Answer: Soap film interference colours

What you're looking at

Soap films are incredibly thin layers of soapy water you see every day when you blow bubbles or wash dishes. They're so common we barely notice them, yet they create some of nature's most stunning visual effects when light interacts with them.

This extreme close-up reveals the intricate interference patterns that make soap films shimmer with rainbow colours. The photograph captures bands of vivid hues - blues, pinks, greens and purples - that form as light waves bounce between the film's two surfaces. When magnified this much, you lose all sense of scale and the familiar bubble shape disappears entirely, leaving only an abstract pattern of shifting colours that's surprisingly difficult to identify.

Search for smooth, flowing bands of rainbow colour with sharp transitions between hues in nature or bubble close-ups.

How players did

20 players made 20 guesses. It took 19 guesses before someone got it right.