One possible explanation of the dramatic changes of the Earth.

[Ophiolite]

Your calculations skipped steps and were formatted in a piss poor wysiwyg rather than a Latex format. I refuse to do your whole question, but I am rather confident that you're off by a matter of 1000 because at some point you substituted metric systems prefixes.

Would you take a look at my earlier calculation and see if you agree with it. I think I show a three order of magnitude differnce from Emil, which matches your suspicion that he is out by 1000.

 

[Neverfly]

We have to get used because I do not watch.
You're just a liar. :deal:
You do not use quote and says things that I did not say never.




That is a lie repeated.

If the Earth's collision with a Near-Earth Object has changed Earth's rotation speed?
May be responsible for the extinction of the dinosaurs?
Sudden change of Earth rotation, can cause major disasters.

Now, call me a liar, again.


Emil: If not a very large impact - Explain clearly, WHAT could cause a severe change in the Earths rotation speed? I've asked you this question twice, now, and you've ignored it each time.
Answer them.

Don't ignore them and then claim later that I'm flat out lying about having asked. Answer them and you'll solve the problem at the start so that you need not fall back on ad hom attacks to account for your failures.

 

[Emil]

Now, call me a liar, again.

Now you do not lie,lied earlier when I said.

Emil: If not a very large impact - Explain clearly, WHAT could cause a severe change in the Earths rotation speed? I've asked you this question twice, now, and you've ignored it each time.
Answer them.

Don't ignore them and then claim later that I'm flat out lying about having asked. Answer them and you'll solve the problem at the start so that you need not fall back on ad hom attacks to account for your failures.

Now I'll have to teach you English is not my native language.
You understand the meaning of "if" and mark "?"

If the Earth's collision with a Near-Earth Object has changed Earth's rotation speed?

You answer a question with another question.This is stupid and pointless.

I will ignore you until you solve the problem with "Moron"

 

[Neverfly]

Now you do not lie,lied earlier when I said.

If I had not lied "now" then I could not have lied "then" considering each time I was saying the same thing.

Now I'll have to teach you English is not my native language.
You understand the meaning of "if" and mark "?"


You answer a question with another question.This is stupid and pointless.

Very well- There is no evidence of any impactor that has changed the rotation speed of the Earth. There is no evidence in any geological nor magnetic marker that demonstrates any change in the Earths rotation.
Furthermore, there is no evidence that anything has changed the Earths rotation speed as that would require another Massive celestial body.

So your proposal still fails flatly.

I will ignore you until you solve the problem with "Moron"

More ad hom. Perhaps when you learn to create reasoned posts, you won't have a problem with your anger issues.

 

[Emil]

Would you take a look at my earlier calculation and see if you agree with it. I think I show a three order of magnitude differnce from Emil, which matches your suspicion that he is out by 1000.

Certainly.
The centrifugal acceleration at the equator is given by V^2/R
where V is the velocity in m/second, R is the Earth's radius in metres.
V^2/R = (463^2)/(6378137) = 0.0336 m/s
Acceleration due to gravity 9.81 m/s
Percentage reduction in gravity due to centrifugal effect, 0.0336/9.81 = 0.34%

Correct.

If the day length were approximately six hours, then equatorial acceleration would be four times faster and the reduction in gravity would be a little less than 1.4%.

It is true only if six hours is day light length( day is 12 hours instead of 24 so the Earth moves 2 times faster).
So centrifugal force is greater than 2 ^ 2=4


If the Earth move five times faster then the centrifugal force is greater than 5 ^ 2=25

 

[Emil]

If I had not lied "now" then I could not have lied "then" considering each time I was saying the same thing.

Your proposal claims that the Earth was struck by an impactor...within recent times (At least 65 million years. LONG after the Big Whack).

I told quite clearly that this is a lie.Have to repeat several times?

There is no evidence in any geological nor magnetic marker that demonstrates any change in the Earths rotation.

You're just ignorant.

http://novan.com/earth.htm
http://en.wikipedia.org/wiki/Tidal_acceleration#Historical_evidence

So your proposal still fails flatly.

Why you have put yourself if that is your opinion?
Maybe others are interested in the topic.

More ad hom.

What?

 

[Neverfly]

I told quite clearly that this is a lie.Have to repeat several times?

