Using gold flakes, salt water, and light, scientists have made the universe’s invisible binding forces visible in color. The discovery opens new possibilities for studying how matter organizes itself at the smallest scales.
When dust clings to a surface or a lizard walks across a ceiling, the effect comes from what scientists often call “nature’s invisible glue.” Researchers at Chalmers University of Technology in Sweden have now developed a fast and straightforward way to investigate these hidden forces that hold the smallest building blocks of matter together. By combining gold, salt water, and light, they created a platform where those forces become visible as shifting colors.
Gold Flakes, Salt Water, and Light
Inside the lab, doctoral student Michaela Hošková holds up a small glass container filled with millions of micrometer-sized gold flakes suspended in a salt solution. Using a pipette, she places a droplet of the mixture onto a gold-coated glass plate positioned under an optical microscope. The flakes are immediately drawn toward the surface but stop just short of fully attaching, leaving nanometer-sized gaps between the flakes and the gold substrate.
These tiny liquid-filled gaps act like miniature light chambers. Light reflects back and forth inside them, producing visible colors. When the setup is illuminated with a halogen lamp and the reflected light is analyzed with a spectrometer, the different wavelengths become clear. On the connected monitor, flakes shimmer and shift in colors such as red and green against a golden yellow background.
