Story of X-Rays.

 X-rays, like the light are electromagnetic radiations and are not visible to the eye. Their wavelengths are smaller than those of the visible light. They are high energy rays. That is why they have high penetrating power. They can pass through the flesh of our body. They travel with the velocity of light. 

X-Rays image of the human hand.

These rays were discovered by Prof. Wilhelm Conrad Roentgen in 1895. They are sometimes called 'Roentgen rays' also. They were called X-rays (X-means unknown) because these were not known earlier. For this wonderful discovery Prof. Roentgen was awarded the first Nobel Prize of Physics in 1901 .

Wavelength of the Electro-magnetic waves.

The apparatus used for producing X-rays is called 'X-rays tube'. This tube is made up of hard glass and is fitted with two electrodes which are connected to high voltage D.C. source. The electrode connected to the negative terminal is called cathode and the one connected to positive terminal is called anode. Low pressure is created inside the tube by pumping out air from it. When high voltage is applied between the electrodes, electrons emerge from the cathode and hit the 'anode' or the 'target'. As a result the X-rays come out of the tube. 

X-rays are very useful for us. They can pass through substances like wood, paper, skin, flesh etc. but are absorbed by bones, iron,lead etc. Doctors make use of X-rays to detect the dislocations and fractures of bones. They are also used to examine the diseases of lungs and presence of stones in kidneys and gall bladder. X-rays are allowed to fall on the body part to be examined and a photograph is taken on the photo film kept behind that part. In this film the portion of bones appears grey. From these X-ray photographs, the disease and defects are located easily. 

X-rays are also used in treating cancer. With the help of these rays, gold and other valuable gems hidden in the body are detected easily. They are also used to detect cracks and bubbles in the iron bars used for constructing bridges and buildings. They are used to study the structure of crystals. With these rays, it is very easy to distinguish between natural and synthetic diamonds.  

What are Infra-red Radiations?

We all know that the sunlight consists of all those colours which are seen in a rainbow. These colours are: violet, indigo, blue, green, yellow, orange and red. Light from the sun travels in the form of waves which are known as electromagnetic waves. The different colours of light have different wavelengths. Our eyes are sensitive only to the wavelengths relating to the above seven colours. Apart from the wavelengths of these seven colours, the sunlight consists of radiations of other wavelengths also, but our eyes are not sensitive to them. Rays having wavelengths higher than that of red light are called infra-red rays and those lower than violet light are called ultraviolet rays. Both infra-red and ultraviolet rays are not visible to our eyes.

Spectral Lines.

Infra-red rays come not only from the sun but from every hot object. Burning wood and coal, electric heater-all produce these rays. These can be recorded on special type of photographic films made of infra-red sensitive materials. Whenever these rays fall on any material body they produce heat. They are very useful to us. 

Wavelength 

Wavelength of Infrared Radiation.

Infra-red radiations are being used for the treatment of several diseases. Special types of infra-red lamps are used for treating the pains of muscles and joints-especially for backpain. They are also used for heating rooms in winter.

Animals Pictures taken under IR Camera.

Infra-red radiations are being used for the guidance and control of missiles and other ballistic weapons. These radiations are also used for transmitting and receiving invisible signals. Molecular structures are studied with the help of these radiations. Impurities present in the materials can also be detected by these rays. 

Light, The Visible Reminder of Invisible Light ---John Green--- 

 Why Does Milk Appear in White Colour?  

Milk and curd looks white when we seen in the sunlight but they appears red in red light and blue in blue light. Have you ever wondered? Why its happens? If you don't know follow my blog page for more curious science thoughts. 

We all know that the sunlight is a mixture of seven colours. There are:  Violet, Indigo, Blue, Green, Yellow, Orange & Red. The colours of the sun light can be separated with the help of a prism. The coloured an object depends upon the colour that reaches our eyes after reflection from the object. 

Colour of an objects depends upon the reflected light. 

 

What ever colour is reflected by the object, is the colour of the that object. The molecular structure of milk and curd is such that they do not absorb any of the colours of the sunlight but reflected all of them, Thus these substances appear white. When milk and curd are viewed in red light, they look red because red colour is reflected by them. The same argument holds good for the colours of the other objects also. 

Colors! What A Deep And Mysterious Language, The Language Of Dreams.   -Paul Gauguin. 

Discovery of Radium:

Radium is one the of the few elements that constantly emit invisible radiations. Such elements are called radioactive elements and the radiations they emits are called "radioactive" rays.

