Though i am not an applied physics /B.S.C physics student ,Science has always been something of my interest :) Presentation during "International School on Astronomy and Space Science organized by Ministry of Environment, Science and Technology and B.P. Koirala Memorial Planetorium, Observatory and Science Museum Development Board "

1. FROM BIG BANG TO PRESENT TIME
Presented by: Uttam Pudasaini
1

2. Presentation Online
 Big Bang
 Timeline of Universe
 Hubble's law and the age of Universe
 Universe and its composition
 Galaxy
 Stars
 Supernova
 Planets
 Formation of solar system
 Information extraction
 Telescopes
 Satellites
2

3. BIG BANG
Prevailing cosmological model that
describes the early development of the
Universe
 Universe was once in an
extremely hot and dense state
 After its initial expansion from
a singularity, the Universe cooled
sufficiently to allow energy to
be converted into
various subatomic particles
3

4. Big Bang contd…
The first element produced
was hydrogen, along with traces
of helium and lithium.
 Giant clouds of these elements
coalesce through gravity to
form stars and galaxies
4

5. 5

6. Hubble's law and age of Universe
Edwin Hubble in 1920 discovered the expansion of the universe.
Farther galaxies are moving at a higher speed following the law,
v=Hod,
where v is the velocity in km/s, d is the distance
in Mpc, and Ho is the Hubble constant in km/s/Mpc.
 Velocity is determined via the redshift in the spectrum and
distance to the galaxy determined using observations of stars
Up until the 1990's, the best estimates for Ho were between 50
km/s/Mpc and 90 km/s/Mpc, giving a range on the age of the
universe between 7 and 20 billion years.
6

7. UNIVERSE (COMPOSITION)
Universe is 13.7 billion years old with an uncertainty of
200 million years. The WMAP value of Ho is 71 ± 4
km/s/Mpc
70% of the energy of the present universe is in the form
of dark energy.
 26% of the energy is in the form of cold (not
thermalized) dark matter, and the remaining 4% of the
energy is in the atoms and photons.
7

8. Dust Particles
Size: Few molecules to few microns in size
Mass spectrometer in the satellites collect them
(They get stuck on Aerogel)
Possesses Scattering property
Analyzed studying the properties of light emitted by
the dust
 ISM(Interstellar Matter),IGM(Inter Galactic Matter) and Inter Planetary Dust
Particle(IDP)
8

9. Dust particles contd…
Universe was homogenous and there was little-to-no structure in it
after Big Bang.
As the universe cooled clumps of Dark matter began to condense,
and within them gas began to condense.
Large scale structure of the cosmos we observe today was formed as
a consequence of the growth of the primordial fluctuations.
The primordial fluctuations gravitationally attracted gas and dark
matter to the denser areas, and thus the seeds that would later become
galaxies were formed.
9

10. Dust particles contd…
40 Tons of extraterrestrial matter falls to Earth
everyday
What happens to the Earth mass?????
Using the isotropic ratio we can differentiate
them from the common dust particle in the Earth
10

11. Formation of Galaxy
 At this point the universe was almost exclusively composed of hydrogen,
helium, and dark matter.

Soon after the first proto-galaxies formed, the hydrogen and helium gas
within them began to condense and make the first stars and finally the first
galaxies were formed.
 The discovery of a galaxy more than 13 billion years old, which existed
only 480 million years after the Big Bang, was reported in January 2011.
 A structure distributed in a great cosmic web of filaments throughout the
universe which contains the fossil clues to this earlier time

12. Galaxy contd..

Come in a variety of shapes, from
round, featureless elliptical galaxies to
the pancake-flat spiral galaxies.
 In Milky Way there are an estimated
6,000 molecular clouds, each with
more than 100,000 solar masses.
12

13. STARS
Higher density regions of the interstellar medium form clouds
or diffuse nebula
Much of the hydrogen is in the molecular (H2) form(molecular
cloud)
The nearest nebula to the Sun where massive stars are being
formed is the Orion nebula, 1,300 ly (1.2×1016 km) away.
13

14. 14

15. Stars contd…
Another site of star formation is the opaque clouds of dense gas and dust
known as Bok globules; so named after the astronomer Bart Bok.
These can form in association with collapsing molecular clouds or
possibly independently.
The Bok globules are typically up to a light year across and contain a
few solar masses.
 Over half the known Bok globules have been found to contain newly
forming stars.
By other process: cloud collapse, empty space
15

16. Supernova
The most massive stars end their lives
as supernova, the explosive destruction
of a star.
Occurs when a massive star suddenly
becomes unable to sustain the core
against its own weight
The explosion expels much or all of a
star's material at a velocity of up to
30,000 km/s (10% of the speed of
light), driving a shock wave into the
surrounding interstellar medium.
16

17. Planets
17

18. Formation of Solar System
 Stars formed by self gravity
 Early solar system was a cloud of interstellar gas that had fairly fast rotation
so not all of the gas could fall into the star forming at the center
 Dust particles stuck by sticking process
 Planetecimals grew by sticiking process
 Protoplantes were formed
 Protoplanets finally formed planets
18

19. Information extraction
Telescope on Earth surface and Satellites in space
collects all the possible information
Huge amount of data is then systematically
processed
19

20. Telescope :Design and
working
A segmented mirror
telescope with
displacement sensors
Instead of eye a CCD
camera as a detector
Wave front distortion is
avoided with the help of
deformable mirror
Fig: Advantage of using a large diameter
telescope
20

21. EELT(42 m diameter
Telescopes)
21

22. Satellites
Hubble Space Telescope
Fitted with telescopes
for images of distant
objects
Infrared detectors of
longer wavelength helps
to take pictures of such
regions
Source:www
22

23. Satellites contd…
Thermal blanket working as a shield
Prior to launch subjected to a thermal vacuum
testing(temp range:-60 to 60 degree Celsius)
Suffers gravity effects, radiations and collision
with debris
High frequency transmission suffers less
attenuation
23

24. SDSS(Sloan Digital Sky Survey)
In February 2003, the WMAP project released an
all-sky map of the radiation emitted before there
were any stars.
Output:
287 million objects
1.3 million spectra
10 TB imaging data
2 TB catalogue data
24

25. Scope of Geomatics students in
Astronomy
 For those who want to continue their higher study
in the filed of Astronomy and Space science
 Site selection project for observation centers at
Earth
 Satellite communication and Space science
 Computer programming and its use in Virtual
Obeservatory
25

26. Some Snapshots
26

27. 27

28. 28

29. 29

30. 30

31. 31

32. 32

33. 33

34. 34

35. 35