What rr sum scams in existance in this world?

My total data capacity in my apartment amounts to about 4.5 TB. When was 4.5 terabytes the total sum of all digital data across the world?

• I would have been beyond mesmerized if a psychic told me this at a fairground 20 years ago. Given that it's still quite a bit, how long ago was this the total sum of the world's data?

• Answer:

  I can only make a guess based on real-life experience of one person in one technology career. In the 1980s I worked in a data center that had a total storage of 35 GB online, mostly in the form of wedding-cake sized disks, fixed and removable, around 350 MB each. The total electronic memory of a hugely expensive multimillion dollar mainframe was 48 MB. There were also about 15,000 tape volumes, mostly 6250 bits per inch, 8 tracks (1 byte) data transverse, for 180 MB per tape or up to 2.7 TB facility-wide depending on degree of offline tape utilization. Some of the offline storage was archival and likely would not be touched, and some of it was overwritten nightly as redundant backups. Therefore if you were to include the capacity of offline storage, two urban-sized data centers employing a total of 200 or so individuals would have had the storage capacity you have now. If measuring online-only from direct-access storage devices (typically disk) it would take 128 such 1980s data centers to match what you have now in a small home. My best recollection is that the data center I worked in was one of about four in the area, with the combined capacity of remaining ones being the equivalent of a fifth, for a scientific wild-assed guess of 175 GB online storage in the entire region. The metro area had a population of about 1.2 million, which would have been about 1/800th the population of the developed world at that time, so from there exrapolate 140 TB online storage in the entire world in the late 1980s as personal computers were making their way into small businesses. By that time in history technology had been moving in certain doubling intervals. Per Moore's Law, attributed to Gordon Moore by Caltech professor Carver Mead in 1970, processor capacity would (and did) double about every 18 months. Other parameters, such as storage capacity, doubled on much longer (but still relatively short) intervals, perhaps every 3 1/2 years. Therefore I could start with a 1987 base year and halve down to 70 TB in 1984, 35 TB in 1981, 17.5 TB in 1977, 8.75 TB in 1973, and finally down to 4.38 TB in 1969. Still missing from the analysis is that not all information storage is electronic. The San Francisco Public Library has 2.1 million books and over 3 million total items. http://blogs.sfweekly.com/thesnitch/2010/12/san_francisco_library.php Among those items there may be microfiche volumes. In pre-WWW days I had occasions to track people down using out-of-town directories at the library, using names of potential employers and acquaintances as clues, with a microfiche pack holding an entire phone book or city directory. Expand such a collection into numbers of words and then into numbers of characters (bytes) and you may get a paper-plastic storage capacity that would have been impressive in itself. The drawback of such paper-plastic storage was that it took time to find and you had to actually go to where the materials were instead of it being at the fingertips. Back then the value of an education was that you had a lot of that knowledge in your head, and an ability to manipulate what you did know, rather than have to walk to places at considerable delay. Now it is still of value to have a lot of knowledge and analytical capacity in your head, but the time saved is potentially shorter. Nonetheless, even with data and information being easier to get than ever before, the majority take the immediate path of least resistance and choose to remain stupid.