Greg Egan’s Diaspora
Posted on July 16th, 2009 at 10:38 amTwelve years after it was first published, I’m finally reading Greg Egan’s Diaspora. Halfway through now.
Twelve years after it was first published, I’m finally reading Greg Egan’s Diaspora. Halfway through now.
Feb 28th:
Here’s part of the abstract for Distant future of the Sun and Earth revisited:
We revisit the distant future of the Sun and the solar system, based on stellar models computed with a thoroughly tested evolution code. For the solar giant stages, mass-loss by the cool (but not dust-driven) wind is considered in detail. Using the new and well-calibrated mass-loss formula of Schroder & Cuntz (2005, 2007), we find that the mass lost by the Sun as an RGB giant (0.332 M_Sun, 7.59 Gy from now) potentially gives planet Earth a significant orbital expansion, inversely proportional to the remaining solar mass.
According to these solar evolution models, the closest encounter of planet Earth with the solar cool giant photosphere will occur during the tip-RGB phase. During this critical episode, for each time-step of the evolution model, we consider the loss of orbital angular momentum suffered by planet Earth from tidal interaction with the giant Sun, as well as dynamical drag in the lower chromosphere. We find that planet Earth will not be able to escape engulfment, despite the positive effect of solar mass-loss. In order to survive the solar tip-RGB phase, any hypothetical planet would require a present-day minimum orbital radius of about 1.15 AU.
Emphasis mine.
Here’s the text of the course overview for CMPS 253:
The free lunch is over. It lasted fifty years.
During that time, Moore’s law meant that our programs go faster when we buy a next-generation processor. Moving forward, while next-generation chips will have more CPUs, each individual CPU will be no faster than the previous year’s model. If we want our program to run faster, we must learn to write parallel programs.
Parallel programs execute in a non-deterministic way, so they are hard to test, and bugs can be almost impossible to detect, reproduce, or fix. Many years of experience has shown that writing a correct parallel programs is typically substantially harder than writing an equivalent sequential program.
In this course, we will survey the state-of-the-art in parallel programming, and the programming languages that support these efforts. We will pay particular attention to the emerging and active field of transactional memory, which adapts many ideas from database transactions to general purpose programming languages. We will also review more traditional lock-based programming, as well as alternative techniques based on functional programming, speculative execution, etc.
I’ve “applied” for membership to the class Google Group (linked from the course page) so that I can peruse the archives. Haven’t been approved yet.
Update (April 14th 2008): I just checked the class Google Group page again only to get an error message telling me that the group doesn’t exist. It was formerly at groups.google.com/group/ucsc-cmps-253-spring-2007. Kind of lame.
Based on the abstract on the research.microsoft.com site, ALADIN: Active Learning of Anomalies to Detect Intrusions by Jack W. Stokes, John C. Platt, Joseph Kravis, and Michael Shilman seems like an interesting paper.
Unfortunately, the link doesn’t work right now because no one has uploaded the actual PDF as of yet. Update: As of Tuesday, March 11th, the PDF is available.
I browsed the directory of papers on the MSR FTP site on the off chance that the paper had been uploaded in PostScript or something, but I don’t see any file that looks like the paper in question.
Update: I found an abstract (for the paper? same title, so…) in PDF form and PowerPoint slides here: NIPS 2007 Workshop on Machine Learning in Adversarial Environments for Computer Security.
I found each of the following links interesting in its own right but either have no comment to make or am too tuckered out to post my comments on each individual page:
Google’s [WWW] Bigtable, a distributed storage system for structured data, is an effective mechanism for storing large amounts of data in a distributed environment. Just as Bigtable leverages the distributed data storage provided by the [WWW] Google File System, HBase provides Bigtable-like capabilities on top of Hadoop. Data is organized into tables, rows and columns. An Iterator-like interface is available for scanning through a row range (and of course there is the ability to retrieve a column value for a specific key). Any particular column may have multiple values for the same row key. A secondary key can be provided to select a particular value or an Iterator can be set up to scan through the key-value pairs for that column given a specific row key.
Modeled after Google’s well known Bigtable project, Hypertable is designed to manage the storage and processing of information on a large cluster of commodity servers, providing resilience to machine and component failures. Hypertable seeks to set the open source standard for highly available, petabyte scale, database systems.
regex-dna benchmark | Gentoo : Intel® Pentium® 4 Computer Language Benchmarks Game:
Match DNA 8-mers and substitute nucleotides for IUB codes N=500,000 (Check that Error or Timeout happened at other values of N with regex-dna full data).
Catspaw, Inc. provides the SNOBOL4 language for many different computer platforms, including DOS, Macintosh, Sun, RS/6000, and others. SNOBOL4 is a programming language tailored to complex pattern matching and text manipulation. SPITBOL is a very high performance, 32-bit implementation of the SNOBOL4 language.
Icon is a high-level, general-purpose programming language with a large repertoire of features for processing data structures and character strings. Icon is an imperative, procedural language with a syntax reminiscent of C and Pascal, but with semantics at a much higher level.
I took the title for this post from the page for the session description on the XTech 2006 site.
The last modified timestamp on the project page is about a year old, but the current version (v. 0.3.1) may be much more recent. I haven’t yet tried downloading and installing Etna. That’s something I’m looking forward to doing in a VM later on.
Gobby is a free collaborative editor supporting multiple documents in one session and a multi-user chat. It runs on Microsoft Windows, Mac OS X, Linux and other Unix-like platforms.
It uses GTK+ 2.6 as its windowing toolkit and thus integrates nicely into the GNOME desktop environment.
Check out Gobby’s list of features, take a look around in our screenshots section, read some testimonials, and download it right now.
Gobby is covered under the GPL (General Public License).
Zile is a small Emacs clone. Zile is a customizable, self-documenting real-time open-source display editor. Zile was written to be as similar as possible to Emacs; every Emacs user should feel at home.
Acme is a text editor and graphical shell from the Plan 9 from Bell Labs operating system, designed and implemented by Rob Pike. It can use the sam command language. The design of the interface was influenced by Oberon. It is different from other editing environments in that it acts as a 9P server. A distinctive element of the user interface is mouse chording.
Acme Stand Alone Complex is a version of Acme that runs on Windows, Linux, and Solaris.
Yi is a text editor written and extensible in Haskell. The goal of Yi is to provide a flexible, powerful and correct editor core dynamically scriptable in Haskell.
- Yi is an haskell interpreter. Very much like emacs is a Lisp interpreter, this makes really easy to dynamically hack, experiment and modify Yi. All tools and goodies written in haskell are also readily available from the editor. This is implemented by binding to the GHC api.
- Frontends. Yi can use either gtk2hs or vty as frontends, so users can choose their favourite interface.
- “Emulation modes”. The primary emulation modes for Yi are vim and emacs. Keybindings for vi, mg and nano and other are also provided. Other editor interfaces can be written by the user to extend Yi.
The long term goal of the project is to make Yi the editor of choice for the haskell hacker.
The main short term goal is to maximize Yi’s Fun Factor. This includes:
- improve hackability (and therefore architecture)
- add cool features