Coral Reefs, Chaos Theory, and Earth's Atmosphere

Plus, drilling into volcanic magma

Good morning. It's Tuesday, April 7, and welcome to this week's Science & Technology newsletter. First time reading? Sign up here or click here to share with friends.

After focusing on astrophysics last week, we're back to featuring fascinating topics across disciplines, starting with coral reefs. Per NOAA's Coral Reef Watch, last year saw coral reefs in the middle of the worst bleaching event in history, with nearly 85% of them impacted by heat stress. After a brutal heatwave across much of the US last month, we wanted to break down why coral reefs are of outsized importance to global ecosystems and why rising temperatures are so dangerous to them.

Then, we'll explore the first mathematics topic ever covered in this newsletter (and probably the one with the coolest name): chaos theory. Elements of this formidable-sounding subject are all around you, including in the air you breathe, making it well worth learning about. Speaking of air, our last topic is Earth's atmosphere, one of the major reasons why our planet is suitable for so many forms of life, despite its pressing down on us with 11.24 quintillion pounds.

Let us know what you think! Whether it's feedback on our email format, a comment on this week's topics, suggestions for future coverage, or something else, we're happy to hear from readers. You can get in touch by simply replying to this email.

—Marco Daniel Machado, 1440 Science & Technology Section Editor

Rainforests of the Seas

Coral reefs, explained

Coral reefs are underwater ecosystems made from the skeletons of hard coral colonies. Each colony is composed of multiple polyps called corals—animals with tentacles around a mouth at one end and sac-like bodies at the other that attach to a surface and secrete calcium carbonate for protection. Over thousands of years, these secretions accumulate to form habitats that support about 25% of marine species, even though they cover less than 1% of the ocean floor (watch coral growth time-lapse).

Known as the "rainforest of the seas," coral reefs are found in tropical and subtropical waters of more than 100 countries, with larger reef systems concentrated in the Indo-Pacific, Caribbean, and the Red Sea (view gallery). Shallow-water coral reefs rely on a symbiotic relationship with colorful photosynthetic algae called zooxanthellae, which provide coral with nutrients and oxygen in exchange for a protective environment within coral tissue. Deepwater corals instead consume plankton and dead organic matter to survive.

In the US, coral reefs provide $3.4B in annual economic value through fisheries, coastal protection against wave damage, and tourism. However, stressors such as rising temperatures, ocean acidification, and pollution have weakened reefs and caused coral bleaching. This phenomenon sees corals expel zooxanthellae, turning corals white, depriving them of their food source, and making them susceptible to disease (watch explainer).

Learn even more by exploring all our findings on Coral Reefs here.

Here's a sample of what we found ...

> See the life cycle of corals, which begins with a spawning event lasting less than an hour, once a year. (Watch)

> About 76% of global coral species can be found in the Coral Triangle. (View)

> Take an interactive trip through the Great Barrier Reef, the world's largest living structure. (Explore)

> Learn how you can help protect coral reefs, even if you don't live near one. (Read)

The Butterfly Effect

What is chaos theory?

Chaos theory is a branch of science and mathematics that explores systems that follow well-defined rules yet produce unpredictable outcomes. Just as a marble repeatedly dropped on a rocky, uneven surface will move according to the established laws of physics but will not travel the same path due to differences in the angle of the first bounce, these systems produce a wide range of results based on small variations in initial conditions. This behavior, called chaos, is not considered random and has been popularized as the butterfly effect (see why).

In the late 19th century, Henri Poincaré became the first person to discover a chaotic system when showing that the motion of three mutually orbiting objects was unstable—the three-body problem (see visualization). In 1961, Edward Lorenz found that when changing one of the starting values in a weather simulation from 0.506127 to 0.506—a then-assumed negligible difference—a significantly different forecast was produced (learn more). This showed that, regardless of model accuracy, limits in precision make it impossible to predict the long-term outcomes of certain systems.

Chaos has since been identified everywhere from heart arrhythmias and turbulence to disease spread and market volatility. Understanding chaos and how minute environmental factors—noise—can produce chaotic behavior has improved numerous mathematical models, such as those describing weather, climate, population growth, and gravitational orbits.

Learn even more by exploring all our findings on Chaos Theory here.

Here's a sample of what we found ...

