How to imagine 1 billion years?
a billion is a 9 zeros: 1,000,000,000
The short answer: it's impossible. No matter how many analogies we try, the human brain simply isn't equipped to grasp such a vast time span. However, before explaining why, here are a few entertaining comparisons that might give some perspective - though it's doubtful they will truly help you perceive such an enormous duration.
Some analogies:
If 1 billion years were scaled down to 1 year, an entire human life would be just a single breath.
If 1 year were compressed into 1 second, then 1 billion years would stretch over 30 years.
1 billion years is roughly 15 million lifetimes - comparable to the entire population of Istanbul living their lives one after another.
Concerned about accuracy? It's rounded for better clarity - precise calculations wouldn't give you a better idea here.
What is wrong with these analogies?
Among these, the first analogy is the most relatable because it uses timeframes we naturally understand. One year is probably the longest period we can intuitively grasp. We have annual events like birthdays, seasons that mark the passage of time, and monthly routines that divide the year into manageable segments. This makes it easier to imagine how a single breath relates to a year. A human lifetime is actually harder to understand, but considering your own current lifetime - no matter how old you are - I think it's an acceptable approximation. You can think about it as a long or short breath.
The second analogy (1 second per year) is harder to process. Even imagining the number of seconds in a single day is challenging, let alone stretching that concept across decades. Similarly, 30 years is difficult to grasp intuitively - even if you're older than 30, you only have a few experiences of that length, making it difficult to conceptualize at scale.
The third analogy (15 million lifetimes) also fails because it tries to explain one enormous number using another. 15 million is already beyond intuitive grasp - we don't have a natural way to experience or visualize such a number. At some point, these enormous spans of time all blur into the same vague idea of "a very long time."
Even if we accept the breath analogy as useful, what happens when we consider 10 billion years? If 1 billion years is a single breath, is 10 billion years just a blink? Would it feel any different? At some point, these durations cease to have distinct meaning - they all collapse into the realm of the indefinite.
This brings us to a fundamental conclusion: trying to truly grasp a billion years is meaningless. Nothing in human experience comes close to it. We can compare numbers mathematically, but in terms of perception, all long time spans merge into the same incomprehensible void. Perhaps a mathematician who regularly works with logarithmic scales might appreciate the significance of the number, but even then, they wouldn't be able to feel it. Time itself is an abstract concept, and when it reaches extremes, it escapes human comprehension entirely.
Instead of a conclusion: do not try to understand it, treat it as an unpredictable phenomenon.