Thursday, May 6, 2010

We're Back !!!

Sorry folks for such a long wait...
The truth is that i had exams and so couldn't post on the blog but now i am back
:D
Now something about relativity:

Ten little known facts about relativity:
(1) Nothing in the known universe travels faster than a bad check.
(2) Energy equals milk chocolate square (attributed to Albert E. Hersey)
(3) Delivery of Christmas gifts by Santa to the children of the world is now accomplished by riding Rudolf the red-shift reindeer.
(4) The general relativity theory of gravitation is responsible for people falling in love.
(5) The speed of an IRS tax refund is constant.
(6) Anger is neither created nor conserved but only changed from one form to another.
(7) The speed of time is one second per second, which is also called the fundamental unity.
(8) Death and taxes are the same for all constantly moving observers.
(9) Moving midgets are shortened.
(10) Divorce and alimony are equivalent but the latter is multiplied by an enormous factor.

Friday, March 26, 2010

Wacky Physicists !!!

image for Particle Physics Is It Fun Einstein thought it was fun.
We report on a recent seminar given at FermiLab by the acclaimed particle physicist, Prof. H. Wonky Legg, the content of which will allow you, the reader, to judge whether particle physics is fun, or just downright daft.

Good morning! In this talk I would like to show some results from the di-parton Drell Yan working group on Higgs weak neutralino studies, who have been working in collaboration with the Arthur Negus Centre for Large Massive Bodies at the University of Upper Wangoby in Tonga.

(first slide shows graph with clouds of points and red lines, annotated in greek letters)

In this slide I show the comdingly mass pairs of frothing di-quarks derived from the parton sea off the coast of Zimbabwe. You will notice the steeply falling Higgs cross-section as a function of chocolate biscuits.

(second slide, shows a photo of Nicole Kidman in the buff)

My collaborators insisted I show this slide.

(third slide, shows a set of formulae featuring large omegas and other lesser-known Greek letters, with numerous subscripts)

It is trivial to show, as seen here, that the upper bound on the tri-muon cross-section for production of sleptons is not unadjacent to the value obtained by adding the age of Mikhail Gorbachev to the number of seconds since the Big Bang.

(fourth slide, shows a photo of a large dildo disappearing inside a moss-lined tunnel)

My collaborators also insisted I show this slide.

(fifth slide, with one word Conclusions)

In summary, if we ignore the minimum bias wing nuts, the oscillating bubble tea, the large edifice recently found on Titan, and the overwhelming evidence for the intelligent life of coffee pots, we conclude that a maximum of one doughnut should be eaten in any given week. Thankyou.

(polite applause.)

Questions

(From the audience)

You bastard! You failed to acknowledge my work on flip flops!

(The speaker)

That work is discredited and you, sir, are a cad and a bounder. Step outside!

(Seminar breaks up into warring factions, with each group wielding their weapon of choice e.g. avocado seeds, gobstoppers and pine cones.)
http://www.youtube.com/watch?v=yupIM0WNPxw

Friday, March 19, 2010

hOPE u all are fine. From June 2010 onwards there's a change in our STATEMENT OF RESULT and our PERCENTAGE GRADES, kindly if you want more info so please download pdf file from (it also contain dummy result sheet)

http://ask.cie.org.uk/system/selfservice.controller?CMD=VIEW_ARTICLE&EXPANDED_TOPIC_TREE_NODES=&USERTYPE=1&ARTICLE_ID=64341&USEFUL_ITEM=USEFUL_ITEM&CONFIGURATION=1035&PARTITION_ID=1&TIMEZONE_OFFSET=null

and you can see this change from Cambridge.

Thankx ..
have a nice day

Tuesday, March 9, 2010

Funny Physics Story

This hilarious story gave me some chuckles:

The following concerns a question in a physics degree exam at the University of Copenhagen: Describe how to determine the height of a skyscraper with a barometer.

One student replied: You tie a long piece of string to the neck of the barometer, then lower the barometer from the roof of the skyscraper to the ground. The length of the string plus the length of the barometer will equal the height of the building.

