The numbers behind Bitcoin’s real power are astronomical. That means to do with counting the stars in the observable universe. Bitcoin relies on encryption standards that humans may find hard to grasp. The challenge of asking someone “if you fold a paper in half 50 times, how high off the table would sit?” can really boggle the mind. We’ll let you do the math but suffice it to say, you’re in outer space.
2 to the power of 256 or 2^256 is the one of the building blocks of the crypto in cryptocurrency. Crypto or Cryptography relies on the fundamental problem of reversing mathematical functions that are made up of such large numbers.
When you learn that to generate a new Bitcoin wallet address, services do not check to see if that number has been used already, you might be left scratching your head. “Shouldn’t they just check to make sure?” shows the lack of understanding how large the key space is.
The chance of a collision, or the duplication of an already existing number, at this scale, is not impossible, but its so unlikely that for practical purposes, it is not reasonable to check.