The movement of the earth in Qur'an

[FearGod]

Hmmm ! Praise to Almighty GOD .

Augustus' and Gnostic's cases are dismissed one and all , though they would in no time post ' Blah , Blah and Blah....'

We rely on the truth and on God's help, actually my answers aren't for them but to defend the truth.

 

[Augustus]

Last attempt to help you.

Haha, this is getting ridiculous, just find anything with a 6 in it and say this is definitive. This is a great demonstration of how stupid the whole hypothesis is and how it relies entirely on quote mining and post hoc straw-clutching.

We can go back to your man Eric Chaisson who wrote your favourite article about the 6 epochs (he doesn't actually work for NASA or represent their opinion btw), he has a more recent book which has the title "Epic of Evolution: Seven Ages of the Cosmos" "Dividing the universe into seven epochs, Chaisson charts the course of its evolution-effected complexity."

But of course, he is only useful when he uses the number 6, so this is to be ignored.

 

[FearGod]

Haha, this is getting ridiculous, just find anything with a 6 in it and say this is definitive. This is a great demonstration of how stupid the whole hypothesis is and how it relies entirely on quote mining and post hoc straw-clutching.

We can go back to your man Eric Chaisson who wrote your favourite article about the 6 epochs (he doesn't actually work for NASA or represent their opinion btw), he has a more recent book which has the title "Epic of Evolution: Seven Ages of the Cosmos" "Dividing the universe into seven epochs, Chaisson charts the course of its evolution-effected complexity."

But of course, he is only useful when he uses the number 6, so this is to be ignored.

Read my signature, it's my advice for you, good luck and study hard.

 

[Union]

I told you FearGOD , in no time they will start ' Blah , Blah , Blah ...'

"I have six big boxes
I have seven small boxes inside them..."

How ? How ? and How ? Augustus lost . He can't understand ; he is pulling his hairs , he is cutting his nails , he is biting his fingers , he is banging his head BUT he doesn't understand ...................

 

[FearGod]

I told you FearGOD , in no time they will start ' Blah , Blah , Blah ...'

"I have six big boxes
I have seven small boxes inside them..."

How ? How ? and How ? Augustus lost . He can't understand ; he is pulling his hairs , he is cutting his nails , he is biting his fingers , he is banging his head BUT he doesn't understand ...................

I think he hates No.6 by now.

 

[Shad]

CP-2156 Life In The Universe - NASA


To place the construction of all matter into perspective, consider figure 1, which summarizes the run of density and temperature throughout all time for a Big-Bang Universe. It represents the consensus of contemporary scientific thought in the broadest sense. Six major epochs are delineated, each corresponding to a major period in the history of the Universe. Specified across the bottom of this figure are the general names of the epochs, along with their time domains. Note that this plot is highly nonlinear, stretching from an incredibly small fraction of a second to the present time, 18 or so billion years after the origin of the Universe. The curves depict the average density and the average temperature of everything in the Universe at any point in time.

This figure suggests that in the beginning there was chaos. One cannot inquire about what happened at the exact moment of the Bang (precisely zero time). Some theorists argue, however, that it is possible to characterize the physical conditions at some extraordinarily small time after the Bang. For example, the currently known laws of physics specify a Universe younger than 10-23 sec to be characterized by an average density greater than 1050 gm/cm3 and an average temperature greater than 1030 K. Of course, it is virtually impossible to appreciate such youth, for 10-23 sec is the amount of time it takes light to cross a proton. Equally difficult to comprehend are the large densities and temperatures characterizing this earliest epoch. The composition of the Universe at this time was indescribable, and its dominant action unimaginable.

The second major epoch is a bit closer to our limits of comprehension, although it is still characterized by severely nonterrestrial conditions - the hadron epoch. The name is derived from the fact that the heavy elementary particles such as protons, neutrons, and mesons, which were the most abundant type of matter at the time, are collectively known as hadrons. Calculations suggest that such particles existed as free unbound entities, considering the high temperature prevalent in the Universe well within its first second of existence. The hadrons unquestionably collided and interacted with one another and with other types of elementary particles, for the density was also extreme. The dominant action at this time is presumed to be the self-annihilation of hadrons into high-energy photons, thus creating a brilliant fireball of radiation. Lacking a solid understanding of elementary particle physics, scientists presently know very little more about this mystifying period.