This highly original answer so incensed the examiner that the student was failed immediately. He appealed on the grounds that his answer was indisputably correct, and the university appointed an independent arbiter to decide the case. The arbiter judged that the answer was indeed correct, but did not display any noticeable knowledge of physics. To resolve the problem, it was decided to call the student in and allow him six minutes in which to provide a verbal answer which showed at least a minimal familiarity with the basic principles of physics. For five minutes the student sat in silence, forehead creased in thought. The arbiter reminded him that time was running out, to which the student replied that he had several extremely relevant answers, but couldn’t make up his mind which to use. On being advised to hurry up the student replied as follows:

Firstly, you could take the barometer up to the roof of the skyscraper, drop it over the edge, and measure the time it takes to reach the ground. The height of the building can then be worked out from the formula H =0.5g x t squared. But bad luck on the barometer.

Or if the sun is shining you could measure the height of the barometer, then set it on end and measure the length of its shadow. Then you measure the length of the skyscraper’s shadow, and thereafter it is a simple matter of proportional arithmetic to work out the height of the skyscraper.

But if you wanted to be highly scientific about it, you could tie a short piece of string to the barometer and swing it like a pendulum, first at ground level and then on the roof of the skyscraper. The height is worked out by the difference in the gravitational restoring force T = 2 pi square root (l / g).

Or if the skyscraper has an outside emergency staircase, it would be easier to walk up it and mark off the height of the skyscraper in barometer lengths, then add them up.

If you merely wanted to be boring and orthodox about it, of course, you could use the barometer to measure the air pressure on the roof of the skyscraper and on the ground, and convert the difference in millibars into feet to give the height of the building.

But since we are constantly being exhorted to exercise independence of mind and apply scientific methods, undoubtedly the best way would be to knock on the janitor’s door and say to him €˜If you would like a nice new barometer, I will give you this one if you tell me the height of this skyscraper’.

The student was Nils Bohr, the only Dane to win the Nobel prize for Physics. -)

Thursday, March 4, 2010

Quotes that make you go WOW !!!

“PHYSICS” is the discipline of Science dealing with the properties of matter and energy. Includes; acoustics, atomic physics, cryogenics, electromagnetism, elementary particle physics, fluid dynamics, geophysics, mathematical physics, mechanics, molecular physics, nuclear physics, optics, plasma physics, quantum physics, solid state physics, statistical mechanics, thermodynamics.

It is a science that deals with matter and energy and their actions upon each other in the fields of aeronautics, electricity, heat, light, mechanics, and sound. Physics (from the Greek, "natural", "nature") is the science of Nature in the broadest sense.

Physicists study the behavior and properties of matter in a wide variety of contexts, ranging from the sub-nuclear particles from which all ordinary matter is made (particle physics) to the behavior of the material Universe as a whole (cosmology). The physics quotes describe the vastness of one of the most important forms or disciplines of Science called Physics. These quotes or sayings may be the beliefs of some of the most famous scientists of the world describing the relevance of this science in our day to day lives.

I ask you to look both ways. For the road to a knowledge of the stars leads through the atom; and important knowledge of the atom has been reached through the stars.
Sir Arthur Eddington

All science is either physics or stamp collecting.
Ernest Rutherford

In physics, your solution should convince a reasonable person. In math, you have to convince a person who's trying to make trouble. Ultimately, in physics, you're hoping to convince Nature. And I've found Nature to be pretty reasonable.
Frank Wilczek

It is impossible to trap modern physics into predicting anything with perfect determinism because it deals with probabilities from the outset.
Sir Arthur Eddington

When you are courting a nice girl an hour seems like a second. When you sit on a red-hot cinder a second seems like an hour. That's relativity.
Albert Einstein

When you sit with a nice girl for two hours, you think it's only a minute. But when you sit on a hot stove for a minute, you think it's two hours. That's relativity.
Albert Einstein

Not only is the universe stranger than we imagine, it is stranger than we can imagine.
Sir Arthur Eddington

When a man sits with a pretty girl for an hour, it seems like a minute. But let him sit on a hot stove for a minute-and it's longer than any hour. That's relativity.
Albert Einstein

When forced to summarize the general theory of relativity in one sentence: Time and space and graviton have no separate existence from matter.
Albert Einstein

I am acutely aware of the fact that the marriage between mathematics and physics, which was so enormously fruitful in past centuries, has recently ended in divorce.
Freeman John Dyson

God does not care about our mathematical difficulties. He integrates empirically.
Albert Einstein

Something unknown is doing we don't know what.
Sir Arthur Eddington

I think that a particle must have a separate reality independent of the measurements. That is an electron has spin, location and so forth even when it is not being measured. I like to think that the moon is there even if I am not looking at it.
Albert Einstein

Put your hand on a hot stove for a minute, and it seems like an hour. Sit with a pretty girl for an hour, and it seems like a minute. That's relativity.
Albert Einstein

We have found a strange footprint on the shores of the unknown. We have devised profound theories, one after another, to account for its origins. At last, we have succeeded in reconstructing the creature that made the footprint. And lo! It is our own.
Sir Arthur Eddington

God does not play dice
Albert Einstein

I don't believe in mathematics.
Albert Einstein

Physics tells us All !!!

