This semester I am TAing Privacy Policy, Law & Technology taught by Lorrie Cranor (my advisor). If you have some free time or are looking for a class to take and you want to explore the depths of privacy law, the philosophical roots of privacy, and the way technology can and should shape privacy in the information age, then I expect to see you this afternoon.

Sidenote: I am really excited to be TAing, it has been a while (haven’t done this since City as Text with Jessica) and since I basically love teaching, it has been way too long. I will likely post more about this as interesting things come up, the semester progresses, and the students start working on – hopefully impressive – projects.

The Symposium on Usable Privacy & Security which is hosted by the Carnegie Mellon Usable Privacy & Security Lab, which I am a member of and which my advisor Lorrie is the director of, is occurring right now.

This year we are also currently hosting our own blog, documenting the sessions, discussions, and events at the conference. It can be viewed here so you can go take a look at how I have been spending my week. Tomorrow I will put up the poster we presented, till then you will have to live with the blog and some photos here.

In 1961 the Buhl Foundation established by the power of money the Buhl Chair in Theoretical Physics at Carnegie Mellon. The Buhl Chair, Dr. Fred Gilman, likely does many interesting things, but the only one I know of, is his responsibility to invite a scientist to the Mellon Institute each year to talk about physics.

This generally highly publicized event is the single physics lecture I go to each year, and is always quite enjoyable. For information on the Buhl Chair, and past speakers you can check their website, here which hasn’t been updated since 2005.

This year’s Buhl lecture was extra-exciting (seriously) as earlier that afternoon the Bruce & Astrid McWilliams Center for Cosmology was announced at Carnegie Mellon. This new center, made possibly by the McWilliams, “will strive to unravel the mysteries of the universe.” While this sounds like quite a hard task, they are going to do it multidisciplinarily and so it is hot.

So in continuing the cosmological astro-physics trend, the Buhl Lecture for 2008 was given by Joel Primack and called “A Brief History of Dark Matter.”

Short notes here (long notes, to come):

A Brief History of Dark Matter

Joel Primack, University of California at Santa Cruz

Part I – History.

Fritz Zwicky is the beginning. Described by Primack as “one of the most profound and annoying astronomers of the 20th century,” this man, while studying the Coma Cluster in 1933 realized something was erm… strange. Without getting too much into real physics, Zwicky calculated the mass of the whole Coma cluster, based on how fast the edge galaxies in the cluster were spinning. He also calculated how much mass should be in the cluster based on the number of galaxies and the amount of light reaching us here on Earth. The numbers didn’t match.

So, let’s say we are hanging out, adding up masses of galaxies 100 Mega-parsecs, which means the light we are looking at is 326 million years old, which is around the time the Appalachian Mountains were formed (i.e. no people hanging out). And as we are hanging out looking at this really old light we realize the masses of the Coma Cluster aren’t adding up. We need to brainstorm some solutions for why this could be the case.

Conveniently, Zwicky has done this in his paper. As summarized by Michael Richmond Zwicky discuss four possibilities:

1. Stars in the Coma Cluster are different from stars in the Milky Way (which is where we had nearly all our information about masses and light emitted back in 1933).
2. The Coma Cluster is not in equilibrium
3. The laws of physics are different in the Coma Cluster!
4. The Coma Cluster has lots of mass which is not part of the stars

And this is Dark Matter. Of course, Zwicky did not call it that, but that is what he is getting at, lots and lots of mass (more than ten times that which the stars account for) which we cannot see.

Alright, but as discussed Zwicky is sort of a hassle and this wasn’t much to go on, so we can basically leave his work as open question, and move on. Also, I leave it as an exercise to the reader to find a digital version of Zwicky’s 1933 paper, which doesn’t seem to be online. Hint: it was published in 1933 in Helvetica Physica acta – if you do procure this, e-mail me.

So then, some 40 years later, Vera Rubin was also hanging out measuring masses and speeds of galaxies and stars. (This is what astronomers do, have you noticed?) Vera measured the speeds of stars near the center and also at the far reaches of spiral galaxies and found something very counterintuitive, which was the stars near the ends of the spiral arms were moving very fast. Just as fast as those closer to the center. However, the gravity out at the edges should have been much weaker than that near center, which means the galaxy should not have been able to hold in those fast moving edge stars and they should have been sped away from the spiral galaxies.

But if the gravity out at the edges was similar to the gravity much closer to the center of the galaxy then Vera decided their must be much more mass throughout the galaxy than could be seen. And by the early 80s the community was convinced, there was a lot of mass in the universe that we simply could not see.

So theoretical physicists jump in, to what is a new and interesting and open question. Questions like: What is dark matter made of (on a particle level)? How fast does it move? Where can it be found? How can we detect it?

Now unfortunately, I must be a bit critical here. Primack is one of the scientists behind the theory of Cold Dark Matter, so when discussing the other proposals for explaining this lack of mass he … brushes them aside faster than he possibly should. However at this point Cold Dark Matter (CDM) – and the Lambda-CDM model does seem to be the leading candidate for the explanation of dark matter.