As the Universe continued its rapid expansion, its contents cooled. A variety of models suggest that about a millisecond after the Bang, the conditions suitable for hadron annihilation had nearly subsided, thus allowing the initially less abundant, lighter elementary particles such as electrons, neutrinos, and muons to predominate. The average density and temperature of this lepton epoch had decreased to about 1010 gm/cm3 and 1010 K. These physical conditions are still excessive by terrestrial standards, but they had diminished considerably compared to the chaotically dense and hot conditions extant a fraction of a second earlier. By the time the first second had elapsed, the leptons were self-annihilating into photons, much as had the hadrons earlier. The radiative fireball of the cosmic bomb was still being fed with new photons.

The radiation density exceeded the matter density by a large amount in these first few minutes; photons of radiation far outnumbered particles of matter. As soon as the elementary particles of matter began to coagulate, fierce radiation destroyed them. For this reason, the first three epochs are [4] often collectively referred to as the radiation era. Whatever matter existed was merely an inconspicuous precipitate suspended in a sea of dense, brilliant radiation.

LATER EPOCHS

The fourth epoch -the atom epoch -extends in time from about 100 sec to about a million years after the Bang. Midway through this epoch, the average density had decreased to about 10-10 gm/cm3, while the average temperature had fallen to about 106 K-values not terribly different from those in the atmospheres of stars today. A principal feature of the atom epoch was the gradual diminution of the original fireball, for the annihilation of hadrons and leptons had all but ceased.

Toward the beginning of the atom epoch, radiation still reigned supreme over matter, for the Universe remained flooded with photons. As the Universe expanded, however, the photon density decreased as the fourth power of the radius of the Universe, while the matter density decreased only as the third power. The early dominance of radiation thus gradually diminished. Sometime between a few minutes and a million years after the Bang, the charged elementary particles of matter were able to coagulate electromagnetically without being broken apart by radiation as quickly as they combined. This was a most important transformation in the history of the Universe. The dominance of radiation had subsided, for matter had gradually become neutralized, a physical state over which radiation has little leverage. Matter had, in a sense, overthrown the cosmic fireball. Henceforth it would dominate radiation as the principal constituent of the Universe. To denote this major turn of events, the last three epochs in figure 1 are collectively known as the matter era.

Once the matter era began, atoms appeared. The influence of radiation had grown so weak that it could no longer prohibit the joining of the leptons and hadrons that had survived annihilation. Hydrogen was the first element to form, since it required only that single electrons be electromagnetically joined to single protons. Copious amounts of hydrogen were synthesized in the early Universe, and it is thus the common ancestor of all things.

Hydrogen was not the only kind of atom formed early in the matter era. Indeed, at the start of the atom epoch, the average temperature of the Universe still exceeded the 107 K necessary to fuse two hydrogen atoms into helium via the proton-proton cycle. The Universe was cooling, but it took time for the average temperature to dip below this critical value. Consequently, some helium atoms must have been produced within the primordial fireball in the same way that they now form in the interior of stars.

[5] Elements heavier than helium, on the other hand, could not have been produced in the early Universe. The synthesis of such elements requires temperatures even greater than 107 K. It also requires lots of helium atoms, for the heavier elements are constructed from lighter ones. The basic difficulty here is that, even though helium atom production was in high gear during the start of the atom epoch, the average temperature was falling quickly. Theoretical calculations suggest that, by the time there were sufficient helium atoms to interact with one another to produce the heavier elements, the temperature had fallen below the threshold value (~108 K) required for the mutual penetration of doubly charged helium nuclei. In contrast to the rapid cooling of the early Universe, the dense interiors of stars in the present Universe are perfectly suited for the generation of hotter temperatures and thus heavier elements. The guts of stars are indeed where the heavies were created-and where they are still being created.

By the end of the atom epoch, matter was in firm control. Sometime during the fifth or galaxy epoch, gravity began to pull some of this matter together into enormous clumps. Galaxies were beginning to form. Indeed, they all must have originated long ago, for observations imply that no galaxies have formed within the past 10 billion years or so. Each galaxy contains substantial numbers of old stars, in addition to an often abundant complement of young stars. The quasars and remote galaxies must have formed in the earliest parts of this epoch.