  • The crippling of individuals I consider the worst evil of capitalism. Our whole educational system suffers from this evil. An exaggerated competitive attitude is inculcated into the student, who is trained to worship material success as a preparation for his future career. Albert Einstein (1879 - 1955)
  • There is only one road to human greatness: through the schools of hard knocks. Albert Einstein (1879 - 1955)
  • I am enough of an artist to draw freely upon my imagination. Imagination is more important than knowledge. Knowledge is limited. Imagination encircles the world. Albert Einstein (1879 - 1955)
  • With fame I become more and more stupid, which of course is a very common phenomenon. Albert Einstein (1879 - 1955)
  • Of all the communities available to us, there is not one I would want to devote myself to except for the society of the true seekers, which has very few living members at any one time. Albert Einstein (1879 - 1955)
  • Imagination is more important than knowledge. For knowledge is limited , wheras imagination embraces the entire world, stimulating progress, giving birth to evolution. Albert Einstein (1879 - 1955)
  • I have never looked upon ease and happiness as ends in themselves- such an ethical basis I call the ideal of a pigsty…The ideals which have guided my way, and time after time have given me the energy to face life, have been Kindness, Beauty and Truth. Albert Einstein (1879 - 1955)
  • Although I am a typical loner in my daily life, my awareness of belonging to the invisible community of those who strive for truth, beauty, and justice has prevented me from feelings of isolation. Albert Einstein (1879 - 1955)
  • I never worry about the future. It comes soon enough. Albert Einstein (1879 - 1955)
  • In the last analysis everyone is a human being, whether he is an American or a German, a Jew or a Gentile. If it were possible to hold only this worthy point of view, I would be a happy man. Albert Einstein (1879 - 1955)
  • Astatine is an element so rare that if you searched the entire planet you’d only find a lump the size of a sugar cube.
  • When a flea jumps, the rate of acceleration is 20 times that of the space shuttle during launch.
  • The maximum speed that raindrops can fall at is around 18mph, depending on their size.
  • If every star in the Milky Way was a grain of salt they would fill an Olympic sized swimming pool.
  • 12 Astronauts have walked on the moon, between them bringing back 382 kilograms of rocks, pebbles, sand and dust.
  • Whales talk to each other by making a loud clicking noise. The sound waves travel extremely well underwater and they can hear each other from 100 miles away.
  • A TV screen shows 24 pictures a second. Because a fly sees 200 images a second, it would see TV as still pictures with darkness in between.
  • Cats can see clearly in one-sixth the amount of light we humans would need. This is due to a special layer of cells at the back of their retinas, which acts like a mirror, reflecting light back to the retina's cells.
  • In 1936 Professor Alfred Gaydon underwent surgery on his eyes after an accident. When his sight began to return he found that he could see ultra-violet light, which is normally beyond the visible spectrum of humans. This helped in his work as a physicist, but it did distort how he saw other colours!
  • Because of thermal expansion the Eiffel Tower is 15cm taller in summer.
  • Some people who have two or more different kinds of fillings in their teeth are able to hear high-power AM broadcast stations when located within a few hundred feet of the stations. In such cases, the strong radio waves act upon the teeth fillings in such a way that the electromagnetic oscillations get transformed to mechanical vibrations in the person's head, and these are heard as sound.
  • The amount of sunlight reaching the earth's surface is 6,000 times the amount of energy used by all human beings worldwide. The total amount of fossil fuel used by humans since the start of civilization is equivalent to less than 30 days of sunshine.
  • Tree crickets are called the poor man's thermometer because temperature directly affects their rate of activity. Count the number of chirps a cricket makes in 15 seconds, then add 37. The sum will be very close to the outside temperature in farenheit!
  • The highest temperature ever recorded at the South Pole was minus 13 degrees centigrade.
  • If our Sun were just inch in diameter, the nearest star would be 445 miles away.
  • If the Sun were the size of a beach ball then Jupiter would be the size of a golf ball and the Earth would be as small as a pea.
  • Neutron stars are so dense that a teaspoonful would weigh more than all the people on Earth!
  • On average, airliners will get struck by lightning once every year.
  • You weigh less if you stand at the equator than if you stood at the north pole. This is because the equator is actually further away from the centre of the earth, so the force of gravity is less.
  • Engineers at NASA claim to have made the loudest noise ever: of 210 decibels. This is so loud that it can make holes in solid materials.
  • The mass of the Earth increases every year because of 3,000 tonnes of meteorite debris that hits its surface from space.
  • Who choked on their own invention? Hubert Cecil Booth, the inventor of the vacuum cleaner. In testing how it would work, he was sucking dirt by mouth through a piece of material and ended up with a lungful of dust!
  • The microwave oven was invented by accident, when Percy Spencer found that his chocolate bar had been melted by an experiment he was running on radar systems. He immediately started experimenting successfully on microwaved popcorn.
  • A supernova is the most energetic single event known in the Universe. Material is exploded into space at about 10,000 kilometres per second. All the stars in our galaxy (about 100,000,000,000) would have to shine for six months to produce the amount of energy released by just one supernova.
  • The planet Venus’s day is longer than its year. It takes 225 ‘Earth’ days to rotate around the Sun (a Venusian year) and 243 ‘Earth’ days to rotate on its axis (a Venusian day).
  • It takes the energy output of at least one power station to keep the traffic lights in the British Isles operating.
  • One kilogram of butter stores as much energy between its atoms as the same quantity of TNT.
  • Men are six times more likely to be struck by lightning than women.
  • IBM's ASCI white supercomputer, the fastest computer in the world, weighs as much as 17 elephants and can do in one second what a calculator would take 10 million years to do.
  • Do astronauts burp? Because you are weightless in space, the contents of your stomach float and tend to stay at the top of your stomach, under the rib cage and close to the valve at the top of your stomach. Because this valve isn't a complete closure (just a muscle that works with gravity), if you burp, it becomes a wet burp from the contents in your stomach. Gross!
  • The Moon is gradually moving away from the Earth and the tides are to blame. Every year, the Moon moves a further 3.82cm from the Earth.
  • Gold leaf is pure gold, but you can cover large areas with it very cheaply because it is very thin. Gold leaf is less than 0.00008 millimeters thick - which is only about 300 atoms thick.
  • Every rainbow is unique - each rainbow is formed from light hitting your eye at a very precise angle. Someone standing next to you will see light coming from a slightly different angle than you and therefore see a different rainbow.
  • A bolt of lightning contains enough energy to toast 160,000 pieces of bread. Unfortunately the bolt only takes 1/10,000 of a second – so turning the bread over might prove difficult.
  • If 10 kilograms of matter spontaneously turned into energy there would be enough energy to power a 100 Watt light bulb for 300 million years - a harrowing thought for all weight watchers.

