energy

The United States hosts more data centers than any other country by every count, but the totals vary from about 3,800 to 5,400 depending on the database. Here is the ranking, why facility counts and megawatts tell different stories, and what the IEA says about data centre electricity.

Four laws govern how energy moves, transforms, and degrades, from the steam engine to every living cell. Thermodynamics explains why engines have limits and why time has a direction.

One splits atoms to release energy; the other fuses them together. Both tap the same fundamental force — and both are transforming how we power civilization.

The battery in your phone contains enough energy to seriously injure you. Understanding it reveals one of chemistry's most elegant solutions.

A Dyson sphere — a structure capturing all of the Sun's energy — would harness 3.86 × 10²⁶ watts, more than a trillion times humanity's current power use. Building it requires more material than exists in any individual planet, but could in principle be done by dismantling Mercury or several asteroids.

Saudi Arabia, Russia, the United Arab Emirates, Iraq, the United States and Canada are among the most important crude-oil exporters, but the ranking changes when analysts switch between gross barrels, net exports, crude, refined products and trade value.

Russia holds the largest proven natural gas reserves, followed by Iran and Qatar. But the sources behind the rankings disagree by a factor of two for some countries, and what a country can sell depends on pipelines and LNG terminals more than on geology. Here is the ranking, the caveats, and the export picture.

Proven oil reserves are the foundation of petrostate power and the lifeblood of the global energy economy. This ranking reveals which countries hold the most oil underground — and why those reserves are simultaneously an enormous economic asset and a geopolitical liability in an era of energy transition.

In 1964, Soviet astronomer Nikolai Kardashev proposed ranking civilizations by the power they command. Type III means a whole galaxy. Humanity sits near 0.73, and the arithmetic of getting from here to Type III is humbling.

Nuclear power has the lowest death rate per kWh of any major energy source. It's also the most feared. Here's what the data actually says — beyond Chernobyl, beyond Fukushima.

Refrigerators don't make cold — they move heat out of one place into another. Here's how the four-step refrigeration cycle keeps your food fresh, and why it works.

Green hydrogen is made by splitting water with renewable electricity, so burning it releases only water. It is promising for industries that cannot easily electrify, but it is costly and wasteful elsewhere.