Hey Reader, Happy Wednesday!

Last week, I experimented with preparing Chinese cuisine at home for every meal.

Let’s look at how Velcro works this week. I aim to write my newsletter issues so one can follow them while traveling on a bus, having a coffee, waiting for food, etc. Let's jump in!

How it works: 15-second answer

Velcro is a hook-and-loop fastener made of two parts: loops and hooks. When pressed together, the hooks latch onto the loops, creating a secure bond. Pulling them apart requires force because the hooks resist separation while the loops stretch.

It’s interesting how Velcro came into existence. Well, velcro was invented by Georges de Mestral when he was on a hike with his dog in the Swiss Alps in the 1940s. The idea came to him after he noticed plant seeds sticking to his dog’s fur. He observed the seeds under a microscope and saw tiny hooks. Thus, the velcro was born.

How does a Velcro work?

All of us have used Velcro at some point in our lives. It is a hook-and-loop fastener consisting of two components: loops and hooks. The next time you use Velcro, take a moment to touch it. You’ll notice that the soft side contains numerous loops made of elastic material as shown in Figure 1 (Top). Meanwhile, the rough side is covered with tiny hooks like fish hooks as shown in Figure 1 (Bottom).

The loops and hooks are elastic and typically made from nylon or polyester.

When the two parts are joined, the hooks catch on to the loops, as shown in Figure 2.

The hooks latch onto the loops, making Velcro difficult to separate and allowing it to function as a fastener. When you pull the two sides apart, the hooks naturally bend, resisting separation, while the loops stretch until they finally slip free, as shown in Figures 3 and 4. The hooks work to hold onto the loops, while the loops struggle to break away.

You might wonder if the loops would tear when pulled away from the hooks. However, they don’t. Because the loops are elastic, they can stretch and return to their original shape, allowing Velcro to be used multiple times.

This is how a Velcro works!

Question of the week

Why do you think the US Army added velcro to their uniforms but later removed it? Reply to this email with your thoughts, and we’ll discuss.

Answer to the question I posed last week

Last week, I asked a couple of questions about barcodes. Let’s take a look at them.

1. Why do we need a barcode when we can use the manufacturer and product code numbers (e.g. 51000-01251) directly?
   Character recognition is more difficult as a technology than scanning black and white lines to decode them. Also, even slight damage or invisibility to the printed numbers will make it difficult to automatically recognize the digits.
2. Why are the code numbers printed along with the barcode when they both refer to the same thing? Isn’t that redundant information?
   If we’re not able to scan the barcode, the cashier can use the product codes to enter them manually.

Shoutout!

In last week’s newsletter, I mentioned a fact about barcodes and QR codes: “In the U.S., about 89 million smartphone users scanned QR codes.”

One of our subscribers (Deepak) was curious about how we estimate these numbers and how accurate they are. So I wanted to explain how they are done to you as well.

The statistics I mentioned about 89 million smartphone users scanning QR codes are only an estimate. They are collected through a combination of voluntary surveys by users like us, device usage data in some cases where people use dedicated apps to scan QR codes like me, and data extrapolated to the broader population based on smartphone ownership statistics and usage.

Thank you Deepak for your questions! Let’s get back to our sticky topic of this week.

Gadget of the week

Stringless Smart Guitar: LibraLive is a lightweight, foldable guitar that can be played without any strings. It uses a paddle mechanism to generate chords, eliminating the need for complex finger placements.

That's all folks. Thank you for reading!

Have an amazing rest of the week, and take care!
Until next to next Wednesday,
Chendur

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