Radium Metal

 There are three types of radioactive rays-alpha, beta and gamma. Radium, due to the emission of the radioactive rays, disintegrates and finally gets converted into lead. Half of this radioactive element gets converted into lead in 1622 years. 

This is called the 'half life' of the radioactive element. In the next 1622 years, half of the remaining substance decays into lead. This process continues indefinitely. The radioactive rays are so powerful that they can pass through different kinds of substances including the human body. These rays are very useful in the treatment of cancer. Do you know who discovered radium?

Marie Curie 

All the credit of the discovery of radium goes to a married couple, Pierre Curie and Marie Curie. The story of its discovery is very interesting.

In 1896 Henri Becquerel discovered the phenomenon of radioactivity. He found that the uranium emits a kind of invisible radiations which are even more powerful than the X-rays. Pierre Curie and Marie Curie, in 1898, also found that thorium also emits similar radiations. They also thought that pitchblende, which is the ore of uranium, must contain some other radioactive substance too. 

 They started refining pitchblende in order to obtain the new radioactive element. They had to work in a tin-shed because they could not afford a proper laboratory on account of limited means. Without caring for rains and storms, they worked day and night Finally, they succeeded in extracting 100 milligrams of radium from several tons of pitchblende. They found that this new element was much more powerful than uranium.

Pure radium is white in colour. It is quite heavy and thousands of times costlier than gold. The quantity of pure radium available in the world is very small. Radioactive rays are very harmful to the body. If handled carelessly its radioactive rays can wound the body. So be careful guys. 

"Nuclear Power Is One Hell Of A Way To Boil Water" - Albert Einstein.

The Cosmological Difficulties of Newton's Theory

There is a second fundamental difficulty attending classical celestial mechanics, which, was first discussed in detail by the Astronomer Seeliger. If we ponder over the question as to how the universe, considered as a whole, is to be regarded, the first answer that suggests itself to us is surely this: As regards space and time, the universe is infinite. There are stars everywhere, so that the density of matter, although very variable in detail, is nevertheless on the average everywhere the same. In other words: However far we might travel through space.  

This view is not in harmony with the theory of Newton. The latter theory rather requires that the universe should have a kind of centre in which the density of the stars is a maximum, and that as we proceed outwards from this centre the group density of the stars should diminish, until finally, at great distances, it is succeeded by an infinite region of emptiness. The stellar universe ought to be a finite island in the infinite ocean of space.   

According to the theory of Newton, the number of "lines of force" which come from infinity and terminate in a mass m is proportional to the mass m. If, on the average, the Mass density p° is constant throughout the universe, then a sphere of volume V will enclose the average man p°V. Thus the number of lines of force passing through the surface F of the sphere into its interior is proportional to p°V. For unit area of the surface of the sphere the number of lines of force which enters the sphere is thus proportional to p°V/ For to p°R. Hence the intensity of the field at the surface would ultimately become infinite with increasing radius R of the sphere, which is impossible. 

 

This conception is in itself not very satisfactory. It is still less satisfactory because it leads to the result that the light emitted by the stars and also individual stars of the stellar system are perpetually passing out into infinite space, never to return, and without ever again coming into interaction with other objects of nature. Such a finite material universe would be destined to become gradually but systematically impoverished.  

In order to escape this dilemma, Seeliger suggested a modification of Newton's law, in which he assumes that for great distances the force of attraction between two masses diminishes more rapidly than would result from the inverse square law. In this way it is possible for the mean density of matter to be constant everywhere, even to infinity, without infinitely large gravitational fields being produced. We thus free ourselves from the distasteful conception that the material universe ought to possess something of the nature of a centre. Of course we purchase our emancipation from the fundamental difficulties mentioned, at the cost of a modification and complication of Newton's law which has neither empirical nor theoretical foundation. We can imagine innumerable laws which would serve the same purpose, without our being able to state a reason why one of them is to be preferred to the others; for any one of these laws would be founded just as little on more general theoretical principles as is the low of Newton...    

" All Knowledge And Understanding Of The Universe Was No More Than Playing With Stones And Shells On The Seashore Of The Vast Impondérable Ocean Of Truth. "    

                                      — Isaac Newton.   

The Four Fundamental Forces in Physics.

 The Four Fundamental Forces in Physics.

There are four fundamental forces in physics:

They are Gravitational, Electromagnetic, Strong Nuclear and Weak Nuclear forces.

