http://www.loebner.net/Prizef/TuringArticle.html

Turing begins his paper with a description of a set of rules for a test he calls the “imitation game,” (what would later come to be known as the Turing Test) as a means of answering the question, “can machines think?” In the game, there is an interrogator, a man, and a woman. The object of the game for the interrogator is to determine who the man is and who the woman is only by asking each of them questions. The questions are administered in such a way that the interrogator gleans no additional information from them besides the answers themselves – for example, through the passing of typed notes. The argument suggested by Turing in the paper is that if the man or the woman were replaced by a machine and the interrogator finds it equally difficult to distinguish between human and computer, then it can be said that the machine in question “can think.”

In the next section of his paper, Turing discusses possible criticisms of the new way in which he has framed the question. He argues that his proposed method factors out the physical appearance of a machine in our perception of whether or not it can think, and that “[t]he question and answer method seems to be suitable for introducing almost any one of the fields of human endeavour that we wish to include.” He argues that even though it seems as if the game heavily favors the human (it’s very difficult for a human to trick someone into thinking they are a computer, too), this doesn’t matter as long as one can accept that it is possible for a machine to be built that can take this test.

In the next few sections of the paper, Turing further clarifies the definition of a “machine” in his description of the game to mean “digital computer” and then goes on to describe various qualities of digital computers. He discusses the elements of a digital computer (“store,” “executive unit,” and “control”) and describes their finite state nature. A reference is made to Babbage’s Analytical Engine as an example of a machine that is a digital computer despite not being an electronic one. A section is also spent arguing that because of the finite state nature of a digital computer, it is possible for a digital computer to simulate any discrete-state machine. This implies that if any one machine can be constructed to play the imitation game, it answers the broader question of “can machines think.”

These sections specifying the machine described in the original outline of the imitation game are followed by a list of possible arguments in opposition to the claim that it is possible to construct a machine that can think. These arguments and my brief interpretations of Turing’s responses to them are as follows:

1. “Thinking is a function of man’s immortal soul. God has given an immortal soul to every man and woman, but not to any other animal or to machines. Hence no animal or machine can think.”

Turing’s response: If God is truly an omnipotent being, then should it not be within his power to assign a soul to an animal, or, similarly, to a machine, and thus also give the power to think?

2. “The consequences of machines thinking would be too dreadful. Let us hope and believe that they cannot do so.”

Turing’s response: This argument is so trivial that it needn’t even be considered.

3. Mathematics has shown that there are problems which cannot be solved mathematically. Doesn’t this mean that there are problems which can’t be solved by digital computers as discrete state machines, which could be solved by humans?

Turing’s response: Although this is a strong argument, do we assign too much importance to our ability to answer questions that a machine theoretically cannot? Those that make this argument would be okay with discussion the question through the criteria of the imitation game anyway.

4. Unless a being can express emotions and be conscious of these emotions, it cannot be said that this being can think.

Turing’s response: It’s possible to test this quality using the imitation game – saying a machine has been programmed such that it writes a poem. It’s possible to for an interrogator to ask questions about the poem to assess whether the machine was conscious of its decisions in the writing of the poem.

5. There will be things that a machine cannot do (“…be kind, resourceful, beautiful, friendly…”).

Turing’s response: This is simply an issue of storage capacity – given infinite storage capacity, machines can have a large diversity of behaviors.

6. Machines can only do what they are programmed to do – they cannot exhibit some behavior that was not already defined in the programming.

Turing’s response: What this argument is really suggesting is that machines cannot surprise. Can it really be said that humans are capable of new thought, if all their ideas are based on things that they have learned?

7. The nervous system is not a discrete state machine – it is continuous. How can a computer simulate human thought as a discrete state machine then?

Turing’s response: A digital machine can simulate a continuous machine so closely that the difference will not be clear to the interrogator in the imitation game.

8. There is no set of rules which can describe what a person should do for every possible scenario.

Turing’s response: Although it may be difficult to comprehend, we cannot say for sure that there is not one set of rules which can be used to predict all of our behavior. Even in a simple case where a computer is given a number and then returns another with no indication of what it has done, it is difficult or impossible to guess the rule that will predict every possible output – that does not mean that one does not exist.

9. A machine cannot exhibit extra-sensory perception.

Turing’s response: In this case, a special imitation game will have to be set up with a “telepathy-proof room” to be sure that the machine is not being influenced by psycho-kinetic powers.

In the final section of the paper, Turing again addresses oppositional argument number 6 – Ada Lovelace’s argument that a computer can only do what it has been programmed to do. Turing discusses a process which he believes could overcome the difficulty in programming a machine that could successfully pass the imitation game as well as disprove the Ada Lovelace argument. In this process, rather than trying to program a fully functional machine from the start, it might be better to create a “learning machine” – a machine that begins with only a base set of rules and then continually updates these rules of interaction as it learns.

This is a summary of “Engadget Primed: SSDs and you,” the “going further” reading from November 7th, when we talked about hardware enhancements. Although the main focus of the article was on modern advances in solid state storage, it started by chronicling previous important developments in the history of data storage. The article is very lengthy, so I’ve tried to summarize it as briefly as I can while still getting the important points, but this post will be a long one.

One of the first systems it mentioned was IBM’s RAMAC, which we also discussed in class. The system included IBM’s first disk storage unit, with a whopping storage capacity of 4.4 MB. We’ve come a long way, in an era where a 60GB disk is considered tiny, and 1TB is par for the course.

