The Order of Time Summary

Time isn’t what we think it is. It moves differently depending on where you are and how fast you’re traveling. Could our understanding of time all be in our minds?

1. Time Moves Differently in Different Locations

Time does not pass uniformly everywhere. Contrary to our intuitive understanding, the speed at which time moves depends on position and elevation. This phenomenon means that time is not a universal constant but is relative to the environment.

For example, a clock situated at sea level ticks slower than one placed at the top of a mountain. Even moving a clock from the floor to a table shows a minuscule but measurable difference. This is due to gravitational time dilation—gravity impacts time itself. It’s not just clocks that are affected. Humans, plants, and everything else experience aging differently based on their environments.

Einstein’s theory of relativity brought this phenomenon to light. It redefined our understanding by demonstrating that each point in space has its own distinct measure of time. Think of time as a malleable fabric rather than a constant ticking clock.

Examples

• A person living at sea level ages slightly slower than someone living at a higher altitude.
• Precision timepieces, like atomic clocks, often illustrate the differences caused by gravitational time dilation.
• The Global Positioning System (GPS) has to adjust for these variations in time to provide accurate positioning.

2. Time and Heat Only Move in One Direction

Time, like heat, flows forward and cannot be reversed. The relationship between time and heat reveals an underlying truth about the universe.

Heat always moves from warmer objects to colder ones, and this transfer is irreversible. Similarly, time also moves forward, forming a sequence of events. Heat and motion at the microscopic level are what create the flow we perceive as time. Without heat, no motion would occur, and without motion and change, the distinction between past and future would dissolve.

This principle underscores why the universe doesn’t run backward. It explains how our understanding of time springs from physical processes like entropy—the measure of disorder—and heat transfer.

Examples

• Heat escaping from a hot stove into a cooler kitchen illustrates one-directional flow.
• Ice melting into water is another process powered by irreversible heat exchange.
• Without entropy increasing, the arrow of time would vanish, blending all time periods into one indistinguishable mass.

3. Speed Alters the Rate of Time

Einstein discovered that speed affects the progression of time. Objects in motion experience time more slowly compared to stationary ones.

Picture someone traveling on a fast-moving train. Their perception of the present differs from someone standing still, with the moving person aging a bit slower. The faster an object moves, the more its experience of time diverges. This is why “now” is not an absolute concept across great distances or speeds.

For example, trying to pinpoint what someone in a galaxy four light-years away is doing "this very moment" is futile. Any observation would be rooted in the past due to how long it takes light to travel.

Examples

• Astronauts moving at high speeds in space age more slowly compared to people on Earth.
• Scientists measure time dilation in laboratory particle accelerators, where particles live longer when traveling close to light speed.
• Communication between Earth and distant planets faces delays, not just due to distance but because of relativistic time differences.

4. Time Is Granular, Not Continuous

Quantum mechanics reveals that time is not a smooth flow but is instead broken into tiny, discrete intervals called quanta.

Granularity means time is composed of the tiniest possible units, similar to how matter consists of atoms. These intervals, known as Planck time, are incredibly small—one followed by forty-four zeros of a second in length. At this microscopic level, time isn't continuous but hops between distinct moments.

This understanding challenges the traditional idea of time as a seamless stream of moments. It forces scientists to rethink how events are ordered and connected in the physical world.

Examples

• Planck time is the smallest measurable interval, far too small to detect in day-to-day life.
• Quantum mechanics experiments reveal behaviors that defy classical expectations of continuous time.
• In subatomic realms, particles can seem to change positions instantly without any “flow” of time as we know it.

5. Time Is Not Independent of Space

Einstein’s work showed that time and space are intertwined parts of a single fabric called spacetime. Together, they create the geometry of the universe.

Rather than treating time as separate from space, think of them as part of the same framework. Events have coordinates in both time and space. This concept means that the gap between two events depends as much on their positions as on the timing.

This interdependence explains phenomena such as black holes distorting both time and space near their event horizons, where gravity becomes overwhelming.

Examples

• GPS satellite clocks correct for time distortion caused by Earth’s gravity and motion through spacetime.
• Time slows and stretches closer to massive gravitational objects like black holes.
• In spacetime diagrams, time and space coordinates align to describe events, making causality clearer.

6. The World Is Made of Events, Not Things

Physicists increasingly view the universe as a network of events rather than a collection of fixed objects. Everything occurs and changes; nothing simply exists eternally.

A stone we might think permanent is, in reality, an event playing out over millennia. Over time, it will erode and eventually cease being a stone. This perspective emphasizes processes and interactions over stable entities, painting a picture of constant flux.

Rethinking the universe in terms of events reshapes how scientists model change and evolves our understanding of the interactions underlying nature.

Examples

• Mountains form and erode over millions of years, showcasing the temporariness of everything.
• Stars ignite, burn, and eventually fade into black holes or white dwarfs, emphasizing events over permanence.
• Rivers cut through stone, demonstrating how even solid rock shifts and evolves over eons.

7. Time Emerges From Our Perception

Time exists because humans perceive it. It’s the result of our minds categorizing change and storing our experiences in chronological order.

Our senses generate a flow of moments by observing order moving toward disorder—entropy increasing. Without our brains organizing these observations, the universe might appear timeless.

This approach suggests we create the experience of time, making it a human-centered construct rather than a universal truth.

Examples

• Memories allow us to create subjective timelines of past, present, and future.
• Without brain patterns organizing sensory inputs, humans would struggle to differentiate one moment from another.
• Over-stimulating environments, like emergencies, seem to “slow time” mentally, even though physical time remains constant.

8. The Sun Fuels Time’s Flow on Earth

Earth’s time and energy dynamics are driven by the sun. The sun provides low-entropy energy, which powers our processes and experiences of change.

The sun radiates high-energy photons, received by Earth. Earth “returns” those photons as less-energetic, higher-entropy forms. This exchange is why everything on Earth, from human life to flowing rivers, constantly transforms.

Without the sun, Earth would lack energy gradients required for change, halting the very processes that allow us to perceive time.

Examples

• Photosynthesis relies on sunlight to power plant growth, which sustains animal and human life.
• Solar radiation drives the water cycle, enabling rivers, agriculture, and flowing time as we know it.
• Trapped solar energy in fossil fuels powers human innovation, history, and growth.

9. Memory and Identity Define Time

Our sense of time is deeply linked to memory and narrative. By organizing past events in our minds, humans create a personal timeline.

Our lives feel like coherent stories because we arrange and connect experiences logically. Even identity, the essence of “who we are,” arises from this mental organization.

Memory forms the bridge connecting past, present, and future, giving human time its unique flavor.

Examples

• People with memory loss lose their sense of past and struggle to imagine their future.
• Cultures define themselves through historical narratives, linking generations via shared time.
• Storytelling across ages, from legends to movies, reflects our innate need for temporal order.

Takeaways

1. Recognize and appreciate how significantly time depends on perception and perspective—there’s no universal “present.”
2. Practice mindfulness by focusing on the events that make up moments instead of racing toward future goals.
3. Use the idea of entropy to embrace change and impermanence in life, understanding everything is in constant motion.