We all know that freezing point of water is 32℉(0℃), which means that the liquid freezes, but sometimes science goes crazy. Supercooling, also know as undercooling, is this concept and means that if you go to a certain low temperature, a liquid will not turn into a solid. Pure water normally freezes at 32 F, but the temperature of supercooling pure water is -55℉(-48.3℃). Droplets of supercooled water often appear in cumulus clouds and stratiform.
A liquid below its freezing point will crystallize in the presence of a seed crystal or nucleus around which a crystal structure can form. However, lacking any such nucleus, the liquid phase can be maintained all the way down to the temperature at which crystal homogeneous nucleation occurs. The homogeneous nucleation can occur above the glass transition where the system is an amorphous—that is, non-crystalline—solid.
If cooled at a rate on the order of 106 K/s, the crystal nucleation can be avoided and water becomes a glass.
If you totally did not understand was was states above, here is the vocabulary section.
Vocabulary
Stratiform - Stratus Cloud
Crystallize - to form in crystals
Seed - nucleus
Nucleation - to form (something) in the nucleus
Amorphous - no particular shape
They form into ice when they are struck by the wings of passing airplanes and abruptly crystallize. Freezing Rain is also caused by supercooled droplets. Some plants are able to supercool the fluid in their cells cytosol and vacuole and thereby survive temperatures down to −40 °C.
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The other concept we will be talking about is pretty much the opposite of supercooling, it is superheating. You might of guessed what it is. We know when you have a pan, add water to it, and heat it up to 212℉, you have boiling point, but it is just like supercooling. Superheating is when you heat it enough to not boil but at a high temperature. In other words, superheating is when you heat something in a chamber, setting the temperature above 212℉, and it will boil, but no water vapor is emitted. If something is say 500 degrees superheat, that means that no water vapor can be present at this pressure by 100 degrees. But some pressure is applied or needed.Superheating is achieved by heating a humongous substance in a clean container, free of nucleation sites, while taking care not to disturb the liquid.A liquid is sometimes observed not to boil even though its vapor pressure does exceed the ambient pressure. The cause is an additional force, the surface tension, which suppresses the growth of bubbles.
Now you can introduce to your friends what superheating and supercooling is, hope you have fun!
Sunday, November 27, 2011
Saturday, November 26, 2011
Electrons
We will today discover the details of the electron and how important it is.
The electron is a subatomic particle that carries a negative charge or a single unit of negative electrivity.
Electrons
We know all mater consists of atoms that contain three subatomic particles known as: protons, neutrons, and electrons. Of these three particles, only the electron are to be fundamental particles that is incapable of being broken down into simpler particles. The absence or presence of an excess of electrons is responsible for all electrical phenomena. It makes most of everything that we know, with the proton and neutron. Suppose you look at a battery, you see a plus and a minus, well that tells you.
Energy
The nucleus of an atom is the part consisting of the protons and neutrons. The size of the nucleus is many thousands of times smaller than the size of the whole atom. Electrons are distributed in specific regions outside the nucleus. At one time, scientist thought that electron traveled in very specific pathways around the nucleus, similar to the orbits of the planets in the solar system.
Vocabulary
Energy Level - A region of the atom in which there is a high probability of finding electrons.
Positron - The antiparticle of the electron. It has the same mass and spin, but it charge, though equal in magnitude, is opposite in sign to that of the electron.
Electric current - A flow of electrons
The uncertainty principle, a fundamental law of physics, says that the pathway traveled by very small particles like an electron can never be defined perfectly. Instead, scientists now talk about the probability of finding an electron in an atom. In some regions of the atom, that probability is very high, although never 100 percent, and in other regions it is very low, but never 0 percent. The regions in space where the probability of finding an electron is high corresponds roughly to the orbits about which scientists talked earlier. Those regions are now called energy levels.
Properties
Electrons have three properties, charge, mass, and spin. By definition, the electric charge on an electron is -1. The mass of an electron is 9.109389 x 10^-31 kilograms. Electrons spin on their axis. Spinning , electrons, with a moving electric charge, create a magnetic field around them. This always changes the way the arrange themselves and how they react with each other in atoms.
