What proof is there on the age of the Earth?

Question

People say it is 4,600 years old but how do they know this?

This isn't religiously - I mean geologicaly - did they just find some rocks or what?

I mean 4,600 million years - sorry

Answer 1

They don't, that answer is strictly based on geneology and not geophysical evidence. The best evidence we have so far is Uranium 235/238 ratios.

Rocks. The evidence is in rocks. (and the moon, another rock).

Answer 2

Carbon dating is rarely used on rocks. Most use radioactive dating, and these scientists state that the earth is 4.5 billion years old. The problem with this type of dating is that three things MUST remain constant: When the rock forms (hardens) there should only be parent radioactive atoms in the rock and no daughter radiogenic (derived by radioactive decay of another element) atoms; After hardening, the rock must remain a closed system, that is, no parent or daughter atoms should be added to or removed from the rock by external influences such as percolating groundwaters; and the radioactive decay rate must remain constant. If any of these things don’t occur, then the results are false. The potassium-argon dating method has failed many times on volcanic rock. There is a lot of “interpretations” and “assumptions” but there really isn’t anything to positively compare the results to. If the readings agree with the geologists’ interpretation of how old they should be, then they are considered to be accurate. As far as Christians believing that the earth is only 6000 or so years old, that is not true with all Christians. I have no idea how many years Adam and Eve were in the Garden of Eden, so it would be impossible to guess. Also to God one day is as a thousand, (which I do not say that it is literal as it could be figurative but it does say that God’s time is not our own) so one week to God would not mean one week to us. So no one REALLY knows how old the earth is. Lastly, Carbon 14 dating can only go back thousands of years, no more.

Answer 3

It's in the rocks, the rocks.
But, a lot of it is estimation. Estimation on how long it took the stars and planets to form, how long it took before the planet became stable, and how long it took for life to develop. After that a lot of it is in the fossil record, which is stored in the rocks.

We know that tree rings are annual, well so is the weather. So Artic and Antarctic ice cores tell us things about the past. They even have some of the air from the past trapped inside them. Once scientists have determined how long ago something happened they could tell the age of the rocks. Troglodytes are some of the first animals we know of (earlier life forms didn’t have bones that could calcify and become fossils.) So if you find troglodyte fossils somewhere then you know how old that is, and these fossils are found worldwide.

Fossilized animals and plants are usually not completely calcified (a process where water carries calcium from the soil and deposits in place of the bone that is slowly worn away). A scientist can dissect a fossil and then search for something that remains of the creature. Usually this piece is to small and too old for DNA samples to be made, but just a few particles are needed to conduct Carbon 14 dating. All plants and animals have carbon inside of them. Carbon and hydrogen are the two basic elements that make up all organic life. Carbon can also be found in ancient deposits of gas, and some of this gas could be trapped in the rocks. Carbon normally has an atomic weight of 6. One isotope (a radioactive form of the element) is carbon 14. We know how much carbon 14 is in the air, and the radioactive half-life of carbon 14. Therefore the amount of carbon 14 that is left in the matter can indicate its age.

For more information about Carbon 14 Dating check out: http://www.howstuffworks.com/carbon-14.htm
http://www.ndt-ed.org/educationresources/CommunityCollege/Radiography/Physics/carbondating.htm

Answer 4

I believe it is the Christian Bible that states the age of the earth is some 4600 years old. Since the Bible is supposedly partially written by God, and God shouldn't be questioned, it is accepted in the Christian faith that the age of the Earth is about 4600 years.

In other religions, the age of the Earth is a bit longer, or much longer (the Jewish faith puts it at over 5700 years old). Science, through what is known as carbon dating and other techniques, tells us the Earth is somewhere over 4.5 billion years old, and might be even older.

It depends on what you believe. If you hold science as your proof (as in what you see, hear and feel is more important than what your religion has you believe), then you might say science is correct. Religion can explain away science: "Your scientific tests are actually tests of your faith in God. He has made your instruments tell you that the Earth is older than the Bible. But would you disbelieve your God?"

I'm not saying either is right or wrong, but science will help you in the reality of day to day things such as building houses or computers or spaceships (and a billion other things), while religion can help you through tough times, as well as help you find friends and give you new hope in life. Happily you can have both science and religion in your life, and they don't need to get in each other's way either. You can use science and religion to move forward in your daily life.

Answer 5

It's based on several things:

1) dating meteorites. When we find a meteorite from this solar system that has a similar composition to earth, you get many young ages, but the oldest and most common date to 4.6 Ga (billion years).

2) isotope trends. When you look at certain isotope ratios that change with time, like Rb/Sr, you find that many rocks with differnt ratios of many ages form a line, and the line traces back to an origin of 4.6 Ga as well.

