According to the National Aeronautics and Space Administration (NASA), Which is in charge of space exploration and scientific discovery for the United States, the Hubble transmits about 120 gigabytes of science data every week. That’s equal to about 3,600 feet (1,097 meters) of books on a shelf. The growing collection of pictures and data is stored on magneto-optical disks. Among its many discoveries, Hubble has revealed the age of the universe to be about 13 to 14 billion years, which is a more accurate estimate than the Big Bang range of between 10 to 20 billion years.
Hubble also played a key role in the discovery of dark energy, a mysterious force that causes the expansion of the universe to accelerate. Hubble has shown scientists galaxies in “toddler” stages of growth, helping them understand how galaxies form. It found protoplanetary disks, clumps of gas and dust around young stars that likely function as birthing grounds for new planets. It discovered that gamma-ray bursts—strange, incredibly powerful explosions of energy—occur in far-distant galaxies when massive stars collapse.
The combine harvester saves the farmers time and labor. Before modern machinery, harvesting crops was a painstaking process. Gathering and removing mature plants from the field had to be done by hand. Farm workers used sharp-bladed, long-handled scythes and curved sickles to cut down cereal crops like wheat. Even the fastest reaper could only clear about a third of an acre a day. Because rain could ruin harvested wheat, workers called sheaf-makers quickly tied it into bundles, so that it could be safely stored if the weather turned stormy. During the long winter months farm workers used jointed wooden tools called flails to thresh or beat the dried wheat in order to separate its edible grain seeds from its stalks.
But in 1786 a machine that threshed wheat by rubbing it between rollers was invented, replacing human threshers. And around 1840 a reaping machine—whose revolving wheel pressed grain stalks against a sharp blade that cut them down— replaced human harvesters. Today, farm machines called combine harvesters do this work in much the same way. These machines are very efficient and combine all three jobs of cutting, collecting, and threshing a crop. A single combine harvester can process five acres of wheat in less than an hour!