> Can flapping butterfly wings really cause tornadoes? (Watch)

> Strange attractors are beautiful mathematical artifacts that help visualize chaos. (View)

> The story of two female programmers running the simulations behind chaos theory's discovery. (Listen)

> Simulate chaos and its dependence on initial conditions using a pair of double pendulums. (Explore)

Earth's Blanket

Earth's atmosphere, 101

Earth's atmosphere is one of its five major systems, consisting of gases that envelop the planet from the ground to more than 10,000 kilometers (6,214 miles) above the surface. It serves as the arena where the sun's uneven heating is circulated across the planet by weather, while insulating against significant temperature changes between day and night. By trapping thermal energy via the greenhouse effect and protecting against most harmful debris and radiation from outer space, the atmosphere sustains suitable conditions for large segments of life on Earth.

The current atmosphere is not Earth's first. Planetary models suggest leftover hydrogen and helium from the formation of the solar system once surrounded the planet but were lost to space due to insufficient gravity. Heavier molecules released by volcanic eruptions, such as water vapor, carbon dioxide, and ammonia, later formed a new atmosphere. Photosynthesis in ancient microorganisms and reactions involving solar radiation then turned these chemicals into the most abundant gases in the modern atmosphere: nitrogen (78%) and oxygen (21%) (learn more).

Although the atmosphere stabilized into its five layers following the production of these gases, it continues to evolve through interactions with the sun and other Earth systems. This includes ozone depletion and increases in greenhouse gas concentrations caused by human activity.

Learn even more by exploring all our findings on Earth's Atmosphere here.

Here's a sample of what we found ...

> Without its atmosphere, Earth's oceans would boil away at freezing temperatures. (Watch)

> Japan used the jet stream to launch attacks on US soil during World War II. (Watch)

> Why suction cups and similar technologies rely on Earth's atmosphere. (Watch)

> Take an interactive adventure through Earth's atmosphere. (Explore)

Science Spotlight

Like all great scientists, we love spending time researching the latest scientific breakthroughs, tech releases, engaging explainers, and the connections between science and society that are making headlines. Here's what we found this week.

> Populations of migrating fish dropped 81% over the last half-century

Yale E360 | Staff. Reported at a UN meeting, hundreds of fish species have been imperiled by warming, pollution, dams, and intensive fishing, threatening the sustenance of hundreds of millions of people who depend on them. Freshwater animal populations are now declining faster than those on land or at sea. (Read)

> Some of the most massive stars may self-destruct rather than form black holes

Monash University | Staff. Analyzing a cosmic census of black holes detected with gravitational wave data, scientists found that those with masses more than 45 times that of the sun are unexpectedly rare. The cores of these stars may convert light into matter and antimatter, driving a supernova that obliterates them and leaves nothing behind. (Read) | Learn about black holes by exploring our write-up and findings here.

> Astronomers discover a molten exoplanet in its own class

University of Oxford | Staff. By combining advanced computer simulations of planetary models with observational data from the James Webb Space Telescope, astronomers have found an exoplanet believed to possess a permanent ocean of magma and characteristics unlike any existing exoplanet categories. (Read) | Learn about the James Webb Space Telescope by exploring our write-up and findings here.

> Over 14,000 network devices found to be part of takedown-resistant botnet

Ars Technica | Dan Goodin. Primarily affecting routers made by ASUS, researchers at a security firm identified that malware dubbed KadNap had exploited vulnerabilities in the devices to create a network that anonymously carried traffic for cybercrime. Compromised devices require a factory reset to remove the infection. (Read) | Learn about computer viruses by exploring our write-up and findings here.

> World's largest offshore wind farm connects its first export cable

Interesting Engineering | Georgina Jedikovska. Located 120 kilometers (75 miles) off the coast of England, construction on the $11.2B installation by Danish energy company, Ørsted, began in 2018. The wind farm is expected to provide electricity to more than 3.3 million UK households and reach a capacity of 2.9 gigawatts by 2027. (Read) | Learn about wind power by exploring our write-up and findings here.

Best of the Week

We curate hundreds of resources into 1440 Topics each week. Here are some of our favorites from the world of science and technology.

Read:

> "Project Hail Mary" has us asking: Could alien life exist without water?

> Check out particle physics labs up close with the winners of the 2025 Global Physics Photowalk contest.
> What happens if you accidentally drill into magma beneath a volcano?
> Bioluminescence can tell us when wine's gone bad.

> How infrastructure can be weaponized by hacking the grid.

Watch:

> With Iran's desalination plants in the news, an explanation of these facilities.

> How playing music can enhance the creation, storage, and retrieval of memories.

> If water is the "universal solvent," why doesn't it dissolve everything?

> The engineering behind creating the motor sounds for electric vehicles.

> What is the fastest way to board all passengers onto an airplane?

Thank you to Greg H. for inspiring us with their questions! Curious about something in science and technology? Tell us here.

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Coral Reefs, Chaos Theory, and Earth's Atmosphere