The oldest life is 3 1/2 Ga, the oldest rock is about 4 Ga, and the oldest date ever found is on the highly durable mineral Zircon from Australia, it's date is 4.2 Ga. So, there is no direct method, it is based on inferences. However, many different inferences lead to the same number 4.559 Ga (to be specific).

And by the way, carbon dating only goes back at most 60,000 years. You need K/Ar or U/Pb to date the earth.

Answer 6

It is about 5 billion years old. Physics is far more accurate than the bible.

Unfortunately, the age cannot be computed directly from material that is solely from the Earth. There is evidence that energy from the Earth's accumulation caused the surface to be molten. Further, the processes of erosion and crustal recycling have apparently destroyed all of the earliest surface.

The oldest rocks which have been found so far (on the Earth) date to about 3.8 to 3.9 billion years ago (by several radiometric dating methods). Some of these rocks are sedimentary, and include minerals which are themselves as old as 4.1 to 4.2 billion years. Rocks of this age are relatively rare, however rocks that are at least 3.5 billion years in age have been found on North America, Greenland, Australia, Africa, and Asia.

While these values do not compute an age for the Earth, they do establish a lower limit (the Earth must be at least as old as any formation on it). This lower limit is at least concordant with the independently derived figure of 4.55 billion years for the Earth's actual age.

The most direct means for calculating the Earth's age is a Pb/Pb isochron age, derived from samples of the Earth and meteorites. This involves measurement of three isotopes of lead (Pb-206, Pb-207, and either Pb-208 or Pb-204). A plot is constructed of Pb-206/Pb-204 versus Pb-207/Pb-204.

If the solar system formed from a common pool of matter, which was uniformly distributed in terms of Pb isotope ratios, then the initial plots for all objects from that pool of matter would fall on a single point.

Over time, the amounts of Pb-206 and Pb-207 will change in some samples, as these isotopes are decay end-products of uranium decay (U-238 decays to Pb-206, and U-235 decays to Pb-207). This causes the data points to separate from each other. The higher the uranium-to-lead ratio of a rock, the more the Pb-206/Pb-204 and Pb-207/Pb-204 values will change with time.

If the source of the solar system was also uniformly distributed with respect to uranium isotope ratios, then the data points will always fall on a single line. And from the slope of the line we can compute the amount of time which has passed since the pool of matter became separated into individual objects. See the Isochron Dating FAQ or Faure (1986, chapter 18) for technical detail.

A young-Earther would object to all of the "assumptions" listed above. However, the test for these assumptions is the plot of the data itself. The actual underlying assumption is that, if those requirements have not been met, there is no reason for the data points to fall on a line.

Answer 7

People say alot of things, and one of them is that it is a few billion years old. By observing faraway planets and star systems form and become destroyed we can see how far along our own is. By knowing the type of star ours is and estimating its own age by its mass and energy output we can determined about when our own planet formed by knowing the average time it takes for other planets to form.

One can plainly see that our earth is not simply 4600 years old. Even if you bypass measuring ancient artifacts and beings with half-life radiation, you can logically see that no ocean or continent can form in such a time span from nothingness... Now if you are a pure believer in the bible and such and truly believe that the earth is only 5000 years or so old- I will not try and convince you, but a year is a scientific measurement of time.... and if you are going to use one scientific constant you must use others, so please don't be a hyppocrite and support your beliefs through science while tainting science itself.

Answer 8

How would you define the birth of the earth? I mean we know galaxies start with just some space dust that collides together and planets form as these balls of 'dust' accumulate and get bigger.
Then eventually compounds come together and 'life' forms and evolves. Then suns implode and destroy all the planets with the life on it, turning it all to dust....so I guess you could ask when does it start, when does it end?

If you want to take it from the point of when these compounds come together, I suspect much longer then 4600 years ago....scientists are basing that on fossils and such....but no one REALLY knows for sure.

Energy can not be created nor destroyed, only transformed.

Answer 9

Earth is much older than 4,600 years. think of history, stuff was going on at 20,000 bc it's about 4.5 billion years old. it is determined by scientific methods and research such as carbon dating on rock and other research. here is a good site.

Answer 10

They say that the Earth is millions or billions of years old, based on the decay rate of certain elements that has been measured as a constant, kind of like a ticking clock that tells us how long the elements have been in the Earth.

Answer 11

Now I’m not sure just how old the world is...but i'm sure dinosaurs and fossil fuels are a good indicator that it's at least older then 4600 years. But then again god could have put it there as a big JOKE...just a whole bunch of bones and oil under the dirt just to mess with our heads ....