11 December 2021

A glimpse of the universe throughout the Big Bang:

It is necessary to consider that the space within a galaxy does not expand. The galaxies are gravitationally bound from within their respective centres, therefore, the light that reaching our eyes form the stars within our galaxy don't experience any such effect that may have caused due to the expansion of space. Besides, there is a zero gravity sphere around all the galaxies, the space beyond that can only expand. Only the space between the galaxies expands due to the effect of mysterious dark energy.
 
However, the rate of expansion is greater as we approach towards the edge of the visible universe. At the edge of the visible universe the galaxies are receding faster than the speed of light and entering into the invisible universe for ever. Light from such distance can never reach us.

Moreover, the age of the universe is known to be 13.8 billion years and the universe has expanded much more than 46.5 billion 'light years' during that time, but the visibility of light is to the extend of 46.5 billion light years, beyond that light cannot reach us, as the invisible universe starts there.

Therefore, since the expansion of space was much faster than the speed of light during inflation, so some form of signals from that originating location still can reach us where our visibility is extended till the boundary of invisibility at 46.5 billion light years.

Furthermore, we are not located at the edge of the universe but more within it, as such some form of signal originated during 13.8 light years ago can still reach us; as space expanded much faster than the speed of light during that inflation of the universal space, making some of those originating energy slower than us and to reach us late.

In this sense, though there is no definite centre of the present Universe, but the point of the Big Bang may be considered the centre point of the Universe, which we have left 13.8 billion years ago.

 Read What was there before the Big Bang?

 

Those Laws of Physics are fragile if based on time, as the concept of time itself is fragile in reality.

Time is indeed a concept and not a real entity as existential events invoke time. What one sees on a clock is the real representation of conceptual time.

Moreover, time does not occupy any of the three perceptible dimensions of space - length, breadth, depth - rather time can prevail in imperceptible, fourth dimensional state, when a lower, three dimensional reality within space would have no influence on time, only such three dimensional existential events can invoke time. The succession of time is irreversible, independent from any external, existential influence within three dimensional space.

Time is more of an abstract concept; like the abstraction in Mathematics - the process of extracting the underlying structures, patterns or properties of a mathematical concept, removing any dependence on real world objects with which it might originally have been connected.

It is wrong to interpret that Time is a real thing. Rather time is a concept.

 Read What was there before the Big Bang?

 

28 November 2021

What was there before the Big Bang?

Before we understanding what was there before the Big Bang, one needs to know the respective conditions before and after the Big Bang so as to enable us to realise what was there before the Big Bang. 

The Cosmic Microwave Background as seen from the Planck satellite.
The Cosmic Microwave Background (CMB) of the Universe as seen from the Planck satellite.
The Big Bang, we know, was the event of rapid expansion of space, known as inflation, from a point like state, corresponding distribution of ultra hot, dense primordial energy in infinite gravity, and the beginning of time. 
  1. The above phenomenon conveys the formation of three dimensional space out of a no-dimensional point.
  2. The phenomenon also conveys distribution and corresponding cooling of the energy that formed the present visible, as well as invisible universe we inhibit, however the energy behind the rapid expansion of the space seems absent in the Big Bang model (or may be not clearly known to me but it is certain that some dominating energy there required to counter-act the infinite gravity at the 0th  second of the Big Bang). [As far as cosmologists can tell, the mysterious force behind the accelerated expansion of the universe, a force that we call dark energy, remains constant. But it may not have done so in the past.(ref#1) The Universe is approximately 13.8 billion years old. However, The acceleration of this expansion due to dark energy began after the universe was already over 7.7 billion years old (5.4 billion years ago) (ref#2).]
  3. Since the Big Bang was the beginning of the events in the primordial existence of energy, so reasonably it was the beginning of time too, (as for time to exist, both existence and events are necessary, and existence without events won't invoke time).

