Recently there was a big fuss (including denouncements from many I know) over a U.S. effort to do away with the leap second. People claimed this was like trying to legislate PI to be 3.I am amazed at the leap the the defense of the leap second. I would be glad to see it go. All our computers keep track of time internally as a number of seconds since some epoch, typically Jan 1 1970 or 1980. They go through various contortions to turn that absolute time into the local time. This includes knowing all the leap-day calculations and the leap day calculations. It’s complicated by knowing that sometimes the day is Feb 29, and by knowing that a very, very few minutes have 61 seconds in them (or if you prefer, that a very few hours have 3601 seconds and rare days have 86401 seconds.)

That’s a mess. A minute should always have 60 seconds. Special casing all time code to deal with this was the wrong approach, and as noted, is subject to errors because the code is very rarely tested in that state.

I’m astounded to see people saying this is the same as declaring pi to be 3. It’s having 86400 seconds in most days and rare leap seconds that is the integerization of a real number. The truly scientific approach would be to declare the day to be 86400.002 seconds, and lengthen that number over the centuries, would it not?

Astronomers, like computers, can and should keep track of time as an absolute number of seconds since some epoch. They actually care very little about what the local time is other than to know when it’s dark, something leap seconds have insignificant bearing on. Indeed, astronomers might be happiest using siderial time (where a day is 23 hours 56 minutes and +4.1 seconds, the true rotational period of the Earth.)

Our system of time is not one scientists would pick in the first place. It is clearly designed for the convenience of the ordinary people, and the legacy of the traditional means of telling time. It’s silly to use this legacy system and at the same demand the general public and its timekeeping systems jump through error-prone hoops to make it reflect noon correctly to the second. Nobody even uses local time anyway, they all use a time zone. The time zone is off by a huge margin from local time, why does it matter in the slightest if it’s off by a few more seconds?

In many centuries, the drift will be noticeable. If we still care about local time, we can fix it then.

As noted, this is a trick question. The simple approach is to note that mass goes up with the cube of radius or diameter, but the force of gravity goes down with the square of radius, so the increase in "g" would be linear with the increase in radius.

Thus, the new Earth would be 10/9.8, or 2% larger in radius. Not much.

But the trick is this. The meter itself was first defined as being 1/40,000,000 of the circumference of the Earth. Thus as you
increase the size of the planet, the people on it would change their definition of the meter, so to them their planet would
always be the same size in meters, up to a point. And so "g" would always be 9.8. It's a function of the density of the planet, not the size.

Today the meter is not even a fundamental unit. It started by defining pole to equator as 10,000 km. Then it became the length between two marks on a bar. Today, the second is the defined fundamental unit (based on cesium vibrations) and the speed of light is defined to be exactly 299,792,458 meters/second -- and thus the meter is calculated from that.

Thus to get exact, since a second is 9,192,631,770 periods of the particular transition in a cesium atom, a meter is defined as how far light goes in 30.664419 of those vibrations.

This is a tricky puzzle question I thought up some time ago, but I figured I would blog it.

As people who study physics know, the acceleration a falling body undergoes if dropped (in a vacuum) at the surface of the earth is known as “g”, or 9.8 meters per second per second.

This is so close to 10 that most students and people doing back of envelope calculations often use 10 as the value of a “g”. It’s easy. Fall for one second and you’re going 10 meters/second.

So I got to wondering, how much would the earth have to change to make “g” equal to 10 instead of 9.80665?

So here’s the puzzle. By what ratio would you have to increase the diameter of the Earth so that the people on this bigger planet would have “g” equal to 10? Assume the average density of the Earth remains the same (5.46 g/cc).

Then click to the Puzzle Answer

Ok, this idea will make no sense to those who have not gone RV camping. RVs have 3 water tanks — one for fresh water, one for the toilet sewage (known as “black water”) and one for the other drains (shower, sinks) known as “grey water.” When you camp in unserviced campsites for a while you become very aware of the capacities of your tanks.

