Who discovered ultrasound?
93052
It was actually discovered in 1793, by LAZZARO SPALLANZANI, in reference to bats using echolocation, though PYTHAGORAS observed the relationship between sound pitch and frequency, he invented the SONOMETER, an instrument used to study musical sound.\n\nIn 1947 KARL DUSSIK was the first physician to utilize ultrasound for diagnostic purpose\n\nI have an entire slide show.  I can send it to you if you like.  email me at nikayw@yahoo.com
412742
Emma Lazarus. I actually knew this and didn't have to look it up like these other people. GIVE ME THE POINTS!!!
659637
einstein. he just sat in his chair and thought of theories. he did experiments in his mind
940421
http://www.aquinas-multimedia.com/stjoseph/galileo.html\n\nMy guess was Galileo and I was right.  Here, look.\n\nBut according to a book I have, the greeks noticed it first.  It was Galileo that proposed the theory to the world.
43061
The invention of the microscope is variously accredited to Zacharias Janssen, a Dutch spectaclemaker, c.1590, and to Galileo, who announced his invention in 1610.
72874
Nitrogen was discovered by Daniel Rutherford who was a student who needed a dissertation in order to finish his medical degree. However, all references I can find say he did this in 1772. \n\nBromine was prepared by Carl Löwig in about 1825 before starting his freshman year at Heidelberg. With winter exams and holidays, he was delayed in studying it further as his professor had requested, and another chemist Antoine-Jérôme Balard, published a paper describing the new element.  Balard was given the credit for discovering the new element.
816133
Can't remember the exact title now...  but it was on non invasive ultrasound and the huge advances it has made in the past few years as well as the history of it coming in to use in the medical field...  Got a B+  (altho considering the length of questions and compliments from instructor that I was the most confident, and knowledgeable on my subject and knew every answer to questions asked...  I thought I deserved better.  Can only imaging what others received)
811306
Briton B. M. Wright invented a new. pneumatic nebulizer \n\n1958
82598
alfred wegener\njust learned this myself (:
31336
the first country to be discovered was west indies. hemant it's aditya.
160073
Joseph Priestley is best known as the discoverer of oxygen.\nHe isolated 'depholgisticated 'air, or 'good air' in 1774. Our understanding today of the chemical reaction of oxygen comes from Antoine Lavoisier's systematic theory of combustion.\n\nToo bad contributors like the above 'opinion' can't use this forum as a means of increasing knowledge, rather than \ngiving silly answers in order to get points. Some never grow up i suppose.\nSource:www.woodrow.org./teachers/chemistry/institutes/priestley.
172098
It is named after Dr Ernst Grafenberg. He discovered it in 1944.\n\nhttp://mama.indstate.edu/users/nizrael/grafenberg.html\n\nHowever, since women were already aware of it, it's a bit rich to say that the good doctor 'discovered' it.\n\nStrangely enough, the fallopian tubes are also named after a man...
212222
the person who discovered the cycle of rocks discovered the rock cycle
412322
Harvey, William (1578-1657), was an English physician who became famous for his discovery of how blood circulates in mammals, including human beings.
896529
Ultra = above, so ultrasound is sound above what you can hear.\n\nAn ultrasound machine is just a form of sonar.  It works in a similar fashion, as does radar.  Sound is sent out, some tissues can absorb it while other tissues can reflect it.  The sound is picked up and with computer processing an image can be produced.\n\nAccording to Wikipedia:  http://en.wikipedia.org/wiki/Ultrasound\n“Ultrasound is sound with a frequency greater than the upper limit of human hearing, this limit being approximately 20 kilohertz (20,000 hertz).”\n\nThe human body is mostly water so the ultrasonic waves can pass through the body into an inside cavity, like the bladder, a kidney, or a woman’s womb.  The strength can be adjusted to penetrate more tissue, but it only works well in a cavity.  The ultrasound waves can pass through tissue like sonar passes through water.\n\nIn the case of a pregnant woman the womb is filled with a fluid, ambotic fluid, that is mostly water.  The ultrasonic waves can easily penetrate this fluid, but they are reflected by the babies body inside.  This creates an outline shape with some rough outlines of the face and the limb.  Even enough definition to make out if a penis is present or not.\n\nUltrasound is considered safer than using x-rays or some other radioactive source (CT or nuclear medical scans for radioactive isotopes).  However, it has been shown that the ultrasound waves can damage the brain of a rat fetus, so ultrasound should only be used on a fetus if there is a medical reason to do so.  Just getting a picture of the fetus is unethetical.\n\nIn my case I have kidney stones and an ultrasound inspection was used to see how large they are and where they were located.  The sound isn’t focused agaisnt my head so the procedure is very safe, and much cheaper than and MRI exam is.  Also the technican can run a long scan searching for something which is more difficult to do with an MRI.\n\nThe Machine has a paddle with a vibrating membrane and a smaller sound absorbing membrane.  The skin is prepared with a gell, to make better contact with the paddle.  As the paddle is placed against the skin it vibrates the skin, and the body itself, then the vibrations are carried to the organ being inspected.  The reflected vibrations are taken in by the paddle and transferred to the machine.  