History and Discovery
In the 1800's, scientist made made a few important basic discoveries about electrical phenomena. But no one could explain the fundamental nature of electricity. In 1897, English Physicist J. J. Thomson that discovered the electron. He showed that the flow of the electric current consisted of individual particles. Thomson obtained the same result using a number of materials and concluded these particles (electrons) are present in all forms of matter. The name of the particles had been suggested a few years earlier by Irish physicist George Johnstone Stoney.Although Thomson was able to measure the ratio of electric charge of mass (e/m) for an electron, he did not know how to determine either of these two quantities individually. That problem puzzled physicists for more than a decade. Finally, the riddle was solved by American physicist Robert Andrew Millikan (1868–1953) in a series of experiments conducted between 1907 and 1913. The accompanying figure outlines the main features of Millikan's famous oil drop experiment.
The oil drops needed for the experiment are produced by a common squeeze-bulb atomizer. The tiny droplets formed by this method fall downward and through the hole in the upper plate under the influence of gravity. As they fall, the droplets are given a negative electric charge. Once droplets enter the space between the two plates, the highvoltage source is turned on. The negatively charged oil droplets are then attracted upward by the positive charge on the upper metal plate. At this point, the droplets are being tugged by two opposite forces: gravity, pulling them downward, and an electrical force, pulling them upward. By carefully adjusting the voltage used, Millikan was able to keep oil droplets suspended in space between the two plates. Since the droplets moved neither upward or downward, he knew that the gravitational force on the droplets was exactly matched by the electric force. From this information, he was able to calculate the value of the electric charge on a droplet. The result he obtained, a charge of 1.591 × 10−10 coulomb, is very close to the value accepted today of 1.602177 × 10−19 coulomb. (The coulomb is the standard metric unit of electrical charge.)
Electron MailHow would you send a letter to an electron? As strange as that question seems, electrons have "addresses," just as people do. Think of an oxygen atom, for example. Every oxygen atom has eight electrons. But those eight electrons are all different from each other. The differences among the eight electrons are represented by quantum numbers. A quantum number is a number that describes some physical property of an object (in this case, of an electron). We know that any electron can be completely described by stating four of its properties. Those properties are represented by four different quantum numbers represented by the letters n, ℓ, mℓ, and s. Quantum number n, for example, represents the distance of an electron from the nucleus. Any electron for which n = 1 is in the first orbit around the nucleus of the atom. Quantum number ℓ represents the shape of the electron's orbit, that is, how flattened out its orbit is. Quantum number mℓ represents the magnetic properties of the electron. And quantum number s represents the spin of the electron, whether it's spinning in a clockwise or counter-clockwise direction. So if you decide to send a letter to electron X, whose quantum numbers are 3, 2, 0, + ½, you know it will go to an electron in the third orbit, with a flattened orbital path, certain magnetic properties, and a clockwise spin.
Positron
Dirac's prediction was confirmed only two years after he announced his hypothesis. American physicist Carl David Anderson (1905–1991) found positively charged electrons in a cosmic ray shower that he was studying. Anderson called these particles positrons, for positive electrons. Today, scientists understand that positrons are only one form of antimatter, particles similar to fundamental particles such as the proton, neutron, and electron, but with one property opposite to that of the fundamental particle. One of the interesting detective stories in science involves the discovery of an electron-type particle called the positron. During the 1920s, English physicist Paul Dirac (1902–1984) was using the new tools of quantum mechanics to analyze the nature of matter. Some of the equations he solved had negative answers. Those answers troubled him since he was not sure what a negative answer—the opposite of some property—could mean. One way he went about explaining these answers was to hypothesize the existence of a twin of the electron. The twin would have every property of the electron itself, Dirac said, except for one: it would carry a single unit of positive electricity rather than a single unit of negative electricity.
Spheres and Circles
We will be talking about sphere and circles, probably the most mysterious shapes of geometry, but it the shape with the most definitions and concepts. There is a lot to remember.
