Many people wonder if the physical mass increases when data is stored. Theoretically, as the amount of stored information increases (i.e., as the arrangement of electrons on a hard drive or memory changes), energy increases very slightly, and according to Einstein's E=mc² law, mass can also be said to 'increase' in extremely small amounts.

So, how much is this difference? Let's calculate it with a simple example.

  1. First, let's roughly estimate the energy required to store one bit. According to various papers and estimates, the energy used to change one bit is approximately 10^-15 J.

  2. To convert this to mass, using E=mc², we have m=E/c², so we divide 10^-15 J by the speed of light squared (approximately 3×10^8 m/s).

    • This results in approximately 10^-15 J / (9×10^16 m²/s²) = about 10^-32 kg (more precisely around 1×10^-32 kg).

  3. Thus, theoretically, each time a bit is stored, the mass increases by about 10^-32 kg.

Now, let's sum up all the data in the world in this way. Nowadays, the total amount of data worldwide is estimated to be in the tens to hundreds of zettabytes (ZB, 1 ZB = 10^21 bytes), so let's assume around 200 ZB.

  • 200 ZB = 200 × 10^21 bytes

  • Since 1 byte = 8 bits, the total number of bits = 200 × 10^21 × 8 = 1.6 × 10^24 bits

If we assume that each of these bits increases by 10^-32 kg, the total would be 1.6 × 10^24 × 10^-32 = 1.6 × 10^-8 kg, or about 1.6×10^-5 g. Numerically, this is approximately 0.000016 g. (The results may vary slightly depending on the assumptions or estimated energy used.)

This amount is less than a fraction of a hair, so it is practically too small to say that "mass increases." In summary:

  1. Theoretically, as data increases, a little more energy is required, and mass increases slightly.

  2. However, the amount is so small that it cannot be felt at all with everyday senses or measuring devices.

  3. Even when calculating all the data stored in all storage devices worldwide, it amounts to only a fraction of a gram (or less).

So, in conclusion, while it is true that "the mass of storage devices increases as data accumulates," the difference is so small that it is difficult to detect in real life or scientific experiments. It can be understood as a matter of scientific curiosity.