LET'S Put it In Perspective!

[Vagabond]

Have you never heard of tenured professorships?

 

Yep - my academic post was tenured.

 

However, increasingly these days, many academics are on short term contracts, which depend on research grants for renewal.

 

There is thus the temptation to tell grant awarding bodies what they want to hear. Its a rat race I'm glad I was never in, but saw it begin to happen to younger colleagues just before I retired. I felt really sorry for them.

 

I remember the hou-ha when a group of scientists thought they had found traces of life on a bit of moon rock. Turned out it was contamination in the lab. Lots of red faces and a couple of careers in tatters.

 

...and BTW note the word hypothesis in my post of 3.56pm yesterday. A hypothesis does not need proof - its an explanation of a set of circumstances which is consistent with what is already known. The explanation is believed to be true until (if ever) some new evidence turns up to disprove it.

 

Show me the little green men, eighty-limbed arthropods or whatever, and I will abandon my hypothesis.

 

Going fishing for a few days - will look at this thread again when I get back.

[chesters1]

what if the earth did have a "population" before our fossil records begin ,perhaps the earth is on its second term in the case of living beings?

perhaps billions of years ago humanoids were pottering about and suddenly the earth was hit by a huge meteor which caused such an impact all the plates floating about on the magma were destroyed and all fossil records were destroyed also by the rock remelting ? ,slowly perhaps everything settled down again and the only signs of this past calamity are the metamorphic rocks ,perhaps cornwall was the birthplace of the first set of beings.

remember all our "knowledge" is little more than guess work based on speculation the big bang is just one line of thinking amoungst several.

the big bang lookes dodgy to me it doesent explain distance ,surely if a big ball exploded everything would go outward at the same speed (theres nothing to slow it down bar the gravity of the "material") which lessens as it thins as the material spreads so should be speeding up rather than slowing down in its travels

also why no big hole (i.e no material where it was?) .it also doesent explain why galaxies are moving in different directions to each other i.e some are at angles moving nearer or further away from each other.

and ofcourse it doesent explain where the material came from in the first place ,perhaps it was attracted there by a huge black hole and life was rampant but destroyed as the stars and planets were dragged into that ball! perhaps its a fluke and life had been existing for trillions of years before or its an ongoing thing that recurs like ice ages here but over a huge time period.

 

as for us being the only ones i doupt that very much were just a drip in the ocean (as it were) life must exist elsewhere just because you havent seen it doesent mean its not there ,new species are found regularly under our feet on earth if we havent spotted them before is it so hard to believe there isnt life outside our atmosphere wheres its far harder to trip over?

 

man as we imagine it has been around for just a blink in time are we so pompouse that we are the supreme beings everywhere ? had man formed and became extinct in the time of the dinosaurs then it would have been just a hiccup in the dinosaurs stint on earth.dinos ruled the earth for 160? million years if they still were here (yes some are) i expect they would chuckle over these puny humans and their so short time in existance and their arrogance

Edited August 20, 2007 by chesters1

[corydoras]

what if the earth did have a "population" before our fossil records begin ,perhaps the earth is on its second term in the case of living beings?

perhaps billions of years ago humanoids were pottering about and suddenly the earth was hit by a huge meteor which caused such an impact all the plates floating about on the magma were destroyed and all fossil records were destroyed also by the rock remelting ? ,slowly perhaps everything settled down again and the only signs of this past calamity are the metamorphic rocks ,perhaps cornwall was the birthplace of the first set of beings.

It's very unlikely chesters. Current estimates for the age of our solar system and the earth itself are about 4.5 billion years. The oldest fossils we know of are cyanobacteria from the Archaean rocks of Western Australia these date to about 3.5 billion years. The oldest rocks that we have been able to find are about 4 billion years old, and these contain minerals that are 4.2 billion years old.

Edited August 20, 2007 by corydoras

[chesters1]

estimates based on what?

[chesters1]

estimates based on what?

why cannot our oldest rocks just be far older ones melted down in a global catastrophy ,it wouldnt be the first time weve been hit by huge lumps of rock perhaps the earth is on its 3rd or 4th "format"

whoops database error then!

Edited August 20, 2007 by chesters1

[Ken L]

AGE OF THE EARTH

So far scientists have not found a way to determine the exact age of the Earth directly from Earth rocks because Earth's oldest rocks have been recycled and destroyed by the process of plate tectonics. If there are any of Earth's primordial rocks left in their original state, they have not yet been found. Nevertheless, scientists have been able to determine the probable age of the Solar System and to calculate an age for the Earth by assuming that the Earth and the rest of the solid bodies in the Solar System formed at the same time and are, therefore, of the same age.