The time scale of the last two epochs shown in figure 1 has been compressed enormously. An important and rapid series of events occurred immediately after the Bang, especially in the first few minutes that constitute the radiation era. However, once the Universe cooled sufficiently to allow atoms to form, subsequent events occurred more slowly.

By the middle of the galaxy epoch, the average density of the Universe had decreased by another factor of 10 billion, to 10-20 gm/cm3. The average temperature of the entire Universe had also diminished to a relatively cool 3000 K. The Universe was becoming thinner, colder, and darker.

Finally, there is the present stellar epoch. Scientists can say with some assurance that it has been at least 10 billion years since the Bang. In fact, the Universe is probably older than that, perhaps as old as 18 billion years, although its precise aye depends on the yet-to-be-determined change of the Hubble constant with time. The present average density is approximately 10-30 gm/cm3, the critical value above which the Universe will eventually contract and below which the Universe will expand forever. The average temperature of everything in the Universe is presently 3 K. This then is the cooled relic of the incredibly hot fireball that existed eons ago, the fossilized grandeur of a bygone era.

The dominant action of the stellar epoch is the formation of stars, intermediate in size between atoms and galaxies. Research during the past [6] several years has provided direct observational evidence that stars are actually forming within galaxies. Galaxies themselves are not forming in the present epoch, but stars within them apparently are - 18 billion years after Bang.

An interesting by-product of star formation is the associated coagulation of matter into planets, life, and intelligence.

This history of the Universe is the prevailing view among most cosmologists. All theoreticians do not agree on specific events before about 1 sec. Depending on the intricacies of the model chosen, the density and temperature during the radiation era can change by several orders of magnitude. In virtually all models, however, the Universe is regarded to have been initially very hot and dense, after which it cooled and thinned.

And here is another source with more than six epochs. This is due to people making up epochs as they go as defining lines between one and another.

Chronology of the universe - Wikipedia, the free encyclopedia

Count the use of epochs. Plank(1), Grand Unification Epoch(2), Electroweak Epoch(3), Quark Epoch(4), Hadron Epoch(5), Lepton, Epoch(6), Photon Epoch(7). There is an 8th if you count the Inflationary Epoch.

Again here are 7 epochs.

Graphical timeline of the Big Bang - Wikipedia, the free encyclopedia
Timeline of the Big Bang - The Big Bang and the Big Crunch - The Physics of the Universe

Your sources are outdated since it is from 77 citations.

Here is one with 5 epochs

History of the Universe

Here is one with over 9

The Scale of the Universe

This happens since epoch is a vague term which can be used by anyone for an period of time they wish.

 

[Union]

And here is another source with more than six epochs. This is due to people making up epochs as they go as defining lines between one and another.

Chronology of the universe - Wikipedia, the free encyclopedia

Count the use of epochs. Plank(1), Grand Unification Epoch(2), Electroweak Epoch(3), Quark Epoch(4), Hadron Epoch(5), Lepton, Epoch(6), Photon Epoch(7). There is an 8th if you count the Inflationary Epoch.

Again here are 7 epochs.

Graphical timeline of the Big Bang - Wikipedia, the free encyclopedia
Timeline of the Big Bang - The Big Bang and the Big Crunch - The Physics of the Universe

Your sources are outdated since it is from 77 citations.

Here is one with 5 epochs

History of the Universe

Here is one with over 9

The Scale of the Universe

This happens since epoch is a vague term which can be used by anyone for an period of time they wish.

Sorry, you are late . Party is over . Your point is already discussed earlier .

 

[Shad]

OMG , I forgot about the 2 periods about the creation of the earth ......

Geologic Time scale

Eons and Eras
The first principal subdivision is called the eon. An eon, the largest division of the geologic time scale, spans hundreds to thousands of millions of years. Geologists generally agree that there are two major eons: the Precambrian eon and the Phanerozoic eon. The Precambrian goes from the formation of the earth to the time when multicellular organisms first appeared - that's a really long time - from 4,500 million years ago to just about 543 million years ago. Then begins the Phanerozoic eon, which continues up to today.

Eons are made up of eras, divisions that span time periods of tens to hundreds of millions of years. The three major eras are the Paleozoic, the Mesozoic, and the Cenozoic. The Cenozoic era is the one we are in today. It began 65 million years ago, right about the time that the dinosaurs went extinct.

