Higher tier: The Steady State theory of the Universe
Another theory about the Universe, called the Steady State theory, says that the Universe has always existed, and that the Universe is expanding and constantly creating matter as it expands.
This idea is supported by the red shift evidence, but not by CMBR.
After the discovery of CMBR, the Steady State theory lost support and is no longer considered likely.
| Evidence observed | Does evidence support the Big Bang theory? | Does evidence support the Steady State theory? |
| More distant galaxies have greater red shift. | Yes | Yes |
| CMBR is everywhere at a temperature of about -270°C. | Yes | No |
| Evidence observed | More distant galaxies have greater red shift. |
|---|---|
| Does evidence support the Big Bang theory? | Yes |
| Does evidence support the Steady State theory? | Yes |
| Evidence observed | CMBR is everywhere at a temperature of about -270°C. |
|---|---|
| Does evidence support the Big Bang theory? | Yes |
| Does evidence support the Steady State theory? | No |
Higher tier: Other theories about the universe
There are numerous other theories about our universe. These include:
- Multiverse – our universe is just one of several disconnected universes.
- Recently, a Harvard scientist has come up with an interesting theory that our universe was formed in a laboratory by a higher “class” of lifeform.
Question
Higher tier only: Many scientists believe that the universe began in an explosion known as the Big Bang.
Describe and explain two observation that supports the Big Bang Theory.
- Red shift - When we look at the spectrum of a star in another galaxy, the pattern of lines in the absorption spectrum has moved, or ‘shifted’, towards the lower frequencyThe number of waves produced each second. The unit of frequency is hertz (Hz)., longer wavelengthThe length of a single wave, measured from one wave peak to the next., red end of the spectrum. The shifting of the light to longer wavelength is an indication that the galaxy is moving away from our galaxy.
- Astronomers discovered cosmic microwave background radiation cosmic microwave background radiationElectromagnetic radiation, detected throughout the Universe that is left over from the Big Bang. CMBR has a wavelength of about 2 mm. in the 1960s. The wavelength of this radiation appears to be the same no matter where in space that it comes from and it corresponds to a temperature of about –270 °C. It comes from all directions and from all parts of space. It is thought that the continuous microwave background radiation is the remains of the heat energy from the Big Bang, spread thinly across the whole Universe.
