The inhabited history of the Las Vegas Valley stretches to 23,000 b.c. , when much of the area was covered by a prehistoric lake. During this period, the indigenous people lived in caves, hunting the mammals that gathered at the shoreline. The landscape of the valley changed dramatically over the next 200 centuries. The glaciers feeding the lake melted away and the lake evaporated. Fossils tell an obscure story of man's slow and sporadic development. Around 3000 b.c. , native Archaic Indians began to develop a lasting hunting and gathering culture. By this time, the valley was in much the same geographic state as it exists in today, with one exceptionthe presence of artesian springs that bubbled to the surface in several areas. These springs fed a network of streams draining through the Las Vegas Wash to the Colorado River. The areas surrounding the springs were desert oases: sprawling collections of grasses, trees, and wildlife. Many springs lay in areas that would eventually become the center of the modern Las Vegas metropolis. For about 4000 years, the Archaics thrived in a culture that included many signs of early civilization. Signs of even more advancement appeared halfway through the first millennium a.d. , when the Anasazi Indians inhabited the valley. Far more progressive than the Archaics, the Anasazi utilized such formal agricultural techniques as irrigation to assist their harvest. This permitted the Anasazi to achieve a benchmark of advanced societythe ability to live in permanent shelters year-round without need to follow wildlife. Mysteriously, the Anasazi vanished from the valley around a.d.

Where did the Anasazi live?

Einstein was displeased with quantum theory and mechanics (the very theory he helped create), despite its acceptance by other physicists, stating that God "is not playing at dice." Einstein continued to maintain his disbelief in the theory, and attempted unsuccessfully to disprove it until he died at the age of 76. In 1917, at the height of his work on relativity, Einstein published an article in Physikalische Zeitschrift that proposed the possibility of stimulated emission, the physical process that makes possible the maser and the laser. This article showed that the statistics of absorption and emission of light would only be consistent with Planck's distribution law if the emission of light into a mode with n photons would be enhanced statistically compared to the emission of light into an empty mode. This paper was enormously influential in the later development of quantum mechanics, because it was the first paper to show that the statistics of atomic transitions had simple laws. Einstein discovered Louis de Broglie's work, and supported his ideas, which were received skeptically at first. In another major paper from this era, Einstein gave a wave equation for de Broglie waves, which Einstein suggested was the Hamilton-Jacobi equation of mechanics. This paper would inspire Schrodinger's work of 1926.

The inspiration for Schrodinger's work came from what equation?

Do all plants live on the land? Some plants do live in the water. To do this, they have evolved special traits. Plants that live in water are called aquatic plants. Living in water has certain benefits. There is certainly plenty of water! The plant does not need special traits to absorb, transport, or conserve water. They do not need a large root system. They do not need a strong stem to hold up the plant. The plant uses the water for support. Dont think water plants have it easy, though. They also face challenges. Living in water isnt that easy. They do need some special traits to survive. It is tough for the plant to reproduce. Pollination by wind or animals cant happen under water. Sunlight cannot reach very far beneath the waters surface. Some aquatic plants have floating flowers and leaves.
Do plants living in water have difficulty