What's the Difference Between Mold and Mildew?

iStock.com/AndreasReh
iStock.com/AndreasReh

We’re all familiar with colorful spots of something growing in our showers and in other dark, damp areas in our homes, but you may not know what to call it. Is it mold, or is it mildew? What is the difference between the two, anyway?

Both terms refer to fungus, but as it happens, it’s a squares-versus-rectangles situation. Mildew is a type of mold. The term typically describes fungi that grows flat, on surfaces like the walls of your shower or window sills. There are also several types of mildew that are specific to plants—powdery mildew and downy mildew are parasites that grow on certain trees, flowers, and crops, for example. While mold might be a colorful green or black, mildew is typically white.

The word mildew originally came from honeydew, a term for sticky secretions aphids and other insects leave on plants, which people used to think came from the sky, like dew. Eventually, the word came to refer to the mold caused by the fungi that fed on these secretions.

Leaves covered in white powder
Powdery mildew on maple leaves
iStock.com/kazakovmaksim

Most of the household growths we refer to as mold belong to just a few families of fungi species. According to the CDC, the most common indoor molds are Cladosporium, Penicillium, Aspergillus, and Alternaria. Household molds can be a variety of colors, from orange-brown to green to gray to black. (Note that not all mold that is black in color is the more toxic species we call “black mold,” or Stachybotrys.) In contrast to the powdery texture of mildew, molds are typically fuzzy or slimy.

In nature, mold can play an important role in the ecosystem, breaking down dead plants and leaves. In your house, those decomposition abilities aren’t quite so welcome. Mold spores fly through the air, and when they land in moist places, they start to grow—whether that’s on food, your ceiling, paper products, wood, carpet, leather, or elsewhere around your house—and in the process, destroy whatever they're growing on. Unlike mildew, most molds grow down into the surface of its habitat, making them more difficult to remove. In porous materials, mold grows into all the empty crevices, which is why it is often impossible to remove all the mold from ceiling tiles (or soft foods like bread).

Mold growing under a windowsill and near the carpet of a home
Mold growing in a Nashville home following a flood
Martin Grube, FEMA // Public Domain

Getting rid of the unsightly growth in your damp bathroom is more than just a matter of aesthetics. Indoor mold can cause allergic reactions, such as a stuffy nose or itchy eyes, and can lead to infections for people with compromised immune systems. Some people are more sensitive to mold than others, and may experience more symptoms when exposed to it. Generally speaking, though, mold spores are everywhere, so you’re never going to live a totally mold-free life. Spores will come into your home through windows, doorways, ventilation and climate control systems, and via your clothing, shoes, and pets.

But there’s only one way to effectively inhibit mold growth at home: Get rid of the moisture. That means fixing leaks, getting better ventilation, and possibly running a dehumidifier, according to the CDC’s recommendations on mold.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

Will the Sun Ever Stop Shining?

iStock.com/VR_Studio
iStock.com/VR_Studio

Viktor T. Toth:

The Sun will not stop shining for a very, very long time.

The Sun, along with the solar system, is approximately 4.5 billion years old. That is about one-third the age of the entire universe. For the next several billion years, the Sun is going to get brighter. Perhaps paradoxically, this will eventually result in a loss of carbon dioxide in the Earth’s atmosphere, which is not good news; It will eventually lead to the death of plant life.

Within 2.5 to 3 billion years from now, the surface temperature of the Earth will exceed the boiling point of water everywhere. Within about about 4 to 5 billion years, the Earth will be in worse shape than Venus today, with most of the water gone, and the planet’s surface partially molten.

Eventually, the Sun will evolve into a red giant star, large enough to engulf the Earth. Its luminosity will be several thousand times its luminosity at present. Finally, with all its usable nuclear fuel exhausted and its outer layers ejected into space, the Sun’s core will settle down into the final stage of its evolution as a white dwarf. Such a star no longer produces energy through nuclear fusion, but it contains tremendous amounts of stored heat, in a very small volume (most of the mass of the Sun will be confined to a volume not much larger than the Earth). As such, it will cool very, very slowly.

It will take many more billions of years for the Sun to cool from an initial temperature of hundreds of thousands of degrees to its present-day temperature and below. But in the end, the remnant of the Sun will slowly fade from sight, becoming a brown dwarf: a cooling, dead remnant of a star.

This post originally appeared on Quora. Click here to view.

Why Do So Many Airports Have Chapels?

Inside Our Lady of the Airways Chapel at Boston Logan International Airport
Inside Our Lady of the Airways Chapel at Boston Logan International Airport

There are only so many ways to kill time during a long layover. You might browse the magazines at a Hudson News or take the time to test out a travel pillow or two. If it's a particularly trying travel day, you may want to while away a few hours at an airport bar. But if you’ve killed enough time in enough U.S. airports, you've probably noticed that most of them have chapels tucked into a corner of the terminal. Some of them are simple, some of them are ornate. Some cater specifically to members of one religion while others are interfaith. So where did they come from, and why are they there?

The biggest surprise in answering the latter part of that question might be that airport chapels weren't originally built for airport passengers at all. According to Smithsonian.com, the first U.S. airport chapel opened in 1951 at Boston's Logan International Airport and was specifically created for the airport’s Catholic staff, largely to offer mass services for workers on longer shifts.

Dubbed “Our Lady of the Airways,” Boston's airport chapel concept was quickly embraced by Catholic leaders around the country. In 1955, Our Lady of the Skies Chapel opened at New York City's Idlewild Airport (which was renamed John F. Kennedy International Airport in 1963). Other Catholic chapels followed.

In the 1960s, JFK added both a Protestant chapel and a Jewish synagogue to its terminals. By the 1980s, Protestant chapels had opened in the Atlanta and Dallas airports as well.

Single-faith chapels dissipated for the most part during the 1990s and into the new millennium. In 2008, The Christian Index ran a story about the changing face of on-the-go religious spaces and declared "Single-faith chapels a dying breed at U.S. airports." As interfaith chapels became the new normal, this inclusiveness extended to the chapels' patrons as well. Instead of remaining gathering places for airport employees, the chapels opened their doors to the millions of passengers traveling in and out of their cities each year.

Today, more than half of America's busiest airports feature chapels, the majority of which are interfaith. Most existing chapels are welcoming to people of all faiths and often include multiple religious symbols in the same room. They have become important spaces for meditation and reflection. Many of them still offer worship services for each of their represented practices, including places like the interfaith chapel at Washington Dulles International Airport, which hosts a Catholic mass on Saturday evenings as well as daily Jewish prayer services. Though each airport chapel is unique in design and services, they all endeavor to offer a much-needed spiritual refuge from the hassle of air travel.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

SECTIONS

arrow
LIVE SMARTER