What is the importance of metastable state? In a three-level laser, the material is first excited to a short-lived high-energy state that spontaneously drops to a somewhat lower-energy state with an unusually long lifetime, called a metastable state. The metastable state is important because it traps and holds the excitation energy, building up a… What […]
What are three scientific theories?
What are three scientific theories? Examples of scientific theories in different areas of science include: Astronomy: Big Bang Theory. Biology: Cell Theory; Theory of Evolution; Germ Theory of Disease. Chemistry: Atomic Theory; Kinetic Theory of Gases. Physics: General Relativity; Special Relativity; Theory of Relativity; Quantum Field Theory. What makes a bad scientific theory? Bad scientific […]
Why is the ground under my house wet?
Why is the ground under my house wet? Most times, water in the crawl space gets there one of three ways: a plumbing leak, water seepage from the surrounding soil (usually after heavy rain), or condensation. Humidity condenses on cold surfaces, like ducts, and drips onto the crawl space floor. How long does it take […]
What happens if you add a second pulley to a pulley system?
What happens if you add a second pulley to a pulley system? The powerful mechanical advantage of a pulley is in using many pulleys at once. Combining multiple pulleys decreases the amount of force necessary to move an object by increasing the amount of rope used to raise the object. How does a single movable […]
Which is the best example of heat being transferred mainly by radiation?
Which is the best example of heat being transferred mainly by radiation? Heat transfer by radiation occurs when microwaves, infrared radiation, visible light, or another form of electromagnetic radiation is emitted or absorbed. An obvious example is the warming of the Earth by the Sun. A less obvious example is thermal radiation from the human […]
What nerve makes the heart beat slower?
What nerve makes the heart beat slower? The word “vagal” refers to the vagus nerve. It’s a long nerve that runs from the brain down through the chest and into the abdomen. The vagus nerve has several functions, including slowing the heart rate. Can your heart continue to beat even if your cerebrum is not […]
Why does a spoon look bigger in a glass of water?
Why did the number of dark peppered moths increase after the 1850s?
Why did the number of dark peppered moths increase after the 1850s? The evolution of the peppered moth is an evolutionary instance of directional colour change in the moth population as a consequence of air pollution during the Industrial Revolution. Later, when pollution was reduced, the light-coloured form again predominated. Did moths used to be […]
How many plates are on Mars?
How many plates are on Mars? two plates Is Olympus Mons still growing? Scientists posit that Olympus Mons is still a fairly young volcano from a geologic standpoint, estimating it to be only a few million years old. That being said, there’s a good chance that it’s still active and could erupt at some point […]
Is there anything that takes space?
Is there anything that takes space? Matter is anything that has mass and takes up space. Is water being traded? Water has joined gold, oil and other commodities that are traded on Wall Street, as worries about the uncertainty of its availability in the future rises. What is the best water stock to buy? The […]