It's about one-two-thousandth as fast as a bolt of Lightning
In other words, 87 knots is 0.0005 times the speed of a bolt of Lightning, and the speed of a bolt of Lightning is 2,200 times that amount.(atmospheric electrical discharge)
A bolt of lightning can travel at up to 190,000 knots when arcing from the atmosphere to the Earth. An estimated 280 million lightning strikes strikes occur each year.
It's about 0.0000002 times as fast as The Speed of Light
In other words, 87 knots is 0.00000014929217020752 times the speed of The Speed of Light, and the speed of The Speed of Light is 6,698,274.9236613 times that amount.(C) (in a vacuum)
The speed of light (and all other electromagnetic radiation) in a perfect vacuum is known as "c" and measures 582,749,918.358530 knots, per the formal definition of the meter. While visible light travels close to this speed in air, it slows to 388,499,945.578830 knots when passing through the glass of a typical window.
It's about 1,000,000,000 times as fast as Grass growing
In other words, 87 knots is 1,100,000,000 times the speed of Grass growing, and the speed of Grass growing is 0.00000000091 times that amount.(for Kentucky Bluegrass, Poa pratensis) (a.k.a. Smooth Meadow grass, a.k.a. Common Meadow grass) (Summer months, ideal growing conditions)
Kentucky Bluegrass, one of the most common grasses in North America, grows about 0.0000000820 knots in the summer months under ideal conditions. When left un-mowed, Kentucky Bluegrass grows to heights of 60 to 90 cm (2 to 3 ft) and blossoms with a blue flower.