Alexander Stepanovich Popov was a man who lived a long time ago and he was very smart. He liked science and he wanted to make things that could help people.
One day, he found out that he could use radio waves to send messages without wires. This was a big discovery because before this, people had to use wires to send messages over long distances. This was very hard to do and sometimes the wires would break or the messages would get lost.
Popov made a machine called a radio that could send messages without wires. He could use it to talk to people far away without having to use wires. This was really cool and a lot of people started using radios to send messages.
Later on, Popov also discovered that he could use his radio machine to pick up signals from lightning strikes. This was important because it helped people know when there was a storm coming.
So, Alexander Stepanovich Popov was a very smart man who discovered how to send messages without using wires and also helped people stay safe from storms.