A particle physicist explains just what this keystone theory includes. After 50 years, it’s the best we’ve got to answer what everything in the universe is made of and how it all holds together.
It turns out that the world is about 4,600,000,000 years old. That’s 4.6 billion years. That’s pretty old!
Marcella Cheng/The Conversation
The world is made of tiny building blocks called ‘elements’. Scientists have worked out how fast some elements change into other elements. That gives us a very big clue about how old the Earth is.
The periodic table of the elements on a T-shirt.
Damon Hart Davis
The periodic table is one of the classic images of science that is found in labs as well as on t-shirts, mugs, even set to music. But what exactly is the periodic table?