Your lack of understanding and clarity does not make me a liar.
You DID make those claims. For you to continue to deny it after I quoted you- for you to call me a liar only makes a liar out of you. It's tiresome and you should grow up, already.

You're just ignorant.

http://novan.com/earth.htm
http://en.wikipedia.org/wiki/Tidal_acceleration#Historical_evidence

Irrelevant. The changes discussed there are small and gradual.

The changes you were proposing were catastrophic and significant.
Posting those links smacks of a lack of honesty on your part... Because those links are not related to what you were discussing.

There is a very large difference between the two. now, I admit, I worded that last post badly, but I was referring to your claim when I wrote it.

 

[Emil]

Neverfly (Enlightened Moron),

You do not understand anything I said.
When I say something,I sayex actly.No less and no more. :deal:
I already tired to show you all the inaccuracy and the crap you post.
Most do not understand why you put in this discussion, as you clearly are not interested? :shrug:

 

[Chipz]

Since once person - Orphiolite other than Emil wants verifications, I will do it from scratch.

Rotation of Earth:
$$\Omega_{e} = 7.2921150 E -05 \ (\frac{rad}{s})$$

Mean radius of Earth:
$$\bar{r_e} = 6,378.1 km = 6,378,100 m$$

If we are to are to assume that the day was at one point 6 hours and not 24 hours.

Then the modified $$\Omega_M$$ is...
$$\frac{24}{6}\Omega_e = 4\Omega_e = 2.916846 E -04 = \Omega_m$$

And the acceleration is equal to: $$\Omega^2 r$$.

Then the present acceleration is:
$$a_0 = \Omega_e^2 r_e = (7.2921150 E -05)^2(6,378,100) =(5.31749412 E -09)(6,378,100) \approx 0.0339 \ \frac{m}{s^2}$$

And the modified acceleration is:
$$a_m = \Omega_m^2 r_e = (2.916846 E -04)^2(6,378,100) =(8.50799059 E-08)(6,378,100) \approx .54426 \ \frac{m}{s^2} $$

Then the actual gravity at any point is equal to:
$$A = 9.81 - a cos(\theta)$$ If we take the equatorial region of $$\theta = 0$$ $$cos(0) = 1$$.

Then the acceleration today A is:
$$9.81 - .03 = a_0 = 9.78$$

Then the modified accelerationA is:
$$9.81 - .54426 = a_m = 9.27$$

And: $$\frac{a_m}{a_0} \approx .95$$

Which is equivalent to saying it was 95% of present acceleration... or 5% less acceleration at the Equator. Which is equivalent to 100 lbs being 95lbs at the equator.

Irregardless of previous statements, those are the facts.

 

[Neverfly]

Neverfly (Enlightened Moron),

You do not understand anything I said.
When I say something,I sayex actly.No less and no more.
I already tired to show you all the inaccuracy and the crap you post.
Most do not understand why you put in this discussion, as you clearly are not interested?

It's perfectly possible that I misunderstood you.

Calling me a liar, calling the actual science I put forth crap or making fun of a jocular status I added to my own profile does not exactly endear me to listen to your claims of misunderstanding.

Your initial post suggests nonsense. If I misunderstood it- Point out what is misunderstood instead of attacking the person angrily-- And you might get a better response.

But what I Observe in this thread is that you ASKED whether or not such could occur; but then argued with every answer given.

This suggests that it was not a question, but a proposal on your part that is very scientifically inaccurate - One you are trying to defend.

 

[Emil]

Since once person - Orphiolite other than Emil wants verifications, I will do it from scratch.

Rotation of Earth:
$$\Omega_{e} = 7.2921150 E -05 \ (\frac{rad}{s})$$

Mean radius of Earth:
$$\bar{r_e} = 6,378.1 km = 6,378,100 m$$

If we are to are to assume that the day was at one point 6 hours and not 24 hours.

Then the modified $$\Omega_M$$ is...
$$\frac{24}{6}\Omega_e = 4\Omega_e = 2.916846 E -04 = \Omega_m$$

And the acceleration is equal to: $$\Omega^2 r$$.

