Big Ideas in Science: The Origins of the Universe

Week 2 content

Big Bang Theory

theory of how the universe was created. Universally accepted in 1980.

Planck epoch

the (earliest period of the universe (

Inflation

lasts from 1043 seconds to 380000 years. Space stretches into itself, everywhere all at once. The universe expands rapidly making it cool down (& removing plasma). As it cools, energy condenses into matter/ subatomic particles. Subatomic particles condense into atoms which become translucent to light.

Dark ages

380000 to 150 million years ago. After all the plasma has cooled, and neutral atoms are created. There is no light as the atoms are translucent.

4 pillars of the big bang

the 4 most important theories that are predicted by the big bang theory but aren’t by others (e.g., the steady state theory). They act as evidence of the big bang theory.

Blue-shift

colours are wavelengths with blue/ violet colours being shorter & red/ orange colours being longer. Pushing wavelengths causes them to contract/ become shorter and thus appear blue.

Red-shift

colours are wavelengths with blue/ violet colours being shorter & red/ orange colours being longer. When puling/ moving wavelengths away, they become elongated/ longer making them appear red.

Hubble’s law

states that everything is moving away from everything else. This aligns with Vesto Slipher’s idea that the further away things are, the faster they are moving.

Relative abundance of atoms

the amount of atoms available in the universe disproves/ challenges the steady state theory. 1 lithium: 4 billion hydrogen: 1 billion helium

Structures for hierarchically

smaller, simpler things will be formed first, thus, objects further away from earth should be simpler.

Particle transparency

occurs when dense, charged particles (which are opaque to light/ visible ) become less dense, neutral hydrogen atoms (which are transparent to light/ invisible). This causes a “flash of light” that is everywhere, relatively even & redshifted.

Steady state theory

states that the universe is expanding & new matter is constantly appearing to maintain consistent density. This is NOT accepted/ disproved by the relative abundance of particles.

Cosmic microwave background

left over radiation from the big bang. It is evidence of the big bang detected as a low hum by detectors. (Pigeon story)

Gravitational wave

a very weak, invisible & fast ripple in the shape of space & time. As the wave passes it stretches and compresses space.

LIGO

laser interferometer gravitational-wave observatory. It is used to detect gravitational waves by using 2 4km long tubes, a laser beam & a detector building. When a gravitational wave passes, the tubes change size causing a misalignment in the laser beams & thus, the detection of light.