May The smallest Force ever detected Be With You
Researchers have detected the smallest force ever measured using lasers and a super-cold gas trapped by waves of light.
This force is so small you’ve probably never even heard it before. We’re talking about a force of 42 YoctoNewtons (I promise that’s not made up). One regular newton of force is a little more than what’s needed to depress a key on a keyboard. One yoctonewton is a septillionth of a newton or about a thousand billion billion times less than a feather lying on your desk. I could punch you in the face with a force of a trillion yoctonewtons and I don’t think you’d even notice.
As you can imagine, it takes an elaborate setup to measure something that tiny. First they chill a gas of 1,200 rubidium atoms close to absolute zero inside an optical trap. This trap consists of mirrors bouncing 2 light beams back and forth inside it creating what’s called standing waves. These waves exert opposing forces on the atoms keeping them put until one of the light waves is changed which induces a very slight motion in the gas cloud. A third light beam called the probe beam is then sent in to measure the minute force exerted on the cloud.
There, that’s easy isn’t it?
Don’t expect much smaller forces in the future because this is so small it’s actually close to the theoretical limit of what’s detectable. Scientists don’t even have a name yet for quantities less than a yocto anyway.
This new measuring ability isn’t just cool for cool’s sake though. It has the potential for new discoveries as well. It could help with our quest to finally detect those elusive and ever so subtle gravity waves. It may also help determine if gravity, which shapes the universe at its largest scale, has any impact at all at the smallest quantum scale.
So try to use the word yocto in every day conversation and let me know how that goes.
Image Credit: Kevin Gutowski