Post on 15-Jan-2015
description
The UniverseThe Universe
Seconde F
Order of MagnitudeOrder of Magnitude
Order of MagnitudeOrder of Magnitude
Humans
Order of MagnitudeOrder of Magnitude
Order of MagnitudeOrder of Magnitude
Order of MagnitudeOrder of Magnitude
Order of MagnitudeOrder of Magnitude
Order of MagnitudeOrder of Magnitude
Order of MagnitudeOrder of Magnitude
Order of MagnitudeOrder of Magnitude
Order of MagnitudeOrder of Magnitude
1 Gm = 1 gigameter = 10^9 meters = 1 000 000 000 m
Order of MagnitudeOrder of Magnitude
1 Gm = 1 gigameter = 10^9 meters = 1 000 000 000 m1 nm = 1 nanometer = 10^(-9) meter = 0.000000001 m
Order of MagnitudeOrder of Magnitude
Order of MagnitudeOrder of Magnitude
Nucleus of an atom
nucleus
Order of MagnitudeOrder of Magnitude
Atom
Order of MagnitudeOrder of Magnitude
Bacteria
Order of MagnitudeOrder of Magnitude
Humans
Order of MagnitudeOrder of Magnitude
Earth
Order of MagnitudeOrder of Magnitude
Sun
Order of MagnitudeOrder of Magnitude
Solar System
Order of MagnitudeOrder of Magnitude
Interstellar distance
Order of MagnitudeOrder of Magnitude
Galaxy
Order of MagnitudeOrder of Magnitude
Observable universe
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1000 kg 1 Kg
Order of MagnitudeOrder of Magnitude
1000 kg 1 Kg
Order of MagnitudeOrder of Magnitude
Order of MagnitudeOrder of Magnitude
Filling of space by the matter is essentially incomplete, at both tiny (atom) and big
(cosmos) scales (essentially void around us)
Speed of lightSpeed of light
Speed of lightSpeed of lightSpeed of light in vacuum is a phyical constant :
Speed of lightSpeed of lightSpeed of light in vacuum is a phyical constant : c = 3.10^8 m/s = 300 000 000 m/s
Speed of lightSpeed of lightSpeed of light in vacuum is a phyical constant : c = 3.10^8 m/s = 300 000 000 m/s The light is composed of photons
Speed of lightSpeed of lightSpeed of light in vacuum is a phyical constant : c = 3.10^8 m/s = 300 000 000 m/s The light is composed of photons and is propagated in straight line
Speed of lightSpeed of lightSpeed of light in vacuum is a phyical constant : c = 3.10^8 m/s = 300 000 000 m/s The light is composed of photons and is propagated in straight line
A.Einstein 1879 - 1955
Speed of lightSpeed of lightSpeed of light in vacuum is a phyical constant : c = 3.10^8 m/s = 300 000 000 m/s The light is composed of photons and is propagated in straight line
Speed of light (speed of propagation) depends only on the medium
A.Einstein 1879 - 1955
Speed of lightSpeed of lightSpeed of light in vacuum is a phyical constant : c = 3.10^8 m/s = 300 000 000 m/s The light is composed of photons and is propagated in straight line
Speed of light (speed of propagation) depends only on the medium
speed(vacuum) = speed(air) = c = 3.10^8 m/s
speed(water) < c
A.Einstein 1879 - 1955
Speed of lightSpeed of lightSpeed of light in vacuum is a phyical constant : c = 3.10^8 m/s = 300 000 000 m/s The light is composed of photons and is propagated in straight line
Speed of light (speed of propagation) depends only on the medium
speed(vacuum) = speed(air) = c = 3.10^8 m/s
speed(water) < cRefraction index n : quantity without
unit
A.Einstein 1879 - 1955
Speed of lightSpeed of light
Speed of lightSpeed of lightGalilée, Romer, Cassini, Newton,
Michelson..
Speed of lightSpeed of lightGalilée, Romer, Cassini, Newton,
Michelson.. using astronomy
Speed of lightSpeed of lightGalilée, Romer, Cassini, Newton,
Michelson.. using astronomy The meter is the distance travelled
by the light in the void during 1/299 792 458 second
Speed of lightSpeed of lightGalilée, Romer, Cassini, Newton,
Michelson.. using astronomy The meter is the distance travelled
by the light in the void during 1/299 792 458 second
Speed of lightSpeed of lightGalilée, Romer, Cassini, Newton,
Michelson.. using astronomy The meter is the distance travelled
by the light in the void during 1/299 792 458 second
v = c (m/s)
m
s
Speed of lightSpeed of light
Speed of lightSpeed of light
d = 1m
Speed of lightSpeed of light
d = 1m
Speed of lightSpeed of light
d = 1m
s m
m/s
Speed of lightSpeed of light
d = 1m
s m
m/s
Speed of lightSpeed of light
d = 1m
d = 150 000 000 Km
s m
m/s
Speed of lightSpeed of light
d = 1m
d = 150 000 000 Km
s m
m/s
s km
km/s
t = 500 sec = 8.3 min
Speed of lightSpeed of light
d = 1m
d = 150 000 000 Km
Even if the light of speed is great, the gigantic distances at the cosmos scale cause delays (we don’t
see things in ‘real time’)
s m
m/s
s km
km/s
t = 500 sec = 8.3 min
Light-yearLight-year
Light-yearLight-yearA light-year is the distance travelled
by the light in vacuum during one year
Light-yearLight-yearA light-year is the distance travelled
by the light in vacuum during one year
Light-yearLight-yearA light-year is the distance travelled
by the light in vacuum during one year
m
m/s
s
Light-yearLight-yearA light-year is the distance travelled
by the light in vacuum during one year
m
m/s
s
1 year converted in seconds
Light-yearLight-yearA light-year is the distance travelled
by the light in vacuum during one year
m
m/s
s
1 year converted in seconds
1 ly
roughly
Light-yearLight-yearA light-year is the distance travelled
by the light in vacuum during one year
The light-year (ly) is not a new unit, it’s used only because it’s handy with the gigantic distances we
have in the cosmos
m
m/s
s
1 year converted in seconds
1 ly
roughly
Light-yearLight-year
Light-yearLight-year
I see dinosaurs
How far are we from this planet?
Light-yearLight-year
I see dinosaurs
How far are we from this planet?Extinction of the
dinosaurs : 65 millions years ago
Light-yearLight-year
I see dinosaurs
How far are we from this planet?Extinction of the
dinosaurs : 65 millions years ago
The aliens are at least 65 000 000 light-years away from us
(6.5 * 10^22 meters)
Light-yearLight-year
I see dinosaurs
How far are we from this planet?Extinction of the
dinosaurs : 65 millions years ago
The aliens are at least 65 000 000 light-years away from us
(6.5 * 10^22 meters)
Watch far = Watch in the past
Light-yearLight-year
Questions ?
Homework