Geology studies Earth’s materials, structure, history, and the processes that shape its surface and interior. Earth’s materials Minerals are naturally occurring substances with organized chemical structures. Rocks are aggregates of minerals or other materials and are commonly grouped as igneous, sedimentary, or metamorphic according to how they form. Earth’s layers Earth has a thin crust,…
Search engines discover web pages with automated crawlers, store information in indexes, and use ranking systems to organize results for a query. Crawling the web Automated crawlers follow links and visit publicly accessible pages. Website owners can provide helpful signals such as sitemaps, clear navigation, and crawl rules, although discovery and indexing are not guaranteed….
Data science combines statistics, computing, subject knowledge, and communication to turn data into useful insights. Defining the question A responsible project begins with a clear question and a practical definition of success. Understanding the intended decision helps determine what data is relevant and what analysis is appropriate. Working with data Data may come from sensors,…
Solar panels use photovoltaic cells to convert light into electrical energy. When light reaches the cells, it causes charged particles to move through an electrical circuit. Photovoltaic cells Most solar panels contain many photovoltaic cells made from semiconductor materials. Light transfers energy to electrons in the material, creating an electric current that can be collected…
3D printing creates physical objects from digital designs by adding material layer by layer. Different printers use plastics, resins, metals, ceramics, or other materials. From digital model to object A 3D model is prepared in slicing software, which divides it into thin layers and generates instructions for the printer. The machine then deposits, cures, melts,…
The Internet of Things describes physical devices that collect data, communicate over networks, and sometimes respond automatically. Examples include sensors, appliances, vehicles, and industrial equipment. How IoT systems work A connected device uses sensors to observe conditions such as temperature, motion, location, or energy use. Software sends and analyzes the data, while an actuator or…
Weather forecasts combine observations from satellites, radar, weather stations, balloons, and aircraft with computer models of the atmosphere. Collecting observations Weather stations measure temperature, pressure, humidity, wind, and precipitation. Radar tracks precipitation and wind, while satellites observe clouds, moisture, temperature patterns, and large weather systems. Balloons and aircraft provide measurements at different altitudes. Computer models…
Photosynthesis is the process by which plants, algae, and some microorganisms use light energy to convert water and carbon dioxide into chemical energy. Capturing light In plants, chlorophyll and other pigments absorb light inside structures called chloroplasts. This energy begins a series of reactions that move electrons and produce energy-carrying molecules. Making sugars Photosynthetic reactions…
Stars begin in large clouds of gas and dust. Gravity pulls material together until pressure and temperature rise enough for nuclear fusion to begin in the core. Stellar nurseries Cold clouds of gas and dust can contain dense regions where gravity overcomes pressure. As material gathers, the region contracts and forms a protostar. Collisions, turbulence,…
Astronomy studies objects and processes beyond Earth, including planets, stars, galaxies, and cosmic radiation. Observations across different wavelengths reveal information that visible light alone cannot show. What astronomy studies Astronomy examines the origins, structure, motion, and evolution of objects in space. It includes nearby worlds in our Solar System, distant stars and galaxies, black holes,…