Now, to explain the last thirty years of work in this field in a paragraph, physicists came up with possible explanations for the type of particles that could possibly make up the dark matter. CDM calls for matter that we can’t see, but isn’t much more specific than that. One possibility could be matter that does not interact with normal matter, except through gravity, possibly some sort of very heavy particle that is similar to a neutrino. Or there could be an abundance of large objects of normal matter that just emits very little (or no) radiation, however this seems unlikely. Simulations tend to favor the first idea, lots of heavy particles that we can’t see. Other proposals involve modifying newtonian dynamics to account for the mass, and revising our definitions of gravity but people don’t seem to like these.

Part II – Pretty.

Primack then moved on to lighter material. Explaining how as you travel further away from us you can see galaxies that look different, as they are younger, he showed images taken from the Hubble Ultra Deep Field. He additionally showed a video of the Millennium Simulation by the Max-Planck Institute. This is a 10 billion particle simulation that attempts to show the possible dark matter distribution in the universe, and gives some sense of scale.

Primack also gave the quick numbers that everyone wants to hear. How much of the universe is dark matter? His current estimates put Cold Dark Matter at 25% and Dark Energy at 70% (note again bias towards the CDM model). He also has an interesting representation of that, which I will re-post here:

© Joel Primack & Nancy Ellen Abrams

(And further I will ignore any sort of distortion given to the percentages by the choice of visualization by cartoon pyramid.)

Videos shown:

• Hubble Ultra Deep Zoom-In (credit – Hubble) – quicktime – 29MB
• Millenium Simulation – Long Version (which is pretty boring) – youtube

Part III – What’s Next.

As Primack believes CDM has nailed it, what is left is actually finding experimental evidence of dark matter – and he thinks this will be done by 2010. He suggests ways this might occur.

• We could produce dark matter. The Large Hadron Collider could possibly produce micro black holes, super symmetric particles, or other particles which could be candidates for dark matter particles. Experiments should begin at the LHC in June 2008.
• We could infer dark matter’s existence through the use of the Planck Surveyor, a cute little satellite, who among other things plans to go find lots of gravitational lensing. It should launch on Halloween this year. (it is really a cat dressed up as a satellite)
• According to NASA’s description of GLAST, The Gamma-ray Large Area Space Telescope – it will: “Search for signs of new laws of physics and what composes the mysterious Dark Matter.” Yes that is right we will determine dark matter with “new laws of physics.” Look forward to that on May 16th, 2008.
• We could also directly detect dark matter using my third favorite noble gas, Xenon! Yes the Large Underground Xenon Detector is an experiment where you put a bunch of Xenon in a cave deep underground and then wait. and hope. and maybe they even pray, for some dark matter particle to crash into the Xenon. So far, nothing, but they keep using more Xenon, so maybe they will get there soon. New results coming this fall.

Conclusion

Within the next two years we might find evidence of dark matter, any sort of material that is invisible on the electromagnetic spectrum, or we may not. Each of the experiments above may turn up nothing and we may be left having to admit that it is possible we have framed the problem incorrectly. As this New York Times article explains dark matter is a practical necessity to make the current theories work.

To give a single example, our understanding (or lack thereof) of gravity has always been a bit of a problem for physicists, it doesn’t quite mesh with quantum mechanics and relativity, and it may not work as we expect when we begin to probe the depths of our universe – and thus may have introduced such a concept as dark matter/energy to fill a void that was only imagined.

But this is how science works, we design tests for the hypotheses that we have, and if these fail we create new hypotheses and new tests. So, now we non-physicists wait for one of these experiments to result in actual experimental evidence for dark matter. Remember to check back in two years to see if Primack was on his game and we are a few steps closer to figuring out what roughly 22% (and more likely 96%) of the universe actually is composed of.

If in the meantime you need some light and physicsy reading material you can check out Primack’s book (co-written with Nancy Ellen Abrams), The View from the Center of the Universe which I have not read and therefore will not comment on the quality of the writing or science within.

Microsoft, while I might rag on them, does occasionally put together good or at least interesting work. One example of this is a document created by Microsoft Research called Being Human (download here)   Being Human is the final report based on a forum Microsoft Research hosted a year ago on what HCI (Human Computer Interaction) would be like in the year 2020. The report came out April 2nd, 2008 and has four parts, a brief history, a categorization of how HCI is changing, how the field should move forward, and recommendations for how the field should change.

I will only focus on the second part of the report today, as the history of computing and interaction with computing is pretty silly and not that interesting. Part 2, titled “Transformations in Interaction” deals with five main changes and I will mention each one (long post!) by their deep and frequently foreboding names.

The End of Interface Stability

We can no longer tell if the computers are touching us or we are touching them.

This, one of their better points, strikes close to home as it firmly deals with issues of privacy. Ubiquitous computing is meant to lead to people interacting with thousands of computers by 2020, and while this seems ridiculous, it is only ridiculous for traditional definitions of computer. We can start to take into account intelligent surveillance cameras, RFID readers and tags in our clothing, groceries, physical access devices, cell phones, vending machines, cars, parking meters, music devices, our shoes, our glasses, our jewelry, let alone traditional computers. And the further we push towards injecting technology into our bodies and having better remote sensing capabilities, the more we lose the once clearly defined interface of keyboard, monitor, mouse. Now our fingertips, our movements, our heartbeat, our glances all become inputs to the myriad computers in the room. And better, they all communicate. The question is how much control do we want, should we have, will we be given?

