Heart Pacemaker
Heart pacemaker was invented in 1986 byWilson Greatbatch 

Electric Chair
The electric chair was invented by a dentist, Alfred Southwick.

Eye Glasses
The Chinese invented eyeglasses. Marco Polo reported seeing many pairs worn by the Chinese as early as 1275, almost 500 years before lens grinding became an art in the West.

Glass
If hot water is suddenly poured into a glass that glass is more apt to break if it is thick than if it is thin. This is why test tubes are made of thin glass.

Hard Hats
Construction workers hard hats were first invented and used in the building of the Hoover Dam in 1933.

Hoover Dam
The Hoover Dam was built to last 2,000 years. The concrete in it will not even be fully cured for another 500
years.

Limelight
Limelight was how we lit the stage before electricity was invented. Basically, illumination was produced by heating blocks of lime until they glowed.

Mobile (Cellular) Phones
As much as 80% of microwaves from mobile phones are absorbed by your head.

Nuclear Power
Nuclear ships are basically steamships and driven by steam turbines. The reactor just develops heat to boil the water.

Oil
The amount of oil that is used worldwide in one year is doubling every ten years. If that rate of increase continues and if the world were nothing but oil, all the oil would be used up in 400 years.