PHYSICS - The Universe Flashcards
What process allows the light going in a prism, split into its different colours?
Refraction/Diffraction
What are the 3 types of spectra?
- Continuous Spectrum
- Absorption Lines
- Emission Lines
What is continuous spectrum?
Where light source has been split into its different colours
What is absorption lines?
When light is emitted from a source and pass through a gas
What is emission lines?
When a gas is heated enough that it gives off its own light
It produces an emission spectra (flame tests)
Why do we get (Fraunhofer) lines in spectra?
I’ll supposedly remember this later?
abd says:
absorbed due to certain wavelengths
^ that ig?
Look at page 3 (I can’t read his writing)
Aw man what the
But i mean it’s similar to “3 types of spectra”
What’s important info about spectra lines?
Unique for each different element.
Thus, they can be identified easily
What causes dark/bright fringes in a spectrum/spectra???
Electrons absorbing/emitting wavelengths
Look at page 5, very useful
Preciate it
What was the red shift?
- Lines moved towards “red spectrum” (increased wavelength)
- Due to stars further away, higher wave length lower energy
Explain Doppler Effect
- When sound move towards you, it’s louder and higher pitch (wavelength of sound shorter)
- When sound moves away from you, it’s quieter and lower pitch (wavelength of sound longer)
What conclusion did Hubble draw from doppler effect and his observations?
Redshift causes by doppler effect but with light waves
The greater the red shift….?
The faster it is moving away from us
&
The further away it is from us
You can look at page 15 if u want
Ok I guess
Oh and look at page 16 and 17, I mean otherwise, somehow make a flashcard on this
Am sorry I dunno how to do this
What happens to every galaxy if we rewind time?
Would move closer to each other
What does the Cosmological Red-shift refer to?
The stretching out and increasing of the wavelength as it moves through expanding space
(different to concept of red-shift)
What causes galaxies to spread out in the universe?
Fabric of space expanding
As waves of light travel through space,
stretches waves and makes wavelength longer
Simple explanation of The Big Bang Theory
- Believed universe started with a huge explosion
- And that’s cuz it seems that galaxies keep spreading away from each other
- If we rewound time, must’ve started from a common point in space
(think of this as a nail bomb)
Look at page 22 - 23, quite useful looking
Yeah sure, if i fucking had an answer for that
What is the Cosmic Microwave Background Radiation (CMBR)?
- From explosion, Electromagnetic Radiation (heat and light) emitted in all directions
- Surroundings get hotter
- Similar to Big Bang theory
- Penzias and Wilson accidentally discovered radiation from Big Bang
How did radiation produced during Big Bang changed its wavelength, and now is in microwave part of spectrum
Cuz universe expanded causing waves to stretch, reaching microwave region (they used to be x-rays & gamma rays at the start)
2 pieces of evidence from CMBR supporting Big Bang theory
- Radiation present in space where they shouldn’t be
- Radiation observed in microwave region, supporting universe expanding
Explain all evidence supporting Big Bang theory
Red shift -
* light from distant stars/galaxies got longer wavelengths than it should
* Everything we look at is moving away
* Everything moving away = must’ve started from a single point
CMBR -
* Left over radiation from big bang
* Now observed as microwaves due to
* Space expanding + wavelength of radiation increasing to microwaves
Simple explanation how CMBR provides evidence supporting Big Bang Theory
It observed microwaves
Why will temperature of space decrease as Universe continues to expand
Frequency and energy decreases due to wavelengths stretching