The Growth of Techno-Dependency

You can’t go back.

While I suppose this is in some ways a change, “technology” as a scary pervasive force has been pretty constant for a good two hundred years. And while there are some interesting policy questions brought up here, like what will happen when computers take over all the human jobs, the implications for HCI here seem to be less about developing new technologies, but more on mitigating the damage caused by the crazy-evil robots. (I exaggerate, but when asked “As society grows ever dependent on technology and the interaction underpinning this, who is accountable?” I laugh as if the answer should be: the scientist should never have given us these powers.)

The Growth of Hyper-Connectivity

I am alone in a crowded room, only if the wifi goes down.

My laptop has had a bit of an issue for about three months now, both of the fans have died. This means I simply cannot run certain programs (EVE, Aperture – for very long), and my computer consistently runs at 70degC – CPU temp. But while it is still under warranty that would involve shipping it off to Apple for a week, and I can’t allow that. I need to be with my laptop all the time, because it is connecting me socially to friends around the world, to news, to the tasks and communications that form my workplace, as well as to my source of all media, my photo archives, my music library, my Netflix subscription. Physical boundaries disappear, new social relationships are formed, and it seriously is HCI that is shaping this.

How do you design for global interaction between different languages, cultures, customs, time zones? How do you prove that I am who I say I am when I hide behind my avatar? How do I maintain thousands of digital links but still keep them personal? How long before online dating is seen not only as socially acceptable, but the obvious choice? And seriously, when can all of my friends be digital?

I think twitter has to be the current best example of hyper-connectivity, I read it through a specialized application, but can check it through the web, it ims me my friend’s messages, txts me direct messages. It is on my computer, on the web, on my phone. On my road trip through the middle of nowhere (the central USA) twitter was our reliable source of communication.

The End of the Ephemeral

I thought it was fleeting, but you remembered!

Buckminster Fuller supposedly had the most documented life in the history of history, he wrote down what he was doing every fifteen minutes, for about seventy years. However fifteen minutes is now entire lifetimes of data. Much of what I covered above in the end of interface stability is recorded, and the point here is that the data now exists.

Research I have been working on involves allowing your friends to query your location through a system we have been working on at Carnegie Mellon by the name of PeopleFinder. While it allows my friends to request my current location, one of the side effects of this, is we have a server which is accepting our users locations every minute. Thus as I move around with my phone or laptop running our application, I am building up a relatively precise history of my location. Through twitter, aim logs, blog posts, Facebook statuses, my web history, I add semantic information to these locations. In 2020, with the addition of more RFID readers, more cameras, more sensors, this history becomes even more powerful. Aggregate it all and my whole life story is there, stored on disk, and it is likely I can’t erase it.

The Growth of Creative Engagement

We are all designers, writers, journalists, curators, creators.

My favorite of the changes is this, the intellectual and artistic power that computing has given to every person who touches these technologies. And while sure this has its downsides, reading every Livejournal is a bad idea, listening to every bad techno remix made by a thirteen year old with garageband and some angst is torture, and not everyone is cut out to design a poster, the potential is huge.

Take the huge success of YouTube, millions(?) of actors, directors, scriptwriters, who would never have been able to have an audience or create a film before they could pick up a Flip and post their video five minutes later. And this is a place for HCI researchers to shine: designing tools that people want to use that allow them to access their potential to create. Designing tools that allow scientists to produce science, and the computer can take care of the processing. And speaking of processing giving artists enough tools that they truly hold the creativity and a single suite does not drive the direction of art.

We are just now nearing the precipice of creativity as a species, where more people than ever are taking part in using their ability to think as a way to make something new, something interesting, to discover something yet unknown, to write something not ever dreamt of, and technology needs to support that.

Summary

There are five main ways in which our interactions with computers will be transformed as we approach 2020. How we define and think about our relationships with computers is radically changing. How we use them and rely on them is also being transformed. At the same time, we are becoming hyper-connected and our actions, conversations and interactions are being increasingly etched into our digital landscapes. There is more scope than ever before to solve hard problems and allow new forms of engagement and creativity.

And that is where Microsoft leaves us with the changing aspects of computing. The points raised are interesting and relevant for anyone designing software, designing experience, or contributing to the internet in any way. Together we can be aware of where we are going, you know – post web 2.0.

I have decided that I do not write enough about my work on my blog. This is a semi-complicated issue, because as with most work, other people also hold stake in it, and it is good to keep certain things close to the chest – even in research there is competition! However, these are just excuses I make for being lazy, and with all good problems once the conditions and limitations are defined there are good solutions.

So, starting next Friday, I will begin posting once a week on topics at least related to Computer Science, Design, User Experience, Privacy, Human Computer Interaction generally, or at least something some what science-related and interesting, and occasionally,

So … look forward to that! (up first a Microsoft Report on the future of HCI)