Skip to main content

4 Mind-Blowing April Fool’s Day Science Tricks

Middle and High School


April Fool's Day (aka All Fools’ Day) is a light-hearted, fun-filled day of practical jokes and hoaxes. So, believe nothing and trust no one on this day! Although determining the day’s origins is a bit tricky, the custom of celebrating April Fool’s Day was brought from Britain to the U.S. centuries ago and is observed in many countries.

Explain to students that using a little science know-how will surely do the trick if they want to pull off the perfect pranks. Scroll down for mind-blowing activities that use concepts that you can include in your science lesson plans. Students can discover how fun it is to learn physics, chemistry, geology, and other science subjects. And that’s no joke!

1. Disappearing Message Activity; A Fun Way to Teach pH 

Now you see it, now you don't. Show students how to use thymolphthalein, ethanol, and sodium hydroxide solution to illustrate the effect of pH change on indicator color. The resulting solution can be used as disappearing ink (Ward’s Science disclaims all responsibility for the mischief). This is a fun one that takes about half an hour.

Get the free activity download here.

2. Fool's Gold

Your turn to play a joke on your students. Tell them you were hiking over the weekend and discovered a large piece of gold. Pull out the pyrite, tell them it is worth thousands, and today will be your last class because you’re retiring. Psyche! It’s just pyrite!

Pyrite (aka Fool’s Gold) is the most common mineral mistaken for gold. But it’s just one of three minerals that appear gold-like. Chalcopyrite and weathered mica can also mimic gold. Compared to actual gold, these minerals will flake, powder, or crumble when prodded with a metal point, whereas gold will gouge or indent like soft lead. In addition, actual gold will leave a golden yellow streak when scraped on a piece of unglazed porcelain. Pyrite and chalcopyrite will leave a dark green to black streak, and the common micas will leave a white streak.

Use Ward's® Exploring Physical Properties of Minerals Lab Activity to demonstrate hardness, color, streak, luster, specific gravity, and other characteristics of eight common minerals, including pyrite.

Your students will easily recognize real gold from Fool’s Gold! Fool me once, shame on you; Fool me twice, shame on me!

3. Using light waves to amaze! 

A light wave travels through a medium using refraction. Refraction is the redirection of a wave as it passes from one medium (or speed) to another. Light waves can travel through mediums like air, water, oil, or glass. Here are two ways students can amaze their friends with light refraction activities: 

The magic breaking pencil activity - Fill a tall, clean, clear glass with half oil and half water. The light waves travel fastest through the air, slower through water, and slowest through oil. Students lower a pencil into the water, then slowly rotate it. The pencil will appear broken as it’s viewed from different angles.  Pretty tricky, huh?

Mesmerizing mirror image activity – Fill a tall, clean, clear glass with water. Draw two arrows on a piece of paper (although drawing two fish is more fun)—one arrow or fish near the top and one near the bottom, facing the same direction. Slowly lower the piece of paper behind the glass of water. Look through the glass of water and watch how the images appear to change direction! The light bends as it travels through the glass into the water and then bends again on its way back into the air. As a result, the light paths cross, and the image appears to flip. April Fools!

For your advanced lessons, use CENCO® AP Physics Lab 21: Refraction of Light. Students examine the path a light ray takes when it passes through various transparent media and then use this understanding to determine the focal length of a lens. Then, they calculate the index of refraction for objects and the critical angle.

4. Count the number of Fs

We're not talking about grades on a test, phew! Ask students to count and write down the number of Fs in this sentence: 

"Finished files are the result of years of scientific study combined with the experience of years."

Give them 30 seconds. Then remove the sentence from view. See how many Fs students counted.

Many people will say there are three Fs. But that sentence has six instances of the letter ‘F’! No kidding! The phenomenon occurs because of the way native English speakers process the language. We are experts in reading the language. However, our unconscious brain tells us that words such as 'of,' 'the,' and 'a’ do not carry much meaning and weight, and therefore, based on our expectations, we tend to ignore them automatically.1

If you think that’s fascinating, consider this, “Aoccdrnig to a rscheearch at Cmabrigde Uinervtisy, it deosn’t mttaer in waht oredr the ltteers in a wrod are, the olny iprmoetnt tihng is taht the frist and lsat ltteer be at the rghit pclae. The rset can be a toatl mses and you can sitll raed it wouthit porbelm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe.”

Speech and language are associated with three areas of the brain: Broca's area (speech production and articulation), Wernicke's area (comprehension), and the angular gyrus (associate words with different images, sensations, and ideas). Get the Advanced Brain Study Bundle to build on students’ curiosity about brain functions. Students can learn brain structure and regional areas normally hidden in a standard brain model.

You can’t go wrong with any of these activities. And don’t be fooled by their simplicity; they’re each as impressive as they are easy to do in the classroom!

1. Itiel Dror, Center for the Forensic Sciences, University College London: Practical Solutions to Cognitive and Human Factor Challenges in Forensic Science.