"Any sufficiently advanced technology is indistinguishable from magic"
Arthur C. Clarke
We're so used to certain things that we don't stop to think about them, and how fortunate we are to live in an era where they are available.Consider this: About half a century ago four very talented young men gathered in a big hall in a large building in St. John's Woods, Westminster, UK. They made sounds with their mouths and various objects. As they made those sounds, alone or together, technicians used sensitive and precise transducers to capture the minute variations in air pressure created by the sounds and transform them, through moving coils and magnets, into electric analogs. The variations in electric current thus created were transmitted through assorted cables and wires to large machines, where those currents were translated into variations of a magnetic field, which in turn reoriented small fragments of metal oxide in a very thin layer over a flexible strip of plastic material, creating magnetic analogs of the original sounds.
Years later other technicians got the strips of plastic material with the magnetic layer, ran them again through some other machines that captured the variations in the magnetic field and generated electric currents which still corresponded to the sounds made decades earlier; this time, however, they were ran through complex circuitry that sampled the electric currents over forty thousand times a second and generated a number summarizing the state of those currents at the moment of sampling, storing the sequence of numbers in other types of plastic stripes of flexible material, now generating a numeric representation, instead of an analogical one.
A binary representation of those numbers was engraved in a thin metallic layer inside a plastic disk, which was sold in the millions, and I eventually bought one of the copies. A device in my computer shone a laser light in the plastic disk, and recovered the numbers kept in the metal. A fairly complex program read those numbers and wrote a kind of summary of the whole series, making the total collection of numbers representing the sound occupy a much smaller space. That collection, now a file in my computer, was copied to a portable phone, itself a small technical wonder, a tiny but powerful computer. The summarized file of numbers is now stored as quantum states within a crystalline layer in the phone, and other complex programs read the numbers of the summarized file and recreate the original numbers; those are fed to another part of the device which translates them yet again into variations in electric current; those are encoded into electromagnetic waves, which jump through the air and are read with no physical contact with the phone by a device in my ears, where they are re-encoded as electric currents, and then those actuate wire coils laying beside magnets, finally recreating the sounds those young men created half a century and an ocean away. And that, my friends, is how I can listen to the digitally remastered Beatles' albums with my Bluetooth headphones paired to my cellphone, where the ripped mp3 files are stored. And that makes me happy. In the end, the love you take is equal to the love you make. But science can help a lot. Oh, and by the way: Beatles 4 Ever! 🙂