Keep in mind that these three eras are all grouped within the Phanerozoic eon. Remember that other eon, the Precambrian eon? Well, that one doesn't get to have any eras inside it. We don't have a lot of information....

http://earthsurfaceprocesses.com/3c-E-MassExtn.html

The Structure of Geologic Time

Geologic Time Scale
A Time Line for the Geological Sciences

Dividing Earth History into Time Intervals


Geologists have divided Earth's history into a series of time intervals. These time intervals are not equal in length like the hours in a day. Instead the time intervals are variable in length. This is because geologic time is divided using significant events in the history of the Earth.


Examples of Boundary "Events"


For example, the boundary between the Permian and Triassic is marked by a global extinction in which a large percentage of Earth's plant and animal species were eliminated. Another example is the boundary between the Precambrian and the Paleozoic which is marked by the first appearance of animals with hard parts.


Eons

are the largest intervals of geologic time and are hundreds of millions of years in duration. In the time scale above you can see the Phanerozoic Eon is the most recent eon and began more than 500 million years ago......

This is what happens when you do not read your own sources.

Figure 1: a simple geological time chart showing the names of the geological time divisions, and the times of each of the Big Five mass extinctions in the blue box on the right side. Major time periods are called Eons, and there are three shown in the diagram: Archean, Proterozoic and Phanerozoic Eons. The most recent (Phanerozoic Eon) is composed of a number of subdivisions, called Periods, starting with Cambrian, and ending at the present day with Quaternary. Read the text for details of the mass extinctions.

Notice it has 3 eons but you say 2. The quote below the figures provides details which you did not. You assume the 2 were subdivisions but were not. Key word you missed here was "eon".

Your second source contradicts your first source. Look at your own picture. It has 2 large eons but has 3 smaller eon within the 1. It still categorize these as eons, look at the column heading. Again not reading your own sources not understanding your sources.

 

[Shad]

Sorry, you are late . Party is over . Your point is already discussed earlier .

None of which covers your misunderstanding of terms used. All you have done is ignore other sources which contradict your own. Ignoring something is selection bias and fallacious. Thus your "discussion" has no merit and is no rebuttal. Your comment just prove that you use fallacious thinking to ignore counter-arguments.

Likewise GB's post shows that these timelines are constructs subject to change. Thus to hold certain sources as absolutes while ignoring new categories and changes is again selection bias thus fallacious thinking. Same non-argument, same fallacies.

You have a number of people pointing out the same fallacies used by both of you. This is perhaps a hint that your thinking is flawed.

 

[Augustus]

Read my signature, it's my advice for you, good luck and study hard.

This is hilarious, you just search for the number 6, you understand nothing of any of the texts except the number 6, you dismiss any text that uses a number other than 6 without any actual attempt to explain why it is not valid.

You love a text written in 1980, but simply ignore any advance made after 1980, even if it is written by the same person who wrote the article you actually quoted in the first place.

If the verse said 7 you would be arguing about how the 7 epochs were a miracle, if it was 3 you would be arguing about 3 eras, were it 9 you wold be arguing 9 epochs. you just look at the number 6 like it is an idol to be worshipped, and find people who have used the number six in a scientific text, no matter how old or how arbitrary the classification is.

I mean you don't even actually read what you post, that thing about '6 phases of cosmic chemistry' draws the number 6 from the man made library cataloging classifications for academic areas of study.

"The totality of cosmic chemistry is represented by a list of 176 classes of phenomena, drawn from the Universal Decimal Classification (UDC) library cataloguing system, and divided into 6 phases: of no chemistry, of prestellar chemistry, of galactic chemistry, of planetary chemistry, of biological chemistry, of human history."

"Why use library classification systems?
First, there is no real hope of developing a ‘natural’ or, even more so, ‘objective’ list of phenomena of given type at a defined level of detail that would enable us to ‘measure’ the growth of complexity of different groups of natural objects. Second, even an intuitive measure that is created simply for convenience may lead to valuable insights,"

It actually says the number 6 is created simply for convenience. But then you think that you are the ones being intellectually honest and other people are being nefarious in the way they deny the clear signs for this miraculous scientific foreknowledge.

I just enjoy seeing how you keep trying to ignore anything with another number in it, its light entertainment and a case study for cognitive dissonance. I've been bored at home cos I'm ill and can't go out this weekend, but you have certainly helped relieve my boredom

Haha, you are the one who needs to look at your signature my friend, it certainly is ironic

 

[Union]

This is what happens when you do not read your own sources.



