At last the complex map was complete. "I remember this moment," says Viren Jain, a neuroscientistNeuroscience is the study of the brain and nervous system. There is a lot of overlap between neuroscience and psychology, but neuroscientists tend to focus more on the way that nerves function. who works for Google. It felt, he adds, "sort of spiritual."

He was looking at a tiny piece of a woman's brain - roughly the size of a sharpened pencil point. But scientists managed to cut it into 5,000 slices, each 34 nanometres thick. That is about as much as a fingernail grows in 30 seconds.

A picture was taken of each slice using a special microscopeAn object that uses lenses to make very small objects look much bigger. . Then Viren Jain put all the photographs together and used them to create a 3D map.

The map covered roughly one millionth of the brain. It showed around 57,000 cells and 150 million of the connections between nerve calls (also known as neuronsNeurons, also known as nerve cells, are cells in the nervous system that use chemical or electrical signals to transmit information throughout the body. ) known as synapses.

The map also revealed some amazing things about neurons. There were pairs that were almost mirror images of each other. And some had tendrilsSomething that is thin and curly - often the stem-like parts of climbing plants that attach themselves to walls. that formed knots around themselves.

The map is a triumph of science. But at the same time, writes David Von Drehle in The Washington Post, it is "awe-inspiring" because it shows us what we do not know. The map shows that we are nowhere near a basic understanding of how the brain works.

But rather than lose hope of ever understanding the world, we should be excited:

"The age of discovery is only beginning, and its durationThe length of time something lasts. is limited only by our willingness to learn and grow. To see the miraculous tangle of connections... is to find nearly infiniteLimitless or endless. An amount impossible to count. possibility and to feel a surge of hope."

Is this the dawn of a new age of discovery?

Yes! The making of the map is an amazing achievement. So are new telescopesDevices which makes things look nearer than they are. , and new discoveries thanks to Artificial IntelligenceArtificial intelligence, or "AI," is the ability for a computer to think and learn. With AI, computers can perform tasks that are typically done by people, including processing language, problem-solving, and learning..

No! Most of the big discoveries - for example, electricity or new medicines - have already happened. We can only make small discoveries now.