4 jan. 2017/ learning physics Gravitational waves.

4 jan. 2017/ learning physics
Gravitational waves are ripples in the curvature of spacetime that propagate as waves at the speed of light, generated in certain gravitational interactions that propagate outward from their source. The possibility of gravitational waves was discussed in 1893 by Oliver Heaviside using the analogy between the inverse-square law in gravitation and electricity.^[1]
In 1905 Henri Poincaré first proposed gravitational waves (ondes gravifiques) emanating from a body and propagating at the speed of light as being required by the Lorentz transformations.^[2] Predicted in 1916^[3][4] by Albert Einstein on the basis of his theory of general relativity,^[5][6] gravitational waves transport energy as gravitational radiation, a form of radiant energy similar to electromagnetic radiation.^[7]
Gravitational waves cannot exist in the Newton's law of universal gravitation, since it is predicated on the assumption that physical interactions propagate at infinite speed.
Gravitational-wave astronomy is an emerging branch of observational astronomy which aims to use gravitational waves to collect observational data about objects such as neutron stars and black holes, events such as supernovae, and processes including those of the early universe shortly after the Big Bang.
Various gravitational-wave observatories (detectors) are under construction or in operation, such as Advanced LIGO which began observations in September 2015.^[8]
Potential sources of detectable gravitational waves include binary star systems composed of white dwarfs, neutron stars, and black holes.
On February 11, 2016, the LIGO Scientific Collaboration and Virgo Collaboration teams announced that they had made the first observation of gravitational waves, originating from a pair of merging black holes using the Advanced LIGO detectors.^[9][10][11]
On June 15, 2016, a second detection of gravitational waves from coalescing black holes was announced.^[12][13][14]

4 jan. 2017/ learning p[ysics. The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole.[2][3].

4 jan. 2017/ learning physics
The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole.^[2][3]


https//www.nyeinchansarpay.blogspot,com/maw

A black hole is a region of spacetime exhibiting such strong gravitational effects that nothing—not even particles and electromagnetic radiation such as light—can escape from inside it.^[1]
The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole.^[2][3]
The boundary of the region from which no escape is possible is called the event horizon. Although the event horizon has an enormous effect on the fate and circumstances of an object crossing it, no locally detectable features appear to be observed.
In many ways a black hole acts like an ideal black body, as it reflects no light.^[4][5]
Moreover, quantum field theory in curved spacetime predicts that event horizons emit Hawking radiation, with the same spectrum as a black body of a temperature inversely proportional to its mass.
This temperature is on the order of billionths of a kelvin for black holes of stellar mass, making it essentially impossible to observe.
Objects whose gravitational fields are too strong for light to escape were first considered in the 18th century by John Michell and Pierre-Simon Laplace.
The first modern solution of general relativity that would characterize a black hole was found by Karl Schwarzschild in 1916, although its interpretation as a region of space from which nothing can escape was first published by David Finkelstein in 1958.
Black holes were long considered a mathematical curiosity; it was during the 1960s that theoretical work showed they were a generic prediction of general relativity.
The discovery of neutron stars sparked interest in gravitationally collapsed compact objects as a possible astrophysical reality.
Black holes of stellar mass are expected to form when very massive stars collapse at the end of their life cycle.
After a black hole has formed, it can continue to grow by absorbing mass from its surroundings.
By absorbing other stars and merging with other black holes, supermassive black holes of millions of solar masses (M_☉) may form.
There is general consensus that supermassive black holes exist in the centers of most galaxies.
Despite its invisible interior, the presence of a black hole can be inferred through its interaction with other matter and with electromagnetic radiation such as visible light.
Matter that falls onto a black hole can form an external accretion disk heated by friction, forming some of the brightest objects in the universe.
If there are other stars orbiting a black hole, their orbits can be used to determine the black hole's mass and location.
Such observations can be used to exclude possible alternatives such as neutron stars.
In this way, astronomers have identified numerous stellar black hole candidates in binary systems, and established that the radio source known as Sagittarius A*, at the core of our own Milky Way galaxy, contains a supermassive black hole of about 4.3 million solar masses.
On 11 February 2016, the LIGO collaboration announced the first observation of gravitational waves; because these waves were generated from a black hole merger it was the first ever direct detection of a binary black hole merger.^[6] On 15 June 2016, a second detection of a gravitational wave event from colliding black holes was announced.^[7]

4 jan. 2017 Learning physics./Nuclear Binding Energy and the Mass Defect.

