Sounds travels slowest in gases (air), faster in liquids, and faster still in solids. Sound waves travel approximately 4.3 times faster in water than air and approximately 15 times faster when passing through iron as opposed to air.
Vision acuity is often expressed as a fraction. If you have 20/20 vision, then you can see what people with normal vision see at 20 feet. If you have 20/40 vision, then you need to be 20 feet away to see what other people can see at 40 feet. At 20/60, you must be as close as 20 feet away to see what others see clearly at 60 feet, and so on. Legal blindness is defined as a medically diagnosed central visual acuity of 20/200 or less in the better eye (with the best possible correction) and/or a visual field of 20 degrees or less.
The original metal Slinky toy was made from exactly 80 feet of metal wire.
The letter J is the only letter that makes no appearance on the Periodic Table—Q appears, but only in temporary placeholder names like ununquadium (which later officially became Flerovium and lost the Q).