Buzz
While the health and skincare industries are focused on anti-aging, scientists and specialists are often more concerned with the opposite concept. However, when they discuss aging, it's not always about growing older—it can also refer to determining the age of an object.
Experts from various fields have mastered the art of aging things using a wide array of unconventional methods. These techniques can be used to date everything from celestial bodies like stars and planets to musical compositions. Many people know that radiocarbon dating helps determine the age of ancient artifacts, but aging methods also help scientists uncover the origins of the universe, assist detectives in solving cases, and even resolve legal disputes. They can even reveal the age of sea turtles. Discover how these techniques work and why they're used in this list of ten remarkable ways experts figure out the age of things.
10. Dendrochronology
Dendrochronology, a term that might sound complicated, refers to the straightforward method of counting tree rings—a technique that many may have learned as children. Trees produce a new layer of wood each year, but these layers vary in type. The wood in spring is generally lighter, while it darkens during the summer, creating visible rings.
However, this method presents a problem, as demonstrated by an incident in 1964 when a scientist accidentally felled a bristlecone pine, only to later realize he had just destroyed the oldest known tree. To prevent this, researchers use a tool called an increment borer. This device is screwed into a tree trunk from the outside, reaching the center, and extracting a small core sample of the tree's trunk, which can then be used to count the rings.
Interestingly, dendrochronology isn’t just limited to trees. It has also been employed to identify shipwrecks, such as the case of the Dolphin, an American whaling vessel that sank off the coast of Argentina in 1858.
9. Static Analysis
Before the days of clicking 'accept' on terms and conditions, people used to sign documents on paper. Sure, this still happens for important matters, but is it really any more secure? For example, if someone argues that their signature on a document must be forged because they couldn’t have been there on the date it was signed, science offers some solutions to this dilemma.
Just as there are techniques to age wood, there are also methods to date paper. Different paper treatments, such as coatings and whitening agents, have been used at various points in history and may fade from common use over time. By identifying the specific techniques used, researchers can narrow down the potential time frame in which a particular piece of paper was produced.
Ink identification follows similar principles, with extensive databases detailing the various ink types and their periods of use. These techniques are known as static analysis. There are also dynamic analysis methods that track the natural changes in ink and paper over time to determine their age.
8. Fly Life Cycles
The life cycles of flies are incredibly useful, not because these insects are particularly interesting, but because they play a role in solving crimes. Forensic investigators can determine the stage of the fly's life cycle on a corpse, then count backward to estimate when the flies first appeared.
The process involves examining factors such as the flies' size, whether they inhabit the interior or exterior of the body, if they've laid eggs, and their feeding patterns. This method works because fly life cycles and behaviors are highly predictable, and flies are remarkably quick at finding corpses.
This technique can provide detectives with a fairly accurate estimate of the time of death—an essential piece of information that can be crucial in cases where a body is found long after death.
7. Elephant Teeth
While it's relatively easy to determine whether an animal is a juvenile or an adult, accurately determining an animal's age can be much more challenging for the untrained eye. However, experts have found some fascinating ways to get closer to the truth. For instance, elephants' physical size may offer a rough estimate of their age, but a more accurate answer requires a closer examination. The most dependable method for determining an elephant's age is by inspecting its teeth—specifically the molars located at the back of the jaw, which it uses to grind plants.
Throughout its life, an elephant will have six different sets of molars, and experts can determine which set it is currently using. For instance, if it's using the fourth set, it is likely between 6 and 28 years old. The sixth and final set of molars corresponds to an age range of 30 to 65 years. Scientists can further refine their age estimates by analyzing the position of the molars and the number of dentine and cement layers surrounding the tooth roots.
6. Skeletochronology
For certain species, the best way to determine their age is simply by their size, even inside their mouths—at least while they're alive. The sea turtle is one such animal. While it's easy to identify whether a sea turtle is a hatchling, juvenile, or adult, determining its exact age based on appearance alone is much trickier. In fact, this can be especially difficult for some species. For example, female hawksbill and green turtles in the Indian Ocean can reach adult size before they are sexually mature.
Therefore, the age of turtles is most accurately determined after their death through a method known as 'skeletochronology,' which, as the name implies, involves examining the turtle's bones to estimate its lifespan. By studying the humerus—a bone from the upper arm or flipper in sea turtles—scientists can determine the turtle's age in a way similar to how tree rings are used to date trees. The bones contain growth rings that can be counted to estimate age.
