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What is computer memory?

What is the limit of computer memory? Created by Brit Cruise.

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  • leaf green style avatar for user 福龍丸
    "Will we ever be able to store a bit on something smaller than an atom?" What do you think?
    (46 votes)
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    • male robot hal style avatar for user Cameron
      One of many theoretical possibilities I could think of include:
      electrons are smaller than atoms, and it would be plausible to store information stored as the excitation state of an atom,
      read by : detecting the photon emitted upon decay to a less excited state
      (we need to send a photon back to the atom matching change in energy to put electron back in the original state before reading)
      write by: allow excitation state to decay to unexcited state, then use a photon of the desired value to excite atom

      There are several excitation states of an atom, thus one could use this to store several bits on an atom.

      Now the big question is: Why would we want to ?
      There was a time in computing when storage was extremely precious. Storing even one full length movie on a computer in the 80s would be impossible for most people.

      Times have changed.

      We are rapidly approaching an era where our ability to store data exceeds our ability to generate data we want to store. Already, the average computer hard drive can easily store text versions of all of the books in a library. However, no person could ever read all of these books. The time where an average computer could store high def copies of all the movies ever made, is not far away.

      This is all achievable with semi conductor technology which is on a scale much larger than atoms.

      When we reach the point where we can easily store more data than we can reasonably want to (within a desired size for the storage device) , researchers will likely stop expending effort on ways to pack more data into a smaller space. We will reach this point long before we reach the size of 1 bit/ atom.
      (71 votes)
  • blobby green style avatar for user Nathan Friedkin
    (6 votes)
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  • leaf red style avatar for user Trent Stowers
    "Will we ever be able to store a bit on something smaller than an atom?" This is a bit of a far-fetched idea but in the future, we could possible store memory in something like a theoretical dimensional locker.
    (6 votes)
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  • mr pants teal style avatar for user box 0f rox
    An atomic hard drive would still have moving parts, right? Will that level of memory capacity ever be possible on a Solid State Drive?

    I'd love a video on SSDs.
    (6 votes)
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  • piceratops ultimate style avatar for user bronzehot
    As computers get smaller we are creating more and more memory in each device, is it possible to merge these small devices into one giant device with a huge memory?
    (4 votes)
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  • aqualine ultimate style avatar for user Sean McNally
    He seemed so excited about atomic storage: "a single ATOM". Proper reaction.
    (4 votes)
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  • aqualine ultimate style avatar for user Andrea Rabinowitz
    Starting at , when the video discusses the possibility of handheld "super drives," even if we were able to store data on what would be an atomic level, would there be any way to prevent corruption of data if say, you dropped the hard drive?
    (3 votes)
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  • male robot donald style avatar for user NicholasVavrina
    will it even be possible in the future to fit a 1000 things in a atom and if it where how would it happen isn't that going to be crazy when some one does find out a way to fit that many in I don't see how its possible I know lots of smart people but all there brains put together I still don't think its possible if any one answers me I will be great ful
    (3 votes)
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  • duskpin ultimate style avatar for user Adam Zuchowski
    How long is the estimated time before something the quality of the super drives could exist?
    (3 votes)
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  • leafers ultimate style avatar for user Michael
    When did computer science come into history before today?
    (3 votes)
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Video transcript

Voiceover: When we perform calculations with a pen and paper, we often need to save intermediate results. And we may do this with, say, scrap paper, and in this case, the paper is acting as a form of external memory. And memory no matter the form, takes up physical space. Computers contain memory, we can think of it as the scrap paper for the computer. And, say, when you construct an array to store values in your program, you require memory. And, at the lowest level, computers read and store all instructions as a string of numbers. But, how do you store numbers in a machine? This was a very difficult problem originally, especially when you need computers to hold their memory after the access to power is lost. This is known as nonvolatile memory. The easiest difference for a machine to detect is simply a presence versus an absence of something. And this is how old punch cards would work. Along the top, we have some data and the vertical columns contain a series of punched holes which represent each character. So, computers really have 2 fingers, base 2, same as a light switch being "on" for 1, and "off" for 0. This is the smallest amount of information, a single difference, which we call a bit. But bits are powerful for storage because the amount of unique states grows exponentially as we add bits together. Remember, one light switch is one bit and it can store 2 states, but 2 light switches can store 4 unique states. And 8 light switches or 8 bits can store 256 unique states. And space is measured in bits, but the physical size of a bit depends on your method of storage. So how do computer store zero's and one's internally? (gentle music) Man in Uniform: Modern data processing systems like these use thousands of magnetic cores. What are magnetic cores? They are tiny rings of nickel alloy or other magnetic materials. They have replaced vacuum tubes for many important functions in data processing systems. Voiceover: And it allowed computers to store bits as clockwise versus counter-clockwise magnetization direction. Because the each core could be magnetized in 2 different ways, depending which direction the current was applied. Man in Uniform: Because a bit can be represented by any bi-stable device and a magnetic core is a bi-stable device. Voiceover: Later on, this was done using thin film magnetic disk where we can think of as each bit as a tiny magnetic cell, which can be charged to store either a 1 or a 0. So, long story short, the size of a bit has been rapidly shrinking since the days of punch cards. A hard drive in a modern computer can be thought of as billions of tiny magnetic cells. Now, you may wonder, well how small can these little magnetic cells be? And current research at IBM is pushing this to the atomic level where they have shown 12 iron atoms can work together as a stable magnetic unit, where they are able to store a 1 or a 0, depending how they are oriented. And this is approaching a theoretical limit where we would hold a single bit on a single atom! And interestingly, IBM estimates that we can put around one quadrillion bits of information in a handheld device, the size of an Ipod, with atomic storage. And, let's call this a super drive, it doesn't even exists yet, as a hypothetical example. A small handheld super drive using atomic storage would hold one thousand terabits, which is one thousand trillion switches or more commonly known as 125 terabytes in the palm of your hand, or to use an example everyone can understand, 125 terabytes is the same as having a 1250 kilometer long book shelf in the palm of your hand. And this is what the future of memory looks like, or we ever be able to store a bit on something smaller than an atom?