Saturday, February 27, 2010

101 Physics facts

    Mechanics

  1. Weight (force of gravity) decreases as you move away from the earth by distance squared.
  2. Mass and inertia are the same thing.
  3. Constant velocity and zero velocity means the net force is zero and acceleration is zero.
  4. Weight (in newtons) is mass x acceleration (w = mg). Mass is not weight!
  5. Velocity, displacement [s], momentum, force and acceleration are vectors.
  6. Speed, distance [d], time, and energy (joules) are scalar quantities.
  7. The slope of the velocity-time graph is acceleration.
  8. At zero (0) degrees two vectors have a resultant equal to their sum. At 180 degrees two vectors have a resultant equal to their difference. From the difference to the sum is the total range of possible resultants.
  9. Centripetal force and centripetal acceleration vectors are toward the center of the circle- while the velocity vector is tangent to the circle.
  10. An unbalanced force (object not in equilibrium) must produce acceleration.
  11. The slope of the distance-tine graph is velocity.
  12. The equilibrant force is equal in magnitude but opposite in direction to the resultant vector.
  13. Momentum is conserved in all collision systems.
  14. Magnitude is a term use to state how large a vector quantity is.


  15. Energy

  16. Mechanical energy is the sum of the potential and kinetic energy.
  17. Units: a = [m/sec2], F = [kg•m/sec2] (newton), work = pe= ke = [kg•m2/sec2] (joule)
  18. An ev is an energy unit equal to 1.6 x 10-19 joules
  19. Gravitational potential energy increases as height increases.
  20. Kinetic energy changes only if velocity changes.
  21. Mechanical energy (pe + ke) does not change for a free falling mass or a swinging pendulum. (when ignoring air friction)
  22. The units for power are [joules/sec] or the rate of change of energy.


