Geologic Age Dating Explained

Earth scientists have devised many complementary and consistent techniques to estimate the ages of geologic events. Annually deposited layers of sediments or ice document hundreds of thousands of years of continuous Earth history. Gradual rates of mountain building, erosion of mountains, and the motions of tectonic plates imply hundreds of millions of years of change. Radiometric dating, which relies on the predictable decay of radioactive isotopes of carbon, uranium, potassium, and other elements, provides accurate age estimates for events back to the formation of Earth more than 4. Historians love to quote the dates of famous events in human history. They recount days of national loss and tragedy like December 7, and September 11, And they remember birthdays: July 4, and, of course, February 12, the coincident birthdays of Charles Darwin and Abraham Lincoln.

Age of the Earth

The age of the Earth is 4. But how do we know this? People have been trying to estimate the age of the Earth for thousands of years.

By dating the rocks in Earth’s ever-changing crust, as well as the rocks in Earth’s neighbors, such as the moon and visiting meteorites, scientists.

The same was long true of the cosmos. The ancient Greeks Eratosthenes and Aristarchus measured the size of the Earth and Moon, but could not begin to understand how old they were. With space telescopes, we can now even measure the distances to stars thousands of light-years away using parallax, the same geometric technique proposed by Aristarchus, but no new technology can overcome the fundamental mismatch between the human lifespan and the timescales of the Earth, stars, and universe itself.

Despite this, we now know the ages of the Earth and the universe to much better than 1 percent, and are beginning to date individual stars. Our ability to measure ages, to place ourselves in time as well as in space, stands as one of the greatest achievements of the last one hundred years. In the Western world, the key to the age of the Earth was long assumed to be the Bible and its account of creation.

Creation dating required careful accounting of the chronology given in Genesis and then matching it to historical events recorded elsewhere. These estimates were not seriously challenged until the emergence of modern geology in the eighteenth century. In the mids, the Scottish geologist James Hutton proposed that the processes of erosion, sedimentation, and volcanism that we observe today happened much the same way in the past. Acting over many millions of years, they could explain the geological record without recourse to the great flood of Noah.

How Old Is Earth?

How do scientists find the age of planets date samples or planetary time relative age and absolute age? If carbon is so short-lived in comparison to potassium or uranium, why is it that in terms of the media, we mostly about carbon and rarely the others? Are carbon isotopes used for age measurement of meteorite samples? We hear a lot of time estimates, X hundred millions, X million years, etc.

Age of rock layers established using radiometric dating. Scientists measure the ages of rock layers on Earth using radiometric dating.

David H. Bailey does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment. In one respect, science and religion have been largely reconciled since the 19th century, when geologists such as Charles Lyell recognised the evidence for a very old Earth.

Within a few decades, most mainstream religious denominations accepted this view as well. But, much to the consternation of scientists, young-Earth creationism , which holds Earth is only about 6, years old, continues to be promoted in some quarters, and remains very popular with the public, especially in the United States. By contrast, and more representative of OECD countries, only about half as many Canadians espouse such beliefs. Such notions, of course, differ vastly to the findings of modern science, which pegs the age of the earth at 4.

While there are numerous experimental methods used to determine geologic ages, the most frequently employed technique is radiometric dating , based on measurements of various radioactive isotopes in rocks. The phenomenon of radioactivity is rooted in the fundamental laws of physics and follows simple mathematical formulae, taught to all calculus students.

Dating schemes based on rates of radioactivity have been refined and scrutinised over several decades, and the latest high-tech equipment permits reliable results to be obtained even with microscopic rock samples.

The age of the Earth: the changing views of science

When asked for your age, it’s likely you won’t slip with the exception of a recent birthday mistake. But for the sprawling sphere we call home, age is a much trickier matter. Before so-called radiometric dating, Earth’s age was anybody’s guess. Our planet was pegged at a youthful few thousand years old by Bible readers by counting all the “begats” since Adam as late as the end of the 19th century, with physicist Lord Kelvin providing another nascent estimate of million years.

Bertram Boltwood first used radiometric dating to determine the ages of rocks and of Earth. Although his calculations were not completely.

By using our site, you acknowledge that you have read and understand our Cookie Policy , Privacy Policy , and our Terms of Service. Earth Science Stack Exchange is a question and answer site for those interested in the geology, meteorology, oceanography, and environmental sciences. It only takes a minute to sign up. Earth Age around 4. Wouldn’t it be more accurate by doing it with its inner materials?

