The asteroid belt is nothing but tourist traps, and the rest stops really thin out after Saturn. Some of you will want to consider flying. Luckily, at a Boeing 777's maximum velocity of 590 miles per hour, the trip to Pluto will take only about 680 years.
Yet structures like the Pantheon and the Colosseum have survived for centuries, often with little to no maintenance. Geologists, archaeologists and engineers are studying the properties of ancient Roman concrete to solve the mystery of its longevity. âRoman concrete is . . . considerably weaker than modern concretes. Itâs approximately ten times weaker,â says Renato Perucchio, a mechanical engineer at the University of Rochester in New York.
As one of the key constituents of modern concrete, cement has been around for a long time. About 12 million years ago in what is now Israel, natural deposits were formed by reactions between limestone and oil shale that were produced by spontaneous combustion. However, cement is not concrete.s one of the key constituents of modern concrete, cement has been around for a long time. About 12 million years ago in what is now Israel, natural deposits were formed by reactions between limestone and oil shale that were produced by spontaneous combustion. However, cement is not concrete.