Notice it has 3 eons but you say 2. The quote below the figures provides details which you did not. You assume the 2 were subdivisions but were not. Key word you missed here was "eon".

Your second source contradicts your first source. Look at your own picture. It has 2 large eons but has 3 smaller eon within the 1. It still categorize these as eons, look at the column heading. Again not reading your own sources not understanding your sources.

You have seen the figure , right ? How many major time scales were there ? 2 . Right ? 2 eons are the major , then it can be subdivided and some also be called eons . It doesn't matter what name the human gives , two major duration of time is the fundamental one .

Simple , but it appears difficult , nay ?

" I have two big boxes
I have three small boxes in them
I have four smaller boxes in them......"

The rest of the story is in couple of post earlier ...

 

[Union]

None of which covers your misunderstanding of terms used. All you have done is ignore other sources which contradict your own. Ignoring something is selection bias and fallacious. Thus your "discussion" has no merit and is no rebuttal. Your comment just prove that you use fallacious thinking to ignore counter-arguments.

Likewise GB's post shows that these timelines are constructs subject to change. Thus to hold certain sources as absolutes while ignoring new categories and changes is again selection bias thus fallacious thinking. Same non-argument, same fallacies.

You have a number of people pointing out the same fallacies used by both of you. This is perhaps a hint that your thinking is flawed.

See you latter , let me give you time in solving the box-puzzle ......

 

[Augustus]

See you latter , let me give you time in solving the box-puzzle ......

Shad should actually give you time to understand the concept of selection bias...

 

[gnostic]

I have already posted references from different scientific sources , which can be summarized as they stated :

" Geologists generally agree that there are two major eons: the Precambrian eon and the Phanerozoic eon..."

However , I got a news for you . Qur'an mentioned also that this 02 eons subdivided into 4 time scales to fashioned the earth to make it inhabitable :

[041:009] Say: Is it that ye deny Him Who created the earth in two Days? And do ye join equals with Him? He is the Lord of (all) the Worlds.

[041:010] He set on the (earth), mountains standing firm, high above it, and bestowed blessings on the earth, and measure therein all things to give them nourishment in due proportion, in four Days, in accordance with (the needs of) those who seek (Sustenance).

You only read what you want, do you?

There used to be 2 eons, but now there are 4 eons. You are using outdated geochronology (or geological time scale).

The old Precambrian eon has been divided into 3 separate eons.

1. 1. Hadean
   2. Archean
   3. Proterozoic

The Phanerozoic makes 4.

And there are 2 geological time scales, which geologists used:

1. Geochronology
2. Chronostratigraphy

Where the geochronology uses eon, era, period, epoch, age and chron, chronostratigraphy uses the corresponding eonothem, erathem, system, series, stage and chronozone instead.

In both eon and eonthem, they exactly same names, and there are 4 of them:

1. Hadean
2. Archean
3. Proterozoic
4. Phanerozoic

You really should keep up to date on stratigraphy.

And in the Big Bang theory, there are lot more than 6 epochs. Eric J Chaisson only listed 6, but there are lot more going on than 6 epochs. There are dozen-and-half epochs.

Again, you really should read more than one (and current) source on the Big Bang model.

These are the earliest epochs after the Big Bang:

1. Plank's epoch
2. Grand Unification epoch
3. Electroweak epoch
4. Inflationary epoch
5. Baryogenesis

The following epochs are what are how matters were form, but before theformation of the 1st stars:

1. Electroweak Supersymmetry Breaking and Quark epoch (began about the same time).
2. Hadron epoch
3. Lepton epoch (1 to 10 seconds after the Big Bang)
4. Photon epoch (duration from 10 seconds to 388,000 years after the Big Bang)
5. Nucleosynthesis (last from 3 minutes to 20 minutes after BB; hydrogen and helium nuclei were formed into hydrogen ions and helium ions, with no electrons)
6. Recombination (after 377,000, hydrogen and helium ions began capturing electrons, creating stable (neutral) atoms, hydrogen and helium elements.)
7. Hydrogen Line (or Dark Ages)
8. Structure Formation (hydrogen element began gathering together by gravity into small and large structures, this occurred before gravitational collapse cause the first stars.)
9. Reionization
10. Stellar Formation (first stars were called Population III; at the beginning, there were no element heavier than beryllium; they are stars with very low metallicity. Only after these Population III stars ended by supernovae, did heavier elements were introduced into the universe. Other Population III stars that were too massive to explode as supernovae, collapsed and formed into black holes.)
11. Formation of galaxies (This didn't occur until after new stars were formed from Population III stars; these stars are listed as Population II stars.)
12. Our solar system were formed 9 billion years later, from materials of past supernovae. Our sun is 3rd or 4th generation star, and grouped as one of Population I stars, stars with the highest metallicity.