Definition
A circle can be defined as a closed curved line on which every point is equally distant from a fixed point within it.
Vocabulary
Diameter - A straight line that goes from the other side, through the center of the circle.
Radius - Half of the diameter.
Circumference - the length around the circle, or the perimeter of the circle
Arc - Any portion of the curved line around the circle (circumference).
Chord - A straight line inside the circle joining the two end points of an arc .
Circumference,Volume, Area, and π
What is π (Pi)? Pi is the ratio of the circumference of a circle to its diameter. The approximation of Pi is 3.1416. On a calculator, if you have the pi button, put that in, but usually put 3.1416. This relates strongly to the circle. The area of the circle is πr^2. You multiply π by the radius squared. The circle in the third dimension is called the sphere. Volume is the area of something, but in three dimensions. With that, the volume of the sphere is (4/3) x π x radius ^3 . You multiply 4/3 by π, you multiply that by pi, and also multiply it by the radius cubed. You will strongly need to know these concepts. The circumference of a circle is π x d (diameter) which is extremely useful. The circumference also equals 2π x r (radius).
Honors for Calculating Pi
5th - Professor Yasumasa Kanada & a nine man team in 600 hours, at the Department of Information Science in the University of Tokyo, Japan, calculated 1,241,100,000,000 digits of π on November 24, 2002
4th - Professor Daisuke Takahashi, using the T2K Open Supercomputer, single node speed is 147.2 gigaflops, 29.2 hours, computer memory of 13.5 TB, Guass-Legendre Algorithm, Center for Computational Science at the University of Tsukuba in Tsukuba, Japan, calculated 2,576,980,377,524 digits of π on April 29th, 2009.
3rd - Fabrice Bellard used Coe i7 CPU at 2.93 GHz with a 7.5 TB of disk storage using five 1.5 TB hard disks. The computation of the binary digits was 103 days and the verification of the binary digits took 13 days. Farbice conversion to base 10 took 12 days. 131 days in total - The verification of the binary digits used a network of 9 Desktop PCs durig 34 hours, Chudnovsky algorithm, for Bellard's homepage. The final calculation was 2,699,999,990,000 decimal places on December 31, 2009.
2nd - Shigeru Kondo used the y-cruncher by Alexander Yee. The Chudnovsky formula was used for the main computation. The verification used the Bellard and Plouffe formulas on different computers, both computed 32 hexadecimal digits ending with the 4,152,410,118,610th. The computatio of binary digits took 80 days, the conversino to base 10 take 8.2 days, and the verificaiton of the conversion: 45.6 hours. The verification of the binary digits to 64 hours (primary), 66 hours (secondary). The total time was 90 days. Shigeru Kondo ended with figuring out 5,000,000,000,000 digits of π on August 2, 2010.
1st - This was also done by Shigeru Kondo also using the y-cruncher by Alexander Yee. The computation took 371 days and the verification day 1.86 days and 4.94 days. The total time was 371 days. It computed 10,000,000,000,000 digits of π on October 17, 2011.
