What Is Time, Really?

You think you know what time is.

You've lived in it your entire life. You measure it in seconds, minutes, hours, days, and years. You understand that "a year" is how long it takes Earth to go around the sun. You've never questioned this. Why would you? It's the foundation of everything.

But now your children might live on Mars. And Mars takes 687 Earth days to orbit the sun—not 365. So your daughter's "year" will be nearly twice as long as yours.

What does this mean? Is she really aging slower? Or are you just measuring different things?

Part 1: Time is a Planetary Measurement

Here's what you've never realized: time isn't objective. It's a measurement we invented based on planetary motion.

We defined "one second" based on Earth's rotation. We defined "one day" as one rotation of Earth. We defined "one year" as one complete orbit around the sun. These definitions are human. They're arbitrary. They're based on where we live.

On Venus, one day is 243 Earth days. One year on Venus is 225 Earth days. So on Venus, a day is longer than a year. Your subjective experience of "time" would be completely inverted.

On Jupiter, one day is 10 hours. One year is 12 Earth years. So you'd have 10,512 Jovian days per Jovian year. Your sense of "how much time passes" would be radically different.

This isn't just a measurement problem. This is an existential problem. Because time isn't just something we measure—it's something we experience. We experience days, seasons, years. We experience how fast we're aging. We experience boredom and anticipation measured in these planetary cycles.

And if the planetary cycles change, so does the experience.

Part 2: What "Getting Old" Means

Let's get specific. You are 40 Earth years old. This means:

• You've experienced 40 complete cycles of Earth's orbit around the sun
• You've experienced 14,600 sunrises (roughly)
• You've experienced 40 distinct seasonal cycles
• Your body has gone through 40 years of biological aging
• Your mind has accumulated 40 years of memories

Now imagine your daughter was born on Mars at the same moment you turned 30 Earth years old. She is now 10 Earth years old. What does this mean for her subjective experience of "growing up"?

In Earth years: She's 10.
In Mars years: She's 5.3.

In Earth sunrises: She's experienced 3,650.
In Mars sunrises: She's experienced 3,650. (A day is still a day, physically.)

In Earth seasonal cycles: She's experienced 10.
In Mars seasonal cycles: She's experienced 5.3.

She has aged biologically the same as you (both of you have lived 10 Earth years). But she has experienced significantly fewer "growing up" cycles if we measure by years.

But here's the unsettling part: which measurement is "real"?

Is she 10 years old, or 5 years old? Her body says one thing (10 years of aging). Her planetary experience says another (5 Martian years).

And this becomes your family's fundamental reality. You will never experience time the same way again.

Part 3: The Real Cost of Multiple Timescales

Here's where it becomes genuinely disturbing.

When you talk to your daughter, you experience time differently. When you say "I've been alive for 40 years," you mean 40 Earth years, 40 seasonal cycles, 40 distinct life chapters. When she says "I've been alive for 20 years," she might mean 20 Earth years of aging, but only 10.6 Martian seasonal cycles.

You feel old. You've lived through decades of seasonal change. You've experienced the weight of time.

She doesn't. Even though she's biologically the same age as you were at the same life stage, she's experienced fewer seasonal cycles. She hasn't "aged" in her own planetary reference frame.

When you look at her, you see someone who should feel "old" based on Earth time. But she doesn't. She feels younger, because Mars seasons pass slower.

When she looks at you, she sees someone who is impossibly old. You've lived through 40 Mars-equivalent seasonal cycles, which is like living 80 Mars years. From her perspective, you're ancient.

But you're the same biological age!

This is the temporal divide. It's not about distance. It's about your fundamentally different experience of what "time" even means. You will never understand how fast or slow your daughter is aging, because you're measuring with different units.

Part 4: Philosophical Implications

If time is subjective experience of planetary motion, then several disturbing conclusions follow:

1. You and your daughter will never be the same "age." Not just in years, but in actual subjective experience of time. You'll experience roughly 1.9 Earth years for every 1 Mars year she experiences. You'll feel like you're aging faster because, in a sense, you are—Earth years are passing faster relative to Mars years.

2. Your sense of mortality will be different. You might feel like you have less time left because you're on a faster temporal cycle. Your Earth-based sense of urgency, of "how many years do I have left," will be completely different from hers. You'll want to accomplish things quickly. She'll have the patience of someone living on a longer timeline.

3. You will experience generational change differently. If your daughter has a child on Mars, that grandchild will experience an even slower temporal cycle. By the time they're 20 Earth years old, they'll have experienced only 10.6 Mars years. They'll feel young in ways you can never understand.

4. Historical perspective becomes impossible. When you tell your daughter "I've lived through X decades of history," she'll nod politely but won't feel it the way you do. She'll have lived through fewer Mars-based historical cycles. Even if the calendar years match, the subjective weight of history is different.

5. Your relationship to death changes. The question "how much time do I have left?" becomes meaningless. Do you have X Earth years left, or Y Mars years left? You'll die at the same number of Earth years as you would on Earth, but you'll have lived through more "time cycles" on Earth than she will have at the same age on Mars.

This is what it means to be temporally divided. Time isn't just a measurement. It's the fundamental experience of existence.

Part 5: What This Means for Families

You might be thinking: "But we can just use a shared calendar. We can agree on what 'one year' means."

And you're right. Intellectually, you can do this. You can say "we'll measure everything in Earth years" or "we'll use a universal standard."

But you can't change the felt experience. You can't make your daughter experience seasons as fast as you do. You can't make yourself experience time as slowly as she does.

When you visit Mars, even for a few months, you'll find yourself desperate for more seasonal change. The slow, grinding passage of Martian days will feel like torture if you're used to Earth's rhythm.

When she visits Earth, the rapid cycling of seasons will feel chaotic, disorienting. She won't be able to keep up with the pace of change.

This is permanent. This is hardwired into the planets themselves. You can't solve it with technology. You can't solve it with good communication. You can only acknowledge that you and your daughter are living in different temporal realities, and learn to love each other across that divide.

The good news: You can understand this. You can see the mathematical beauty of it. You can appreciate what it means.

The hard truth: You will never feel the same way about time again.