Many independent measurements have developed that the Earth and the universe are billions of years old. Geologists have found yearly layers in ice the are easily counted come multiple 10s of countless years, and also when merged with radio isotope dating, we discover hundreds of thousands of years of ice cream layers. Utilizing the recognized rate of change in radio-active facets (radiometric dating), some planet rocks have actually been displayed to it is in billions of years old, while the earliest solar system rocks are dated in ~ 4.5 billion years. Astronomers usage the street to galaxies and also the rate of irradiate to calculate that the light has actually been traveling because that billions of years. The expansion of the world gives period for the universe as a whole: 13.8 billion year old.

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Astronomers and geologists have established that the universe and also Earth are billions of years old. This conclusion is not based upon just one measure up or one calculation, but on many types of evidence. Here we will describe just two varieties of proof for an old Earth and also two species of evidence for an old universe; more types deserve to be found under further reading. These techniques are greatly independent of every other, based upon separate observations and arguments, yet all allude to a background much longer than 10,000 years. As Christians, we think that God created the world and also that the civilization declares his glory, so us can’t overlook what nature is informing us around its history.

Age that the earth from seasonal rings and layers

If you’ve ever before seen a horizontal part of a tree trunk, you’ve seen just how a tree forms a new growth ring each year. In years of drought, the tree grow less easily so the ring is narrower; in great growing periods the ring is thicker. A tree’s period can be uncovered by merely counting that is rings. By compare the pattern of thick and also thin ring to weather records, scientists deserve to verify that the technique is accurate. This an approach can even be provided on dead trees that dropped in a woodland long ago. For example, the last 200 rings in the dead tree might complement up v 200 rings beforehand in the life that the living tree, for this reason the 2 trees together have the right to count back many years.


In this way, multiple trees deserve to be offered to develop a grasp chronology for a forested region. Europe oak trees have actually been supplied to construct a 12,000-year chronology.1 The annual ice layers in glaciers provide a similar technique that goes earlier much more in history. Every year, snowfall different throughout the seasons and also an yearly layer is formed. By closely extracting ice cream “cores” (like coring an apple) that glaciers, researchers see that more than 50,000 years of past history are plainly visible. This an approach can be verified and extended by compare to historic records for weather, as well as to documents of volcanic eruptions around the globe that left slim dust great on the glaciers. Below the clearly shows layers the snowfall, by compare chemical isotope with other studies, scientists have actually drilled ice cores deep right into glaciers and found ice that is 123,000 years old in Greenland2 and also 740,000 years old in Antarctica.3 These yearly layers go ago farther than the 10,000 years promoted by Young planet Creationists, and the isotope studies disclose ice the is lot much older. The earth is at least 740,000 years old.

Age that the Earth and solar mechanism from radiometric dating

In her high institution science classroom, girlfriend may have seen a large poster that the regular table hanging ~ above the wall. The regular table mirrors the types of atom that comprise the world about us. An facet in the routine table deserve to come in various flavors called isotopes. Part isotopes are unstable, and over time these isotope “decay” right into isotopes of various other elements. Because that example, Potassium-40 is unstable and also decays into Argon-40. As time passes, a rock will have more and more Argon-40 and also less and less Potassium-40. Radiometric dating is feasible because this degeneration occurs in ~ a recognized rate, called the “half-life” the the radioactive element. The half-life is the moment that that takes for half the radioactive sample to adjust from one element into the other.

Some isotopes have brief half-lives of minute or years, yet Potassium-40 has a half-life the 1.3 exchange rate years. Radiometric dating needs that one know the initial ratio of the two elements in a offered sample by part means. In this case, Argon-40 is a gas that conveniently bubbles out and also escapes as soon as it is produced in molten rock. As soon as the absent hardens, however, all the Argon-40 is trapped in the sample, offering us precise record of just how much Potassium-40 has decayed because that time. So, if we find a rock v equal components Potassium-40 and Argon-40, we recognize that fifty percent the Potassium-40 has actually decayed right into Argon-40, and also that the rock hardened 1.3 billion year ago.4

It’s hard to find rocks ~ above the surface of the earth that have not been altered over time. Most old rocks have been eroded by wind and also water or submerged by continental plates. The oldest reliably date rock formation is in Greenland, wherein several various isotopes were provided to find an age of 3.6 billion years.5 Scientists likewise recently date zircon seed (which withstand erosion) in western Australia come 4.4 billion year old.6 To uncover older rocks the haven’t to be eroded, we must look beyond Earth. Meteorites are rocks native the solar system that have actually fallen to earth recently and haven’t suffered much erosion. Your pristine interiors give an age that dates back to their formation at the start of the solar system. Nearly all meteorites have the very same radiometric age, 4.5 billion year old.7 Thus, the solar system, including the Earth, is around 4,500,000,000 year old.

