(PhysOrg.com) -- The noise that we produce can be a lot of things. It can be a valid means of communication. It can be an annoyance when you are trying to get to bed at night. It can be a migraine waiting to happen, and depending ...
The Saturn V carried man to the moon and remains the most powerful rocket to successfully launch to orbit. It captures the imagination—but sometimes, it might capture a bit too much imagination. Abundant internet claims ...
Space Exploration
Aug 23, 2022
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The sound of silence isn't so golden for consumers, and both marketers and advertisers should take note, says new research from a University of Illinois expert in new product development and marketing.
Social Sciences
May 14, 2012
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(PhysOrg.com) -- A team of Finnish physicists has developed a novel way to amplify a microwave signal that unlike other amplifiers, produces noise that is just barely above that which is necessary due to the laws of quantum ...
Though famous for their mid-air hovering during hunting, tiny hummingbirds have another trait that is literally telltale: males of some hummingbird species generate loud sounds with their tail feathers while courting females. ...
Plants & Animals
Sep 8, 2011
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(PhysOrg.com) -- Researchers studying the lesser water boatman have discovered that adjusting for size, M. scholtzi, a tiny freshwater bug, is the apparent world champion at producing the loudest noise. At only 2.3mm (about ...
(PhysOrg.com) -- Imagine sitting down for your early morning coffee when your nice little suburban morning is disrupted by the sound of highway traffic from a quarter mile away. When you purchased your home far from the ...
From construction projects to busy roads, airplanes and railways, human noise is everywhere. It is an invisible cause of stress, posing serious risks to human health and well-being. However, noise also harms animals living ...
Plants & Animals
Aug 23, 2022
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Groundbreaking innovations on antenna technology, based on a collaboration between Lockheed Martin Space and Penn State, are now under consideration for use in the next generation of GPS satellite payloads.
Engineering
Jan 14, 2019
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Any day now, billions of cicadas with bulging red eyes will crawl out of the earth after 17 years underground and overrun the East Coast. The insects will arrive in such numbers that people in the southern state of North ...
Plants & Animals
May 6, 2013
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The decibel (dB) is a logarithmic unit that indicates the ratio of a physical quantity (usually power or intensity) relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities. A decibel is one tenth of a bel, a seldom-used unit.
The decibel is used for a wide variety of measurements in science and engineering, most prominently in acoustics, electronics, and control theory. In electronics, the gains of amplifiers, attenuation of signals, and signal-to-noise ratios are often expressed in decibels. The decibel confers a number of advantages, such as the ability to conveniently represent very large or small numbers, and the ability to carry out multiplication of ratios by simple addition and subtraction.
The decibel symbol is often qualified with a suffix, that indicates which reference quantity or frequency weighting function has been used. For example, dBm indicates a reference level of one milliwatt, while dBu is referenced to 0.775 volts RMS.
The definitions of the decibel and bel use base 10 logarithms. The neper, an alternative logarithmic ratio unit sometimes used, uses the natural logarithm (base e).
A change in power ratio by a factor of 10 is a 10 dB change. A change in power ratio by a factor of two is approximately a 3 dB change.
This text uses material from Wikipedia, licensed under CC BY-SA
