Transcript Spectroscopy Applications - Astrophysics and

Astrophysics and Cosmology
How do we know what we know about the
universe around us?
Astrophysics and Cosmology
How do we know what we know about the
universe around us?
The farthest from the Earth we have been to
return “direct evidence” has been Mars
Astrophysics and Cosmology
How do we know what we know about the
universe around us?
The farthest from the Earth we have been to
return “direct evidence” has been Mars
The rest of the universe is understood by
“looking” that is, by the collection of
electromagnetic waves
Astrophysics and Cosmology
Tools:
Telescopes – can receive information both
inside and outside of the visible window
Astrophysics and Cosmology
Tools:
Telescopes – can receive information both
inside and outside of the visible window
Most of what is in the (currently) observable
is gaseous.
Astrophysics and Cosmology
Tools:
Telescopes – can receive information both
inside and outside of the visible window
Most of what is in the (currently) observable
is gaseous.
Spectroscopic analysis of emission and
absorption spectra most common tool
Part 3(e): Atomic Physics
Spectral Properties of Incandescence
Energy
High Temp
Low Temp
Blue
Red
Wavelength
Astrophysics and Cosmology
Astrophysics and Cosmology
Click here to view a temperature adjustable continuous spectrum
Astrophysics and Cosmology
Absorption Spectrum of the Sun
Gas
Astrophysics and Cosmology
Absorption Spectrum of the Sun
Moving one step closer to finding the fingerprints of life in a
habitable planet beyond the solar system, astronomers have for
the first time detected carbon dioxide in the atmosphere of a
planet that orbits a star other than the sun
Fall 2008
Moving one step closer to finding the fingerprints of life in a
habitable planet beyond the solar system, astronomers have for
the first time detected carbon dioxide in the atmosphere of a
planet that orbits a star other than the sun
Fall 2008
How on Earth do they know
this??????
Astrophysics and Cosmology
Astrophysics and Cosmology
Emission
Heat
Astrophysics and Cosmology
Astrophysics and Cosmology
The Universe contains vast amount of
hydrogen.
Other elements are being synthesized
Complex molecules are also being synthesized
in gas clouds
Astrophysics and Cosmology
A strange observation:
When spectra were first collected about the
universe, there were no known fingerprints
that matched what was observed.
Astrophysics and Cosmology
A strange observation:
When spectra were first collected about the
universe, there were no known fingerprints
that matched what was observed.
?
Astrophysics and Cosmology
A strange observation:
When spectra were first collected about the
universe, there were no known fingerprints
that matched what was observed.
It was realized that the spectra fit known
elements, but that all of the wavelengths in the
spectra had been “shifted” to longer
wavelengths
Astrophysics and Cosmology
The Red and Blue Shift
Astrophysics and Cosmology
The Red and Blue Shift
Astrophysics and Cosmology
The Red and Blue Shift
The Wavelengths are the same in all directions
only if the atoms in the gas are not moving.
Astrophysics and Cosmology
The Red and Blue Shift
The Wavelengths get “squished” in the direction of
motion, and “stretched” in the opposite direction.
Astrophysics and Cosmology
The Red and Blue Shift
The Wavelengths get “squished” in the direction of
motion, and “stretched” in the opposite direction.
Astrophysics and Cosmology
It was further observed that ALL spectra
form ALL deep space objects were shifted
toward the red, ie, longer wavelengths
The implications is that ALL objects in the
universe, on the average, are moving away
from the Earth.
Astrophysics and Cosmology
The only way ALL objects in the universe can
be moving away from the Earth is if the
universe is expanding.
Astrophysics and Cosmology
Expanding FROM where and TO where?
?
?
Astrophysics and Cosmology
The Big Bang
The universe exploded into existence approximately 15
billion years ago (the Big Bang).
Shortly after the Big Bang, the hydrogen that makes up
the current universe was formed. Other elements were
subsequently synthesized from the hydrogen.
All of the material in the universe (including you) is 15
billion years old.