Therefore, from the above said items (1 to 3) or phenomenon. It is obvious that before the Big Bang there was no dimension or the absence of three dimensional space (but it may or may not be a lower dimension).


Moreover, we are three dimensional lives and we can perceive things between one and three dimensions that too when these dimensions existing within our three dimensional space. And.


If the universe was in no-dimensional point or in one dimensional state and without space, such an universe would be a meaningless proposition  to us.

References:
#1 https://www.space.com/universe-age-14-billion-years-old
#2 https://en.wikipedia.org/wiki/Inflation_(cosmology)

 

16 September 2021

A question in the formation of black holes:

It is imminent due to the exhausted Hydrogen atoms in the nuclear fusion of a sufficiently massive star and its strong gravity that collapses such a dead star that stopped its nuclear fusion. The lack of gravitational compression in the core will cause the process of nuclear fusion to stop, since there will no longer be any force capable of fusing atomic nuclei together.

Nuclear fusion is the process that powers active or main sequence stars and other high-magnitude stars, where large amounts of energy are released. Energy released in most nuclear reactions is much larger than in chemical reactions, because the binding energy that holds a nucleus together is greater than the energy that holds electrons to a nucleus.

The difference in mass between the reactants and products is manifested as either the release or the absorption of energy. So the difference in mass arises due to the difference in atomic binding energy between the nuclei before and after the reaction in a nuclear fusion.

After the supply of hydrogen is exhausted in the cores of stars heavy enough, their cores start fusing helium to carbon.

In the most massive stars, the process is continued until some of their energy is produced by fusing lighter elements to iron. Iron has one of the highest binding energies; reactions producing heavier elements are generally endothermic.

Therefore significant amounts of heavier elements are not formed during stable periods of massive star evolution, but are formed in supernova explosions. Most black holes form from the remnants of a large star that dies in a supernova explosion.

#NuclearFusion #BlackHole

15 September 2021

The waves – electromagnetic and mechanical (sound):

The electromagnetic waves are energy carrying waves. The orders of electromagnetic waves from highest to lowest energy are - gamma rays, X-rays, ultraviolet radiation, visible light, infrared radiation, and radio waves. 

The seven types of electromagnetic waves with applications are - Radio waves: Communication; Microwaves: Heating and data transmission; Infrared waves: Used in remote control and imaging applications; Visible light: Help us see everything around us; Ultraviolet Waves: Useful in the study of galaxies; X-rays: Medical instruments to view bone structure; Gamma rays: Nuclear energy.

  

Waves                    Frequency Range (Hz)    Wavelength Range

Gamma-rays         10^20 - 10^24                < 10-12 m

X-rays                   10^17 - 10^20                1 nm - 1 pm

Ultraviolet             10^15 - 10^17                400 nm - 1 nm

Visible                   4-7.5*10^14                   750 nm - 400 nm

Near-infrared        1*10^14 - 4*10^14        2.5 μm - 750 nm

Infrared                 10^13 - 10^14                25 μm - 2.5 μm

Microwaves           3*10^11 - 10^13           1 mm - 25 μm

Radio waves          3*10^3 < 3*10^11          > 1 mm

The energy of a single photon is E=hf or (h/2π) ω where 'h' is Planck's constant 6.626×10^−34 Joule.Second. They always travel at the speed of light i.e. 3x10^8 m/s.

The lowest energy radio waves travel at the speed of light, the electromagnetic spectrum is longer than infrared light and they have frequencies from 300 GHz to as low as 3 kHz.

Notable categories of mechanical waves are - transverse waves, longitudinal waves, and surface waves.

Sound waves, are mechanical waves, its frequency between 20Hz and 20KHz, and its wavelength is between 17 m and 17 mm, and travel at the speed of 343 m/s. Sound waves carry a small amount of mass with them as they travel.

The kinetic energy of the moving material particle E = (mv^2)/2 Joules, where its potential energy=0. They always travel as mechanical waves.