There is a story about how Albert Einstein was traveling to universities, giving lectures on his famous theory of relativity. One day while on their way to a university,
The driver said:" Dr. Einstein, I've heard that lecture more than 30 times. I have learned it by heart and bet I could give it myself."
"Well, I'll give you the chance," said Einstein,
"They don't know me at the next school, so when we get there I'll put on your cap and you introduce yourself as me and give the lecture." Einstein continued.
At the hall, the driver gave Einstein's lecture so wonderfully that he didn't make any mistakes.
When he finished, he started to leave, but one of the professors stopped him and asked him a question which was very difficult. The aim of the question was not gaining knowledge but embarrassing Einstein.
The driver thought fast.
"The answer to that problem is so simple," he said,
"I'm surprised you have to ask me. In fact, to show you just how simple it is, I'm going to ask my driver to come up here and answer your question."!
Then Einstein stood up and gave an incredible answer to the question of that professor.
~ Moral of the story: No matter how genius you pretend to be, there is always someone who is more genius than you despite his position.
Today, the National Science Foundation (NSF) announced the detection of gravitational waves by the Laser Interferometer Gravitational-Wave Observatory (LIGO), a pair of ground-based observatories. But…what are gravitational waves?
Let us explain:
Gravitational waves are disturbances in space-time, the very fabric of the universe, that travel at the speed of light. The waves are emitted by any mass that is changing speed or direction. The simplest example is a binary system, where a pair of stars or compact objects (like black holes) orbit their common center of mass.
We can think of gravitational effects as curvatures in space-time. Earth’s gravity is constant and produces a static curve in space-time. A gravitational wave is a curvature that moves through space-time much like a water wave moves across the surface of a lake. It is generated only when masses are speeding up, slowing down or changing direction.
Did you know Earth also gives off gravitational waves? Earth orbits the sun, which means its direction is always changing, so it does generate gravitational waves, although extremely weak and faint.
What do we learn from these waves?
Observing gravitational waves would be a huge step forward in our understanding of the evolution of the universe, and how large-scale structures, like galaxies and galaxy clusters, are formed.
Gravitational waves can travel across the universe without being impeded by intervening dust and gas. These waves could also provide information about massive objects, such as black holes, that do not themselves emit light and would be undetectable with traditional telescopes.
Just as we need both ground-based and space-based optical telescopes, we need both kinds of gravitational wave observatories to study different wavelengths. Each type compliments the other.
Ground-based: For optical telescopes, Earth’s atmosphere prevents some wavelengths from reaching the ground and distorts the light that does.
Space-based: Telescopes in space have a clear, steady view. That said, telescopes on the ground can be much larger than anything ever launched into space, so they can capture more light from faint objects.
How does this relate to Einstein’s theory of relativity?
The direct detection of gravitational waves is the last major prediction of Einstein’s theory to be proven. Direct detection of these waves will allow scientists to test specific predictions of the theory under conditions that have not been observed to date, such as in very strong gravitational fields.
In everyday language, “theory” means something different than it does to scientists. For scientists, the word refers to a system of ideas that explains observations and experimental results through independent general principles. Isaac Newton’s theory of gravity has limitations we can measure by, say, long-term observations of the motion of the planet Mercury. Einstein’s relativity theory explains these and other measurements. We recognize that Newton’s theory is incomplete when we make sufficiently sensitive measurements. This is likely also true for relativity, and gravitational waves may help us understand where it becomes incomplete.
*** GALILEO – Î’ULLET / MISSILE THEORY - NEWTON : if you shoot (horizontally and straight to the target) with a gun G3 kneeling or lying a target at 300 meters, given that the bullet runs with 800 m / sec , at 1/3 sec the bullet goes to the center of the target and it has not gone down (having a greater range). (I've done it personally hitting the center of the target with 10 continious bullets). If you leave it from the same small height it takes again 1/3 sec the most to reach the ground. (The same happens to a space without air -air resistance- , except that there the target must be put a little farther or a little closer than 300 meters since the speed changes a little). Thus the Galileo proposal that a body that is pushed horizontally will fall to the ground at the same time with a body that is vertically left to fall at the same time from the same height , is not exactly correct but it is quite statistic and has to do with a rather weak push. Further on the basis of Galileo – Newton , in the fall of bodies, the vertical distance is proportional (analogic) to the square of the time since Galileo let objects to fall to the ground from a ski slope : when the body left the ski slope it traveled a horizontal distance (the shadow of which in the ground is the time of the drop) , and also it traveled a vertical distance (which is the distance between the edge of the ski slope and the ground) and this distance is the space of the fall. However , if we select a different – bigger ski slope with much larger vertical length (in the same distance from the ground as before) we shall see that the horizontal vector-time-shadow will be bigger than before because the body in the ski slope has taken much more speed than before. So the analogy is rather ruined. Therefore we see that the physics of proposals (calculus Principia propositions) of Galileo - Newton (F = G mM / r2 , etc.) is a good and reasonable statistical technical approach that weakens in bigger conditions. THE TRUE MAN IS THE MEASURE OF ALL FLUID THINGS.
