Why Reddit is losing it over doorknobs

This popular section of Reddit is dedicated to the question, “What did you learn today?” And the answer that went off, with 1863 results (and counting), was to do with the humble brass doorknob and its magical, self-cleaning powers.

Well, not quite magical. The scientific term is the oligodynamic effect, which refers to the toxic effect of metal ions on living cells, including bacteria. In plainer English, this means the metal kills bacteria, thereby disinfecting its surface. It was discovered by botanist Carl von Nageli in the late 1800s. 

The oligodynamic effect works better with copper, which can partly disinfect itself within 15 minutes. However, copper is expensive, so the superhero doorknob is more likely to be made of brass. With brass, a common alloy of zinc and copper, the process takes about eight hours.

An article posted to subreddit notes this also “explains why silver works so well for eating utensils”, and points out that aluminum and stainless steel handles don’t have this property. So you might still want to apply the antibacterial wipes to those, if you’ve got them around the place.

There’s also the problem of only using the doorknob and attached door every eight hours or so, because the power of brass can only extend so far, sadly. Perhaps you could experiment with propping them open.

To get your brass doorknob to it’s germ-killing best, you should apparently remove any coating the manufacturer has used to keep them shiny; you can still polish them regularly if you want that effect. 

Or you can leave them be, and spend that time browsing other recently discovered via the internet facts like this one about moving sofas around corners.