i got 3 *including today* to answer this, kill me
6.1 Understanding the Universe

Scientists estimate that the universe is about ______________ years old? The Earth is about _______years old? (p.445).

Since scientists cannot make direct observations of most astronomical objects, they must study _______ from these ________

___________ to gain ______________ about them.

Scientists can then use this ____________ from the _________ _________ to better understand the ___________ __ the ________________.

Advances in _______________ over the last century have allowed _______________ to make observations of ____________ and more___________objects across the entire ______________ __________.

These observations have yielded evidence about the origin of the _____________.

With this evidence, scientists developed a __________ to explain the ___________ ___________ of the _____________.

___________ ___________ are ways of ____________ why things happen in the ______________ __________.

They begin with a _________________, or an _________ of how scientists think __________ _________.

Scientists then collect________ to ______ the ___________.

__________ __________ are thought ___________ until new ____________ suggests _____________ ____________.

Scientists always check _____________ by collecting more _____________ and by _____________.

Sometimes, ____ _______________ cause a _________ to be ____________ or ______________ to match the new __________(p.447).

The theory of how the __________ came to be is explained by the ____ ________ _________; it was first proposed in ______(year).

The ____ ______ __________ is generally accepted because ?

However, details about the theory are still being?

Less than a century ago, the ___________ was thought to be _______ (unchanged) and __________(limitless).

The _____ _____ __________ held that the universe had ________existed in its ________ ________, with ________ ______ _________.

However, in the _________s, American astronomer ________ ___________ discovered that the _________ was in fact ________.

This showed the _____ ______ _______ to be ________?

The ___ ______ ______ eventually too its place as the ________ _________ ____________ to explain the origin of the __________?

The Big Bang theory states that the ___________ formed during a ________ ____ in which all _______ and _______ suddenly __________ from an extremely _______ ________.

This point, called _____________, is thought to have been ______________, _________ ______, and ________ ____.

It is thought to have been smaller than a ________ _______ and made of _______ ________.

One of the biggest mysteries of the ____________ is how the _________ __________ inflated at an extremely _____ _____ from a ________ to the size of a _________ almost ____________.

This mystery continues to ____________ (bother) __________, but the laws of ___________ do allow for such an _____.

To measure the age of the universe, scientists exploit the fact that _________ travels at ________(defineabe) ___________.

Scientists express _________ in the universe units called ______- ________.

A ______- ______ is the measure of the ________ in ________ equal to the distance that ________ travels in one ________?

One light-year equals about ________________kilometers(km).

Because objects in space are ,many ______-_______ away, the _______ and other _________________ _________that an observer on ___________ detects actually originated many ______ ____.

An observer is literally seeing _____ the _____.

This means that if scientists look back in ______ far enough, they can make observations about ________ states of the ___________.

By determining the _____ at which the __________ is __________, scientists can work _____________ to determine the age of the ____________: approximately ___________years.

During the initial expansion of the ___ ______, the laws of physics _______ into _______(.p447)

Science assumes that the universe works as a _______ _______ and the interactions of ______ and _________ are governed by the same _________ everywhere.

The theories and laws we develop from _____________ on _____ can be used to _______ the formation of the ______________.\

Our understanding of __________ is a good _______ of this.

Scientists say that the exact amount of ______ necessary to produce the __________ existed in the ____________.

Too little ________, and ___________ would exist because ________ would have _______ formed.

Too much ________, and _________ but a series of ________ ________ would have ______.

Because ______ _______ gravity existed, some of the tremendous _______ of the ____ _____ converted to _______ in the form of ___________ and other _____________ ____________.

All the objects of the ___________ are made of _______ that developed during the _____ __________ of a ________ following the ____ _________.

The Law of _________________ of _______ states that __________ can neither be _________ nor ___________, but only ________ from one _________ to another.

The theory of ___________ states that E=_______, which means that __________ os equal to _________ times the ______ of _________ squared.

That means that ________ can be changed into _________ and that ______ changed into __________.

Scientists use these two laws to explain how the ________from the expansion of a ____________ can form the _____________ in the _____________.

After the initial expansion, the ___________ was a hot _____ of ____________ and other ____________ particles.

As the universe slowed and ________ in the first second of the expansion, ___________ and ____________ formed.

Within the first three minutes of ___________, ___________ was still too ____ to form _______.

The universe was a dense _____ of _____, _____, and ________ from which no ________ could escape.

Mass exists in two opposing forms called ____________ and _________ (p.448).

For example, an __________(also called a positron) has a ________ _______ _______.

An _______________ has a _________ ________.

__________ and _____________ annihilate______ ______ when they come into _______.

This contact releases __________.

For anything to exist in the ___________, there had to be more __________ than __________.

All ___________ in the universe are made of this ________ ________.

Some scientists have found ______________(a combination of statements, ideas, or features of a situation that are opposed to one another.) between the law of ____________of _______ and the __ ____ ________, since neither addresses where the ___________ of _______ ______ originated.

However, the Big Bang Theory only refers to the time _____the ______________ began to ________, and where the law of __________ of _______ applies.

The two most common elements in the universe are ___________ and __________.

This is because __________ and ________ are the simplest _______ to ______.

