At 5:56 PM -0500 12/11/00, R. A. Hettinga wrote:

At 9:48 PM +0000 on 12/11/00, Ben Laurie wrote:

...

Chambers defines geodesic as "the shortest line on a surface between two points on it"

Thank you. It works in all dimensions, and, thus it's topological, right?

Topology is typically not concerned with distance metrics. Doughnuts and coffee cups and all. Geometry is what you're thinking of, presumably. Not as sexy as saying something is "a topologically-invariant geodesic fractally-cleared auction space," but that's what happens when buzzwords are used carelessly. By the way, one topological aspect of a geodesic dome, to go back to that, is that each node is surrounded by some number of neighbors. Applied to a "geodesic economy," this image/metaphor would strongly suggest that economic agents are trading with their neighbors, who then trade with other neighbors, and so on. Tribes deep in the Amazon, who deal only with their neighbors, are then the canonical "geodesic economy." This is precisely the _opposite_ of the mulitiply-connected trading situation which modern systems make possible. So, aside from the cuteness of suggesting a connection with geodesic domes, with buckybits as the currency perhaps?, this all creates confusion rather than clarity. --Tim May -- (This .sig file has not been significantly changed since 1992. As the election debacle unfolds, it is time to prepare a new one. Stay tuned.)

On Mon, 11 Dec 2000, R. A. Hettinga wrote:

...

Chambers defines geodesic as "the shortest line on a surface between two points on it"

Thank you. It works in all dimensions, and, thus it's topological, right?

Topology does not deal with dimension or distance. Pure geometry. Not even affine or anything. As I've seen them defined, geodesics do not necessarily mean the shortest path but rather the shortest path based on local knowledge. I.e. if you have a wormhole in general relativity, the possible shortcut does not affect the definition of geodesics in any way. You calculate the geodesic based on the local curvature measure of the space, that's it. Sampo Syreeni , aka decoy, student/math/Helsinki university

Sampo A Syreeni wrote:

On Mon, 11 Dec 2000, Ben Laurie wrote:

...

Chambers defines geodesic as "the shortest line on a surface between two points on it" and that is precisely the meaning in general relativity.

No question about it. The term also doesn't mean a whole lot when applied as-is in the many instances it is on this list. As Tim put it, it pretty much equates to "cyberpunkish".

Not being subscribed to cypherpunks (has S/R improved?) I will have missed that.

What little I've grasped of RAH's usage is that "geodesic" often translates as "distributed", one of the main features of which is that it "operates based on locally available information". Hence... Besides, if you know your Einstein (or Riemann, or Minkowsky) even a little bit you will recognize that one of the prime reasons for the development of a geometric interpretation of physics is the need to have a solid theory not reliant on instantaneous transfer of information ("local"). My interpretation is not unreasonable at all, considering the alternatives. Wanna drop it?

:-) Certainly not. AFAIK, RAH has always used "geodesic" in conjuction with "settlement", which clearly says to me that he's talking about the quickest/easiest way to do money transfer. You may, or may not, achieve that with distributed systems, but so what? And, to hit relativity, for completeness, geodesic in that sense is about figuring out curvature. That is, knowing all geodesics tells you the shape of space-time. And, natch, light follows geodesics, which is the glue that holds it all together (and brings in your non-instaneous transfer, too, but again, that is neither a consequence of, nor a requirement for, geodesics).

...

Saying that it has anything to do with distributed systems is making it up as you go along.

Ain't everybody?

I'm taking the fifth on that one.

...

And if RAH is now going to claim that's what he meant then he's making it up as he goes along, too (well, we knew that anyway, but redefining geodesic in this way is going too far).

It's good to know you're hip to this.

Like, yeah, daddy-o. Cheers, Ben. -- http://www.apache-ssl.org/ben.html "There is no limit to what a man can do or how far he can go if he doesn't mind who gets the credit." - Robert Woodruff

Tim May wrote:

At 7:42 PM +0000 12/12/00, Ben Laurie wrote:

...

Sampo A Syreeni wrote:

...

On Mon, 11 Dec 2000, Ben Laurie wrote:

...

Chambers defines geodesic as "the shortest line on a surface between two points on it" and that is precisely the meaning in general relativity.

No question about it. The term also doesn't mean a whole lot when applied as-is in the many instances it is on this list. As Tim put it, it pretty much equates to "cyberpunkish".

Not being subscribed to cypherpunks (has S/R improved?) I will have missed that.

Signal happens when good writers contribute good articles. Noise happens in the expected ways. Noise is what the delete key, and filters, were made for.

Hmm. So, please send me your noise filter. I could do with one.

As you are apparently reading this from the "DBS" list, you are not seeing any of my contributions. Regrettfully, DBS (and DCSB, or Bearebucks, or whatever Bob is calling his list(s)) is not an "open system." The Cypherpunks tried such a censored list a few years ago, and we rejected the approach.

The list I'm writing to is not censored, AFAIK.

I wrote a large article debunking the "geodesics is about topology" point of view. Others have said similar things.

Actually, they're really about geometry, though there are some kinds of topology which can support geodesics (not the standard rubber-sheet kind most people are familiar with, though). For example, a graph can support the notion of a shortest distance between two points, and that is definitely a topological entity.

Please don't contribute articles to the Cypherpunks list if you are, as you say, not subscribed. While we don't reject articles by nonsubscribers, as per the above, it is tacky and rude for nonsubscribers to address articles to lists they are not tracking.

This is an email, not an article. Is it tacky and rude to copy to a list to which you'd prefer I didn't reply? I think so. Is it polite to include all recipients in a mail to which you reply? I think so. Cheers, Ben. -- http://www.apache-ssl.org/ben.html "There is no limit to what a man can do or how far he can go if he doesn't mind who gets the credit." - Robert Woodruff