The Four Fundamental Forces in Physics.

Gravitational Force:

Gravitational force is a force between two masses and it is universal in nature. Our planets are bound to the sun through gravitational force of the sun. We are in the earth because of Earth's gravitational attraction on our body.

Electromagnetic Force:

Electromagnetic force is a force between two charges, and We are standing on the earth's surface because of the Electromagnetic force between atoms of the surface of the earth with atoms in our feet.

Strong Nuclear Force:

The force between two nucleons, there exists a strong nuclear force and this force is responsible for stability of nucleus. Strong Nuclear force holds the protons and neutrons together in the nucleus of an atom. The atoms in our body are stable is due to strong nuclear force. 

Weak Nuclear Force:

Weak force is even shorter in the range than the strong nuclear force. During the fusion of hydrogen into helium in the sun, neutrinos and enormous radiations are produced through weak force.

" A Physicist is just an atom's way of looking itself " 

                   --Niels Bohr-- 

Rutherford's Alpha Particles Scattered with Scattering Angle

 Rutherford's Alpha Particles Scattered with Scattering Angle.

In 1911, Geiger and Marsden did the experiment based on the Rutherford's scattering alpha particles by gold foil.

A source of Alpha particles are kept inside a thick lead box with with a hole. The alpha particles coming through the hole made of lead box pass through another hole made on the lead screen. These particles are now allowed to fall on a thin gold foil and it is observed that the alpha particles passing through gold foil are scattered through different angles. A movable screen (from 0° to 180°) which is made up of zinc sulphide (ZnS) is kept on the other side of the gold foil to collect the scattered alpha particles. Whenever alpha particles strike the screen, a flash of light is observed which can be seen through a microscope. 

Rutherford's Alpha Particles Scattered with Scattering Angle 

Rutherford proposed an atom model based on the results of the alpha scattering experiment. In this experiment alpha particles were allowed to fall on the atoms of a metallic gold foil.

(a) Most of the alpha particles were un-deflected through the gold foil and went straight.

(b) Some of the alpha particles were deflected through a small angle.

(c) A few alpha particles (one in thousand) were deflected through the angle more than 90°.

(d) Very few alpha particles returned back (back scattered) - that is, deflected back by 180°.

" An alleged scientific discovery has no merit unless it can be explained to a barmaid. " 

                                          ---Ernest Rutherford--- 

Astronauts Living In Space.

 Astronauts Living In Space : 

A bed on the wall, baby wipes for a wash, footholds, and edible  toothpaste! Life on the space station is very different from life on earth.  

 

Life in Space Station. 

Ordinary Days :

                                             Astronauts need to do everything that you do. They eat, exercise, sleep, work, and play, but they have to do all these things in a home without the gravity

Astronaut Chris Hanfield in Space.

.      

New Arrivals :

                                          When astronauts arrive at a space station, they bring supplies with them. Imagine trying to unpack your suitcase when you are floating. some astronauts suffer temporary hearing problems after living on a space station, this is because the necessary air filters, fans, and pumps make it very noisy.          

Keeping Healthy :

                                                   Astronaut's muscles don't work very hard in micro gravity, so they quickly lose strength, so astronauts exercise for about two hours a day. This athlete completed a marathon on the International Space Station treadmill.  

     

Astronaut on Treadmill.

   

Time for Work :

                                             Experienced scientists regularly jion the astronauts in the space station to carry out a variety of experiments and record the results.  

 

Astronaut in space station.

A Tasty Food :

                                          Food is supplied in sealed packets and some of it is dehydrated. That means that water has to be added before the food can be eaten.   

 Nutritional Food for Astronauts. 

Time for Bed :

                                Most of the crew use sleeping bags, which have to be strapped to the walls of the space station. The bag holds astronauts' arms in place. Otherwise they would float above their head.   

Bed for Astronauts.

     

They like to keep clean, like us !

                                                                                         Astronauts use combs and toothbrushes, and toothpaste. But the toothpaste doesn't froth, and gets swallowed. Wet wipes are useful for a speedy wash...  

      

Bathing in Space.

Showering in Space Station.

" Building One Space Station For Everyone Was And Is Insane: We Should Have Built A Dozen. "  

                                                                    ---Larry Niven.---           

      

The Space Stations

The Space stations :  

                                           Imagine living 380 km ( 235 miles ) above everybody eise, experiencing a sunrise every 45 minutes, sending your cloths to burned up in the atmosphere rather than  washed, and having no floor or ceiling. welcome to Space Station.  

