Everyone can agree on the power of good night's sleep. Sleep is as essential as food and water and often, much easier to take for granted. While there may be a consensus as to it importance, there is a wide range of arguments as to what a good night's sleep entails. The course of history gives us a remarkable cross-section of how past generations sought that sweet sleep.

For the ancients, especially the ancient Egyptians, beds seem to have been little more than layers of straw or vegetation piled in the corner of their homes. The Greeks, on the other hand, crafted wooden frames and sought to get clear of the ground and free of the draft. Moreover, it seems their beds were designed to fold, making the Greeks the progenitors of the adjustable bed.

Curiously, the use of the expression "sleep tight" has nothing to do with old civilizations. Rather, it was a saying popular during the American colonial era. The beds of the colonists were held together with ropes woven into a grid pattern holding the mattress in place. A good bed, and accordingly a good night's sleep, depended on how tightly the ropes were fastened.

With the invention of the spring coil and the inclusion of the box spring, merchants began to standardize mattress sizes. Now, most countries have a standard set of four mattress sizes. They range from twin to double to queen to king. Of course, in keeping with all things being bigger and better in the Golden State, there is the California King, which is a slightly taller version of the king sized bed.

Perhaps the best feature of any bed is its ability to conform and comfort. Emboldened by Howard Hughes's invention of the adjustable bed (as we know it) in 1953, avid sleepers have a variety of positions they can sleep - and dream - in. From mounds of palm fronds to hydraulic mattresses, the push of generations has been the same: a good night's sleep.