More Digits
3.141592653589793238462643383279502884197169399375105820974944592307816406286 208998628034825342117067982148086513282306647093844609550582231725359408128481 117450284102701938521105559644622948954930381964428810975665933446128475648233 786783165271201909145648566923460348610454326648213393607260249141273724587006 606315588174881520920962829254091715364367892590360011330530548820466521384146 951941511609433057270365759591953092186117381932611793105118548074462379962749 567351885752724891227938183011949129833673362440656643086021394946395224737190 702179860943702770539217176293176752384674818467669405132000568127145263560827 785771342757789609173637178721468440901224953430146549585371050792279689258923 542019956112129021960864034418159813629774771309960518707211349999998372978049 951059731732816096318595024459455346908302642522308253344685035261931188171010 003137838752886587533208381420617177669147303598253490428755468731159562863882 353787593751957781857780532171226806613001927876611195909216420198938095257201 065485863278865936153381827968230301952035301852968995773622599413891249721775 283479131515574857242454150695950829533116861727855889075098381754637464939319 255060400927701671139009848824012858361603563707660104710181942955596198946767 837449448255379774726847104047534646208046684259069491293313677028989152104752 162056966024058038150193511253382430035587640247496473263914199272604269922796 782354781636009341721641219924586315030286182974555706749838505494588586926995 690927210797509302955321165344987202755960236480665499119881834797753566369807 426542527862551818417574672890977772793800081647060016145249192173217214772350 141441973568548161361157352552133475741849468438523323907394143334547762416862 518983569485562099219222184272550254256887671790494601653466804988627232791786 085784383827967976681454100953883786360950680064225125205117392984896084128488 626945604241965285022210661186306744278622039194945047123713786960956364371917 287467764657573962413890865832645995813390478027590099465764078951269468398352 595709825822620522489407726719478268482601476990902640136394437455305068203496 252451749399651431429809190659250937221696461515709858387410597885959772975498 930161753928468138268683868942774155991855925245953959431049972524680845987273 644695848653836736222626099124608051243884390451244136549762780797715691435997 700129616089441694868555848406353422072225828488648158456028506016842739452267 467678895252138522549954666727823986456596116354886230577456498035593634568174 324112515076069479451096596094025228879710893145669136867228748940560101503308 617928680920874760917824938589009714909675985261365549781893129784821682998948 722658804857564014270477555132379641451523746234364542858444795265867821051141 354735739523113427166102135969536231442952484937187110145765403590279934403742 007310578539062198387447808478489683321445713868751943506430218453191048481005 370614680674919278191197939952061419663428754440643745123718192179998391015919 5618146751426912397489409071864942319615679452080951465502252316038819301420937621
What is π (Pi)? Pi is the ratio of the circumference of a circle to its diameter. The approximation of Pi is 3.1416. On a calculator, if you have the pi button, put that in, but usually put 3.1416. This relates strongly to the circle. The area of the circle is πr^2. You multiply π by the radius squared. The circle in the third dimension is called the sphere. Volume is the area of something, but in three dimensions. With that, the volume of the sphere is (4/3) x π x radius ^3 . You multiply 4/3 by π, you multiply that by pi, and also multiply it by the radius cubed. You will strongly need to know these concepts. The circumference of a circle is π x d (diameter) which is extremely useful. The circumference also equals 2π x r (radius).
Honors for Calculating Pi
5th - Professor Yasumasa Kanada & a nine man team in 600 hours, at the Department of Information Science in the University of Tokyo, Japan, calculated 1,241,100,000,000 digits of π on November 24, 2002
4th - Professor Daisuke Takahashi, using the T2K Open Supercomputer, single node speed is 147.2 gigaflops, 29.2 hours, computer memory of 13.5 TB, Guass-Legendre Algorithm, Center for Computational Science at the University of Tsukuba in Tsukuba, Japan, calculated 2,576,980,377,524 digits of π on April 29th, 2009.
3rd - Fabrice Bellard used Coe i7 CPU at 2.93 GHz with a 7.5 TB of disk storage using five 1.5 TB hard disks. The computation of the binary digits was 103 days and the verification of the binary digits took 13 days. Farbice conversion to base 10 took 12 days. 131 days in total - The verification of the binary digits used a network of 9 Desktop PCs durig 34 hours, Chudnovsky algorithm, for Bellard's homepage. The final calculation was 2,699,999,990,000 decimal places on December 31, 2009.
2nd - Shigeru Kondo used the y-cruncher by Alexander Yee. The Chudnovsky formula was used for the main computation. The verification used the Bellard and Plouffe formulas on different computers, both computed 32 hexadecimal digits ending with the 4,152,410,118,610th. The computatio of binary digits took 80 days, the conversino to base 10 take 8.2 days, and the verificaiton of the conversion: 45.6 hours. The verification of the binary digits to 64 hours (primary), 66 hours (secondary). The total time was 90 days. Shigeru Kondo ended with figuring out 5,000,000,000,000 digits of π on August 2, 2010.