As you can see there are more than 6 epochs, and Chaisson had only listed 6 epochs.

 

[Augustus]

You only read what you want, do you?

No, they rely on a thorough, objective analysis of all available data which undergoes a thorough, peer reviewed process that guarantees that someone, somewhere has ever used the number 2 or 6 in some context and that the point in which they used these numbers was indeed the apogee of scientific sophistication and automatically refutes all future advances in scientific knowledge that don't contain the numbers 2 or 6 without need for further evidence.

You are just ignorant and blinded by your hate filled rejection of obvious and incontrovertible truths revealed in the 1980s and don't realise that modern advances are simply petty minded attempts to refute the scientific miracle hypothesis that common sense would tell you is undeniably true.

I pity you.

 

[gnostic]

No, they rely on a thorough, objective analysis of all available data which undergoes a thorough, peer reviewed process that guarantees that someone, somewhere has ever used the number 2 or 6 in some context and that the point in which they used these numbers was indeed the apogee of scientific sophistication and automatically refutes all future advances in scientific knowledge that don't contain the numbers 2 or 6 without need for further evidence.

You are just ignorant and blinded by your hate filled rejection of obvious and incontrovertible truths revealed in the 1980s and don't realise that modern advances are simply petty minded attempts to refute the scientific miracle hypothesis that common sense would tell you is undeniably true.

I pity you.

Say what?

I am NOT the one who advocate 6 epochs for the universe and 2 for Earth's stratigraphy.

 

[gnostic]

Union, Chaisson may have only listed 6 main epochs, but that doesn't mean a dozen (if not more) epochs exist.

Chaisson didn't get rid of the other epochs in the Big Bang theory, he just simplified it with only naming 6, but there are 18 (or more) epochs.

And there 4 eons, not 2 for the geological time scales.

 

[Augustus]

Say what?

I am NOT the one who advocate 6 epochs for the universe and 2 for Earth's stratigraphy.

Only because you are blinded to the "truth".

God chooses who to enlighten and who stays ignorant after all

(wish forums had a 'slide-whistle' sound effect instead of smilies)

 

[Shad]

You have seen the figure , right ? How many major time scales were there ? 2 . Right ? 2 eons are the major , then it can be subdivided and some also be called eons . It doesn't matter what name the human gives , two major duration of time is the fundamental one .

Simple , but it appears difficult , nay ?

" I have two big boxes
I have three small boxes in them
I have four smaller boxes in them......"

The rest of the story is in couple of post earlier ...

You seem not to understand column categories. Everything under Eon is considered an eon. Your second source confirms there are 3 not 2 by this quote under the linked figure

Figure 1: a simple geological time chart showing the names of the geological time divisions, and the times of each of the Big Five mass extinctions in the blue box on the right side. Major time periods are called Eons, and there are three shown in the diagram: Archean, Proterozoic and Phanerozoic Eons. The most recent (Phanerozoic Eon) is composed of a number of subdivisions, called Periods, starting with Cambrian, and ending at the present day with Quaternary. Read the text for details of the mass extinctions.

It clearly says 3. You mistakenly combined to since you didn't actually read anything in your sources. Both sources have the same column header for the 3. The second link clearly states the difference between a period and the two eons below.

 

[Shad]

See you latter , let me give you time in solving the box-puzzle ......

No need. I read the sources unlike yourself.

Figure 1: a simple geological time chart showing the names of the geological time divisions, and the times of each of the Big Five mass extinctions in the blue box on the right side. Major time periods are called Eons, and there are three shown in the diagram: Archean, Proterozoic and Phanerozoic Eons. The most recent (Phanerozoic Eon) is composed of a number of subdivisions, called Periods, starting with Cambrian, and ending at the present day with Quaternary. Read the text for details of the mass extinctions.