4 jan. 2017
Learning physics./Nuclear Binding Energy and the Mass Defect.
http://physics.bu.edu/~duffy/sc546_notes10/mass_defect.html

Nuclear Binding Energy and the Mass Defect

A neutron has a slightly larger mass than the proton.
These are often given in terms of an atomic mass unit, where one atomic mass unit (u) is defined as 1/12th the mass of a carbon-12 atom.

Particle	Mass (kg)	Mass (u)	Mass (Mev/c2)
1 atomic mass unit	1.660540 x 10-27 kg	1.000 u	931.5 MeV/c2
neutron	1.674929 x 10-27 kg	1.008664 u	939.57 MeV/c2
proton	1.672623 x 10-27 kg	1.007276 u	938.28 MeV/c2
electron	9.109390 x 10-31 kg	0.00054858 u	0.511 MeV/c2

Einstein's famous equation relates energy and mass:
E = mc²
You can use that to prove that a mass of 1 u is equivalent to an energy of 931.5 MeV.
Something should strike you as strange about the table above. The carbon-12 atom has a mass of 12.000 u, and yet it contains 12 objects (6 protons and 6 neutrons) that each have a mass greater than 1.000 u, not to mention a small contribution from the 6 electrons.
This is true for all nuclei, that the mass of the nucleus is a little less than the mass of the individual neutrons, protons, and electrons. This missing mass is known as the mass defect, and represents the binding energy of the nucleus.
The binding energy is the energy you would need to put in to split the nucleus into individual protons and neutrons.
To find the binding energy, add the masses of the individual protons, neutrons, and electrons, subtract the mass of the atom, and convert that mass difference to energy. For carbon-12 this gives:
Mass defect = Dm = 6 * 1.008664 u + 6 * 1.007276 u + 6 * 0.00054858 u - 12.000 u = 0.098931 u
The binding energy in the carbon-12 atom is therefore 0.098931 u * 931.5 MeV/u = 92.15 MeV.
In a typical nucleus the binding energy is measured in MeV, considerably larger than the few eV associated with the binding energy of electrons in the atom.
Nuclear reactions involve changes in the nuclear binding energy, which is why nuclear reactions give you much more energy than chemical reactions; those involve changes in electron binding energies.

3 jan. 2017 no matter how full your life may seem, there’s always room for a couple of Beers with a friend.

3 jan. 2017
  no matter how full your life may seem, there’s always room for a couple of Beers with a friend.

Tin Win Akbar shared Tribble Reese's photo.
https://www.facebook.com/photo.php?fbid=525979527419752&set=a.242726992411675.66946.234373109913730&type=1

A professor stood before his philosophy class and had some items in front of him.
When the class began, he wordlessly picked up a very large and empty mayonnaise jar and proceeded to fill it with golf balls. He then asked the students if the jar was full. They agreed that it was. The professor then picked up a box of pebbles and poured them into the jar. He shook the jar lightly. The pebbles roll ed into the open areas between the golf balls. He then asked the students again if the jar was full. They agreed it was. The professor next picked up a box of sand and poured it into the jar. Of course, the sand filled up everything else. He asked once more if the jar was full.. The students responded with a unanimous ‘yes.’ The professor then produced two Beers from under the table and poured the entire contents into the jar effectively filling the empty space between the sand.The students laughed.. ‘Now,’ said the professor as the laughter subsided, ‘I want you to recognize that this jar represents your life. The golf balls are the important things—-your family, your children, your health, your friends and your favorite passions—-and if everything else was lost and only they remained, your life would still be full. The pebbles are the other things that matter like your job, your house and your car.. The sand is everything else—-the small stuff. ‘If you put the sand into the jar first,’ he continued, ‘there is no room for the pebbles or the golf balls. The same goes for life. If you spend all your time and energy on the small stuff you will never have room for the things that are important to you. Pay attention to the things that are critical to your happiness. Spend time with your children. Spend time with your parents. Visit with grandparents. Take your spouse out to dinner. Play another 18. There will always be time to clean the house and mow the lawn. Take care of the golf balls first—-the things that really matter. Set your priorities. The rest is just sand. One of the students raised her hand and inquired what the Beer represented. The professor smiled and said, ‘I’m glad you asked.’ The Beer just shows you that no matter how full your life may seem, there’s always room for a couple of Beers with a friend.
A professor stood before his philosophy class and had some items in front of him. When the class began, he wordlessly picked up a very large and empty mayonnaise jar and proceeded to fill it with golf balls. He then asked the students if the jar was full. They agreed that it was. The professor then picked up a box of pebbles and poured them into the jar. He shook the jar lightly. The pebbles roll ed into the open areas between the golf balls. He then asked the students again if the jar was full. They agreed it was. The professor next picked up a box of sand and poured it into the jar. Of course, the sand filled up everything else. He asked once more if the jar was full.. The students responded with a unanimous ‘yes.’ The professor then produced two Beers from under the table and poured the entire contents into the jar effectively filling the empty space between the sand.The students laughed.. ‘Now,’ said the professor as the laughter subsided, ‘I want you to recognize that this jar represents your life. The golf balls are the important things—-your family, your children, your health, your friends and your favorite passions—-and if everything else was lost and only they remained, your life would still be full. The pebbles are the other things that matter like your job, your house and your car.. The sand is everything else—-the small stuff. ‘If you put the sand into the jar first,’ he continued, ‘there is no room for the pebbles or the golf balls. The same goes for life. If you spend all your time and energy on the small stuff you will never have room for the things that are important to you. Pay attention to the things that are critical to your happiness. Spend time with your children. Spend time with your parents. Visit with grandparents. Take your spouse out to dinner. Play another 18. There will always be time to clean the house and mow the lawn. Take care of the golf balls first—-the things that really matter. Set your priorities. The rest is just sand. One of the students raised her hand and inquired what the Beer represented. The professor smiled and said, ‘I’m glad you asked.’ The Beer just shows you that no matter how full your life may seem, there’s always room for a couple of Beers with a friend.