As the technican moves the ultrasound paddle then they create a scan image, sort of like what a radar does.  There are seveal sound receptors (the smaller vibrating membrance) inside the paddle so a single sweep can create a larger image.  The patient doesn’t feel anything, there is no bone conduction to the ear or any other sensation.  This is another reason why it is a very safe scanning method.\n\nThe returning signals are compiled by the ultrasound machine’s internal computer and displayed as a pie shapped image on the screen.  It takes a trained technican to make sense of that image.  I didn’t understand what was on the screen during my ultrasound.  Since the paddle has audio receptors, it is easy to include one that can pick up a fetus’s heartbeat.  Also part of the heart beat sound is in the ultrasonic frequency so the machine can pick it up.\n\n“Medical sonography (ultrasonography) is a useful ultrasound-based diagnostic medical imaging technique used to visualize muscles, tendons, and many internal organs, their size, structure and any pathological lesions. They are also used to visualize a fetus during pregnancy. Ultrasound scans are performed by medical health care professionals called sonographers. Obstetric sonography is commonly used during pregnancy.\n\nUltrasound is generally regarded as a "safe test" because it does not use ionising radiation as in x-rays, nuclear medicine, or CT. But it is a form of energy, and scans should only be performed for a suitable medical indication by trained operators (sonographers). Scans performed for baby photos are considered by the profession to be unethical
515997
I can give you a nice one for this:\n\nIts called Sonoluminescence\n\nSonoluminescence is the emission of short bursts of light from imploding bubbles in a liquid when excited by sound.\n\nHistory\nThe effect was first discovered at the University of Cologne in 1934 as a result of work on sonar. H. Frenzel and H. Schultes put an ultrasound transducer in a tank of photographic developer fluid. They hoped to speed up the development process. Instead, they noticed tiny dots on the film after developing, and realized that the bubbles in the fluid were emitting light with the ultrasound turned on. It was too difficult to analyze the effect in early experiments because of the complex environment of a large number of short-lived bubbles. (This experiment is also ascribed to N. Marinesco and J.J. Trillat in 1933).\n\nMore than 50 years later, in 1989, a major advancement in research was introduced by Felipe Gaitan and Lawrence Crum, who were able to produce single bubble sonoluminescence (SBSL). In SBSL, a single bubble, trapped in an acoustic standing wave, emits a pulse of light with each compression of the standing wave. This technique allowed a more systematic study of the phenomenon, because it isolated the complex effects into one stable, predictable bubble. It was realized that the temperature inside the bubble was hot enough to melt steel. Interest in sonoluminescence was renewed when an inner temperature of such a bubble well above one megakelvin was postulated. This temperature is thus far not conclusively proven, though recent experiments conducted by the University of Illinois at Urbana-Champaign measured the temperature at about 20,000 kelvins or 20 kilokelvin.\n\n\nProperties\nSonoluminescence may or may not occur whenever a sound wave of sufficient intensity induces a gaseous cavity within a liquid to quickly collapse. This cavity may take the form of a pre-existing bubble, or may be generated through a process known as cavitation. Sonoluminescence in the laboratory can be made to be stable, so that a single bubble will expand and collapse over and over again in a periodic fashion, emitting a burst of light each time it collapses. For this to occur, a standing acoustic wave is set up within a liquid, and the bubble will sit at a pressure anti-node of the standing wave. The frequencies of resonance depend on the shape and size of the container in which the bubble is contained.\n\nSome facts about sonoluminescence:\n\nThe light flashes from the bubbles are extremely short—between 35 and a few hundred picoseconds long. \nThe bubbles are very small when they emit the light—about 1 micrometre in diameter. \nSingle-bubble sonoluminescence pulses can have very stable periods and positions. In fact, the frequency of light flashes can be more stable than the rated frequency stability of the oscillator making the sound waves driving them. \nFor unknown reasons, the addition of a small amount of noble gas (such as helium, argon, or xenon) to the gas in the bubble increases the intensity of the emitted light dramatically. \nThe wavelength of emitted light is very short; the spectrum can reach into the ultraviolet. Light of shorter wavelengths has higher energy, and the measured spectrum of emitted light seems to indicate a temperature in the bubble of at least 20,000 kelvins, up to a possible temperature in excess of one megakelvin. Some estimates put the inside of the bubble at one gigakelvin .These estimates are based on models which cannot be verified at present, and may include too many unsupported assumptions.\n\nTemperatures this high make the study of sonoluminescence especially interesting for the possibility that it might produce a method for achieving thermonuclear fusion. If the bubble is hot enough, and the pressure in it is high enough, fusion reactions like those that occur in the Sun could be produced within these tiny bubbles. This possibility is sometimes referred to as bubble fusion. Recent experiments (2002,
272160
Leonardo da Vinci.  Not a scientist, per se, but he did explore scientific thought and was a remarkable engineer and inventor.  Fascinating guy.