However, the RV uses the fresh water tank to “flush” the toilet. It seems to me that with a small extra water pump, one could use the grey water, or a mixture — grey with a final spurt of fresh to rinse the bowl.

RVs don’t really flush the toilet, that would use way too much water. You rinse the bowl after #1 and you pre-fill the bowl before #2 and rinse later.  read more »

The EFF is holding a Blog-a-thon on our 15th anniversary inviting people to describe things that made them decide to fight for freedom.

That seemed like a good time for me to add some details to one of my early stories, about the banning of my moderated newsgroup rec.humor.funny. I've told the the RHF ban story before and even the story of how it led to the creation of ClariNet and I'll be adding more details in my upcoming history of ClariNet later this year.

Today, at 18 years old (Aug 7, 1987) rec.humor.funny and the netfunny.com site qualify as one of the oldest blogs in existence, if not the oldest. The first blog as far as I can tell was the moderated newsgroup mod.ber, created by Brian Redmond in 1984. Mod.ber is long gone, so something else is the oldest blog. Blog, short for weblog, means a personaly created serialized publication on the web. The web, though many people have forgotten it, is and was defined by Tim Berners-Lee as including not just HTTP and HTML but the other procols such as USENET, FTP, Gopher and Telnet that existed before HTTP. So the rare USENET groups that were moderated for content were the first blogs, and some remain today, and this is thus the story of the first banned blog.

(Other suggested candidates for oldest blog include RISKS digest, Telecom Digest and Human-Nets, though they were more discussion boards than blogs.)

I had always been a defender of free speech to that point, but nothing brings it home like being banned yourself. It's also remarkable to me how many threads of my life run through that banning. These include business threads (the creation of ClariNet) and even personal ones (it's how I met John McCarthy, who introduced me to a past girlfriend a decade later.) I wasn't unknown before but the events did a lot to boost my visibility.

Being censored was a remarkably emotional experience. It didn't help that it was on the front pages of the newspaper every day and that the best (if most frustrating ) thing to do was to keep silent and let the press coverage blow over. It did teach me the truth of the aphorism that censorship doesn't protect people from exposure to violent ideas because censorship is violence.

The EFF didn't exist during this period. Had it existed, it would proably have come to my aid. But many others did, which was heartening. And I learned a bit more about how useful satire is as a tool in these battles. Having fought in the online trenches, I was ready to support it when (in another strange coincidence) my friend of 10 years earlier, Mitch Kapor, led the drive to create it. And later, of course, I have become very proud to be involved in it.

Blog-a-thon tag:
EFF15

I blogged earlier about my being in the Silicon Valley 100, a group generated by a marketing company to send out free stuff to hopefully influential folks. In that posting, I link to Dan Gillmor’s reaction to the program, where he writes about how “spooky” it is to him. I didn’t agree that it was that spooky, but there is a definite irony to the fact that I recently got a set of books via the SV100, and in that set was Dan’s own book “We the Media.”

Dan’s eyes rolled up when I told him that at dinner this evening. Of course, it was his publisher Tim O’Reilly who put the book out to the group, and again I don’t find much spooky about it. Publishers have sent out free copies of books to folks, hoping for reviews and buzz, since the dawn of books.

I was with Dan at the first event in our program celebrating the EFF’s 15th birthday, a BayFF panel on blogging and blogger’s rights which attracted an overflow crowd with an engaged audience. I’ll remember to announce some of the other events in our program in advance. We sang Happy Birthday based on the older lyrics which are out of copyright.

On 9/11, we all wondered how 19 men had lived for a year among us and still given their lives to carry out such acts. Now people wonder even more at how young native British men would give their lives to kill random fellow Britons.

But there is something different here that troubles me. Most suicide terrorists ostensibly use this tactic because there are targets you can only attack if you give your life. Suicide was an essential part of flying a plane into a building.