Then the present acceleration is:
$$a_0 = \Omega_e^2 r_e = (7.2921150 E -05)^2(6,378,100) =(5.31749412 E -09)(6,378,100) \approx 0.0339 \ \frac{m}{s^2}$$

And the modified acceleration is:
$$a_m = \Omega_m^2 r_e = (2.916846 E -04)^2(6,378,100) =(8.50799059 E-08)(6,378,100) \approx .54426 \ \frac{m}{s^2} $$

Then the actual gravity at any point is equal to:
$$A = 9.81 - a cos(\theta)$$ If we take the equatorial region of $$\theta = 0$$ $$cos(0) = 1$$.

Then the acceleration today A is:
$$9.81 - .03 = a_0 = 9.78$$

Then the modified accelerationA is:
$$9.81 - .54426 = a_m = 9.27$$

And: $$\frac{a_m}{a_0} \approx .95$$

Which is equivalent to saying it was 95% of present acceleration... or 5% less acceleration at the Equator. Which is equivalent to 100 lbs being 95lbs at the equator.

Irregardless of previous statements, those are the facts.

Correct.
How beautiful were If you would have started like that.
What is your opinion?
Can we calculate the shape of earth for an equivalent weight of 80%.?
After my calculations that means a rotation of the Earth 7.7 times faster(3h 6min instead of 24h).
To simplify assume that land is homogeneous and liquid.
But keep in mind that earth radius at the equator is changing and is no longer 6,378,000m.

 

[Ophiolite]

Correct.

So dipshit, Chipz's calculation result is approxiamtely the same as mine. Both are substantially different from yours. Please now concede that you were wrong. Or are you a coward as well as a fool?

 

[Emil]

So dipshit, Chipz's calculation result is approxiamtely the same as mine. Both are substantially different from yours. Please now concede that you were wrong. Or are you a coward as well as a fool?

You're simply a liar.

If the day length were approximately six hours, then equatorial acceleration would be four times faster and the reduction in gravity would be a little less than 1.4%.

If we are to are to assume that the day was at one point 6 hours and not 24 hours.
Which is equivalent to saying it was 95% of present acceleration... or 5% less acceleration at the Equator. Which is equivalent to 100 lbs being 95lbs at the equator.
Irregardless of previous statements, those are the facts.

So for you 1.4 = 5

 

[Chipz]

Emil, you're a crack pot. The Earth was never rotating exceptionally fast providing the capabilities of large growth in dinosaurs. You're simply a crack pot.

 

[Emil]

Emil, you're a crack pot. The Earth was never rotating exceptionally fast providing the capabilities of large growth in dinosaurs. You're simply a crack pot.

Now I understand.
You entered this thread to say that "You're simply a crack pot."
I respect your opinion but I want to talk to those who find something interesting in the following:

The Earth's rotation is slowing but at a much slower rate than 1 leap second every so many years. The length of time it takes the Earth, at the present time, to rotate once is 86,400.002 seconds compared to 86,400 seconds back in 1820. The rotation has slowed roughly only by 2 milliseconds since 1820. That seems like an insignificant amount of time BUT over the course of the planet's entire lifetime, it has had very profound effects on the geophysics of the planet.

It has caused mountains to rise, earthquakes, etc. to occur as we will see. This article is about, factoring in the tremendous geophysical activity that was caused, by the Earth's slowing rotation, in the interior of the planet, its crust, oceans and atmosphere over its entire lifetime.

The Sub-bureau for Rapid Service and Predictions of Earth Orientation Parameters of the International Earth Rotation Service (IERS), located at the US Naval Observatory, monitors the Earth's rotation. Part of its mission involves the determination of a time scale based on the current rate of the rotation of the Earth.

They estimate that the Earth's rotation is slowing at about 1.4 milliseconds per solar day per century which roughly agrees with the rate of rotation of the Earth has actually slowed down since 1820.

Tracing these tiny milliseconds back for 4.5 billion years adds up to a very significant amount of time for a solar day. I have determined that the day/night rotation was 63,000 seconds shorter than the present 86,400 seconds it is today. This would put the Earth's rotation at about 6.5 hours per day/night cycle, when it was created, 4.5 billion years ago. (This is a much faster rate of rotation than the Cassini-Huygens mission (2003 to 2004) determined Saturn's 10.5 hours rotation period to be.)