1st - This was also done by Shigeru Kondo also using the y-cruncher by Alexander Yee. The computation took 371 days and the verification day 1.86 days and 4.94 days. The total time was 371 days. It computed 10,000,000,000,000 digits of π on October 17, 2011.
More Digits
3.141592653589793238462643383279502884197169399375105820974944592307816406286 208998628034825342117067982148086513282306647093844609550582231725359408128481 117450284102701938521105559644622948954930381964428810975665933446128475648233 786783165271201909145648566923460348610454326648213393607260249141273724587006 606315588174881520920962829254091715364367892590360011330530548820466521384146 951941511609433057270365759591953092186117381932611793105118548074462379962749 567351885752724891227938183011949129833673362440656643086021394946395224737190 702179860943702770539217176293176752384674818467669405132000568127145263560827 785771342757789609173637178721468440901224953430146549585371050792279689258923 542019956112129021960864034418159813629774771309960518707211349999998372978049 951059731732816096318595024459455346908302642522308253344685035261931188171010 003137838752886587533208381420617177669147303598253490428755468731159562863882 353787593751957781857780532171226806613001927876611195909216420198938095257201 065485863278865936153381827968230301952035301852968995773622599413891249721775 283479131515574857242454150695950829533116861727855889075098381754637464939319 255060400927701671139009848824012858361603563707660104710181942955596198946767 837449448255379774726847104047534646208046684259069491293313677028989152104752 162056966024058038150193511253382430035587640247496473263914199272604269922796 782354781636009341721641219924586315030286182974555706749838505494588586926995 690927210797509302955321165344987202755960236480665499119881834797753566369807 426542527862551818417574672890977772793800081647060016145249192173217214772350 141441973568548161361157352552133475741849468438523323907394143334547762416862 518983569485562099219222184272550254256887671790494601653466804988627232791786 085784383827967976681454100953883786360950680064225125205117392984896084128488 626945604241965285022210661186306744278622039194945047123713786960956364371917 287467764657573962413890865832645995813390478027590099465764078951269468398352 595709825822620522489407726719478268482601476990902640136394437455305068203496 252451749399651431429809190659250937221696461515709858387410597885959772975498 930161753928468138268683868942774155991855925245953959431049972524680845987273 644695848653836736222626099124608051243884390451244136549762780797715691435997 700129616089441694868555848406353422072225828488648158456028506016842739452267 467678895252138522549954666727823986456596116354886230577456498035593634568174 324112515076069479451096596094025228879710893145669136867228748940560101503308 617928680920874760917824938589009714909675985261365549781893129784821682998948 722658804857564014270477555132379641451523746234364542858444795265867821051141 354735739523113427166102135969536231442952484937187110145765403590279934403742 007310578539062198387447808478489683321445713868751943506430218453191048481005 370614680674919278191197939952061419663428754440643745123718192179998391015919 5618146751426912397489409071864942319615679452080951465502252316038819301420937621
Pulsars
If someone asked you what a pulsar is, you might have a idea, but, if you wanted a good definition of a pulsar a would read this post. You also probably know it's a star in space, but we will discuss details.
Basic Definition
A pulsar is a rapidly rotating-neutron star that emits brief "pulses" of energy, usually radio waves.
Discovery
Pulsars started at Cambridge university with Antony Hewish and his students built a radio telescope to study a scintillation effect on radio sources caused by clouds of electrons in the solar wind. In 1967, it quickly recorded a signal from a unexpected source. Jocelyn Bell Burnell notice a strong sparkling effect opposite the sun, when the affect was strong, and should have been weak.An improved recorder was installed, the signals were received again as a series of sharp pulses with intervals of about a second. In late 1968, it was clear Antony Hewish and his students had discovered a rotating neutron star, a remnant of a supernova, which we now called a pulsar.
Binary Pulsars
A binary pulsar is two stars that rotate each other and one of them is a neutron star. This was discovered by Russell A. Hulse and Joseph H. Taylor, who received and shared a physics Nobel Prize in 1993. With this, they tested the general theory of relativity. Several dozen binary pulsars are known in space. This bursting pulsar, another class of pulsars, is currently the strongest source of X rays and gamma rays in the sky.
