The cosmos lives within everyday moments.
I was sitting in the METU EE Canteen, watching an aquarium. Air bubbles rose through the water — their motion, viewed from different angles through different glass panels, created perspective shifts. And I realized: this is relativity in a fish tank.
Buoyancy and Gravity
The bubbles rising through water behave in a way that mirrors projectile motion under gravity. Buoyancy in water acts as an analogue to gravitational force — the medium changes, but the physics rhymes.
We don’t yet fully understand what we mean by the mass of the object — the concept hides layers of complexity. Viewing the aquarium from different panels is analogous to viewing spacetime from different reference frames. Einstein showed us that perspective isn’t just geometry; it’s physics.
The question remains open: what is gravity, really? Perhaps observing bubbles in water brings us one step closer to the answer.