All posts by Lenore Edman

About Lenore Edman

Co-founder of Evil Mad Scientist Laboratories.

Quick hack: The $1 C-to-D adapter

Quick C to D adapter

Here’s a common problem: You want to power your gizmo that runs on D cells, but all that you have handy are C cells.

In many (but not all) circumstances, you can solve this problem by using the C cell and making up the battery length difference with a few quarters– typically three or four. There is a 12 mm length difference between a C cell and a D cell, and quarters are about 2 mm thick, so if your gizmo has a really weak spring it could take up to six quarters to do the job.

Yes, commercial battery size adapters are available.

They typically cost between 1.5 and three dollars and can only be used for the one purpose– adapting battery sizes. (Well, that, and as a set of matryoshki.) Using quarters can also potentially end up costing as much as $1.50, but it can go straight back into your wallet when you’re finished! Much more importantly, when you really need it, you can probably find a few quarters no further away than your pocket.

Humane population control for feral golf balls

Natural environment
One of our neighbors is retired and, so far as we can tell, spends approximately twelve hours per day golfing. Golfing from his front lawn, that is. While he’s an agreeable fellow and we will not begin to question the motives or reason of someone that has this compulsion, we will simply observe that our neighborhood has an infestation of foam practice golf balls.

Beyond the many hundreds of balls that are successfully reclaimed each day, some dozens accumulate in the yards, bushes and hanging potted plants of our house and the houses of our other neighbors. They get stuck in the trees and bushes, confusing us when we go to pick lemons. People remember to shut the windows of their cars when they park. Sometimes it gets so bad they clog the gutters. You can even find them in places that they could have only gotten to after three reflections, leaving you quite puzzled. But, you get the idea.

Once behind a fence, they seem to have particular trouble getting out. (Especially if there’s a dog.) Case in point: This weekend we were at one of our (non-golfing) neighbors houses for a birthday barbecue. In the back yard, down below the little bushes, approximately twenty yellow balls were visible. I didn’t look hard; these were just the ones in plain view. When I pointed them out to our hosts, I learned that they had already thrown the day’s catch (a few dozen balls) back over the fence.

What do do? We decided to practice a humane method of dealing with pests: catch, tag and release.

The whole bandMany of the partygoers got involved in the process. Most of the balls were tagged with simple designs, but some were quite elaborate. We particularly liked this set (which we didn’t make), showing four foam balls as members of Kiss. We tossed them over the fence, and they disappeared early in the morning. We’re waiting to see if any of the tagged ones reinfest the yard, or if we get new ones every day.

If our golfing neighbor is sufficiently annoyed by people writing on his little foam balls, it may even be effective as a means of population control.

 

Maker Faire 2007 – now with pictures!

The Disgusting Spectacle

Maker Faire is shaping up to be a fantastic event! I’ve taken a few pictures, and I’ll add more to the set as I manage to get them uploaded. Pictured above is a very giggly evil mad scientist operating The Disgusting Spectacle.

Please also check out Scott Beale’s coverage so far. He shot a beautiful portrait of one of our dodecahedrons.

We’re having a blast, and we hope to see you there!

Evil Mad Scientist Forums

Our new forums have been quietly live and gathering dust (and a few posts) for a little while now, so we thought it was about time to announce their presence.

We hope that the forums will be a good place to share information. Got stuck building one of our electronics projects? Want to know where to find parts in your town? Want to tell us what projects you want to see us cover?

Some of the places you can ask and answer those questions are:

Whether you are seeking help on a project, want to beseech us to stop posting articles about peeps (sorry– there’s one more coming this year), or just want to help out your fellow evil mad scientists, please join in!

Weekend project: Phylm contest entry

As we mentioned before, the deadline for the entering the Phylm contest is 12:00 am (GMT) May 1, 2007 extended to May 14, 2007, which is rapidly approaching. That leaves you just one weekend two weeks! We know that many people work better under a deadline, so our challenge to you is to make this your weekend project. We’re sure you can put together a two and a half minute film featuring physics over the weekend. So, let’s see your submissions!

Videos will be judged on clarity, accuracy, and creativity. The winner will receive a check for $100 (US) to be dispersed in June 2007. Once again, you can watch the video announcement at YouTube or (embedded) here:

How to Find Dry Ice for Your Projects

Bubble Wok Whether you’re floating bubbles on carbon dioxide, making a cloud chamber or wanting to keep the contents of your freezer frozen during a power outage, you are going to need dry ice. We’ve gotten a lot of questions about where to get dry ice. We found our local dealer by stumbling on a flyer at the grocery store, which isn’t the most reliable method. Luckily, we’ve found a fantastic resource for you (if you’re in the US): Airgas has a dry ice retailer locator on their website.

We have had mixed luck just showing up at the store (and one long dry ice dry spell during the period after a fire at the local plant) so we recommend calling ahead to check availability. Conveniently, Airgas includes phone numbers in their retailer listings.

Here’s your obligatory warning: dry ice is cold. Dangerously cold. Don’t allow prolonged (and by prolonged, we mean anything more than momentary) contact with skin. We don’t recommend using a hard plastic cooler for transporting dry ice as the very low temperature can make it brittle and prone to cracking. A styrofoam cooler is a better option, but a nice thick towel will do nicely for insulation in transit as well.

For an added bonus, here’s the Airgas page of Cool Uses for Dry Ice. You’ve got to love an industrial supplier that has a recipe for “Witch’s Brew” on their website!

[Related: Floating Bubbles on CO2AirGasRetailer LocatorCool Uses ]

Cashew folktale

Yesterday we received an anonymous comment on our cashew story with a Sri Lankan folktale about the cashew. If this is your comment, thanks for sharing your story– Let us know who you are and we’ll give you credit!

Here is the story:

My mother told me a story (From Sri Lanka) about why the Cashew fruit has its seed on the outside.

Apparently, as God was creating the world he was approached by the Devil, who was upset that he had not been allowed to make something. So, in an act of kindness, God asked the Devil to make a fruit.

The Devil went to work and formed what we now know as the Cashew fruit. He took it to God and said, “See? I can make something just as good as your creations.”

On looking it over, God asked, “But where is the seed?”

The Devil, realising his mistake, just muttered, “Oh, I’ll stick it here.” And with that, placed the seed on the bottom of the fruit.

And there you have it.

[Related: Cashews: the nut you can’t buy in a shell]