Educator How-To: The magic of magnetic fields

What better way to understand how magnetic fields work than to see them for yourselves?

•    Magnetic field line cards (green) – one per child
•    Magnetic nail polish
•    Clear nail polish
•    Assorted magnets of various shapes and sizes
•    Large clear glass playing pieces
•    Button magnets (at least ½ inch)
•    E-6000 or other silicone glue

1. You will need to purchase some magnetic field viewer cards. They are sturdy and fairly inexpensive, so a single class set will last you a while. (You may also choose to just buy the magnetic film and make your own cards, but it doesn’t have the explanation printed on it.)

Educator How-To: Magnetic Field Magnets

2. Pass out a magnet and a magnetic field viewing card to your students. Try the magnets with the field line cards. What looks the same, what’s different? How do you think the field line cards work? [See the magnetic field viewer cards for more explanation.]

Educator How-To: Magnetic Field Magnets

3. Have the students trade their magnets around and see how the various shapes and sizes of the magnets affect the field viewer.

Educator How-To: Magnetic Field Magnets

4. Give each student a glass piece and place it on the table with the rounded side down.
5. Paint a thin coating of clear polish on the flat surface.

Educator How-To: Magnetic Field Magnets

6. Paint a reasonably thick coating of magnetic nail polish on the flat side of the piece. (Don’t shake your fingernail polish if it has been sitting on a shelf for a while. Instead roll it back and forth in the palm of your hands.)

Educator How-To: Magnetic Field Magnets

7. Quickly (there’s only a small window of time for this) use magnets to create a design now that you know what the magnetic fields will do to the nail polish! You want to put the glass playing piece and the magnets as close as possible without touching one to the other.

Educator How-To: Magnetic Field Magnets

8. Do not pick this up for a few minutes, and allow it to dry.
9. Once dry, use a silicone glue to attach a ceramic button magnet.

Educator How-To: Magnetic Field Magnets

10. Now use your magnets to hang up masterpieces, papers with no name and missing homework!

Educator How-To: Magnetic Field Magnets

How do magnets work?

Questions that often come up are, “How do magnets work?” or “Why is iron magnetic? or “What makes a magnet?” or “What is the magnetic field made of?”

Those are good questions, and they deserve a good answer. However, there is a lot about magnets at the atomic level that isn’t known yet. Just like with most of the other basic forces we are familiar with, such as gravity, electricity, mechanics and heat, scientists start by trying to understand how they work, what they do, whether there are any formulas that can be made to describe (and thus predict) their behavior so we can begin to control them, and so on.

The work always starts by simple observation (that’s the fancy word for playing around with the stuff!) That’s why it’s so important to have some hands-on experience with magnets.

Have your students take two magnets and tried to push like poles together. How far away do you start to feel the repulsion? How does the force vary with the distance between them? When the magnets are moved off-axis to each other (moving them to the side and not head on) what does it feel like? Could you describe it like trying to push two tennis balls together? When you flip one around, what changes? What about moving one around the other in a circle?

Encourage your students to try these things; that’s how you learn! Only when they play with magnets will they begin to understand how they work. This is the stuff great scientific pioneers did, like Faraday, Lenz, Gilbert, Henry and Fleming.

What we can find out through play are some of the basics of magnetism, like:

•    The north pole of the magnet points to the geomagnetic north pole located in Canada above the Arctic Circle.
•    North poles repel north poles
•    South poles repel south poles
•    North poles attract south poles
•    South poles attract north poles
•    The force of attraction or repulsion varies inversely with the distance squared
•    The strength of a magnet varies at different locations on the magnet
•    Magnets are strongest at their poles
•    Magnets strongly attract steel, iron, nickel, cobalt, gadolinium
•    Magnets slightly attract liquid oxygen and other materials
•    Magnets slightly repel water, carbon and boron

Free SEM Images! Where do I sign up?

Scanning electron microscopes are hardly what I’d call a ‘household item’, but it doesn’t mean you don’t have the opportunity to use one! ASPEX is providing any and everyone the chance to see their favorite mundane objects under the powerful magnification afforded by SEMs with their ‘Send Us Your Samples’ campaign.

Some of you may be asking, “Erin, what the heck is a scanning electron microscope, why do I even need to know, and just what does it have to do with me?’

Great question! Unlike most pictures we are used to viewing, the SEM uses electrons to capture images instead of light. The image we get to see is built up from the number of electrons emitted from each spot on any given sample. (Fun fact folks: Electrons are cobalt blue! Neat-o, huh?) The last time I got to use an SEM was as an undergrad in my biological imaging class. I had the privilege of taking some astounding pics of my favorite bugs. Really, insects of any kind look infinitely more fantastic and creepy using a scanning electron microscope. Where do you think Hollywood gets its inspiration for movie monsters?

Moldy Cheese – Before Moldy Cheese – After

So now we are all super stoked to see our hairbrushes and chocolate chip cookies scanned with an incredibly powerful tabletop SEM, right? Well…how do we do it? EASY! Simply download and print this form from the ASPEX website. Fill it out and send it along with the sample you’d like scanned to:

ASPEX Corporation
Free Sample Submissions
175 Sheffield Dr.
Delmont, PA 15626

Once ASPEX has finished the scan, the images and report will be posted here on ASPEX’s website. The results should be up in about two weeks, and they will notify all submitters by email when you can see your before and after images. Make sure you can part with what you send in as samples will not be returned!

Your everyday objects will be transformed into alien landscapes. Don’t believe me? Try looking up scanning electron micrographs of pollen. The images truly speak for themselves, but what kind of blogger would I be if I didn’t bury you in a deluge of graphic and evocative descriptions?! I’ll limit myself to one short example – no, it’s not the mold in delicious, delicious blue cheese, it is the common flea. This mighty jumper may surprise you when you meet him up close and personal. You might just find out that fleas have mustaches to rival even the likes of Tom Selleck and Burt Reynolds, the mustache greats.

This opportunity is perfect for educators, students, fun loving families, and all inquisitive folks in general! So grab your cat toys, the dried fly that is undoubtedly stuck in your window sill, your old toenail clippings, or anything else you want to see uber-mega-ultra close up and send it in! All for free, courtesy of ASPEX. Want to see more? Check out the SEM Image Gallery for some incredible examples!

Toy Bunny Before Toy Bunny After

Did you know?

It’s time for some random factoids!!!

I am the type of person who is always looking to learn something new. Since I work in a museum and have a general thirst for knowledge, this usually happens on a daily basis! Because of this, I have ended up a veritable storehouse of somewhat useless facts. Here, I share a few of my favorites:

Electrons are cobalt blue.

Creative Commons License photo credit: Raphael Goetter

When first born, baby boys are more fragile than baby girls, despite being slightly larger. This is due to the hormone testosterone.

Starting in the 1920s, pink was generally associated with males because its base was red-a firm and masculine color. Blue was associated with girls because of its feminine and dainty qualities. This all changed in the 1940s when societal norms dictated they switch! (So, men, be proud. Wear pink.)

The following equation will be helpful for anyone familiar with the game ‘Flour Tower.’
[Flour + Sweat = Dough down your back]

Regular old shaving cream can strip dye from your hair.

Phone numbers are 7 digits long because that is about the number of things you can hold in your short term memory all at once.

Genghis Khan’s battle strategies are still taught at West Point today.

And finally,
Polydactyly, or extra digits, is a dominant trait in cats!

If these few tidbits haven’t quite sated your thirst for knowledge, come down to the Museum today and drink your fill of fun facts!