But you very plainly don’t need to kill yourself to set off a subway bomb. Even with increased vigilence, anybody could leave a backpack behind, rush out the doors just as they are about to close, and then blow up the bomb as the train enters the tunnel, without dying or even getting caught (except perhaps on camera.) There was almost no tactical need for these men to kill themselves. Yes, it makes it a little more certain to do it that way, but we hope that committed terrorists (especially with such clean pedigrees) are not so many in number that they can be wasted this way.

But they were wasted this way, and I think deliberately. I suspect they were chosen not as the most committed, but as the most unlikely, just for the shock value, the idea that your neighbour could be a suicide bomber. And strong shock value it is, because while you don’t have to die to bomb a train, there are a lot of targets where willingness to die is tactically necessary to carry it off, and it’s close to impossible to defend against such attacks.

Those who think careful ID checks and national ID cards will stop terrorists now must step back. These kids had clean ID. The security cameras have helped discover the story but of course could do nothing to prevent it.

I have contended (to much opposition) that terrorism and suicide bombing is a tool used against democracies that are accused of oppression. A recent book (Dying to Win by Robert Pape) now backs this up. The answers are not good.

I wrote before on the ideal car dock for an MP3 player but the truth is we could use something even simpler sooner. On my recent trip, we brought the cassette adapter but there was no tape player in the rental car. We forgot the FM transmitter, but that’s not as good anyway.

So right away let’s see a small headphone plug on the car stereos to do a nice aux input, especially if you are taking away the tape. Duh.

But we can go beyond that with a USB jack, since all music players can plug into that though with different results. A few of them will be clever enough to draw power and recharge from it — indeed, it is time for cars to have USB jacks just for power since now my cell phones and PDA can all charge from that, and use a cigarette lighter plug with USB jack to do so — but we want something with the data.

With some music players, plug into USB and they look like a hard drive with music files on it. The stereo could be an MP3 player, but might have trouble with the DRMed music. We could also leave the MP3 player in control, but develop a protocol for it to stream digital audio to the stereo, and for the stereo to send back commands (FF/Rew, Pause, skip track etc.) to the player. Yeah, you could also do this over bluetooth but why wouldn’t you want power when in the car, so wires remain the right choice.

Perhaps down the road we might see music players splitting into two halves — drive and UI electronics/power. The drive unit, be it flash stick or hard disk, holds your music and files, and the UI unit does the rest, and can be mated with any drive, as can the computer and as can the car stereo.

As I noted earlier, last weekend I was at Oregon Country Fair, which is a great time. OCF has permanent facilities and has become more popular than it wants to be. All the booths, including food, have to be juried in and can in theory be kicked out to allow new ones in if popularity drops.

This results in much, much better food boths than you see at a typical random fair with vendors coming in simply if they pay their money.

And I wondered, can we extend this concept into the everyday restaurant world? For example a food mall, where the restaurant tennants are regularly judged for quality, and kicked out if they don’t make the cut. Where you are assured a good meal at a reasonable price. If the idea works, people would go to this mall and make it worth the effort by the restaurants to stay.

This might work the same way movieplexes took over from solo cinemas. People go to a movieplex for the hot movie, but it often is sold out, so they go to a 2nd or 3rd or sometimes even 10th choice of what they want to see. This sells a lot more tickets and avoids people driving home without a movie at all — though in my case I still sometimes bail out. Here, you could go to the restaurant mall with a particular restaurant in mind, but know that if it’s too busy a fine meal is assured unless the whole mall is packed. There could even be a central line for “the next available restaurant.”

Has this been done before? And what about going further and combining facilities…  read more »

All my sites were off today as I did an emergency switch of servers.

The whole story is amusing, so I’ll tell it. I used to host my web sites with Verio shared hosting, but they were overpriced and did some bad censorship acts, so I was itching to leave. One day my internet connection went out, so I went onto my deck with my laptop to see what free wireless there was in the area. One strong one had an e-mail address as the SSID, though it was WEP-locked. Later, I e-mailed that address with a “hi neighbour” and met the guy around the corner. He had set the SSID that way to get just such a mail as mine. (I have a URL as my SSID now for the same purpose.)

