Light is incredibly important to just about everything on the planet. There are exceptions - especially in extreme environments - but it's safe to say that light is a pretty crucial part of our day-to-day life. But what do you really know about light? What is light, really?An examination of the science of light reveals that it's a whole lot more than just a sunbeam across your face: light can be slowed and stopped, it can force your brain to stop making hormones, it can make you sneeze following a matinee showing of a summer movie. Some light facts are odd (clapping northern lights!) and some are weirdly comforting (all humans emit light!), but they all display just how complex such a seemingly simple topic can be. Enjoy these illuminating facts about light and dazzle your friends with them at every turn!
Crystals Generate Light When Warmed
It's no wonder humans have assigned magical or supernatural properties to crystals for thousands of years: they do behave in peculiar (if scientifically sound) ways, especially with regards to light. Heating up a crystal like fluorite will cause it to glow like a weak lightbulb, via a process called thermoluminescence.
Light Can Make You Sneeze
The human mind is a wonderful, complex, glorious thing - but even it makes mistakes sometimes. Regardless of your IQ, your mind can sometimes misunderstand what the world is trying to tell it. This explains why nearly a third of the population sometimes sneezes when suddenly exposed to bright light: the current theory is that the brain "mistakes" the light as a signal to sneeze instead of a signal to restrict the pupils. Oops!
Light Can Connect You to the Internet
Your lightbulbs may soon be doing double-duty as an emitter of a high speed Internet signal. Scottish professor Harald Haas is the pioneer behind "Li-Fi," a wifi-like method of pumping the Internet through the air to your devices using LED bulbs. Paired with a solar cell, the prototype Li-Fi bulbs act as an all-in-one Internet transmitter that promises to be faster and more secure than the wifi used around the globe today.
Light Can Push a Small Spacecraft Into Orbit
Everyone loves the feeling of the sun on their faces, but did you know that light is literally pushing against your face? As well, in the right conditions, light can have enough momentum to propel objects in space. That's right: even without mass, packets of light energy called photons can push against objects and transfer momentum; it's called "flight by light." So-called "solar sailing" is currently being developed by a team from the citizen-funded Planetary Society.