Tim “I invented the web” Berners-Lee was in town this week giving a lecture at the Royal Society (just off The Mall in London). The Royal Society broke with their usual policy & announced that no tickets were required – given the amount of potential interest this was a brave move, but in the event they got it perfect with the room filling to capacity just as the clock struck 7.00pm. Starting off with a quick history of the web, Tim quickly moved onto his current area of interest: ‘The Semantic Web’. An active research area, this is concerned with providing information in metadata rich document formats, such that machines can perform some form of semantic analysis of the documents.
For example, consider viewing a notice advertising a lecture. With technology as it is, you might cut & paste details into your calendar (having first found the date) & type the postal code in Street Map to find where it is being held & perhaps fill out a form to register for attendance. Where as you really want to do is say ‘I want to go to this’. In the semantic web vision, you literally just select the ‘I want to attend’ link. Your calendar program would grab the time & date from metadata, another agent would find out if it required registration & if so fill out your details & the location would be sent to your GPS enabled phone which would guide you to the destination.
After several years of everyone saying that ‘XML can do anything’, it turns out they were wrong (but at least heading in the right direction), for it seems that an application of XML known as RDF can in fact do everything! Time for proof by example (well with a little handwaving):
Consider your company has 3 XML document formats, each of which have information on different aspects of a product. Now you want to have all this information in one place / format, so you go along to your XML wizard & ask them to ‘do his magic’ to merge the documents. They’ll go off, talk to the people who wrote each format, think a little, and come up with a fourth format with enough elements to represent all 3 other docs. Now how does this all work in RDF ? So, you’ve got 3 documents in RDF & need a single view of all the data. Simple, you just concatenate the files!
Apparently, the key to RDF is that each type of metadata stored in a document is given a unique URI. So even though the XML document may be a tree structure, by matching nodes with identical URIs, rules engines can form webs across the tree. So provided you can markup elements in each of the 3 documents with common URIs for their common metadata, concatenation really is enough. Neat!
Oh yes, here are the slides
While reading through ZZZ online | Number 176, I happened to take a look at the comments & came across an amuzing exchange (yes I was bored at the time too):
- Question Why would a person die if jumping from say a golden gate bridge into water?
What if you fell in like pin straight, feet first, would that help the survival rate?
- If you can guarantee that you stay nice and pin-straight, you can cut the water, though it can still hurt like all get-out on the parts that hit water first. But if you don’t cut the water just right you’ll do yourself some serious damage, either killing yourself, knocking yourself out so you drown, or receiving serious enough injury so that you can’t swim and quickly drown. That’s 220 ft of fallin’ (just from the bridge deck to the water) to build up some speed. The water molecules can’t get out of your way fast enough at the speed you’ll be traveling and it will almost feel like hitting a solid surface. Yes, I’m bored at work.
- I think the more important question is: if you threw a cat off the Golden gate Bridge, would it land buttered side up?
- I hear that throwing a cat off before you jump will break the waters surface allowing you to survive said jump…
- Ah, but the cat has a lower terminal velocity than that of a flailing human. You’d have to throw it off with enough time allowance for it to drop the distance, cut the water and then paddle clear just before you hit. If you jump to late the waters will subside. Too early and the cat will hit you…
- All things fall evenly only in an evacuated environment. Add air, fur and surface area and things change. If all things fell at an even rate… ooer… horizontal and vertical components of displacement would be something entertaining to watch – aircraft would have to be launched in ballistic arcs from ground impulse… plus, of course under uniform gravity items would pick up velocity at 9.8 m/s/s until they either hit the ground or hit c…
ah but the cat… yes. The cat would land buttered side down but would slip over so fast you would never tell.
- Cats leg muscles can absorbe the impact of them falling at their terminal velocity. You could chuck one out a plane at 20 thousand feet and it’d survive.
Someone compiled data on (which probably means he cucked cats out of windows) it and found cats jumping from less than 3 stories did get injuries (but didn’t die)because they didn’t have time to orient themselves, but any higher than 3 stories and they were fine
- The potential flaw is this: the study was based only on cats that were brought into the hospital. Clearly dead cats, your basic fell-20-stories-and-looks-like-it-came-out-of-a-can-of-Spam cats, go to the Dumpster, not the emergency room. This may skew the statistics and make falls from great distances look safer than they are.
Technically, if you studied statistics based on the number of skydiver injuries reported at hospitals and not the morgue;
http://www.greenharbor.com/fffolder/unlucky.html
You’d think sky diving wasn’t that dangerous.
For more information on cat see this article
http://www.komotv.com/qt/bouncing_bear.mpg.
What’s amazing is not so much the positioning of the trampoline – it did bounce after all – but that
it wasn’t big enough & no one thought an unconcious bear might not be in a position to stop itself
bouncing off on to its head.
Still, it is funny :-)
The Blues Bar. Hidden away behind Liberty & Hamleys, this is the kind of place you’d never find except by chance or word of mouth. Not only has it got live Blues every night, but its free every night bar Friday & Saturday! When I visited on Monday evening, it was nice relaxed atmosphere & not too crowded in the early part of the evening. Then come about 8.30 it is transformed as people started filing in ready for the live music from about 9ish onwards. All in all, a brilliant discovery.
If you’re tired of bad web design and want to try something that might just make a difference, then take a look at log screaming