Transcript Bez tytułu slajdu

On
the
Track
of
Modern
“If the world has begun with a single quantum, the
notions of space and time would altogether fail to have
any meaning at the beginning; they would only begin to
have a sensible meaning when the original quantum had
been divided into a sufficient number of quanta. If
this suggestion is correct, the beginning of the world
happened a little before the beginning of space and
time.”
Georges Lemaître
Big Bang
The Belgian priest Georges Lemaître was the first to propose, in 1927, that the
Universe began with the explosion of a primeval atom. His proposal came after
observing the red shift in distant galaxies. Two years later, Edwin Hubble made
systematic measurements of the red shift. He found that distant galaxies in every
direction are going away from us with speeds proportional to their distance.
Physics
Nucleosynthesis
2109K
4108K
Electromagnetic
decoupling
3000 K
1s
100s 1000s
Forming of
the galaxies
106y
109y
Evolution of the temperature of the Universe
Birth
Today
of the Sun
2.73 K
1010y
1.51010y
Our Universe started somewhat 14.5 billion years ago. It took
less than one millionth of a second to make disappear heavy
quarks, one hundredth of a second to make protons and three
minutes to make hydrogen and helium but 300,000 years to
decouple the light from the matter.
“This is the most beautiful and satisfactory
explanation of creation to which I have ever
listened.”
Albert Einstein
If You observe a picture like this on Your TV, do not
change the channel. This can be a hidden massage from
distant civilizations, and for sure 1/3 of this noise comes
from the Big Bang fossil radiation.
The fossil radiation
When the temperature of the primordial plasma was low enough to allow electrons stick to nuclei, the
Universe become transparent for light and the radiation decoupled started to wander around the Space. In the
adiabatic expansion this radiation cooled down. Now its temperature is 2.73 K, corresponding to microwaves.
In 1964, Penzias and Wilson, two engineers of Bell Telephones, working on communication with a satellite,
observes a strange noise. They got Nobel prize for it in 1978.
Gamma Rays
10-16
X-Rays
10-14
10-12
10-10
Ultraviolet
10-8
Visible
Infrared
10-6
Microwaves
10-4
10-2
Radio, TV
100
102
Electromagnetic Wavelength (metres)
The light that is reaching us has been stretched out as the universe has stretched, so light that was
once visible now is reaching us in the form of microwaves.
What is the geometry of the Universe?
The density of matter inside the Universe determines its geometry: for a high
density we will obtain a closed universe with a positive curvature, but with a
density lower than the critical density, we will obtain an open universe.



Flat Universe
 ++ =180o
Open Universe looks
like a horse saddle
 ++ <180o
Time evolution of the Universe for
different mass density parameter
0 which measures the ratio
between the density  of the
studied universe and a particular
density, called the critical density
c. (about 610-27 kg/m3 ).
0<1
0=1
time


A microwave map of the whole sky made the Cosmic Background Explorer
(COBE) Differential Microwave Radiometer (DMR).
http://map.gsfc.nasa.gov/m_mm.html
0>1

Closed Universe looks like
the surface of a sphere
 ++ >180o
size
COBE in 1990 and WMAP in 2003 showed not only that Universe started
as a ball of wriggly plasma but also that it is flat to the most remote corner.
Some scientist say that time-space is
closed, and folded inside like the Swiss
cheese. But recent observations show
that it is flat, or better, cubic.
Moreover, the Universe accelerates its
expansion and we do not know why!



Georges Lemaître (1894-1966) from 1935
was a canon of the cathedral in Malinas.
Mikołaj Kopernik (1473-1543) from 1510
was a canon of the cathedral in Frombork.