This rate of rotation would have exerted tremendous stress throughout the newly formed planet. If the rate of rotation has been slowing fairly constantly, over the ages, we can see that the earth was rotating very fast originally, for it to slow down to the present 24 hour rate it is today. What ever it was - its angular momentum was much faster and therefore its "centrifugal force" was tremendously strong when the planet was very young. This caused the young, fast spinning, Earth to have a much more pronounced oblate shape, possibly even having a "Saturn type ring" orbiting around it.

In the past, when the Earth was younger and spinning faster, the stronger angular momentum caused the Earth to assume a more pronounced oblate spheroid shape much greater than the twenty-seven miles it is today. A 15% increase in the equatorial circumference of the faster rotating young planet, relative to its present rotation, could produce approximately 3600 more miles of surface around the young planet's equatorial zone.

This was a lot of surface to crunch into the ever changing shape of the planet as its rotation gradually slowed over the ages. Since the ratio of strength of gravity and angular momentum (centrifugal force)is always changing, the shape of the planet never reaches equalibrium - it is always changing.

(The fast spinning star, Vega, makes a full rotation about its axis once every 12.5 hours, (only about 1/2 the Earth's early rate) which causes it to assume a 23% ellipical bulge at its equator, so a 15% greater bulge for the faster spinning Earth is not out of the question.)

The constant struggle between gravitational force and the weakening angular momentum caused by the slowing of the Earth's rotation, has had a profound effect on the Earth's geophysical activity throughout the ages. This constant struggle between these two gigantic forces has caused a continual adjusting of the Earth's shape as the ratio of the strengths of angular momentum and gravity have changed.

http://novan.com/earth.htm

Historical evidence
This mechanism has been working for 4.5 billion years, since oceans first formed on the Earth. There is geological and paleontological evidence that the Earth rotated faster and that the Moon was closer to the Earth in the remote past. Tidal rhythmites are alternating layers of sand and silt laid down offshore from estuaries having great tidal flows. Daily, monthly and seasonal cycles can be found in the deposits. This geological record is consistent with these conditions 620 million years ago: the day was 21.9±0.4 hours, and there were 13.1±0.1 synodic months/year and 400±7 solar days/year. The length of the year has remained virtually unchanged during this period because no evidence exists that the constant of gravitation has changed. The average recession rate of the Moon between then and now has been 2.17±0.31 cm/year, which is about half the present rate.

http://en.wikipedia.org/wiki/Tidal_acceleration#Historical_evidence

 

[Emil]

Unfortunately, until now I had to argue the accuracy of mathematical calculations.
I was angry because the calculations were correct and I believe the discussion was hijacked.
Only Neverfly once reached the theme asking about the impact.
But I do not want to convince anyone that I am right. I'm looking for conversation partners, to explore this hypothesis and eventually to reach a conclusion.
Those who want their opinion to be mentioned, namely that this topic is crap,
say their opinion but do not insist.
Those who come with arguments for and against are welcome.
The proposing is not a statement.It is a working hypothesis.Those who worked in research know what that means (I hope Google translate correctly translated.I check several times but even so may appear inaccurate and incorrect sentences.)


Indices for which I think is worth exploring this hypothesis are:

Kinetic energy of a body is mV ^ 2 / 2.
In my opinion, energy loss due to water movement is not a linear function.

The Sub-bureau for Rapid Service and Predictions of Earth Orientation Parameters of the International Earth Rotation Service (IERS), located at the US Naval Observatory, monitors the Earth's rotation. Part of its mission involves the determination of a time scale based on the current rate of the rotation of the Earth.They estimate that the Earth's rotation is slowing at about 1.4 milliseconds per solar day per century which roughly agrees with the rate of rotation of the Earth has actually slowed down since 1820.

In my opinion is not a simple multiplication between the number of days and 1.4 milliseconds.
To have a clearer picture should form a team of specialists, geologists, mathematicians and programmers specialize in computer modeling of dynamic systems.To do a dynamic model of the Earth.