ISS (International Space Station)

A Quick History :

                 The first space station was launched in 1971. Since then a number of stations have orbited Earth. The International Space  Station ( ISS ) , has been built by 16 nations working together. The  largest space station ever built, it's been occupied since 2000 . 

ISS launched in 1971 

 

First Ideas : 

                        Ideas for the space stations existed a long time before they became reality . In the 1950s, a 76 metre ( 250 ft )  - wide wheel-shaped design  ( like in the Interstellar ) was proposed by space scientist Wernher Von Braun .  

 

Wernher Von Braun

What is Space station : 

                                   It's a space laboratory that orbits Earth, operated by the crews of astronauts who take turns crew stays for several months. Occasionally, an astronaut  has stayed a whole year! , The solar panels are used to power the space station.   

Body Parts of International Space Station 

Some of the Space Station :

                                              Salyut 1 : Launched in 1971 and in orbit for 175 days.

                                           Salyut 7 : Launched in 1982 and in orbit for 3,216 days.

                                          Skylab :  Launched in May 1973 by the USA. It burned up in 1979.

                                          Mir : Built in space by the Soviet Union, beginning in 1986. It fell into the atmosphere in march 2001.     

                       

“ Building one space station for everyone was and is insane: we should have built a dozen. ”

                           ______Larry Niven.______       

 

    

Journey To The Moon

MOON JOURNEY  :  

During the 1960s there was a race between the USA and the former Soviet Union to put a man on the moon. The USA landed the first man on the moon with APOLLO 11 in 1969.     

Apollo 11's mission crew members (1969).
Left side -  Commander Neil Armstrong ; Middle - Command module Michael Collins ; Right side - Lunar module pilot Buzz Aldrin.  

What was Apollo 11 ?  

                                       🌕  Apollo 11 was made up of three modules, or parts: the tiny command module, the service module, and the lunar module.Apollo 11 mission reached the moon because of a huge rocket called SATURN V. Most of SATURN V contained the fuel needed to blast it into space. 

The  Journey Plan for the Moon Landing {1969}.  

                  🌕 Three astronauts sat in a tiny capsule at the top of the rocket. The service module contained the power and life-support systems. The three astronauts worked and slept in the command  module. And the Mission commander Neil Armstrong struggled to find a flat landing site. He succeeded with just seconds to spare. 

   

The Body Parts of Saturn V's that was carried the Lunar Module called Eagle.  

The Eagle has landed : 

                                           🌕  The lunar module ( the part of apollo 11 that landed ) was also known as the Eagle.It touched down on the moon on 20 July, 1969.  

Lunar Module named Eagle.  

The Different Stages of Apollo 11 Mission : 

                                                                                           🚀  STAGE 1 :  Five F1 engines blast the SATURN V rocket into space from the Kennedy Space Center.  

                                     🚀  STAGE 2 : The rocket's engines fire to set the craft on a course to the moon. 

                                     🚀  STAGE 3 : The command and service modules separate from the rocket and perform a 180° turn.   

                                     🚀 STAGE 4 :  The command and service modules reattach to the lunar module, which is still connected to the rocket.  

                                     🚀 STAGE 5 :  The rest of the rocket is discarded while the commanded, service, and lunar modules  continue to the moon.  

                                     🚀  STAGE 6 :  The journey has taken 102 hours, 45 minutes. The lunar module is ready to land.  

                                     🚀  STAGE 7 :  The command and service modules orbit the moon ( one astronaut remains on board ) while the lunar module lands. Two astronauts walk on the moon.    

                                     🚀  STAGE 8 :  The lunar module joins the command and service modules so the two lunar astronauts can climb through. The lunar module is then abandoned.   

                                     🚀  STAGE 9 :  The service module is ejected before re-entry into Earth's atmosphere.    

                                     🚀  STAGE 10 :  The command module is the only part of the mission to return to Earth.

   

Stages of Moon Landing Mission. 

   "  THE ORIGIN AND EVOLUTION OF LIFE ARE CONNECTED IN THE MOST INTIMATE WAY WITH THE ORIGIN AND EVOLUTION OF THE STARS .  "   

                     ______ CARL SAGAN. ______          

    

 

                              

Short Story of Moon Landing 1969. ( was it conspiracy, theories.)