*** ΑΒΟUT THE ACCELERATION ¨ further , simply put , Galileo's acceleration a =S/t2 means that '' a body moves with eg 4 m/1sec2 '' (ie 1 sec squared). This means that '' the body in 1 sec is moving at 4 m/sec '' or that '' in the end of 1 sec the body covers 4 m in 1 sec i.e. 0,4 min 0,1 sec as momentum speed''. However (since as we said if we choose another Galileo ski slope the Galileo square analogy in time would not be exactly correct) -since the momentum ιnstantaneous speed is fluid , it could be said that : '' at the end of 1 sec the body covers 0 ,4 m in 0.1 sec at the end of which 0.1 sec the body covers 0,04 m in 0,01 sec '' and the acceleration could be defined as a =S/t3 ie 4m/1sec3 (ie sec cubed and not squared). Thus other equations should also be changed. Eg the equation of Galileo for the ''average speed' of an accelerated body S =(1/2)at2 has to do not only with the acceleration of gravity ''G = 9,8 m / sec2'' but also with any other acceleration even larger , so it also could be cubed instead of squared. (Even if we accept the Galileo square , the truth is that a falling accelarating body does not easily accept a definition of a stable ''average speed'' 5m / sec , because if in the first sec it has traveled 5 m, in the 2nd sec it will have traveled much greater distance , for example at least 20 m. And if we put the cube in the acceleration equation it would be even bigger with obvious consequences in the Newtonian ''F = GmM/r2''. So we are talking about rather fluid and calculus type equations that do not involve much wider and bigger conditions.
Trully if you accept ''average speed'' 5m/sec = in 1 sec 5 m , you cannot easilly accept ''average speed'' 20m/2 sec=10m/sec=in 1 sec 10 m , so it is all statistic and fluid.
Trully if you accept ''average speed'' 5m/sec = in 1 sec 5 m , you cannot easilly accept ''average speed'' 20m/2 sec=10m/sec=in 1 sec 10 m , so it is all statistic and fluid. The most famous guy for straight smooth movement is the u =S / T. The guy who gave himself Galileo to express the average speed of an accelerated college is x = (1/2) a t2, whom I have. As I mentioned the guy under the galilean concerns expression of the average speed of an accelerated college and no rectilinear smooth movement (U= s / T) neither of the acceleration (a =S / T2). If in a mean in acceleration put the g so the acceleration due to gravity 9,8 m / sec2, we get 5 M IN 1 SEC AND 20 M IN 2 sec so we have an expression of the average speed for A falling body as follows: average speed of 5 M IN 1 sec and average speed of 20 metres in 2 sec and average speed of 45 M IN 3 SEC, etc.
A black hole is a region of space time with a very strong gravitational force that even the light cannot escape from the inside of a black hole. Black hole can as big as millions of sun together or as small as a atom. Here is a list of 10 crazy facts about black holes.
1. Black holes decide the number of stars in the galaxies
Some scientists believe, the number of stars in the universe are limited by the number of black holes in our universe.
2. Laws of physics don’t work at the center of a black hole
According to some theories, a black hole is crush matter to infinite density. When this happens, the laws of physics break down because it is not possible to conceive of anything with a zero volume & infinite density.
3. Any matter like Iron can become a black hole
Most people believe that stars are the only things that can convert into black holes. If your car were shrunk down to a infinite small point and still able to retained all of their mass, Its density would reach tremendous levels which would make its force of gravity strong enough to become a black hole.
4. Dense
To pull light into itself a black hole should have enough gravity. Black hole has to contain a enormous amount of mass in a small space.
5. Albert Einstein did’t discovered the black holes
Albert Einstein only revived a theory about black holes in 1916. In 1783, John Mitchell was the one who developed the theory after he wondered if its possible that a gravitational force could be so strong that even particles of light couldn’t escape from it.
6. Different kinds of black holes
Modern astronomers and scientists believe that black holes come in different types. There are spinning black holes and electrical black holes and also the spinning electrical black holes.
7. You’ll be killed in horrible way near a black hole
Although it obvious that a black hole will probably kill you, most people think they would just get crushed by the black hole. But that isn’t true, your body would most likely get stretched to death.
8. Black holes do spin
When collapses of the core of a star happens, the star start rotating faster and faster and also becomes smaller and smaller. But then it reaches the point where it doesn’t have much amount mass to convert into a black hole, it gets squeezed together and form a neutron star and also continues to spin rapidly. Same thing applies to black holes.
9. Massive black hole at the center of the Milky Way galaxy
The one in the center of the Milky Way is one of the biggest discovered yet. It’s 30,000 light years away from us and is more than 30 million times massive than our sun.
10. Black hole near to the Earth
The nearest black hole to our earth is 1,600 light years away.