Angular momentum and energy
The gravitational torque between the Moon and the tidal bulge of the Earth causes the Moon to be promoted in its orbit, and the Earth to be decelerated in its rotation. As in any physical process within an isolated system, total energy and angular momentum are conserved. Effectively, energy and angular momentum are transferred from the rotation of the Earth to the orbital motion of the Moon (however, most of the energy lost by the Earth is converted to heat, and only about one 30th is transferred to the Moon). The Moon moves farther away from the Earth, so its potential energy (in the Earth's gravity well) increases. It stays in orbit, and from Kepler's 3rd law it follows that its velocity actually decreases, so the tidal action on the Moon actually causes a deceleration of its motion across the celestial sphere. Although its kinetic energy decreases, its potential energy increases by a larger amount. The tidal force has a component in the direction of the Moon's motion, and therefore increases its energy, but the non-tidal part of the Earth's gravity pulls (on average) slightly backwards on the Moon (which on average has a slight outward velocity), so the net result is that the Moon slows down. The Moon's orbital angular momentum increases.
The rotational angular momentum of the Earth decreases and consequently the length of the day increases. The net tide raised on Earth by the Moon is dragged ahead of the Moon by Earth's much faster rotation. Tidal friction is required to drag and maintain the bulge ahead of the Moon, and it dissipates the excess energy of the exchange of rotational and orbital energy between the Earth and Moon as heat. If the friction and heat dissipation were not present, the Moon's gravitational force on the tidal bulge would rapidly (within two days) bring the tide back into synchronization with the Moon, and the Moon would no longer recede. Most of the dissipation occurs in a turbulent bottom boundary layer in shallow seas such as the European shelf around the British Isles, the Patagonian shelf off Argentina, and the Bering Sea.[10]
The dissipation of energy by tidal friction averages about 3.75 terawatts, of which 2.5 terawatts are from the principal M2 lunar component and the remainder from other components, both lunar and solar.[11]
An equilibrium tidal bulge does not really exist on Earth because the continents do not allow this mathematical solution to take place. Oceanic tides actually rotate around the oceans basin as vast gyres around several amphidromic points where no tide exists. The Moon pulls on each individual undulation as Earth rotates—some undulations are ahead of the Moon, others are behind it, while still others are on either side. The "bulges" that actually do exist for the Moon to pull on (and which pull on the Moon) are the net result of integrating the actual undulations over all the world's oceans. Earth's net (or equivalent) equilibrium tide has an amplitude of only 3.23 cm, which is totally swamped by oceanic tides that can exceed one metre.

http://en.wikipedia.org/wiki/Tidal_acceleration

With this dynamic model of Earth, we can give time back and forth and we could simulate the Earth's rotation from the past.


Other indices:

The Permian–Triassic (P–Tr) extinction event, informally known as the Great Dying,[1] was an extinction event that occurred 251.4 million years ago,[2][3] forming the boundary between the Permian and Triassic geologic periods. It was the Earth's most severe extinction event, with up to 96% of all marine species[4] and 70% of terrestrial vertebrate species becoming extinct; it is the only known mass extinction of insects.[5][6] 57% of all families and 83% of all genera were killed. Because so much biodiversity was lost, the recovery of life on Earth took significantly longer than after other extinction events.[4] This event has been described as the "mother of all mass extinctions.

Researchers have variously suggested that there were from one to three distinct pulses, or phases, of extinction.[2][8][9] There are several proposed mechanisms for the extinctions; the earlier phase was likely due to gradual environmental change, while the latter phase has been argued to be due to a catastrophic event. Suggested mechanisms for the latter include large or multiple bolide impact events, increased volcanism, and sudden release of methane clathrate from the sea floor; gradual changes include sea-level change, anoxia, increasing aridity,[10] and a shift in ocean circulation driven by climate change.

