True altitude is height above mean sea level (MSL), crucial for situational awareness and safe flight operations. True altitude calculation involves indicated altitude and temperature; colder ...

Pressure altitude is the height above a standard datum plane (29.92 inHg at sea level), used to calculate aircraft performance in non-standard atmospheric conditions. It's calculated using the formula ...

Determining a carbon footprint is easier said than done, and it’s not clear how much weight we should put on it. One way to gain a quantifiable understanding of the impacts of our actions, for good ...

Fighting the climate crisis on an individual level can feel futile, but knowledge is power. Here's how to understand and calculate your own carbon footprint. Our team tests, rates, and reviews more ...

At last, you’ve arrived in Cuzco, Peru — you’re ready for your dream trek to Machu Picchu. There’s just one problem: You can barely catch your breath, your stomach is churning and, in the morning, ...