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17 Cards in this Set

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Universe must be....

why scientist ignored it

Georges LeMaitre

He deduced that if Einstein's theory were true (and there had been good evidence for it since 1919), it meant the universe must be expanding.

the expanding universe was the same in all directions, the same laws applied, and its composition was the same -- but it was not static. He had no data to prove this, so many scientists ignored it.


«no evidence

how it began?

formed what atoms?

«one-millionth of a second was a mass of subatomic particles

«hydrogen and helium

«less than a second

« begin with H's

how galaxies formed?

What is still expanding?

« gravity caused clouds of gas to collapse, forming stars and galaxies.

«The present day Universe is still expanding

«gas clouds collapsing

«still expanding

Was it a bang?

What was it really?

How long ago?

«There was no “bang” per se. it was where one thing erupts into the space of something else.

«an unfolding of space and matter from a region no larger than the period at the end of this sentence.

« 13-15 billion years ago



« in the billions

What happened a fraction in a second after the big bang?

«fraction of a second after the Big Bang the Universe was a hot seething mass of radiation and exotic particles


how were elements made?

«mass expanded and cooled and more familiar particles formed, including neutrons, protons, and electrons

«got bigger and cooler

3 pieces of evidence

«The Red Shift of the Galaxies

«The relative amounts of certain chemical elements in the Universe (H and He)

«The existence of Cosmic Radiation

«red shift

«amounts of H and He

« type of radiation

red shift

«galaxies are looked at through a Spectroscope they appear to be shifted toward the Red

«Galaxies are moving away from us and each other


«moving in what way

chemical make-up

«the Universe today retains an imprint of its initial cosmic mixture


cosmic background radiation

«an evenly distributed all-sky glow detected at the short end of the radio spectrum.

«last signs of heat from the Big Bang itself

«sky glow

«last signs

more CBR

what temp is it cooled too?

«–455 F



How many years after?

«Cosmic Background Explorer (COBE) satellite had detected slight temperature deviations in the CBR


«300,000 years

future of the universe

what does it depend on?

«ranging from never- ending expansion to a long return journey that ends with a Big Crunch

depends on the density of the Universe,

big crunch

enough matter in the Universe eventually gravitational forces will stop expanding

gravity causes universe to reverse direction and begin to collapse under its own weight.

big crunch

Universe will collapse into a super dense massive black hole

big rip

by who?

expanding so fast that it literally rips apart all bound objects ripping all matter

Robert Caldwell of Dartmouth.

before big rip

billion years before the end, all galaxies will have receded so far and so fast from our own as to be erased from the sky

Milky Way begins to fly apart, there are 60 million years left

Planets in our solar system will start to wing away from the Sun three months before the end of time

Earth explodes, the end is momentarily near