How long do bed sheets last?

On average, you will need to replace your sheet set every two years. However, luxury cotton sheets made from materials like percale and sateen can last up to a year longer. Linen sheets have an even longer lifespan of three to five years or more.


Sleepwalking is not a type of dream.

Contrary to what most people believe, sleepwalking is a disorder and not part of the dreaming stage of sleep. Sleepwalking often occurs in school-age children, and is more common in boys. However, if sleepwalking happens later in life, this may be due to stress or other medical cases.


Nothing can go faster than light.

While light can move unimpeded at 299,792,458 meters per second in a vacuum, it slows down when it travels through different substances. For example, light moves 25% slower through water and 59% slower through diamond.

Charged particles like electrons can sometimes outpace photons of light in such materials — though they have to bleed off energy as a radiation when they do. It’s like an optical version of a sonic boom, and nuclear reactors create a lot of it by knocking electrons loose from water molecules with gamma rays.

What about light in a vacuum? Even then, the expanding fabric of space once exceeded light-speed during the Big Bang.

Physicists also think two quantum-entangled particles might be able to “move” or teleport their states instantly, no matter how much distance separates them.