5 Everyday Household Questions, Answered

Why Does Wi-Fi Have Dead Zones?

Wi-Fi, which stands for “Wireless Fidelity,” uses radio waves to send signals, and just as with regular radio waves, it can be disrupted or impeded — mainly by thick walls and metal barriers. It also degrades over distance.

While AM and FM radio broadcasts cover the ranges of kilohertz and megahertz, respectively, Wi-Fi transmits in gigahertz (or a billion cycles per second). That allows Wi-Fi signals to carry an immense amount of information, while severely limiting its range. Many Wi-Fi routers come with two network frequencies — 2.4 GHz and 5 GHz. The first frequency carries a lower bandwidth (aka speed) but can reach farther distances, whereas 5 GHz is faster but can’t travel as far. If you’re experiencing Wi-Fi dead zones, try switching to the farther-reaching 2.4 GHz frequency (if available), or investing in a Wi-Fi extender that can boost these data-heavy signals.

Interestingly, microwave ovens operate on a frequency very similar to Wi-Fi networks, at around 2.412 GHz to 2.472 GHz, so sometimes Wi-Fi can be disrupted when you’re warming up your dinner. Speaking of which …

How Do Microwaves Work? (And Why Shouldn’t You Microwave Metal?)

You might think the science behind microwaves is relatively simple — the machine produces microwaves (as its name suggests), which in turn warm up your food. However, that’s only partially correct. While it’s true that microwaves warm up food, it’s not the food itself that’s being warmed, but the water inside the food. Microwaves, along with X-rays, radio waves, gamma rays, and visible light, are part of the electromagnetic spectrum. But microwaves contain an interesting property — they’re readily absorbed by water, fats, and sugars. These materials absorb microwaves as atomic motion, essentially vibrating the water molecules in food, which in turn produces heat. Of course, this is only part of the microwave’s convenient food-warming equation, as this slice of the electromagnetic spectrum isn’t absorbed by plastic, glass, and most ceramics, making it a convenient way to heat up food without heating up its container.

But have you ever accidentally put a piece of metal in a microwave? Yikes. What’s happening to create this explosive situation is that the microwaves are moving the free electrons found in the conductive metal’s surface, which causes the object to reflect microwaves. If the metal is smooth all over, such as a spoon, this won’t likely be a problem, but sharp edges like the tines on a fork will produce sparks and potentially catch some flammable material in the microwave on fire. A microwaved metal will also create an imbalance with dielectric breakdown in air, which can cause an electrical arc that can punch a hole in the interior wall, rendering the microwave too unsafe to use. Long story short, just don’t put metal in the microwave — ever.

What Causes Static Electricity?

Static electricity was the doorway through which humanity first explored the phenomenon known as electromagnetism. The ancient Greek thinker Thales of Miletus, occasionally considered the world’s first scientist, rubbed a piece of amber against hemp and cat fur to study its effects (the name for “amber” in Greek is actually elektron). Today scientists call Thales’ discovery the triboelectric effect, or the process of producing electricity by rubbing. This effect sometimes occurs when two insulators (materials that inhibit the flow of electricity) rub together. One insulating object, such as a wool carpet, will lose electrons, while another, maybe a rubber-soled shoe, gains electrons. After rubbing these two insulators together, your body now possesses a small electric charge. Because those rubber shoes on your feet inhibit electrons, you can’t dissipate this charge, so once your body touches a conductor (such as a metal door handle), you experience an electric shock. Because dry air is also an insulator, the triboelectric effect is particularly prominent during the cold and dry winter months.

Want to circumvent those nasty little shocks? Avoid wearing wool socks and rubber-soled shoes in the house, and run a humidifier or two. Because water is a great conductor, more moisture in the air will help dissipate an electric shock accumulated within your body.

What Is Hard Water?

Not all water is the same, though it may look similar at first glance. Towns and cities throughout the U.S. have varying degrees of “hard” or “soft” water. Despite the more common uses of these adjectives, “hard” and “soft” don’t refer to the actual texture of water, but instead serve as shorthand for the amount of calcium, magnesium, and other dissolved metals found in a particular water supply. Hard water, for example, has high levels of these two minerals, at around 121 to 180 mg/L, whereas soft water comes in at less than 60 mg/L.

There are a few easy ways to tell if your home has hard or soft water. The most common side effect of hard water is that it tends to leave your hands somewhat slimy after washing with soap. That’s because soap reacts with the calcium in the water to create a thin film of soap scum. Hard water can also leave residue on plates and cutlery run through the dishwasher, decrease a home’s water pressure due to mineral deposits in pipes, and also affect the performance of appliances such as electric water heaters and coffee makers.

Luckily, hard water isn’t considered hazardous to a person’s health (and can even supply a healthy dose of calcium and magnesium). However, due to some of its annoying side effects, some homeowners choose to install water-softening systems that use a porous plastic resin to replace calcium and magnesium ions with less disruptive sodium ions.

How Do Surge Protectors Work?

According to a 2022 survey, the average American home has 22 connected devices, and many of those gadgets — along with others not connected to Wi-Fi — need to be protected from transient voltage, otherwise known as a power surge. The most common example of a power surge is often lightning strikes, but that’s actually the least common cause (and a surge protector can’t withstand the millions of volts delivered by a lightning strike anyway). What’s more common are power-hungry devices, whether hair dryers, refrigerators, or air conditioners, disrupting the flow of electricity in the home with their voracious energy demands. That’s why surge protectors are always a good idea, but especially when you need to plug a lot of things into a single outlet, such as for a media center or office.

Most outlets in U.S. homes are rated for 120 volts. If an unexpected surge sends voltage higher than that threshold for even a few nanoseconds, the results can be disastrous. Surge protectors serve as a kind of pressure valve protecting your gadgets from an electronic meltdown. Any time a surge protector detects voltage above the 120-volt threshold, it diverts excess voltage with a metal oxide varistor to its own grounding wire, protecting all your plugged-in devices in the process. Also, if you think you can rely on your home’s circuit breaker to protect your stuff — think again. Circuit breakers are only designed to protect against current overload, not surges and spikes.