 

The ages of Earth and Moon rocks and of meteorites are measured by the decay of long-lived radioactive isotopes of elements that occur naturally in rocks and minerals and that decay with half lives of 700 million to more than 100 billion years to stable isotopes of other elements. These dating techniques, which are firmly grounded in physics and are known collectively as radiometric dating, are used to measure the last time that the rock being dated was either melted or disturbed sufficiently to rehomogenize its radioactive elements.

 

 

Click on the image to see a graphical representation of geologic time

[344K]

 

Ancient rocks exceeding 3.5 billion years in age are found on all of Earth's continents. The oldest rocks on Earth found so far are the Acasta Gneisses in northwestern Canada near Great Slave Lake (4.03 Ga) and the Isua Supracrustal rocks in West Greenland (3.7 to 3.8 Ga), but well-studied rocks nearly as old are also found in the Minnesota River Valley and northern Michigan (3.5-3.7 billion years), in Swaziland (3.4-3.5 billion years), and in Western Australia (3.4-3.6 billion years). [see Editor's Note.] These ancient rocks have been dated by a number of radiometric dating methods and the consistency of the results give scientists confidence that the ages are correct to within a few percent. An interesting feature of these ancient rocks is that they are not from any sort of "primordial crust" but are lava flows and sediments deposited in shallow water, an indication that Earth history began well before these rocks were deposited. In Western Australia, single zircon crystals found in younger sedimentary rocks have radiometric ages of as much as 4.3 billion years, making these tiny crystals the oldest materials to be found on Earth so far. The source rocks for these zircon crystals have not yet been found. The ages measured for Earth's oldest rocks and oldest crystals show that the Earth is at least 4.3 billion years in age but do not reveal the exact age of Earth's formation. The best age for the Earth (4.54 Ga) is based on old, presumed single-stage leads coupled with the Pb ratios in troilite from iron meteorites, specifically the Canyon Diablo meteorite. In addition, mineral grains (zircon) with U-Pb ages of 4.4 Ga have recently been reported from sedimentary rocks in west-central Australia. The Moon is a more primitive planet than Earth because it has not been disturbed by plate tectonics; thus, some of its more ancient rocks are more plentiful. Only a small number of rocks were returned to Earth by the six Apollo and three Luna missions. These rocks vary greatly in age, a reflection of their different ages of formation and their subsequent histories. The oldest dated moon rocks, however, have ages between 4.4 and 4.5 billion years and provide a minimum age for the formation of our nearest planetary neighbor. Thousands of meteorites, which are fragments of asteroids that fall to Earth, have been recovered. These primitive objects provide the best ages for the time of formation of the Solar System. There are more than 70 meteorites, of different types, whose ages have been measured using radiometric dating techniques. The results show that the meteorites, and therefore the Solar System, formed between 4.53 and 4.58 billion years ago. The best age for the Earth comes not from dating individual rocks but by considering the Earth and meteorites as part of the same evolving system in which the isotopic composition of lead, specifically the ratio of lead-207 to lead-206 changes over time owing to the decay of radioactive uranium-235 and uranium-238, respectively. Scientists have used this approach to determine the time required for the isotopes in the Earth's oldest lead ores, of which there are only a few, to evolve from its primordial composition, as measured in uranium-free phases of iron meteorites, to its compositions at the time these lead ores separated from their mantle reservoirs. These calculations result in an age for the Earth and meteorites, and hence the Solar System, of 4.54 billion years with an uncertainty of less than 1 percent. To be precise, this age represents the last time that lead isotopes were homogeneous througout the inner Solar System and the time that lead and uranium was incorporated into the solid bodies of the Solar System. The age of 4.54 billion years found for the Solar System and Earth is consistent with current calculations of 11 to 13 billion years for the age of the Milky Way Galaxy (based on the stage of evolution of globular cluster stars) and the age of 10 to 15 billion years for the age of the Universe (based on the recession of distant galaxies).

 

For additional information on this subject, see G. Brent Dalrymple's The Age of the Earth, published by the Stanford University Press (Stanford, Calif.) in 1991 (492 p.).

[chesters1]

Ancient rocks exceeding 3.5 billion years in age are found on all of Earth's continents. The oldest rocks on Earth found so far are the Acasta Gneisses in northwestern Canada near Great Slave Lake (4.03 Ga) and the Isua Supracrustal rocks in West Greenland (3.7 to 3.8 Ga), but well-studied rocks nearly as old are also found in the Minnesota River Valley and northern Michigan (3.5-3.7 billion years), in Swaziland (3.4-3.5 billion years), and in Western Australia (3.4-3.6 billion years). [see Editor's Note.] These ancient rocks have been dated by a number of radiometric dating methods and the consistency of the results give scientists confidence that the ages are correct to within a few percent. An interesting feature of these ancient rocks is that they are not from any sort of "primordial crust" but are lava flows and sediments deposited in shallow water, an indication that Earth history began well before these rocks were deposited YYYY