 Men On The Moon:

🌕  On 20 July 1969, Neil Armstrong became the first person to walk on the Surface of the moon. He was joined by Buzz Aldrin. A third astronaut, Mike Collins, remained in orbit with the command and service modules.

Neil Armstrong on the Moon.

🌕  What was it Like:

                                     Buzz Aldrin described the moon's Surface as like nothing on Earth. He said it consists of a fine, talcum - powder - like dust, strewn with pebbles and rocks.

 

Surface of the Moon in Apollo 11 mission.

     

                                     Why is there no blue sky on the moon?   — Because the Moon has no atmosphere.

🌕   What did they do there: 

                                        Armstrong and Aldrin spent almost 22 hours on the moon. About 2.5 hours of this was spent outside the Eagle, collecting rock and soil samples, setting up experiments, and taking pictures.

The Lunar module was nicknamed as the Eagle.

🌕   How did they talk ? 

                                      There's no air in space, so sound has nothing to travel through. Lunar astronauts use radio equipment in their helmets.

🌕    Here comes Earth: 

                                 Instead of the moon rising, the astronaut saw Earth rising over the moon's horizon — it looked four times bigger than the moon looks from Earth.

Earth rising over the moon's Surface.

🌕    We have Transport  !

                                    Three later Apollo missions each carried a small electric car, a lunar rover, which allowed the astronauts to explore away from the lander. These were left on the moon when the astronaut left.

Transport over one lunar rover reached a top speed of 22km/h (13.5 mph). 

🌕    Splashdown to Earth:

                                      The astronaut returned to Earth in the Apollo 11 command module. This fell through the atmosphere and landed in the Pacific Ocean. A ringed float helped to keep it stable.

Apollo 11 mission command module landed in the Pacific Ocean.

              

                                             Sounds that so weird :  The lunar module computer on Apollo 11 had just 71 K of memory. Some calculators can now store more than 500 K of memory.        

" That's One Small Step for man, One Giant Leap for mankind. "

                                                             ———  Neil Armstrong  ———      

The Short Story Of Atomic Bomb with Oppenheimer. { Manhattan Project }

 💣  Scientist of the Manhattan Project complete the Atomic Bomb destined to end World War - II :     

In the Movie Oppenheimer shows the Atomic Bomb Explosion.
 ( By Director "Christopher Nolan" ).   

💣  During World War the United States used an unprecedented $2 billion to feed an ultra-secret research and development program, the outcome of which would alter the relationships of nations forever Known as the Manhattan Project, it was the search by the United States and her closest allies to create a practical atomic bomb: a single device capable of mass destruction, the threat of which alone could be powerful enough to end the war.   

" Trinity Test " Atomic Bomb explosion effect.

  

💣  The motivation was simple. Scientists escaping the Nazi regime had revealed that research in Germany had confirmed the theoretical viability of atomic bombs in 1939, in support of their fears that the Nazis might now be developing such a weapon, Albert Einstein and others wrote to President Franklin D. Roosevelt (FDR) warning of the need for atomic research By 1941 FDR had authorized formal, coordinated scientific research into such a device. Among those whose efforts would ultimately unleash the power of the atom was Robert Oppenheimer (1904-1967), who was appointed the project's scientific director in 1942. Under his direction the famous laboratories at Los Alamos would be constructed and the scientific team assembled.  

Albert Einstein And Robert Oppenheimer ( 1947).

Robert Oppenheimer in Manhattan Project {Theoretical Physicist}.

💣  An atomic bomb initiates a nuclear chain reaction, thereby releasing truly vast amounts of energy. An initial problem was the production of enough "enriched" uranium to sustain such a reaction Instrumental in the solution was Italian physicist " Enrico Fermi "in a former squash court under Chicago University, he and other scientists created the first ever controlled, self-sustaining nuclear chain reaction. The project ultimately created the first, man-made nuclear explosion, which Oppenheimer called " Trinity ", at Alamagordo, New Mexico, on July 16, 1945...  

      

Mushroom like Structure of the Atomic Bomb Blast, Trinity Test, Alamagordo, New Mexico,on July 16, 1945{ Manhattan Project } By Oppenheimer.   

 💥  " The Atomic Bomb Made The Prospect Of Future War Unendurable. It Had Led Us Up Those Last Few Steps To The Mountain Pass; And Beyond There Is A Different Country. "

                                      ———— J. Robert Oppenheimer. ———— 💣