Impact event
Evidence that an impact event caused the Cretaceous–Tertiary extinction event has led to speculation that similar impacts may have been the cause of other extinction events, including the P–Tr extinction, and therefore to a search for evidence of impacts at the times of other extinctions and for large impact craters of the appropriate age.
Reported evidence for an impact event from the P–Tr boundary level includes rare grains of shocked quartz in Australia and Antarctica;[71][72] fullerenes trapping extraterrestrial noble gases;[73] meteorite fragments in Antarctica;[74] and grains rich in iron, nickel and silicon, which may have been created by an impact.[75] However, the accuracy of most of these claims has been challenged.[76][77][78][79] Quartz from Graphite Peak in Antarctica, for example, once considered "shocked," has recently been reexamined by optical and transmission electron microscopy. It was concluded that the observed features were not due to shock, but rather to plastic deformation, consistent with formation in a tectonic environment such as volcanism.[80]
Several possible impact craters have been proposed as possible causes of the P–Tr extinction, including the Bedout structure off the northwest coast of Australia,[72] the so-called Wilkes Land crater of East Antarctica,[81][82] and, even more speculatively, the Gulf of Mexico.[83] In each of these cases the idea that an impact was responsible has not been proven, and some have been widely criticized. In the case of Wilkes Land, the age of this sub-ice geophysical feature is very uncertain – it may be later than the Permian–Triassic extinction.

Sea level fluctuations
Marine regression occurs when areas of submerged seafloor are exposed above sea level. This lowering of sea level causes a reduction in shallow marine habitats, leading to biotic turnover. Shallow marine habitats are productive areas for organisms at the bottom of the food chain, their loss increasing competition for food sources.[104] There is some correlation between incidents of pronounced sea level regression and mass extinctions, but other evidence indicates there is no relationship and that regression may itself create new habitats.[10] It has also been suggested that sea-level changes result in changes in sediment deposition rates and effects water temperature and salinity, resulting in a decline in marine diversity

The supercontinent Pangaea
Map of Pangaea showing where today's continents were at the Permian–Triassic boundary
About half way through the Permian (in the Kungurian age of the Permian's Cisuralian epoch) all the continents joined to form the supercontinent Pangaea, surrounded by the superocean Panthalassa, although blocks which are now parts of Asia did not join the supercontinent until very late in the Permian.[111] This configuration severely decreased the extent of shallow aquatic environments, the most productive part of the seas, and exposed formerly isolated organisms of the rich continental shelves to competition from invaders. Pangaea's formation would also have altered both oceanic circulation and atmospheric weather patterns, creating seasonal monsoons near the coasts and an arid climate in the vast continental interior.
Marine life suffered very high but not catastrophic rates of extinction after the formation of Pangaea (see the diagram "Marine genus biodiversity" at the top of this article) - almost as high as in some of the "Big Five" mass extinctions. The formation of Pangaea seems not to have caused a significant rise in extinction levels on land, and in fact most of the advance of the therapsids and increase in their diversity seems to have occurred in the late Permian, after Pangaea was almost complete. So it seems likely that Pangaea initiated a long period of increased marine extinctions but was not directly responsible for the "Great Dying" and the end of the Permian.

Combination of causes
The possible causes which are supported by strong evidence (see above) appear to describe a sequence of catastrophes, each one worse than the previous: the Siberian Traps eruptions were bad enough in their own right, but because they occurred near coal beds and the continental shelf, they also triggered very large releases of carbon dioxide and methane.[54] The resultant global warming may have caused perhaps the most severe anoxic event in the oceans' history: according to this theory, the oceans became so anoxic that anaerobic sulfur-reducing organisms dominated the chemistry of the oceans and caused massive emissions of toxic hydrogen sulfide.[54]
However, there may be some weak links in this chain of events: the changes in the 13C/12C ratio expected to result from a massive release of methane do not match the patterns seen throughout the early Triassic;[11] and the types of oceanic thermohaline circulation which may have existed at the end of the Permian are not likely to have supported deep-sea anoxia.[108]
In a paper published in the December 2002 issue of the American Association of Petroleum Geologists' publication "Explorer", Canadian geologist Michael S. Stanton proposed that the Gulf of Mexico is a giant astrobleme created at the time of the Permian extinction event. Stanton stated the various reasons for his theory by explaining that if the gulf is of impact origin, it would be similar in size to the Moon's smallest maria.

http://en.wikipedia.org/wiki/Permian–Triassic_extinction_event


Another clues:

The K–T boundary is a geological signature, usually a thin band, dated to (65.5 ± 0.3) Ma (megaannum, or million years ago).[1] K is the traditional abbreviation for the Cretaceous period, and T is the abbreviation for the Tertiary period. The boundary marks the end of the Mesozoic era and the beginning of the Cenozoic era, and is associated with the Cretaceous–Tertiary extinction event, a mass extinction.[2] With "Tertiary" being discouraged as a formal time or rock unit by the International Commission on Stratigraphy, the K–T extinction event is now called the Cretaceous–Paleogene (or K–Pg) event by many researchers.[3]

