LIGO is like a super-sensitive seesaw that can feel tiny wobbles from across the universe.
Imagine you and your friend are sitting on a seesaw at the park. When one of you jumps off, the other goes up, that’s how a regular seesaw works. But LIGO isn’t just any seesaw; it's two super long arms, each 4 kilometers long, connected by a laser.
The Laser Seesaw Trick
The laser in LIGO acts like a very clever ruler. It splits into two beams that travel down the arms and bounce back. If everything is perfectly still, both beams come back at the same time, just like you and your friend jumping off together.
But when a gravitational wave passes through, it’s like someone gently pushes one side of the seesaw while pulling the other. This makes one beam travel a tiny bit more than the other, just like if your friend jumped off a little earlier than you.
LIGO notices this difference, super tiny, but real, by looking at how the beams combine again. That’s how it knows a gravitational wave has arrived!
Examples
- Imagine a very long string that stretches and shrinks when something big happens in space, like two black holes colliding.
- Think of LIGO as a super-sensitive ruler that measures tiny changes in distance caused by gravitational waves.
- If you’re on a boat and feel the ocean ripple because of a huge wave far away, LIGO feels ripples in space-time from cosmic events.
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See also
- What are gravitational wave detectors?
- How Does Discovery That Changed Physics! Gravity is NOT a Force! Work?
- How Does Time Dilation Explained in 6 Minutes Work?
- How Does General Relativity Explained simply & visually Work?
- What happens if youre hit by a primordial black hole?