GRAVITY AND LIGHT

     Hello all and welcome to my Blogspot EVERYTHING ASTRONOMICAL. In this blog, I am going to talk about the relationship between gravity and light is fundamental to our understanding of black holes.
Gravity:
    The scientific foundation for black holes has been developed by numerous scientists contributing ideas throughout history. But among them, Einstein was responsible for the biggest development, in his theory of gravity, which describes the gravitational attraction between massive objects such as a black hole or a star by associating the force of gravity with an equivalent curvature of space.

Spacetime curvature by the Black Hole's gravity.

    All physical objects including rocketships and individual particles of light called photons travel on curved spacetime.

    A black hole is a region of space where the force of gravity becomes so strong that the curvature of spacetime prevents light from escaping. And these gravitational forces depend on their mass. I will discuss how it gains this huge mass later. By these strong gravitational forces, they represent an inescapable vortex, whose strength can stretch astronauts into spaghetti, and even eat whole stars. Falling into a black hole is irreversible and once inside, there is no chance to escape ever.

    So after knowing its strong gravitational force, will you wish to make a trip to black holes if we have the advancement to travel?🤔 ( Leave your comments, I'm anxious to know.)

Light:

    It's impossible to discuss the concept of a black hole without first developing into the details about light or electromagnetic radiation. In the absence of light, we get darkness or blackness, which is how black gets into the name black hole.

    Black holes don't allow light to escape from their interior, so they appear completely dark. But the light that is emitted from objects in the neighbourhood of a black hole is still able to escape when it is away from the spherical boundary surrounding the black hole, which scientists call the event horizon. In a recent study, astronomers detected light behind a black hole. The detection of bright flare confirms Albert Einstein's theory of relativity as photons bent around the black hole.

(Graphic: NASA)

    Let me discuss some basics about the light. Light waves are characterized by their properties of wavelength, frequency, and propagation speed. 

• The symbol c is used to denote the speed of light which has a precise value of 299,792,458 m/s. 

• Light waves are actually a type of transverse electrical and magnetic wave.

• Scientists use the term electromagnetic radiation to describe light.

• The individual particles of light are called photons. Since the physical theories describe that light behaves both as a particle and as a wave. This is the same as saying the light is quantized, each photon is a small discrete packet of energy.

• The energy that a photon carries is proportional to its frequency and inversely proportional to its wavelength. 

• The wavelength range of light between 400 nm and 700 nm is often called visible light.     

    As we approach the shorter wavelength waves such as X-rays, gamma rays, ultraviolet rays in our black hole study, don't mind about visible light.

   

     Now that we have covered the basics of light, let's take a look at how we can measure and use light and Doppler shift to gain a greater understanding of black holes and the universe in my next blog. Engage with me.😊

    And I have a question for you people, as light from a source spreads out and weakens, due to this expanding universe at infinite speed, do gaps form between the photons? 🤔( Leave your thoughts in the comment. )