Alvarez impact hypothesis
In 1980, a team of researchers consisting of Nobel prize-winning physicist Luis Alvarez, his son, geologist Walter Alvarez, and chemists Frank Asaro and Helen Michels discovered that sedimentary layers found all over the world at the Cretaceous–Tertiary boundary contain a concentration of iridium many times greater than normal (30 times background in Italy and 160 times at Stevns[4]). Iridium is extremely rare in the earth's crust because it is a siderophile, and therefore most of it travelled with iron as it sank into the earth's core during planetary differentiation. As iridium remains abundant in most asteroids and comets, the Alvarez team suggested that an asteroid struck the earth at the time of the K–T boundary.[5] There were other earlier speculations on the possibility of an impact event, but no evidence had been uncovered at that time.[6]

Chicxulub Crater
When it was originally proposed, one issue with the "Alvarez hypothesis" (as it came to be known) had been that no documented crater matched the event. This was not a lethal blow to the theory; while the crater resulting from the impact would have been larger than 250 kilometres (160 mi) in diameter, Earth's geological processes hide or destroy craters over time.[11]
Subsequent research, however, identified the Chicxulub Crater buried under Chicxulub on the coast of Yucatan, Mexico as the impact crater which matched the Alvarez hypothesis dating. Identified in 1990 based on the work of Glen Penfield done in 1978, this crater is oval, with an average diameter of about 180 kilometres (110 mi), about the size calculated by the Alvarez team.[12]

Multiple impact event
Several other craters also appear to have been formed about the time of the K–T boundary. This suggests the possibility of near simultaneous multiple impacts, perhaps from a fragmented asteroidal object, similar to the Shoemaker-Levy 9 cometary impact with Jupiter. Among these are the Boltysh crater, a 24 km (15 mi) diameter impact crater in Ukraine (65.17 ± 0.64 Ma); and the Silverpit crater, a 20 km (12 mi) diameter impact crater in the North Sea (60–65 Ma). Any other craters that might have formed in the Tethys Ocean would have been obscured by tectonic events like the relentless northward drift of Africa and India.[17][18][19]
A very large structure in the sea floor off the west coast of India has recently been interpreted as a crater by some researchers.[20] The potential Shiva crater, 450–600 km (280–370 mi) in diameter, would substantially exceed Chicxulub in size and has also been dated at about 65 mya, an age consistent with the K–T boundary. An impact at this site could have been the triggering event for the nearby Deccan Traps.[21] However, this feature has not yet been accepted by the geologic community as an impact crater and may just be a sinkhole depression caused by salt withdrawal.

Maastrichtian marine regression (not a sea level fall)
Clear evidence exists that sea levels fell in the final stage of the Cretaceous by more than at any other time in the Mesozoic era. In some Maastrichtian stage rock layers from various parts of the world, the later ones are terrestrial; earlier ones represent shorelines and the earliest represent seabeds. These layers do not show the tilting and distortion associated with mountain building; therefore, the likeliest explanation is a regression, that is, a buildout of sediment, but not necessarily a drop in sea level. No direct evidence exists for the cause of the regression, but the explanation which is currently accepted as the most likely is that the mid-ocean ridges became less active and therefore sank under their own weight as sediment from uplifted orogenic belts filled in structural basins.

http://en.wikipedia.org/wiki/K–T_boundary

Another clues:

Confirmed impact craters listed by size
Only the largest craters (20km or more diameter) are listed below; the rest are listed by geographical region on subsidiary lists. These features were caused by the collision of large meteorites or comets with the Earth. For eroded or buried craters the stated diameter typically refers to an estimate of original rim diameter and may not correspond to present surface features.

http://en.wikipedia.org/wiki/List_of_impact_craters_on_Earth


But land is only 30% of the earth.But the events that took place on ocean surface?