5. Epigenetic Clocks
While scientists have developed precise methods to estimate the age of animals, they are still lagging behind when it comes to their own species. Artificial intelligence may provide some future solutions, but even in the 21st century, the most reliable way to guess someone's age without documents is still by looking at them. From bone growth to blood cells, numerous studies have been conducted with limited success. Epigenetic clocks can provide an estimate of someone's age within three years, though they are not always accurate, as they measure biological age instead of chronological age.
Essentially, epigenetic clocks measure how fast someone is aging compared to others of their age. The biological age determined by these clocks may differ from their actual age, as demonstrated by biotech CEO Bryan Johnson, who reportedly reversed his epigenetic age by 5.1 years. These tests work by examining chemical markers called methyl groups that attach to DNA as a person ages. Unhealthy habits can accelerate this process, while cutting them out might slow it down. While epigenetic clocks offer insights into the aging process, they are not useful for verifying the ages of underage gymnasts or confirming world records.
4. Musical Periods
Science is often used when people need to calculate something precise, like chronological age. However, when only a rough estimate is needed—such as narrowing down a piece of artwork to a specific century or period—scientific methods are not required. Even non-experts can achieve surprisingly accurate results with some practice. Classical music is one such example.
Although some might argue that all classical music sounds the same, any trained musician or enthusiast can quickly identify the era in which a piece was composed. The term 'classical' is commonly used today to refer to the period from 1750 to 1830. Before this, the Baroque era spanned from 1600 to 1750, followed by the Romantic period and the 20th century.
Each musical period has its own distinct characteristics. These can range from the types of instruments used—some of which were either not invented or more popular in specific eras—to how the instruments are played and the number of melodies being performed simultaneously. These clues can help accurately date a piece of music.
3. Old Stars and the Hubble Constant
Everyone is familiar with the Big Bang theory and the idea that it occurred billions of years ago—13.8 billion years, to be precise, which is an almost incomprehensible span of time. But someone had to come up with that figure. How did they do it? The full explanation involves the cosmic microwave background of the universe and Einstein's theory of general relativity. However, the estimate essentially boils down to two simpler concepts: one of which is using the oldest stars to help establish the universe's age. Large stars burn brightly but also consume their fuel much faster.
While the Sun could burn for approximately nine billion years, a star half its size might last up to 20 billion years. When scientists identify clusters of these smaller stars, they can estimate the possible age of the universe. Their estimates must fall within that range. Another method used is the Hubble Constant, which calculates the speed at which objects are moving away from Earth due to the expanding universe. By analyzing changes in light, scientists can work backward and estimate when the universe began, similar to calculating the starting point of a journey by knowing the arrival time, distance, and speed.
2. Radionuclides
Certain objects have their own natural clocks that scientists can read to determine their age. One example is radionuclides, which can be used to date space objects like planets and meteorites. Radionuclides are atoms that release energy over long periods of time, making them ideal for determining the age of objects containing them. However, the drawback is that physical samples are required for accurate dating.
By analyzing soil samples from the Moon, scientists determined that the Moon is over four billion years old. Without such a sample, scientists would have relied on the older method of counting craters to estimate the age. This method is still used for planets and other celestial bodies where no samples are available.
Stars have proven easier to study for age estimation. Although they maintain steady brightness, temperature, and size for billions of years, subtle shifts in their color and rotation speed offer clues about their age. In addition, 'asteroseismology,' which studies the vibrational patterns on a star's surface, can distinguish between young and old stars.
1. Pinning Points
The ice caps are rapidly melting, and human activity plays a significant role in this acceleration. But how do scientists know humans are to blame? One key piece of evidence lies in the 'pinning points'—shallow areas where ice shelves along the edges of Antarctic glaciers become lodged in the water. These pinning points are crucial because they act as barriers, preventing the rest of the glacier from sliding into the sea and melting. This makes the process of ice flow slower, which has been beneficial in delaying ice loss.
Although some ice continues to melt, it must flow over these pinning points, creating surface bumps that can be tracked by satellites. A 2024 study monitored these bumps over three periods: 1973-1989, 1990-2000, and 2000-2022. The study showed a troubling acceleration in the melting process: only 15% of the bumps shrank in the first period, 25% in the second, and 37% in the third. This suggests the melting is speeding up, and the study also found that the process began as early as the 1970s in some areas, though it didn't affect many places until the 1990s.
