קלײַב אַלץ אױס

Here’s a kid-friendly way to think about the ideas you mentioned: - What changes with the watcher vs what doesn’t - Things that change when you watch from different speeds or directions: how long something takes, how long it looks, and how fast it seems to go. - Things that stay the same no matter …

Here’s a kid-friendly way to think about the ideas you mentioned: - What changes with the watcher vs what doesn’t - Things that change when you watch from different speeds or directions: how long something takes, how long it looks, and how fast it seems to go. - Things that stay the same no matter who is watching: a special kind of distance between events (think of it as a “spacetime distance”) and the rest mass (how heavy something would be if it weren’t moving). - The gamma idea (why speed mat