turn.  Bad news.

A and I did what any good scientist would do, we went back and did more research.  Okay she researched and I experimented.  I had a vague memory of a different version of the can car that would come back to you, so I tried that one from memory (couldn’t find it online).  After a lot of tinkering we got it to work.  The success factors were two-fold.  First was using a metal nut between the lid and the chop stick.  Second was using liquid soap to grease the lid on the chop stick end.

And I tell you, that thing when wound up tight, flies across the floor.  And bonus, because it’s a can with covered ends, it can carry stuff!

Bonus points!

For A, this was a good experience in research, trial and error, and experimentation.  For me it was just fun to play with science and share that with my kids.

Post from: Homely Scientist

Let’s face it: GeekDad projects are sometimes more fun for the older kids than for the younger ones. So when it comes to flying planes at the park, we’re always looking for something that everyone can do.

We’ve found that with the Hobbico line of free-fly electric planes. They’re amazing. Ranging from $12-$15, they’re beautifully-made with built-up foam bodies and electric motors, rechargeable batteries and chargers. They range from a toy-like 14″ wingspan to a small R/C plane size of 27″ wingspan.
Source: Geekdad – Wired News

I will be looking for these in town (Victoria).  Come on pick up a little plane that if it gets trashed isn’t a huge loss…sounds like a winner to me.

Interesting to note that the plane that did the best was the smallest and cheapest.  Less risk of smashing it on the ground I guess.

Post from: Homely Scientist

The premise is simple, what materials conduct heat (through water) best.  While this is an awesome experiment for the kids, the best part was that on the first try the set up didn’t work.  The modeling clay used to keep the objects to test conduction got wet and so the objects fell into the water.

Undaunted, they tried again and had a successful experiment.

Lesson here…some times finding the right way to test you hypothesis is the hardest part.

Post from: Homely Scientist

Looks like I know what I’ll be doing this weekend with the kids!  Oh, what to choose, what to choose…

Post from: Homely Scientist

Can you imagine?  Dad, I need a DNA swab from you, we suspect you ate half of the last cookie ….

Tags: science for kids  DNA

Post from: Homely Scientist

I know!  Cool eh?  How do you do it?  Read here.

Tags: glowing grapes

Post from: Homely Scientist