Scientists think that the first atoms of __________ began to form _______ minutes after the big bang.

____________ atoms contain only one ______, so when the universe cooled enough to form _____, these were the _____ to ______.

As the universe cooled further, _______atoms formed.

Next to form were ________ atoms with _____ protons.

As the ________ of soupy ________, ______, and ________ ordered itself into __________, _________ penetrated through the universe for the ______time, about ___________ years after the _____ ________.

List three forms of evidence for the Big Bang Theory.

What is Cosmic background radiation? Of what was it made?

Why can scientists conclude that nearly all the light within the early universe was released at the same time–this evidence supports the ___ ______ ________?

The small temperature variations found in the cosmic microwave background (CMB) radiation represent slight ________ differences (p.449).

These density differences illustrate variations in the __________ of ____ throughout the early ___________.

Areas of more mass in the early universe have what today?… which gives further support to the big bang theory.?

Scientific __________ is based upon the __________ that the laws of __________ operate the same ________ as they did in the _______.

Using data collected from the ________ __________, CMB________, and ___-____ evidence, scientists can infer (predict according to data analysis) conditions of the _________ using ____ that are now know to be ______.

Applying the law of __________of _______ and the theory of ____________ to _____________ ______, scientists have developed a __________(very possible) explanation of the ___________of the _____________.

The expansion of the universe can be ___________ and _____________.

Observing the _____________ of the __________ provides strong ___________ for the ___ ______ ___________.

Measuring the ________ of ______________ allows scientists to work _______________ to determine the __________age of the _____________, beginning with the ___ ________.

In the 1920s American astronomer _______ _________ made some first ________________ of the _________ of the ___________ employing principles of the __________ _____(p.450).

The Doppler effect is the apparent ______ in the _______ of a wave caused by changing _________ between the _____________ and the object _____________ the ___________.

When the _________ are moving toward an __________, they appear to be ______________, resulting in an apparent __________ of the ____________ and an increase in _____________.

When the waves are moving __________ from an ___________, the waves appear to be _________, resulting in an apparent _____________ of the wavelength and a __________ in ___________.

With light waves, the apparent change in wavelength _______ the light toward different _________.

Redshift is the apparent _______ of the ______ wavelengths toward the ____ end of the _______________spectrum.

Redshift happens when a _____________(well-lit) object is moving away from Earth.

Blueshift is the apparent shift of ______ ___________ toward the _______ of the ____________ spectrum;and, Blueshift happens when a __________ object is moving toward __________.

Both Redshift and Blueshift can be explained by the __________ ________.

If the Universe is __________, one would expect most objects in the universe to have a ___________, meaning they are moving ____ from _______.

____________ observed the __________ of most ____________ in the universe.

Scientists apply the _____ of ______________ backwards to estimate the _________ of the ____ ______.

The relative abundance of _______ in the universe and the known laws of ___________ provide additional evidence for the big band theory.

The two most common elements in the universe are _____ and _________–in fact, both may compose more than __________% of ordinary _________ in the universe.

The next most common element is ________.

Remember that ______, ________, and ___________ respectively contain ____, ____ and ______ protons.

They are the three simplest __________, and so they would have been the _____ to form out of the soupy mix of free ________ and ___________ produced by the big bang.

The fact that most of the matter in the universe consists of these three simple elements is further ________ for the ____ _______ _________.

The remaining elements on the ___________ _____ were made much _______ than the first three.

___________in density of the early universe allowed gravity to exert an _________pull on the _________ in the universe.

This uneven pull of _________ allowed _______ gas _________ to come ___________.

Countless collisions between these ____________atoms generated tremendous ________.

Eventually, they __________ to form the _______ ___________.

The Universe’s early stars firmes the first __________, including the ______ ___ galaxy.

The ___ _____ galaxy us thought to be one of the oldest _________ in the universe–about __________ years old.

_____ and ________ now contain most of the visible ____ of the ___________.

Stars are fueled by a process called ________ _______.

Fission is a __________ reaction in which the _______ of certain ____ elements, particularly __________, combine with ________ with ______ nuclei.

This process is accompanied by an enormous release of _______.

The nucleus of the hydrogen atom contains ____ _______.

During nuclear fusion, hydrogen nuclei fuse together to form ________ atoms with nuclei that contain ___ protons.

These heavier atoms sink towards the core of the __________(gravity).

They fuse into new ______ of heavier ___________ with more __________ in their nuclei.

The heavier elements continue to sink towards the _______ of the _______.

The nuclear fusion process continues until ____ is formed.

______ does not give off ______ through nuclear fusion.

When most of the _________ in the star have fused into iron, the star ____ out of ________.

Then, the star becomes more and more ______ until it ______ into a ____________.

This explosion spreads the _________ elements throughout the ___________.

The__________ form the explosion causes more _____ to occur, producing even __________ elements.

The _____ of the first _____ gave birth to the _________ of the ___________.

The processes that first began immediately after the big bang continued, and they are still continuing ______.

About ________years ago, ____ began to coalesce (condense/gather) to form a star known as the _____.

______ and ____ coalesced around this star _____ years ago to form our _________.

Nuclear fusion is still happening in the______ and countless other ________–and our universe is still ____________!