Relativity of mass

 According to theory of relativity, mass of any object have two state. 

Mass of static object and the mass of dynamic object. 

Dynamic objects mass is less than that of static object. With the increasing of motion objects mass tends to decreases. 

Mass when object in rest is invariant mass and mass when object in motion is relativistic mass. 

Invariant mass is equal to rest energy and relativistic mass is equal to relativistic energy. 

Invariant mass is usually preferred over rest energy. The inertia of any object is determined by relativistic mass. 

Photon have zero rest mass but have inertia, weight in gravitational field. 

Black body radiation

The object that can absorb all of the wavelength of light is called Black body. The emission of wavelength of light that was absorbed by black body is called Black body radiation.

Black body radiation is a thermal radiation. How much the energy will radiates depend on the temperature of the surface of the black body.

There have some laws concerning radiated energy and temperature.

Stafen Boltzmann law According to stafen Boltzmann law the radiated energy from the surface of the black body is proportional to the fourth power of temperature.

Wein displacement law says the radiated energy wavelength will be inversely proportional to the fifth power of temperature.

Fundamental interaction

Fundamental interaction is the interaction in nature not reducible to more basic interaction. There have four fundamental interaction in nature. Gravitational force 

 Electromagnetic force 

 Strong nuclear Force 

 Weak nuclear force 

 Gravitational and electromagnetic interaction produces long range effect that is found in our daily life.

 But strong nuclear force and weak nuclear force acts in subatomic level. 

 Each of the fundamental interaction described as field. Gravitational force is attributed to the space time curvature. Other three force can describe by standard model. These three forces are discrete quantum field. According to Standard model, Gluon is a particle that carries strong interaction. Due to strong interaction Quark binding happens and forms hardons, like proton and neutron. Due to residual effect creates nuclear force and binds other particles all together and forms nucleus. Weak interaction is carried by particles called W and Z boson. Weak interaction acts on the nucleus and responsible for radioactive decay. Electromagnetic force is carried by a particle called photon and creates electric field and magnetic field. These electric field and magnetic field interact in small scale within atom. For that reason negatively charged electron and positively charge nucleus attract each other and holds together with a revolving state. Moreover, it is also responsible for chemical bonding and electromagnetic wave, like visible light. But for large scale object like stars , planets there have large astronomical distence. Here no electromagnetic force is effective. Gravitational force holds the planets together.

Theory of relativity

According to theory of relativity, Mass, space and time is not absolute, but relative. Two consecutive theory of relativity is Special theory of relativity General theory of relativity Special theory of relativity focusses on the theory of motion, space, time and mass relation. According to Einseein Energy and mass have no difference rather a transformation. Special theory of relativity based on two basic postulation 1. In all of the inertial frame all of the theory of physics is same. 2 Speed of light in all inertial frame is constant.

Inertial frame and non inertial frame

If the position of any point relative or determined to other fixed point object in three dimensional space, the fixed point object is called reference frame. These objects are inertial frame that follows Newtonian classical mechanics and these objects motion can describe by Newtons law of motion. Inertial frame are these objects that that have a constant velosity relative to any objects, having no acceleration. Acceleration means speeding up and slowing down of velocity. That complying with newtons laws of motion, because, According to Newtons laws of motion, If no external force excerted static object will remain static and dynamic object will remain dynamic along with a straight line motion with constant velocity. But non inertial frame are these object in motion in three dimensional space that have acceleration, having no constant velocity.

Modern physics

physics including quantum physics, theory of relativity, atomic physics, nuclear physics, statistical mechanics and solid state physics is termed as modern physics In 1900, discovery of planks quantum theory that describes black body radiation as quantization evolves the concepts of quantum physics. In 1905, theory of relativity by Albert Einstein introduces new dimension in modern physics. Above these conception leads to develop other organ of modern physics.