Pulsars have a strong magnetic field and a lot of plasma, which means it has a large source of radio waves. The electrons (which have lots of energy) of the plasma orbit (,or spiral) around the magnetic field and emit radio waves and other types of waves from the electromagnetic spectrum.
Vocabulary
Synchrotron Radiation - Electromagnetic radiation emitted by a charged particle (normally an electron)
moving in a magnetic field at a velocity very close to that of light.
Gyrosynchrotron Radiation - Electromagnetic radiation emitted by a charged particle moving in a magnetic field at an appreciable fraction of the speed of light, this is similar to synchrotron radiation.
Cyclotron Radiation - Electromagnetic radiation emitted by a charged particle circling in a magnetic field substantially below the speed of light, and is also similar to gyrosynchrotron radiation.
Rotation-powered pulsars, where the loss of rotational energy of the star provides the power.
Acceration-powered pulsars - where the gravitation potienal energy of accreted matter is the power source (producing X-rays that are observable from the Earth).
Ratation-powered pulsars - Where the loss of rotational energy of the star provides the power.
More
This synchroton radiation is highly directional. Since 1968, more than 700 pulsars have been observed.The first pulsar with planets is currently SR BL257+12.
Pythagorean Theorem
If you are in highschool, you probably have heard of the Pythagorean Theorem. If you are in Elementary School, like me, you also might have heard of it, but was is it. Pythagoras (570-495 BC) was a mathematician, a (Ionian) Greek Philosopher, and founder of Pythogeranism, who changed mathematics forever.
Equation
His equation was you can figure out one side of a right-triangle with knowing the other two sides of the right-triangle.
If we said a was the base was a, b adjacent to a, and c the hypotenuse (the long side). If you squared a and added that to b squared you would get c squared.
(sqrt.= square root)
Giving that you would simplify that to this
c=√(a^2+b^2)
And if you wanted to figure out a you would write
a=√(c^2-b^2)
To figure out b you right
b=√(c^2-a^2)
This theorem contains more than 370 proofs inside of the book The Pythagorean Proposition. If you didn't already know this I hope you remember this, you will always need to know it.
You Try
Problem: If I had a triangle that a was 4 in. and b was 8 in. what is the measure of c? Post your answer in the comments.
Problem: If I had a triangle that a was 4 in. and b was 8 in. what is the measure of c? Post your answer in the comments.
Hourglasses, How they came to come
Introduction
An hourglass is a object used for measuring time with usually sand. There are many possibilities for how much time is holds. It's factors are: how much sand, what type of sand, diamter of the orifice, and the volume of the hourglass.Appearance
The hourglass is also known as the sandglass. It could have been introduced by 8-century monk named Luitprand. It was not after is while in the 1300's that the fresco Allegory of Good Government, while Temperance is holding a basic hourglass, in 1338 by Italian painter Ambrogio Lorenzetti (1290-1348).
Competition
The hourglass was popular during this time, it was better than the clepsydra, temperatures did not affect the hourglass, unlike the clepsydra.
In the eighteenth century Ferdinand Magellan had used 18 hourglasses per ship while he was circumnavigating the globe.
Formula
In 1996, a few British reasearchers from the University of Leicester found a equation on an hourglass. Ballotini gave good results for there formula for the time that it takes to fall (period).The aperature has to at least be 5 times the particle diameter. Here is the formula:
P=KV(D-d)^-2.5
P - Period
K - depends on the shape of the reservoir, the researchers found different values for K for conical container shapes and hourglass shapes.
V- bulk volume of the ballotini
d - maximum bead diameter in millimeters
D - the diamteter of the circular orifice in millimeters
Large Hourglasses
There was a 39ft. hourglass built in 2008 in Moscow, Russia. Charlemagne of France had a 12 hour hourglass which he enjoyed. Holbein, the artist, made a hourglass for Henry the VIII of England.
You Try!
This formula is helpful, but sort of hard to figure out. If you are good at math and have a opening/closing hourglass with ballotini, try it out!
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