  23. Electricity

  24. A coulomb is charge, an amp is current [coulomb/sec] and a volt is potential difference [joule/coulomb].
  25. Short fat cold wires make the best conductors.
  26. Electrons and protons have equal amounts of charge (1.6 x 10-19 coulombs each).
  27. Adding a resistor in parallel decreases the total resistance of a circuit.
  28. Adding a resistor in series increases the total resistance of a circuit.
  29. All resistors in series have equal current (I).
  30. All resistors in parallel have equal voltage (V).
  31. If two charged spheres touch each other add the charges and divide by two to find the final charge on each sphere.
  32. Insulators contain no free electrons.
  33. Ionized gases conduct electric current using positive ions, negative ions and electrons.
  34. Electric fields all point in the direction of the force on a positive test charge.
  35. Electric fields between two parallel plates are uniform in strength except at the edges.
  36. Millikan determined the charge on a single electron using his famous oil-drop experiment.
  37. All charge changes result from the movement of electrons not protons (an object becomes positive by losing electrons)


  38. Magnetism

  39. The direction of a magnetic field is defined by the direction a compass needle points.
  40. Magnetic fields point from the north to the south outside the magnet and south to north inside the magnet.
  41. Magnetic flux is measured in webers.
  42. Left hands are for negative charges and right hands are for positive charges.
  43. The first hand rule deals with the B-field around a current bearing wire, the third hand rule looks at the force on charges moving in a B-field, and the second hand rule is redundant.
  44. Solenoids are stronger with more current or more wire turns or adding a soft iron core.


  45. Wave Phenomena

  46. Sound waves are longitudinal and mechanical.
  47. Light slows down, bends toward the normal and has a shorter wavelength when it enters a higher (n) value medium.
  48. All angles in wave theory problems are measured to the normal.
  49. Blue light has more energy. A shorter wavelength and a higher frequency than red light (remember- ROYGBIV).
  50. The electromagnetic spectrum (radio, infrared, visible. Ultraviolet x-ray and gamma) are listed lowest energy to highest.
  51. A prism produces a rainbow from white light by dispersion (red bends the least because it slows the least).
  52. Light wave are transverse (they can be polarized).
  53. The speed of all types of electromagnetic waves is 3.0 x 108 m/sec in a vacuum.
  54. The amplitude of a sound wave determines its energy.
  55. Constructive interference occurs when two waves are zero (0) degrees out of phase or a whole number of wavelengths (360 degrees.) out of phase.
  56. At the critical angle a wave will be refracted to 90 degrees.
  57. According to the Doppler effect a wave source moving toward you will generate waves with a shorter wavelength and higher frequency.
  58. Double slit diffraction works because of diffraction and interference.
  59. Single slit diffraction produces a much wider central maximum than double slit.
  60. Diffuse reflection occurs from dull surfaces while regular reflection occurs from mirror type surfaces.
  61. As the frequency of a wave increases its energy increases and its wavelength decreases.
  62. Transverse wave particles vibrate back and forth perpendicular to the wave direction.
  63. Wave behavior is proven by diffraction, interference and the polarization of light.
  64. Shorter waves with higher frequencies have shorter periods.
  65. Radiowaves are electromagnetic and travel at the speed of light (c).
  66. Monochromatic light has one frequency.
  67. Coherent light waves are all in phase.


  68. Geometric Optics

  69. Real images are always inverted.
  70. Virtual images are always upright.
  71. Diverging lens (concave) produce only small virtual images.
  72. Light rays bend away from the normal as they gain speed and a longer wavelength by entering a slower (n) medium {frequency remains constant}.
  73. The focal length of a converging lens (convex) is shorter with a higher (n) value lens or if blue light replaces red.


  74. Modern Physics

  75. The particle behavior of light is proven by the photoelectric effect.
  76. A photon is a particle of light {wave packet}.
  77. Large objects have very short wavelengths when moving and thus can not be observed behaving as a wave. (DeBroglie Waves)
  78. All electromagnetic waves originate from accelerating charged particles.
  79. The frequency of a light wave determines its energy (E = hf).
  80. The lowest energy state of a atom is called the ground state.
  81. Increasing light frequency increases the kinetic energy of the emitted photo-electrons.
  82. As the threshold frequency increase for a photo-cell (photo emissive material) the work function also increases.
  83. Increasing light intensity increases the number of emitted photo-electrons but not their KE.


