The Brief History of The Sun.

The Sun:

The Sun is the star at the centre of our solar system. Its gravity holds the solar system together, keeping everything from the - biggest planets to the smallest bits of debris - in its orbit.

Heat and light are produced by nuclear events that occur deep beneath. In order to produce this energy, The Sun has been using four million tonnes of hydrogen fuel each second since its formation, or around 4.6 billion years ago.

Solar Flares:

A solar flare is a massive eruption that occurs on the Sun when energy that has been trapped in "twisted" magnetic fields- which are typically found above sunspots, Chromosphere -is suddenly released.

They may heat materials to millions of degrees in a matter of minutes, resulting in a burst of radiation that includes: radio waves, X-rays, and gamma rays.

Sun Spots:

Sunspots are areas where the magnetic field is about 2,500 times stronger than Earth's, much higher than anywhere else on the Sun. Because of the strong magnetic field, the magnetic pressure increases while the surrounding atmospheric pressure decreases.

This in turn lowers the temperature relative to its surroundings because the concentrated magnetic field inhibits the flow of hot, new gas from the Sun's interior to the surface.

Sunspots tends to occur in pairs that have magnetic fields pointing in opposite directions.

Why Sun Spots are Dark?

The sunspots are large concentrations of strong magnetic field. Some energy is partially prevented from passing through the surface by this magnetic field.

As a result, sunspots experience a lower surface temperature than other areas of the surface. It appears darker when the temperature is lower.

Coronal Mass Ejections (CMEs):

Coronal mass ejections (CMEs) are large expulsions of plasma and magnetic field from the sun's atmosphere the corona.

Compared to solar flares bursts of electromagnetic radiation that travel at the speed of light, reaching Earth in just over 8 minutes.

Formation of CMEs:

The more explosive CMES generally begin when highly twisted magnetic field structures (flux ropes) contained in the Sun's lower corona become too stressed and realign into a less tense configuration - a process called magnetic reconnection.

Near Earth CMEs Effects:

Auroras:

The CMEs causes stunning light displays known as auroras, visible in the polar regions of the earth.

Geomagnetic Storms:

CMEs can cause significant disturbances in Earth's magnetosphere, leading to geomagnetic storms which are; Satellite Operations, Power Grids, Communication Systems.

Radiation Hazards:

It Increases radiation levels at high altitudes, especially near the poles.

Preventing & Monitoring:

SPACE WEATHER FORECASTING:

To provide early alerts of possible CMEs, organisations such as NASA and NOAA's Space Weather Prediction Centre (SWPC) track solar activity.

AID:

Continuous monitoring and improved prediction models are essential to prevent the bad impacts of CMEs.

How to Find the Sun Spots Area:

To find the area of sunspots, I use the manual formula to calculate the area of the sunspots.

As = ((Af x n) / cos (B) x cos (L))

Where,

As - Area of the sunspot,

Af - Area factor constant for the solar chart image (i.e., 63.66),

n - Number of grid sares occupying the sunspot,

B- Heliographic latitude,

L - Angular distance of the sunspot from the solar disk centre.

The physical unit for the calculated area is a millionth of a hemisphere (MHS). 

Solar Cycle:

About every 11 years, the Sun's magnetic field gradually changes polarity, a process known as the solar cycle. This reversal causes changes in solar activity.

The solar cycle has been observed and recorded since the mid-18th century, with the current cycle being Solar Cycle 25. 

 "Sun, in fact, is the center of the universe" -Nicolaus Copernicus. 

Particle Nature of light: Einstein's Explanation.

 Particle Nature of light: Einstein's Explanation.

Einstein extended Planck's quantum concept to explain the photoelectric effect in 1905. According to Einstein, the energy in light is not spread out over wavefronts but is concentrated in small packets or energy quanta. Therefore, light (or any other electromagnetic waves) of frequency v from any source can be considered as a stream of quanta and the energy of each light quantum is given by E=hv.
[1] 

He also proposed that a quantum of light has linear momentum and the magnitude of that linear momentum is p=h/c. The individual light quantum of definite energy and momentum can be associated with a particle. can behave as a particle and this is called photon. Therefore, photon is nothing but particle manifestation of light.

Light is made up of particles called Photons.

Characteristics of photons:

According to particle nature of light, photons are the basic constituents of any radiation and possess the following characteristic properties:

i) The photons of light of frequency v and wavelength & will have energy, given by E=hv= hc/λ

ii) The energy of a photon is determined by the frequency of the radiation and not by its intensity and the intensity has no relation with the energy of the individual photons in the beam.

iii) The photons travel with the speed of light and its momentum is given by hhv P=h/λ =hv/c

iv) Since photons are electrically neutral, they are unaffected by electric and magnetic fields.

v) When a photon interacts with matter (photon-electron collision), the total energy, total linear momentum and angular momentum are conserved. Since photon may be absorbed or a new photon may be produced in such interactions, the number of photons may not be conserved.... 

“Matter is Energy… Energy is Light…We are all Light Beings” —Albert Einstein.

  

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-- 

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.

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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.______