Why Did Einstein Believe Time Was an Illusion?

The roots of Einstein’s idea: relativity flipped everything

Albert Einstein didn’t just shake physics — he turned our entire understanding of time on its head. Before him, time was thought to be this steady, universal thing. A ticking clock for the whole cosmos. But then Einstein comes along and goes, “Nope, not quite.”

With his theories of special and general relativity, he showed that time is not absolute. It bends. It stretches. It slows down. It literally depends on where you are and how fast you're moving.

And here's the wild part: that led him to the idea that past, present, and future all exist simultaneously. That’s where the illusion comes in.

Time is relative — literally

In special relativity, time moves differently depending on your frame of reference. If you're moving close to the speed of light, your time slows down compared to someone standing still. This isn’t sci-fi — it’s been tested with atomic clocks on airplanes. It actually happens.

So... if time can run at different rates for different people, then how can it be the same "thing" for everyone? Boom. Illusion.

The block universe: past, present, future… all at once?

A four-dimensional reality

Einstein’s equations led to a view of the universe known as the “block universe” — a 4D model where time is treated like space. Imagine the universe as a giant loaf of bread. Each slice is a moment in time. The past slices? Still there. The future slices? Already there. You just happen to be in this slice.

From this perspective, the flow of time is just how our brains interpret change. But all the “moments” are laid out together. Einstein once wrote, “For us physicists, the distinction between past, present and future is only a stubbornly persistent illusion.” Yup — that’s the quote.

Personal anecdote: the letter about his friend’s death

This wasn’t just abstract math for Einstein. When a close friend of his, Michele Besso, died in 1955, Einstein wrote a letter to Besso’s family saying something deeply poetic — and totally in line with his beliefs:
"Now he has departed from this strange world a little ahead of me. That means nothing. People like us... know that the distinction between past, present and future is only a stubborn illusion."

It's honestly one of the most touching scientific philosophies ever put into words.

The illusion of "now"

Our brains are hardwired for sequence

Humans experience time as a continuous flow. Seconds ticking. Days passing. We remember the past and imagine the future, but only feel the present. That’s mostly due to how our brain is wired — perception, memory, and expectation all create the “illusion of now”.

But physics doesn’t really care about what “now” means. For the universe, every “now” is equally real.

Whoa... but wait. Doesn't stuff change?

Great question. Things do change — from our point of view. But change doesn’t mean the past is gone. It just means our location in the block universe is moving (or feels like it’s moving). There’s no cosmic clock saying, “This is the present.” It’s all present, depending on where you look.

So... was Einstein right?

Look, not all physicists agree on the “block universe.” Some argue time does have a direction. Others think we just don’t fully understand it yet. Quantum physics throws even more complexity into the mix.

But Einstein’s belief — that time is not something that "passes" but something that is — has held up pretty strongly in the world of physics.

And yeah, it messes with your head. But also? Kinda beautiful.

Bottom line: Einstein believed time was an illusion because, in the framework of relativity, there’s no universal “now”. Time behaves more like space — all points existing at once, and movement through time just being part of the bigger structure. Whether it’s a cosmic trick or deep truth… we’re still trying to figure it out.

Is 165 cm normal for a 15 year old?

The predicted height for a female, based on your parents heights, is 155 to 165cm. Most 15 year old girls are nearly done growing. I was too. It's a very normal height for a girl.

Is 160 cm too tall for a 12 year old?

How Tall Should a 12 Year Old Be? We can only speak to national average heights here in North America, whereby, a 12 year old girl would be between 137 cm to 162 cm tall (4-1/2 to 5-1/3 feet). A 12 year old boy should be between 137 cm to 160 cm tall (4-1/2 to 5-1/4 feet).

How tall is a average 15 year old?

Average Height to Weight for Teenage Boys - 13 to 20 Years

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Staying physically active is even more essential from childhood to grow and improve overall health. But taking it up even in adulthood can help you add a few inches to your height. Strength-building exercises, yoga, jumping rope, and biking all can help to increase your flexibility and grow a few inches taller.

Is 5.7 a good height for a 15 year old boy?

Generally speaking, the average height for 15 year olds girls is 62.9 inches (or 159.7 cm). On the other hand, teen boys at the age of 15 have a much higher average height, which is 67.0 inches (or 170.1 cm).

Can you grow between 16 and 18?

Most girls stop growing taller by age 14 or 15. However, after their early teenage growth spurt, boys continue gaining height at a gradual pace until around 18. Note that some kids will stop growing earlier and others may keep growing a year or two more.

Can you grow 1 cm after 17?

Even with a healthy diet, most people's height won't increase after age 18 to 20. The graph below shows the rate of growth from birth to age 20. As you can see, the growth lines fall to zero between ages 18 and 20 ( 7 , 8 ). The reason why your height stops increasing is your bones, specifically your growth plates.