The universe is vast, containing all matter, energy, planets, stars, galaxies and spacetime itself. It is the totality of all space, time, matter and energy. Understanding the origins and workings of the universe has been a fundamental question that various scientific disciplines like astronomy, physics and cosmology have sought to answer. The universe is estimated to be around 13.8 billion years old based on observations of the cosmic microwave background radiation and other cosmological data.

1. The Universe
Dr. Hafiz Kosar

2. The universe is the vast expanse that contains
everything that exists, including all matter,
energy, planets, stars, galaxies, and even the
fabric of spacetime itself. It is the totality of all
space, time, matter, and energy.
Understanding the universe and its origins is a
fundamental question that has intrigued
humanity for centuries, and various scientific
disciplines, including astronomy, physics,
and cosmology, seek to unravel its mysteries.
.
The Universe

3. 1. Scale and Size:
The universe is unimaginably vast, with an estimated observable diameter of
about 93 billion lightyears. However, the entire universe may be much larger than
what we can currently observe.
It consists of countless galaxies, each containing billions to trillions of stars, as
well as other celestial objects like planets, moons, asteroids, and comets.

4. 2. Composition:
The basic building blocks of the universe are elementary particles, such as quarks
and leptons, which combine to form atoms. Hydrogen and helium are the most
abundant elements in the universe, with heavier elements produced in stars
through nuclear fusion.

5. 3. Structure:
The largescale structure of the universe is characterized by the arrangement of
galaxies in vast structures known as filaments, sheets, and voids. These structures
are shaped by the gravitational pull of dark matter, a mysterious and invisible
substance that makes up a significant portion of the universe's mass.

6. 4. Cosmic Microwave Background
(CMB):
The cosmic microwave background radiation is a faint glow that permeates the
entire universe. It is the residual heat left over from the Big Bang; the event
believed to have marked the beginning of the universe around 13.8 billion years
ago.

7. 5. Expansion:
The universe is expanding, as evidenced by the observation that galaxies are moving
away from each other. This discovery, made in the early 20th century, led to the
formulation of the Big Bang theory, which posits that the universe began as an
extremely hot and dense state and has been expanding ever since.

8. 5.
EXPANSION:

9. 6. Dark Energy:
The universe is expanding, as evidenced by the observation that galaxies are moving
away from each other. This discovery, made in the early 20th century, led to the
formulation of the Big Bang theory, which posits that the universe began as an
extremely hot and dense state and has been expanding ever since.

10. 7. Dark Matter:
Dark matter, comprising about 27% of the universe's energy density, is another
enigmatic component. It does not emit, absorb, or reflect light, making it invisible
and detectable only through its gravitational effects on visible matter.

11. 8. Galaxies:
Galaxies are massive systems containing stars, stellar remnants, interstellar gas,
dust, and dark matter, all bound together by gravity. The Milky Way, our galaxy, is
just one of billions in the observable universe.

12. 9. Black Holes:
Black holes are regions of spacetime where gravity is so intense that nothing, not
even light, can escape. They form when massive stars collapse under their own
gravitational pull.

13. 10. Fate of the Universe:
he ultimate fate of the universe is a topic of ongoing research. Depending on the
amount of dark energy, the universe may continue expanding indefinitely,
eventually slow down and contract, or reach a stable size.
Understanding the universe is an ongoing process, with advancements in
technology and scientific knowledge continually reshaping our understanding of
its intricacies. Observatories, space telescopes, and particle accelerators play
crucial roles in unraveling the mysteries of the cosmos.

14. 10. Fate of the Universe....

15. 10.
Fate
of
the
Universe....

16. The age of the universe is estimated to be approximately 13.8 billion
years. This age is based on observations of the cosmic microwave
background radiation, the afterglow of the Big Bang, as well as other
cosmological data. The estimate has been refined over the years
through observations from telescopes such as the Hubble Space
Telescope and measurements of the largescale structure of the
universe.
How old is the universe?

17. How
old
is
the
universe?...

18. How has our view of the universe
changed over time?
Our understanding of the universe has evolved significantly over time
through a combination of scientific observations, technological
advancements, and changes in philosophical and cultural
perspectives. Here is a brief overview of how our view of the universe
has changed over different historical periods:

19. How has our view of the
universe changed over time?
01
Ancient Cosmologies (Prescientific
Revolution):
Ancient civilizations, such as the Greeks, Egyptians, and Indians,
developed various cosmological models based on philosophical
reasoning and observational astronomy.
Geocentric models, where Earth was considered the center of the
universe, were prevalent. Examples include the Ptolemaic system
in the West and the geocentric models in ancient India.

20. How has our view of the
universe changed over time?...
02
Scientific Revolution (16th17th centuries):
The heliocentric model, with the Sun at the center of the solar system,
was proposed by Nicolaus Copernicus.
Kepler's laws of planetary motion and Galileo Galilei's telescopic
observations provided empirical support for the heliocentric model.
Isaac Newton's laws of motion and universal gravitation explained the
motion of celestial bodies and laid the groundwork for a mechanistic
view of the universe.

21. How has our view of the
universe changed over time?...
03
19th Century:
Advances in optics and telescopic technology allowed astronomers
like William Herschel and John Herschel to observe and catalog distant
galaxies and nebulae. The development of spectroscopy by scientists
like Joseph Fraunhofer and Gustav Kirchhoff provided insights into the
composition of stars and galaxies.

22. How has our view of the
universe changed over time?...
04
Early 20th Century:
Albert Einstein's theory of general relativity revolutionized our
understanding of gravity, describing it as the curvature of spacetime
Edwin Hubble's observations led to the realization that the universe is
expanding, and he formulated Hubble's Law relating the recessional
velocity of galaxies to their distance.

23. How has our view of the
universe changed over time?...
05
Mid to Late 20th Century:
The development of radio telescopes and other technologies allowed
astronomers to explore the universe across different wavelengths.
The discovery of the cosmic microwave background radiation provided
evidence for the Big Bang theory, suggesting that the universe had a hot and
dense beginning.

24. How has our view of the
universe changed over time?...
06
Late 20th Century to Present:
Advances in space telescopes, such as the Hubble Space Telescope, and
space missions have provided unprecedented views of distant galaxies and
cosmic phenomena.
The identification of dark matter and dark energy has become a significant
aspect of cosmological models, addressing the observed dynamics of the
universe on large scales.

25. How has our view of the
universe changed over time?...
07
Current Frontiers (21st Century):
Ongoing exploration of exoplanets has expanded our understanding of
planetary systems beyond our solar system.
The development of gravitational wave astronomy has opened a new
window to observe the universe through the detection of ripples in
spacetime.

26. THANK YOU
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