A very large structure in the sea floor off the west coast of India has recently been interpreted as a crater by some researchers.[20] The potential Shiva crater, 450–600 km (280–370 mi) in diameter, would substantially exceed Chicxulub in size and has also been dated at about 65 mya, an age consistent with the K–T boundary. An impact at this site could have been the triggering event for the nearby Deccan Traps.[21] However, this feature has not yet been accepted by the geologic community as an impact crater and may just be a sinkhole depression caused by salt withdrawal.

The probability that these impacts alter the rotation axis and rotation of the earth are very high.As the impact direction is perpendicular to the earth's surface is very small.
In my opinion these events have not been sufficiently analyzed in terms of change of rotational speed of the Earth and even change the axis of rotation.

 

[Ophiolite]

Unfortunately, until now I had to argue the accuracy of mathematical calculations.

That's because your calculations are screwed up.

 

[Neverfly]

Emil, I took my time and I read that entire long post.

Here is my basic understanding of what you are saying...:

That all the scientists that studied the impact craters, all the celestial mechanics, all the math- Is wrong. And You, solely, are right.

That IS possible, although that possibility is very remote. And, again, examination and independent verification on your part is a Great Thing.

But here's what I suggest... If you truly think it's ALL wrong- show how it is. In the process, if you are wrong, you'll learn a lot along the way and come out stronger.
If you're correct, you can take your findings to peer reviewed journals and universities and be recognized and do a service for science.

About the only thing you can do on this forum is MAYBE check your work. That's it.

Now, my two bits:
Many of those impact craters show evidence as to the direction of the impact. In the cases of some, they impacted at an angle toward the rotation of the Earths rotation. The change in Earth rotation for the vast majority of them is quite negligible. The mass of the Earth is significantly greater than the mass of those objects that hit it.
Additionally, the force and results of the impacts is due to Speed upon impact and not mass upon impact.
Some of the impacts were against the rotation of the Earth, causing a very slight acceleration in the opposite direction. Again, pretty negligible.

You must remember, the Earth is mostly Fluid. It's not a solid ball.

In order to significantly (As Your OP Asked-- because yes, the Earths rotation has slowly accelerated in the opposite direction due to tidal forces, etc Significantly enough to cause mass extinctions) alter the Earths rotation, an impact event must cause an acceleration in either direction and be the result of a mass about (Back of envelope guess with Earth mass at 5.98 x 1024 kg and "Significant" as defined as greater than 2 seconds per day even though that amount is not significant enough to cause mass extinctions) ...
the size of Montana * Correction, I forgot to convert English to Metric <blush> make that closer to Two Montanas- Which is more than big enough to kill all life on Earth including bacteria.

Anything larger, that can cause a more significant change in the rotation speed of Earth, obviously is no more deadly to what's already dead.

 

[Emil]

I understand your position.
I still remain to my conclusion and my position.

In my opinion these events have not been sufficiently analyzed in terms of change of rotational speed of the Earth and even change the axis of rotation.

If you're correct, you can take your findings to peer reviewed journals and universities and be recognized and do a service for science.

I seriously say this does not interest me.
I wanted a discussion on this issue in a pleasant and modest circumstances. (What has failed, at least in the first part.)


What interests me and upset me because nothing happens,is my first thread.
http://www.sciforums.com/showthread.php?t=101648
And I think people are more stupid than I thought as before.

 

[Neverfly]

I understand your position.
I still remain to my conclusion and my position.

If you're taking a stance as you clearly are- You must DEFEND that "against the mainstream position." You do this by showing your work and your math and explaining WHY you reached the conclusion that you reached.

If you do not know, then you cannot be standing to a position, can you?

"I don't know" can be an acceptable answer if you're asking innocent questions.
But it is not acceptable if you have reached a conclusion, now is it?

And that's why I've been harsh with you. Because you're taking a stance and not showing your work, you're attacking others. You're not demonstrating why you have concluded what you have- You are insulting other posters.

You're making a stand without standing up. Without answering basic questions.

I seriously say this does not interest me.
I wanted a discussion on this issue in a pleasant and modest circumstances. (What has failed, at least in the first part.)

And I just explained why it is failing.

And I think people are more stupid than I thought as before.

Yes, that's a great way to make pleasant conversation...

Fact is; if you want a pleasant conversation when you've put forth a conclusion- You're not going to get one.

You're going to get scrutinized and demanded to support your conclusion with hard evidence.

Deal With It.