3 jan. 2017 Applying medicine where there is no injury. တလဲြဆံပင္ေကာင္းသလိုျဖစ္ေနျပီ ။

3 jan. 2017 Applying medicine where there is no injury.
တလဲြဆံပင္ေကာင္းသလိုျဖစ္ေနျပီ ။
laughter is the best medicine.


ဦးဝင္းနိုင္ဆိုသူစစ္ျပန္လူပိ် ုျကီးတဦးကို ေျပာင္ေလွာင္တတ္ေသာအဖိုးျကီးတဥိီးက (တလဲြဆံပင္ေကာင္းသလိုျဖစ္ေနျပီ)ဟုေျပာလိုက္ပါသည္္ ။

ဦးဝင္းနိုင္သည္နဖူးက်ယ္သူတဥိီးျဖစ္ပါသည္္ ။


Applying medicine where there is no injury.
တလဲြဆံပင္ေကာင္းသလိုျဖစ္ေနျပီ ။

3 jan. 2017 my missions

3 jan. 2017 my missions
are to protect environment; to enhance human rights; to grow trees; to give people the power to share and make the world more open and connected; this is exactly the sacred mission of every person; if our thoughts, words & deeds interfere or block free flow , we are committing ah ku sala dhamas "sins". Hla myint from mandalay with love.

30 dec. 2016 Learning physics./an inertial frame of reference.

30 dec. 2016 Learning  physics./an inertial frame of reference

In classical physics and special relativity, an inertial frame of reference (also inertial reference frame or inertial frame, Galilean reference frame or inertial space) is a frame of reference that describes time and space homogeneously, isotropically, and in a time-independent manner.^[1] The physics of a system in an inertial frame have no causes external to the system.^[2]
All inertial frames are in a state of constant, rectilinear motion with respect to one another; an accelerometer moving with any of them would detect zero acceleration. Measurements in one inertial frame can be converted to measurements in another by a simple transformation (the Galilean transformation in Newtonian physics and the Lorentz transformation in special relativity). In general relativity, in any region small enough for the curvature of spacetime and tidal forces^[3] to be negligible, one can find a set of inertial frames that approximately describe that region.^[4][5] Systems in non-inertial frames in general relativity don't have external causes because of the principle of geodesic motion.^[6]
Physical laws take the same form in all inertial frames.^[7] By contrast, in a non-inertial reference frame in classical physics and special relativity, the physics of a system vary depending on the acceleration of that frame with respect to an inertial frame, and the usual physical forces must be supplemented by fictitious forces.^[8][9] For example, a ball dropped towards the ground does not go exactly straight down because the Earth is rotating. Someone rotating with the Earth must account for the Coriolis effect—in this case thought of as a force—to predict the horizontal motion. Another example of such a fictitious force associated with rotating reference frames is the centrifugal effect, or centrifugal force.