. In Western Australia, single zircon crystals found in younger sedimentary rocks have radiometric ages of as much as 4.3 billion years, making these tiny crystals the oldest materials to be found on Earth so far. The source rocks for these zircon crystals have not yet been found. The ages measured for Earth's oldest rocks and oldest crystals show that the Earth is at least 4.3 billion years in age but do not reveal the exact age of Earth's formation. The best age for the Earth (4.54 Ga) is based on old, presumed single-stage leads coupled with the Pb ratios in troilite from iron meteorites, specifically the Canyon Diablo meteorite. In addition, mineral grains (zircon) with U-Pb ages of 4.4 Ga have recently been reported from sedimentary rocks in west-central Australia. The Moon is a more primitive planet than Earth because it has not been disturbed by plate tectonics; thus, some of its more ancient rocks are more plentiful. Only a small number of rocks were returned to Earth by the six Apollo and three Luna missions. These rocks vary greatly in age, a reflection of their different ages of formation and their subsequent histories. The oldest dated moon rocks, however, have ages between 4.4 and 4.5 billion years and provide a minimum age for the formation of our nearest planetary neighbor. XXXXX

Thousands of meteorites, which are fragments of asteroids that fall to Earth, have been recovered. These primitive objects provide the best ages for the time of formation of the Solar System. There are more than 70 meteorites, of different types, whose ages have been measured using radiometric dating techniques. The results show that the meteorites, and therefore the Solar System, formed between 4.53 and 4.58 billion years ago. The best age for the Earth comes not from dating individual rocks but by considering the Earth and meteorites as part of the same evolving system in which the isotopic composition of lead, specifically the ratio of lead-207 to lead-206 changes over time owing to the decay of radioactive uranium-235 and uranium-238, respectively. Scientists have used this approach to determine the time required for the isotopes in the Earth's oldest lead ores, of which there are only a few, to evolve from its primordial composition, as measured in uranium-free phases of iron meteorites, to its compositions at the time these lead ores separated from their mantle reservoirs. These calculations result in an age for the Earth and meteorites, and hence the Solar System, of 4.54 billion years with an uncertainty of less than 1 percent. To be precise, this age represents the last time that lead isotopes were homogeneous througout the inner Solar System and the time that lead and uranium was incorporated into the solid bodies of the Solar System. The age of 4.54 billion years found for the Solar System and Earth is consistent with current calculations of 11 to 13 billion years for the age of the Milky Way Galaxy (based on the stage of evolution of globular cluster stars) and the age of 10 to 15 billion years for the age of the Universe (based on the recession of distant galaxies).

 

For additional information on this subject, see G. Brent Dalrymple's The Age of the Earth, published by the Stanford University Press (Stanford, Calif.) in 1991 (492 p.).

YYY therefore the earth must be far older than the rocks

XXXX if the moon hasent been disturbed by techtonics then thos rocks returned would be new rocks the oldest will be far down and certainly out of reach of chaps having a holiday.its the minimum age not the eldest the moon is therefore theres only speculation that the earth is younger.if it could be proved the moon came from putside our solar system it could ofcourse be older ,but its strange the moon is old the earth and meterorites are just 4.5 billion years old

 

the whole aging thing is based on the recession of distant galaxies which is ofcourse based on the big bang theory

ansd also based on the notion that the meterorites and earth were formed at the same time again another supposition.

the dating revolves around radioactive decay ,had the earth had a cataclysm as i have suggested the separation from the mantle of the elements would be 4.5 billion years ago but whats to say its the first time the metals separated from the mantel? the melting of rocks would ofcourse start the decay off again as they left their comfy mantel pool maybe not for the first time.

 

theres far to much presumption ,speculation and supposition but little if any fact to back it up and ofcourse in my scenario as well

Edited August 20, 2007 by chesters1

[Ken L]

Now I thought your theory was confined to previous life on the Earth which is rather unlikely as acording to all the evidence found so far, this would require:

The Earth to be several times older than the rest of the solar system.

Ideal conditions for the evolution of not only life but advanced intelegent life to have occured not once but twice.

Some sort of catastrophie big enough to wipe clean all traces of both the life and the rocks that were originally at the surface of the prior Earth.

Some way of getting the Earth into our newly forming solar system at the same time as it's own rocks were forming.

 

I'll go with Okham on this one.

 

 

The wider idea of inflating and contracting universes is a little more plausable but by definition, there would be no evidence of the existance of previous universes because both space and time would cease to exist between expantions.

Edited August 22, 2007 by Ken L

[corydoras]

I'll go with Okham on this one.

Me too. Have you never heard of Okham's Razor Chesters?

Edited August 21, 2007 by corydoras

[Bobj]

Rejuvenating this thread again. Have a squiz in this lot....I dare you

 

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