Why Physicists Think The Future Changes the Past - Retrocausality Explained?

Physicists think the future can change the past because sometimes events act like time travelers who go back and affect what already happened.

Imagine you have a bag of marbles, some red, some blue. You pick one without looking. Later, your friend tells you that they knew which marble you’d pick before you even picked it. That sounds strange, right? But if the future can influence the past, maybe your friend got a message from tomorrow telling them what you'd choose.

Think of it like getting a letter from the future that helps you make a decision today. If you receive a letter saying “Pick the red marble,” and you do, then even though you picked the marble first, the letter came after your choice. That’s like retrocausality, where something in the future affects something in the past.

It's kind of like when you decide to eat a cookie now because you know it’ll be gone later. The future (no cookies) changes your present (you eat one now). In physics, this idea helps explain some strange things that happen with particles and light, but it’s still as simple as picking marbles or eating cookies!