🚀 How Many Times Do You Have to Double a Foot to Reach the Edge of the Universe?

 

👀? Ever had one of those wild “what if” thoughts while staring at the night sky? 

Like:

“If I started with a 1-foot piece of string and kept doubling its length, how many times would I need to do that to stretch it all the way to the edge of the known universe?”

Well, the Orangutan Dad sometimes thinks about cosmic extremes so grab your tape measure, your curiosity, and your love for mind-blowing math—because we’re about to find out.

🌌 The Setup: 1 Foot and a Big Dream

Let’s say you start with a single foot of string. Every time you double it, it becomes twice as long:

• After 1 doubling: 2 feet

• After 2 doublings: 4 feet

• After 3 doublings: 8 feet

• …

• After n doublings: you get $2^n$ feet

That’s exponential growth. Things get big fast.

📏 But How Far Are We Talking?

The edge of the observable universe—that’s the farthest light has traveled since the Big Bang—is about 46.5 billion light-years away in every direction. And just how far is one light-year in feet?

Let’s break it down:

• 1 light-year ≈ 5.878 trillion miles

• 1 mile = 5,280 feet

• So 1 light-year = roughly 31 quadrillion feet

• Multiply that by 46.5 billion…

• And you get about 1.442 x 10²⁷ feet to reach the edge of the universe

That’s a 1 with 27 zeros behind it. (You’ll need a cosmic calculator for this one.)

🧠 Time for the Big Reveal

So the question becomes:
What power of 2 gets you close to 1.442 x 10²⁷?

We take the log base 2 of that number and boom:

$n ≈ \log_2(1.442 \times 10^{27}) ≈ 90.2$

🎉 Answer: Just 91 doublings!

That’s it. Just 91 rounds of doubling your 1-foot string and suddenly you’re brushing up against the cosmic microwave background.

📊 Visualizing the Cosmic Climb

Let’s take a look at how the length explodes with each doubling:

As you can see, the red dashed line is the edge of the known universe (46.5 billion light-years), and the curve zips fast it like it’s late for an intergalactic meeting.

🤯 Takeaways to Blow Your Mind

• Exponential growth is wild. In fewer than 100 steps, you go from 1 foot to billions of light-years.

• This is why doubling gets dangerous in things like pandemics… and glorious in things like compound interest.

• The universe is vast—but math lets us leap across it in just a few mental steps.

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So the next time someone says you can’t get far with just a foot… tell them you only need 91 doublings to touch the edge of the universe.

Now go forth, and think big. Or should we say… think exponentially. 💫