  84. Internal Energy

  85. Internal energy is the sum of temperature (ke) and phase (pe) conditions.
  86. Steam and liquid water molecules at 100 degrees have equal kinetic energies.
  87. Degrees Kelvin (absolute temp.) Is equal to zero (0) degrees Celsius.
  88. Temperature measures the average kinetic energy of the molecules.
  89. Phase changes are due to potential energy changes.
  90. Internal energy always flows from an object at higher temperature to one of lower temperature.


  91. Nuclear Physics

  92. Alpha particles are the same as helium nuclei and have the symbol .
  93. The atomic number is equal to the number of protons (2 for alpha)
  94. Deuterium () is an isotope of hydrogen ()
  95. The number of nucleons is equal to protons + neutrons (4 for alpha)
  96. Only charged particles can be accelerated in a particle accelerator such as a cyclotron or Van Der Graaf generator.
  97. Natural radiation is alpha (), beta () and gamma (high energy x-rays)
  98. A loss of a beta particle results in an increase in atomic number.
  99. All nuclei weigh less than their parts. This mass defect is converted into binding energy. (E=mc2)
  100. Isotopes have different neutron numbers and atomic masses but the same number of protons (atomic numbers).
  101. Geiger counters, photographic plates, cloud and bubble chambers are all used to detect or observe radiation.
  102. Rutherford discovered the positive nucleus using his famous gold-foil experiment.
  103. Fusion requires that hydrogen be combined to make helium.
  104. Fission requires that a neutron causes uranium to be split into middle size atoms and produce extra neutrons.
  105. Radioactive half-lives can not be changed by heat or pressure.
  106. One AMU of mass is equal to 931 meV of energy (E = mc2).
  107. Nuclear forces are strong and short ranged.


  108. General

  109. The most important formulas in the physics regents are:
  110. Physics is fun. (Honest!)

Fun Facts !!!

The Roman poet Lucretius (ca. 94–ca. 55 B.C.) wrote a poem in 56 B.C. describing the views of Greek philosophers who, like him, thought the universe to be composed of atoms. This poem is the only record of the beliefs of these early atomists, whose works were lost due to their unpopular views. Lucretius' poem was lost as well, but in 1417, however, a copy was discovered. Its views helped to persuade chemists to consider the atomic theory of matter, a theory that won out eventually.

In 1903, Albert Michelson, one of the 19th century's top physicists, commented "The more important fundamental laws and facts of physical science have all been discovered, and these are so firmly established that the possibility of their ever being supplemented in consequence of new discoveries is exceedingly remote". Two years later, Einstein published his revolutionary Theory of Special Relativity.

The Ancient Greek philosopher Thales noticed that amber decorations on spinning wheels attracted threads, feathers, and other objects through what we now know to be static electricity. The Greek word for amber is elektron, from which William Gilbert, physician to Queen Elizabeth I, coined the word "electricity".

In 1905 Albert Einstein wrote his famous Special Theory of Relativity. It was published in a scientific journal that same year, but took many years to gain general acceptance. In fact, it was not verified by actual experiment until 25 years later. Two years after that paper was published, Einstein wanted a job as assistant professor of mathematics. This job required the applicant to submit a thesis paper, so Einstein submitted his Special Theory of Relativity. The university rejected it.

The quark, a building block of the proton, got its name from James Joyce's Finnegans Wake, from the line "Three quarks for Muster Mark! Sure he hasn't got much of a bark". [

According to the laws of gravity, the moon technically does not orbit the Earth. The two bodies actually both orbit around their common centre of gravity, which is located 1,000 miles beneath the surface of the Earth and is on a straight line between the centres of the Earth and moon. The centre of the Earth makes a small circle around that centre of gravity every 27 1/3 days. [

According to the rules of logic, the question "What would happen if an irresistible force met an immovable object?" is meaningless. In a universe where one of the above conditions exists, by definition the other cannot exist.

