scientists

astronomy – How do we know what the sun is made of?

by

How do we know what the Sun is made of? You look up at the Sun and see a brilliant, featureless light. Yet, you are actually looking at a massive nuclear furnace composed of a specific cocktail of elements. We know exactly what is inside this sphere without ever having taken a physical sample. Astronomers … Read more

astronomy – What is dark matter and how do we know it exists?

by

The Evidence for Dark Matter: Moving Beyond Theory Dark matter accounts for approximately 27% of the total mass-energy content of the universe, while ordinary matter—stars, planets, and gas—makes up less than 5%. We know this not through direct observation, but through precise gravitational measurements. Think of dark matter as the invisible scaffolding of a skyscraper; … Read more