Age of galaxies indigenous the take trip time that light

What about the ages of stars and also galaxies, and also the period of the totality universe? One means to measure these ages is v the travel time that light. Irradiate travels exceptionally fast – 300,000 kilometers per second, or 186,000 miles per second. Top top Earth, the hold-up due come light take trip time is a tiny fraction of a second. However in space, the distances are so large that the light takes a substantial amount that time to take trip to us: 8.3 minute from the Sun, 4.3 year from the nearest star, and about 8500 year from the facility of the Milky means galaxy. That delay means that we don’t check out these objects as they are appropriate now, yet as castle were as soon as the irradiate left. The universe actually functions as a kind of “time machine,” in i beg your pardon we deserve to see into the past just by looking much away.

The calculate of the light take trip time is an easy once you understand the speed of light and have a measure of the distance. The rate of light is famed from experiment on Earth, and also various expensive observations confirm that the rate of light has not readjusted over the background of the universe. However measuring ranges in astronomy is not trivial – girlfriend can’t just string a measuring ice from right here to the center of the galaxy! Instead, astronomers use number of interlocking techniques to determine the distances, such together geometric calculations and also brightness measurements. For example, part galaxies look lot smaller and also fainter than other galaxies of the exact same kind, showing they room much more away.8

The Andromeda galaxy, a near neighbor to our own Milky way galaxy, is 2.3 million light years away. That is, we are seeing it as it to be 2.3 million years ago. However that is just our local neighborhood. In current decades, astronomers have actually detected galaxies situated several billion irradiate years away. If the light has actually been traveling billions of year to with us, then the universe must be at the very least that old. This is completely independent of radiometric dating of the solar system, but both methods allude to period of billions of years, not thousands.


Age the the universe from expansion

Not only can astronomers measure up the distance of galaxies, they can measure exactly how galaxies room moving. Galaxies are not holding still in space, nor are they moving randomly. Part galaxies are moving towards their neighbors, attractive by their common gravity. But the best pattern we watch is that galaxies are moving apart from one another. This activity apart is no all in ~ the same speed; instead it follows a pattern wherein galaxies the are further apart room moving more quickly.

This details pattern suggests the totality universe is expanding. To check out why, think about a loaf of raisin bread. The raisins are choose galaxies and the dough is like the fabric of an are in the universe. Together the dough rises, it carries the raisins along, pulling castle apart from each other. Raisins that began out ~ above opposite sides of the loaf will certainly be a couple of inches farther apart ~ the dough rises, if raisins that started out near each other might only move half an inch. So, the speed of their activity is proportional to the separation between them. In the same way, the room of the world pulls galaxies further apart together the universe expands.

Astronomers detect a galaxy’s motion by looking in ~ its irradiate spectrum. As soon as a galaxy is carried away through the growth of space, its light waves space stretched out, make it show up redder. The adjust in the galaxy’s color is referred to as the red shift, and also can be used to calculation its velocity. Indigenous the measurements of numerous galaxies, astronomers deserve to accurately measure up the growth rate the the cosmos as a whole.

The age of universe deserve to be determined by imaging what the cosmos looked favor in the past, “rewinding” the expansion. In the previous the galaxies must have been closer together, and in the distant past castle would have actually been packed together in a small point. If we assume the the growth rate is consistent over time, the period for the universe as a whole is about 10 billion years. However, astronomers have been working over the last twenty years to determine how the development rate changes with time. We now recognize that beforehand in the universe the growth was slow down, however now it is speeding up. Using mindful measurements the this adjust in expansion rate, the period of the world is now known quite specifically to be 13.79±0.02 billion years.9


Many different and also complementary scientific measurements have developed with close to certainty the the universe and also the earth are billions of year old. Great in glaciers display a history much much longer than 10,000 years, and also radiometric dating areas the formation of the earth at 4.5 billion years. Light from galaxies is reaching us billions of years after that left, and also the growth rate that the universe days its period to 13.8 exchange rate years. These are simply a sampling that the varieties of evidence for the an excellent age of the Earth and also the universe; view the resources below for more.

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