Why do we use meteorites if they hit the Earth after its formation? We are able to determine the age of certain rocks and minerals using measurements of radioactive and radiogenic isotopes of certain elements. Simply put, the resulting date is the time that has passed from the crystallisation of that mineral.

Obviously there are complexities, but there are not critical for this answer. Short answer : because the meteorites formed together with the Earth and the rest of the Solar System.

The Age of the Earth

This page has been archived and is no longer updated. Despite seeming like a relatively stable place, the Earth’s surface has changed dramatically over the past 4. Mountains have been built and eroded, continents and oceans have moved great distances, and the Earth has fluctuated from being extremely cold and almost completely covered with ice to being very warm and ice-free. These changes typically occur so slowly that they are barely detectable over the span of a human life, yet even at this instant, the Earth’s surface is moving and changing.

provides accurate age estimates for events back to the formation of Earth more than billion years ago. These and other dating techniques.

Nineteenth century geologists recognized that rocks formed slowly as mountains eroded and sediments settled on the ocean floor. But they could not say just how long such processes had taken, and thus how old their fossils were. He came up with that figure by estimating how long it had taken for the planet to cool down to its current temperature from its molten infancy. But Kelvin didn’t, and couldn’t, know that radioactive atoms such as uranium were breaking down and keeping the planet warmer than it would be otherwise.

An older Earth At the dawn of the twentieth century, physicists made a revolutionary discovery: elements are not eternal. Atoms can fuse together to create new elements; they can also spontaneously break down, firing off subatomic particles and switching from one element to another in the process see figure, right.

While some physicists used these discoveries for applications ranging from nuclear weapons to nuclear medicine, others applied them to understanding the natural world. The sun was once thought to burn like a coal fire, but physicists showed that it actually generates energy by slamming atoms together and creating new elements. The primordial cloud of dust that came to form the Earth contained unstable atoms, known as radioactive isotopes.

Since its birth, these isotopes have been breaking down and releasing energy that adds heat to the planet’s interior.

The Age of the Universe is a Function of Time

Lisle Oct 27, Geology , Origins , Physics. We are told that scientists use a technique called radiometric dating to measure the age of rocks. We are also told that this method very reliably and consistently yields ages of millions to billions of years, thereby establishing beyond question that the earth is immensely old — a concept known as deep time. This apparently contradicts the biblical record in which we read that God created in six days, with Adam being made on the sixth day.

From the listed genealogies, the creation of the universe happened about years ago. Has science therefore disproved the Bible?

Radiometric dating is the method of using nature’s natural clocks to date events such as when rocks were first formed. Once again, as with the coroner faced with​.

Here I want to concentrate on another source of error, namely, processes that take place within magma chambers. To me it has been a real eye opener to see all the processes that are taking place and their potential influence on radiometric dating. Radiometric dating is largely done on rock that has formed from solidified lava. Lava properly called magma before it erupts fills large underground chambers called magma chambers. Most people are not aware of the many processes that take place in lava before it erupts and as it solidifies, processes that can have a tremendous influence on daughter to parent ratios.

Such processes can cause the daughter product to be enriched relative to the parent, which would make the rock look older, or cause the parent to be enriched relative to the daughter, which would make the rock look younger. This calls the whole radiometric dating scheme into serious question. Geologists assert that older dates are found deeper down in the geologic column, which they take as evidence that radiometric dating is giving true ages, since it is apparent that rocks that are deeper must be older.

But even if it is true that older radiometric dates are found lower down in the geologic column, which is open to question, this can potentially be explained by processes occurring in magma chambers which cause the lava erupting earlier to appear older than the lava erupting later.

Done with your visit?

October 23, The Earth is 4. How do scientists know that? Since there’s no “established in” plaque stuck in a cliff somewhere, geologists deduced the age of the Earth thanks to a handful of radioactive elements.

that could date samples that are billions of years old. However, before the ‘s, scholars in many cultures tried to estimate the age of the earth and of life.

How Old is Old? When did the earth form? When did life begin? When did humans and the other primates first appear? Reasonably accurate scientific answers to these questions did not develop until the ‘s and ‘s when radiometric dating techniques were invented that could date samples that are billions of years old. However, before the ‘s, scholars in many cultures tried to estimate the age of the earth and of life.

In the past, estimates often were based on counts of generations of people in sacred texts. Manetho , an ancient Egyptian historian, listed all of the dynasties of pharaohs and gods that reigned down to his time 3rd century B. This made the earth about 38, years old from our time. In the early 17th century A.

Dating the Earth – How old is it?