Channel 9 - Entries tagged with Theory

What is a database, really?

Charles — Thu, 31 May 2012 18:12:10 GMT

Alice wanders down a rabbit hole one day and finds Erik Meijer and Brian Beckman in the C9 studio. What's going to happen? What does she find? There's a plastic mouse, a hard drive, a hammer, database acid, a whiteboard and a couple geniuses in very rare form.

Erikand Brian explain what a database really is... Erik drinks hard drive acid, takes a hammer to a mouse in search of the database it hides (Brian's brawn is also employed in this endeavor), and Brian paints category theoretic expressions on the whiteboard. This isn't what you think it is, Alice. It's much, much more.

Enjoy. You don't want to miss this one.

C9 Lectures: Yuri Gurevich - Introduction to Algorithms and Computational Complexity, 2 of n

Charles — Wed, 16 Feb 2011 17:29:56 GMT

Yuri Gurevich is back on C9!! Yuri is a logician, computer scientist and inventor of abstract state machines. He currently works at Microsoft Research (he's a member of Wolfram Schulte's RiSE team).

This is the second part in a series of lectures exploring the fundamental logic-recipe powering all that we do as software engineers and computer scientists—the algorithm. What is an algorithm? You may be surprised to learn that this is not a simple question. Nonetheless, in this video, Yuri presents an answer—one that is perhaps somewhat controversial in nature—based on his own research and philosophy.

Thank you, Yuri, for taking the time to share your extensive knowledge and gentle, kind spirit with Niner Nation. We all really appreciate it! Thanks, too, to Wes Dyer and Bart De Smet for being our live audience for this lecture and asking great questions!

See Part 1
See Part 3

C9 Lectures: Dr. Brian Beckman - Covariance and Contravariance in Physics 1 of 1

Charles — Wed, 25 Nov 2009 18:22:00 GMT

By now, you know Brian Beckman given how many times he's been featured on Channel 9 and, well, just how amazing he is. Brian is an astrophysicist and software architect currently working on a technology we can't talk about...yet... Stay tuned for that. Dr. Beckman is the perfect choice for a new lecture in the C9 Lectures series. This is a single lecture, but there will be more interesting conversations to come on this deep and beautiful topic (in some sense, this is all about symmetry).

In the Rx interview with Brian and Erik Meijer, a short discussion on covariance and contravariance took place as a tangential topic (which often happens in real conversations - and we love that!). The concepts of co/contravariance can confuse and confound. Also, they are not just related to programming.

Here, Dr. Beckman teaches us about covariance and contravariance in physics. Are these universal properties? Do they apply to the mathematics of physics (from quantum mechanics to black holes) in the same basic way they do for general purpose programming with objects and lists, for example?

Tune in. This is a deep dive lecture and quite mathematical. Don't be scared. As usual, Brian explains complex things in a readily understandable fashion for mere mortals. If you have no experience with math and physics, this may be a bit challenging, but certainly not entirely over your head.

Enjoy.

NOTE: You should download the supporting document and slides (you should download the MathType fonts here). This will help you learn faster!

Silverlight 2 powering Netflix on Mac

Ben Waggoner — Tue, 28 Oct 2008 00:38:00 GMT

It's been discussed for a while, but the time is now - Netflix has just announced Silverlight 2 will power their streaming video service, which had been Windows-only until now. Silverlight 2 adds support for PlayReady DRM, so we now have the same DRM support on Mac and Windows. The service will be available on Xbox 360 as well.

You have to be a Netflix subscriber of course, but the content is commercial-free and much higher quality than the various free video services. They encode up to a full 720x480, in proper 4:3 or 16:9, at a range of bitrates. The higher rates definitely outperform standard def cable and satellite in video quality.

Lots of good stuff in the press release, but I had a couple of things I wanted to call out (bolding mine).

Netflix, Inc. (NASDAQ: NFLX), the world's largest online movie rental service, today announced it has begun the deployment of Microsoft Silverlight to enhance the instant watching component of the Netflix service and to allow subscribers for the first time to watch movies and TV episodes instantly on their Intel-based Apple Macintosh computers. The deployment, which will initially touch a small percentage of new Netflix subscribers, is the first step in an anticipated roll-out of the new platform to all Netflix subscribers by the end of the year.

Note that this won’t be immediately available to all customers.

Silverlight is designed for delivery of cross-platform, cross-browser media experiences inside a Web browser. It is expected that Netflix members who watch movies and TV episodes instantly on their computers will enjoy a faster, easier connection and a more robust viewing experience with Silverlight, due to the quality built directly into the player. Among the viewing enhancements with the new player is a breakthrough in timeline navigation that vastly improves the use of fast-forwarding and rewinding. The new Netflix player takes advantage of PlayReady DRM, which is built into Silverlight, for the playback of protected content on both Windows-based PCs and on Macs. That had not been possible with previous generation technologies.

This is one of the first big rollouts of PlayReady with Silverlight in the USA. When you see the new navigation, it’s a real testament to the difference between a media player plugin like the WMP OCX, and a rich application runtime that plays media well like Silverlight.

The rich user experience support and DRM, what else does Silverlight bring to the equation? One big thing is that PlayReady DRM supports http delivery of pre-encrypted content, unlike other platforms that require a proprietary streaming server and protocol be used to deliver protected content, applying DRM on the fly. Pre-encrypted content is both more scalable (since the encryption processing is only done once, not per user), and more secure (since an in-the-clear media file doesn’t need to be transmitted and stored on the server).

There’s been two big technical challenges in web video for the last dozen years or so.

How do we deliver the best experience to each user, in a world of variable bandwidth and hardware power
How do we deliver that experience as cost effectively as possible, enabling new business models in video distribution.

We’re at the point now where a user with a fast connection and a decent computer should have a darn good video and audio experience. Netflix is a testament to what’s possible as the cost to deliver a MB of video gets low enough, from a business perspective. While finally delivering a user experience better than VideoCD.