IBM 350 Disk Storage Unit - Engadget

After recounting the early players in mechanical storage, the article goes on to explain the technology behind modern mechanical drives like the ones still in predominant usage today. Surprisingly, at its roots the technology is barely different from that in the first IBM hard drives. A hard drive has one or more spinning magnetic platters. Bits (0’s and 1’s) are recorded based on how each magnetic grain is polarized. The primary difference between early rotary hard drives and newer models is the speed at which they rotate (the IBM 350 spun at 1200RPM, modern hard drives typically spin at 7400 RPM), and most importantly, the data density. There is a limit to how much data can physically be stored in a given area of a magnetic disk though:

Eventually, though, magnetic storage runs into fundamental laws of physics. In this case, those immutable rules are represented by the superparamagnetic effect (SPE). Once we shink magnetic grains below a certain threshold, they become susceptible to random thermal variations that can flip their direction.

Essentially, traditional hard drives are physically running out of space to store any more data. Manufacturers have pushed the limits to about 3TB, but at some point, it’s not possible to store more data without drastically affecting performance.

Finally, after working through the background information, the article delves into SSDs and how they work. I’ve been using an SSD for about 6 months now, and had read some articles about them previously, but hadn’t learned about the inner workings in nearly this much detail. I suggest you read the article, because I can’t possibly fit all of the details into this space, but here’s an overview.

So how does flash work, and what makes it different from traditional magnetic drives? The short answer is that instead of storing data magnetically, flash uses electrons to indicate ones and zeroes. You might already recognize why this is a plus: no moving parts. That means no noise, no head crashes, and greater energy efficiency since you don’t have to move a mechanical arm. And unlike DRAM, it’s non-volatile — it doesn’t need constant power to retain information.

Non-magnetic storage has actually existed for many years, and has previously been used in specialized applications such as space probes and data acquisition systems for oil exploration. The first consumer-targeted flash storage for use as a storage disk on a regular computer showed up around 2005 in a Samsung laptop. With 32GB of flash storage, the laptop cost almost $4000. If you thought SSDs are expensive now, think again.

The article goes on to explain in-depth how the underlying physics of solid state storage work. To summarize a few of the most interesting points:

• There are two types of flash memory: SLC and MLC (single level cell and multi level cell). MLC memory can store twice as much data in a given amount of space, but takes longer to read and write. MLC also degrades faster.
• SSDs slow down over time as they fill up with data. This has to do with how the memory cells are wear leveled and how data is actually written to the SSD. Some SSDs actually ship with extra space built in (which is used by the device but not reported to the operating system) to account for this.
• SSDs wear out relatively quickly. Most MLC-based flash has a limit of around 100,000 cycles. This limit can be reached in as little as a year. An article on Coding Horror about the hot/crazy scale of SSDs recounts numerous SSD failures, with none lasting more than 2 years.
• SSDs are more power efficient than HDDs because they have no moving parts
• The controller chip being used has a huge impact on performance. Early SSD controller were often low-quality, resulting in poor performance and longevity.

SSDs are still a rapidly evolving technologies. Just recently have prices started to come down into the $1/GB range. As the technology advances, it will become increasingly affordable – right now, SSDs are primarily used by developers, gamers, and other power users, but they are starting to make their way into the mainstream, especially when integrated with consumer products like tablets and ultralight laptops. The big question that remains is, are they worth it?

In my view, not quite yet. As the price continues to drop, SSDs will soon reach the point where they are economically feasible for everyone, but presently, it’s impractical to store large amounts of data on them. A popular choice right now is to have a relatively small (60-160GB) SSD with boot files, applications, and some working data on it, and a secondary mechanical hard drive to store large files for which transfer speed is less important. This is a challenge in laptops though, where space is at a premium and it’s often difficult to fit both a hard drive and solid state drive into one machine. The solution I use is an optical bay caddy: I’ve removed the DVD burner from my laptop, and put a hard drive caddy in its place. I have a 128GB SSD as my primary drive, and store large files on the hard drive. Some laptops are now shipping with a hard drive and a small SSD both built in, as well.

Solid state storage is a fascinating technology, both for its physical underpinnings and the effects it’s having on the computing industry. I foresee a time in the near future when SSDs will be standard fare, and we will all wonder how we lived without them. For those of us who’ve already had a taste, that question has already presented itself.

Link to article: http://www.wired.com/geekdad/2009/10/is-online-privacy-a-generational-issue/

To start the article, West divides internet users into two groups: digital immigrants and digital natives. Digital immigrants were born before the existence of certain digital technologies, which in this article is the internet. A digital native is someone who was born after the creation of these technologies and has grown up using them. In the context of the internet teenagers and young adults would be considered digital natives while middle-age and elderly internet users would be considered digital immigrants.

According to West, there is a perception that digital natives do not value their privacy as much as digital immigrants. This may be because digital immigrants think about their privacy in terms of the ability to conceal information from others. Digital natives on the other hand think about privacy as sharing certain information to specific groups and not to others.  This is why social networks, such as Facebook, now allow their users to choose what content they want to be public and what content they only want certain groups of people to see.

The article goes on to cite a Pew study about online privacy. According to the study, 60% of adults and 66% of teens restrict access to information on their social networking profiles. The article concludes by saying that privacy is not all or nothing, public or private. Instead we should expect to be able to choose the level of privacy that we want certain information to have. This allows us to have the benefits of communicating and sharing online without the loss of privacy that comes with it.