A "light year" is a measure of distance, not time. It is defined as the distance light travels in one year. Light moves at a velocity of about 300,000 kilometres each second, so in one year, it travels about 9,500,000,000,000 kilometres. [

To the nearest ten-thousandth of a mile, light travels at 186,282.3959 miles per second. At that rate, it takes slightly more than eight minutes to get to Earth from the sun. However, it takes light hundreds of years to travel from the sun's centre to its surface. The light must take a very indirect path to the surface due to the large number of collisions with particles within the sun.

In 1940, the Tacoma Narrows Bridge (popularly known as "Galloping Gertie"), which spanned the Puget Sound south of Seattle, opened. At the time it was the third longest bridge in the world and narrower than any comparably-sized bridges. Although the bridge was criticized for being too slender, Leon Moisseiff, the consulting engineer to the project and an expert on suspension bridges, assured people that the bridge would be safe. However, only three months after it opened, the bridge collapsed in a 42 mph wind after going into harmonic oscillation.

An atomic clock kept at the National Bureau of Standards in Boulder, Colorado, U.S.A., 1650 metres above sea level, gains about five microseconds each year relative to an identical clock kept at the Royal Greenwich Observatory, 25 metres above sea level. The reason is that gravity gets stronger as one gets closer to the Earth's core, and, according to Einstein's Theory of Relativity, time is slower in stronger gravitational fields.

A perpetual motion machine would violate the laws of thermodynamics. No-one has ever built one, and no-one ever will.

According to the Second Law of Thermodynamics, the amount of entropy in the universe always increases, which means that eventually, the universe must run down and life in the universe will cease.

Information about what has fallen into a black hole is stored on the event horizon of a black hole. Recent calculations by the folks who study quantum gravity theory and superstrings have confirmed what Stephen Hawking and his collaborators proposed a decade or more ago. Evidently, the information contained in matter that falls into a black hole is by some curious means encoded in the pattern of frozen quantum fields at the horizon. This raises some interesting possibilities that we could resurrect clocks, humans, spacecraft, and whole planets into something like their pristine form if we could magically reverse the in-fall and collapse process. Many believe that this mathematical result means that we have reached a watershed moment in history in understanding the connection between quantum mechanics and gravitation theory. Quantum mechanics deals with statements about the information that we can extract about a quantum mechanical process involving observation. Now this same information language can be applied to configurations of the gravitational field and space-time itself. [

Light has weight. The weight of sunlight on the earth's surface has been determined to be two pounds per square mile.

The sky is blue because of refraction. The sun's light is of all colours of the rainbow, mixed together to make white light. The reds and yellows pass through air easily, but some of the blue portion of sunlight is scattered in every direction by air molecules. This scattering causes the sky to be blue.

An article in the April 26, 1993 article of Physical Review Letters, titled "First Measurement of the Left-Right Cross-Section Asymmetry in the Boson Production by e+ e- Collisions", had 407 authors.

Can you hear in space? In theory, if there is nothing to receive the sound, there is no sound. Because there are no "air waves" in space to conduct the sound, it would not carry. So, the object would make a noise, but it would not carry to any receiver, and no one would hear it. [

There is sound in space. What is sound? It is a pressure wave. So long as you have some kind of gaseous medium, you will have the possibility of forming pressure waves in it by "shocking" it in some way. In space, the interplanetary medium is a very dilute gas at a density of about 10 atoms per cubic centimeter, and the speed of sound in this medium is about 300 kilometers per second. Typical disturbances due to solar storms and "magneto-sonic turbulence" at the Earth's magnetopause have scales of hundreds of kilometers, so the acoustic wavelengths are enormous. Human ears would never hear them, but we can technologically detect these pressure changes and play them back for our ears to hear by electronically compressing them. [

Since the 1950s, physicists have discovered over 200 different kinds of particles.

The difference between the appearance of a real object and its reflection in a mirror is that the clockwise and counterclockwise directions are switched.

Newton's Third Law of Motion states that for every action there is an equal and opposite reaction.

When an airplane travels at a speed faster than sound, density waves of sound emitted by the plane accumulate in a cone behind the plane. When this shock wave passes, a listener hears a sonic boom.

It is not known exactly what gravity is. We can define what it is as a field of influence, and with general relativity we can define a language which states that it is a property of our real world that is mathematically equivalent to not just the geometry of space-time, but equivalent to space-time itself. Some think that it is made up of particles called gravitons, which flit about at the speed of light just as photons do. In any true fundamental sense, we do not know what gravity is, we only know how it operates in various corners of our universe. Without gravity, there would be no space and time.

Around one percent of the static on a television set tuned between stations is a relic of the Big Bang.

