How to Spot a Counterfeit Bill

Chung Sung-Jun/Getty Images
Chung Sung-Jun/Getty Images

When you hand over a $100 bill at a store, it’s not uncommon to see a manager hold it up to the light to verify its legitimacy. But what are they looking for? There are a few subtle features on larger bills that are designed to protect against counterfeiting.

To find out how to make sure a bill isn't a fake, dive into this infographic from On Stride, a financial services company based in the UK. It covers the basic security features of both dollar and pound bills. Remember: Always look for the watermark.

An infographic showing security features of dollars and pounds
Courtesy On Stride

Turn Your LEGO Bricks Into a Drone With the Flybrix Drone Kit

Flyxbrix/FatBrain
Flyxbrix/FatBrain

Now more than ever, it’s important to have a good hobby. Of course, a lot of people—maybe even you—have been obsessed with learning TikTok dances and baking sourdough bread for the last few months, but those hobbies can wear out their welcome pretty fast. So if you or someone you love is looking for something that’s a little more intellectually stimulating, you need to check out the Flybrix LEGO drone kit from Fat Brain Toys.

What is a Flybrix LEGO Drone Kit?

The Flybrix drone kit lets you build your own drones out of LEGO bricks and fly them around your house using your smartphone as a remote control (via Bluetooth). The kit itself comes with absolutely everything you need to start flying almost immediately, including a bag of 56-plus LEGO bricks, a LEGO figure pilot, eight quick-connect motors, eight propellers, a propeller wrench, a pre-programmed Flybrix flight board PCB, a USB data cord, a LiPo battery, and a USB LiPo battery charger. All you’ll have to do is download the Flybrix Configuration Software, the Bluetooth Flight Control App, and access online instructions and tutorials.

Experiment with your own designs.

The Flybrix LEGO drone kit is specifically designed to promote exploration and experimentation. All the components are tough and can totally withstand a few crash landings, so you can build and rebuild your own drones until you come up with the perfect design. Then you can do it all again. Try different motor arrangements, add your own LEGO bricks, experiment with different shapes—this kit is a wannabe engineer’s dream.

For the more advanced STEM learners out there, Flybrix lets you experiment with coding and block-based coding. It uses an arduino-based hackable circuit board, and the Flybrix app has advanced features that let you try your hand at software design.

Who is the Flybrix LEGO Drone Kit for?

Flybrix is a really fun way to introduce a number of core STEM concepts, which makes it ideal for kids—and technically, that’s who it was designed for. But because engineering and coding can get a little complicated, the recommended age for independent experimentation is 13 and up. However, kids younger than 13 can certainly work on Flybrix drones with the help of their parents. In fact, it actually makes a fantastic family hobby.

Ready to start building your own LEGO drones? Click here to order your Flybrix kit today for $198.

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How Coronavirus and 31 Other Infectious Diseases and Viruses Got Their Names

Rotavirus—from the Latin rota, for "wheel"—is named for the wheel-like appearance of its particles.
Rotavirus—from the Latin rota, for "wheel"—is named for the wheel-like appearance of its particles.
Dr_Microbe/iStock via Getty Images

As you may already know, the corona in coronavirus has no relation to a certain refreshing beer often served with a slice of lime. Corōna means “crown” in Latin—and Spanish and Italian, too—and virologists chose it in 1968 to describe the group of viruses characterized by crown-like spikes that protrude from their surfaces.

So how do other viruses and diseases get their names? Based on the infographic below, created by Adam Aleksic for his website, The Etymology Nerd, there isn’t just one way. Some, like the coronavirus, are named for how they look under a microscope. The rota in rotavirus, for example, which means “wheel” in Latin, reflects the virus’s wheel-like appearance when viewed beneath an electron microscope.

Others are named after the locations where they were discovered or studied. In 1947, scientists named a newly identified mosquito-borne virus after Uganda’s Zika Forest. In 1977, Yale researchers investigating a string of pediatric arthritis cases in the town of Lyme, Connecticut, started referring to the illness as “Lyme arthritis.” Later, the name was modified to “Lyme disease” when scientists realized patients were exhibiting other symptoms, too.

Still others are characterized by the symptoms they cause. People with tetanus—from the Greek tetanos, for “tension”—usually experience muscle stiffness, and the skin of yellow fever sufferers often takes on a yellow tint due to jaundice.

Find out the origins of malaria, measles, and more below. And follow The Etymology Nerd on Instagram for more fascinating etymological explanations.

etymology nerd infectious disease names infographic
Unsurprisingly, there's a lot of Latin in this infographic.