Ordinary matter consists almost entirely (99.9999999999999%) of empty space.

Bell's Theorem states that certain measurements made on one particle can instantaneously affect the measurements made on a second particle that, in theory, could have been removed to the opposite side of the galaxy, with no physical connection between the two.

The size of Earth is roughly the geometric mean of the size of the universe and the size of an atom, and the mass of a human is roughly the geometric mean of the mass of Earth and the mass of the proton.

Interesting Facts of Physics

E=mc2


1.The effect of Relativity made Astronaut Sergei Avdeyev a fraction of a second younger upon his return to Earth after 747 days in space. Submitted by: Moi - Canada

Dead Sea

2.The Dead Sea is so dense with salt, you can easily float on it without drowning.

Lake Baikal

3.Lake Baikal in Russia contains more water than all the North American Great Lakes combined.

black ironwood tree

4.The world's densest wood, the Black Ironwood (Olea laurifolia), does not float on water and therefore sinks.

5.The mass of our entire atmosphere is estimated to be some 5.5 quadrillion tons (55 followed by 14 zeros).

6.Chewing gum was invented by a dentist, named William Semple - as a way to exercise your jaws.

7.The diameter of a proton is approximately 0.000000000001 mm (1/25,000,000,000,000 inch).

diamond

8.You can convert graphite into diamond by applying a temperature of 3000 Celsius and pressure of 100,000 atm.

9.The amount of water beneath our ground soil is 50 times as much as all the water in the rivers and lakes combined.

10.The first ten feet of the ocean hold as much heat as the Earth's entire atmosphere.

lightning bolt

11.The lightning bolt is 3 times hotter than the sun. Submitted by: Jieian

12.On average, our bodies constantly resist an atmospheric pressure of about 1 kilogram per square inch.

mariana trench

13.The deepest location on Earth is Mariana Trench, about 11km deep in the North Pacific ocean.

Redwood tree

14.The bark of the redwood tree is fireproof.

Everest in ocean at Mariana Trench

15.If Mount Everest were placed at the bottom of the deepest part of the ocean, its peak would still be a mile underwater. Submitted by: Nikhil, India

16.If given the same mass, our body would actually be hotter than the sun. Submitted by: Eddy - United States

wormhole

17.Many physicists believe wormholes (a "shortcut" through space and time) exist all around us but they are smaller than atoms. Submitted by: Jay - United States

mojave desert

18.A solar panel 100 miles by 100 miles (161x161km) in the Mojave Desert (USA) could replace all the coal now burned to generate electricity in the entire U.S.

19.The Atlantic Ocean grows at about the same rate as your fingernails.

20..If you yelled for 8 years, 7 months and 6 days, you would have produced just enough sound energy to heat up one cup of coffee.

21.The average ice berg weighs 20,000,000 tons.

lightning

22.Lightning strikes about 6,000 times per minute on our planet.

23.A gallon of water weighs 8.34 pounds (3.8kg).

24.If an item moves very, very fast, it becomes smaller and heavier.

25.Minus 40 degrees Celsius is exactly the same temperature as minus 40 degrees Fahrenheit.

26.Hot water freezes quicker than cold water.

Pumice floating

27.The only rock that floats in water is pumice.

28.Mexico City is sinking at a rate of 18 inches (46cm) per year as a result of draining water.

29.1 inch (25mm) of rain water is equivalent to 15 inches (381mm) of dry, powdery snow.

largest meteorite crater

30.The oldest and largest clearly visible meteorite crater site in the world is The Vredefort Dome in Free State, South Africa. It is 380km across.

31.The greatest tide change on earth occurs in the Bay of Fundy. The difference between low tide and high tide can be as great as 16.6 meters (54 ft.)

32.The temperature in fahrenheit can be determined by counting the number of cricket chirps in 14 seconds and adding 40.

33.The average ocean floor is about 3,600 meters deep (12000ft).

34.Sunlight can penetrate clean ocean water to a depth of 73 meters (240ft.)

35.The North Atlantic gets 2.5 centimetres (1in) wider every year.

36.Hawaii is moving toward Japan 10 centimetres (4 inches) every year.

37.Due to gravitational effects, you weigh slightly less when the moon is directly overhead.

Lake Baikal

38.Lake Baikal is the deepest lake in the world.

39.When hydrogen burns in the air, water is formed.

diamond
40.Diamonds are the hardest known substance.