My neighbour, it turned out, knew some people I knew in the biz, and told me about a special club he was in, called “Root Club.” The first rule of Root Club, he joked, was that you do not talk about root club. Now that I’m out, I can tell the story. Root Club was started as a group of sysadmins who shared a powerful colocated web server, and all shared the root password and sysadmin duties.  read more »

Having completed a long fly-n-drive road trip, I have some lessons and observations.

1. If you will be driving a lot, use a rental car even if leaving your own city. We put 3000 miles on our rental car for $300 — far less than the depreciation cost would have been on my own car.

2. It’s great to have a cooler in the car, you can buy perishables and get cold drinks when you want them, but forget about those $5 styrofoam coolers for any long trip. Within a few days ours was leaking, we fixed it by putting a plastic bag inside and out, but they are not very sturdy. There are collapsible coolers and we have one but didn’t have luggage room. You can buy a cheap solid cooler for under $20 at wal-mart or Costco, but it seems wasteful to throw it away. If you have extra luggage, you can fill a cooler with stuff, duct tape it and check it as luggage, however.  read more »

When you take pictures on the road, you would love to have the latitude and longitude coordinates of each picture stored with it. Indeed, if combined with a digital compass clever software could even tell you what landmark was in the photograph. (ie. if standing on rim of Grand Canyon looking north, it's probably a picture of the canyon.)

To attain this, some digital cameras allow you to plug a GPS into the camera, which is unwieldy to say the least. There's been talk of a bluetooth connection which is better but uses power. On a recent trip Kathryn suggested that the log from the GPS could later be matched up with the timestamps of the photos, which is a great idea -- and a web search reveals a few software packages out there do indeed do this. (And thus also allow photo organizing by geographic location, map-based browsing of photos and other such useful features.)

For the user not wanting to hook up all the devices and use software, I came up with a possible interesting design. Place a memory card slot in the GPS, or allow it to plug in USB or other memory card interfaces. The GPS could then look over the photos on an inserted memory card, read their timestamps, and use its own onboard history of where the GPS was at those exact times, and write coordinates into the files on the flash card. If it can write them on the end of the file that's easiest, if it has to rewrite each entire file that would be a bit slower.

Most digital cameras also have their own USB interface, so the GPS could simply have a USB controller and the camera could be plugged into the GPS after shooting to update the photo files with their location stamps. Most, though perhaps not all digital cameras can act like a USB drive in addition to doing camera control. Of course a standard protocol for updating locations would make this easier, but the main idea allows work with existing digital cameras. (Though they all have their own custom USB plugs and provide their own cable.)

As noted, this can give you great photo organizing. You can see your photos as thumbnails or pushpins in a map. You could link photos to google maps or satellite imagrery of the area. Directories on disk could be created by placename, or even without names photos could be grouped by each major shooting area, instead of just one new directory per 100 photos.

The cameras will eventually get smart enough to be the smart device, but for now the GPS can easily be it. Older GPSs don't have very large track log memories, but today memory is cheap and that's not as much of an issue.

I recently visited the Oregon Country Fair, which among many other things has entertainment acts which pass the hat to earn their living. (OCF only costs about $13 to attend, not enough to pay much if anything to acts.) This is a pretty common setup.

And perhaps this has been done where I haven't seen it, but I was wondering about a solution to what one busker called the "magic disappearing audience trick." Most people don't put into the hat. So along the lines of my microrefunds concept, where I suggest a solution may be to push people into making one decision, instead of many, over whether they will pay for things that don't have compulsory payment, I propose a system for busker fairs.

The plan would be for the Fair to raise their price and provide each fairgoer with "busker chips" to put in the hats of buskers. Once paid for, the chips would, at least officially, be good only for that. The Fair would also probably keep a small fraction of the money, ie. pay each busker 90 cents for each $1 busker chip turned in. People could of course also toss regular money into the hats.

These chips, aside from providing more revenue for the entertainment, would allow the fair to know what acts were the most popular, and thus who to bring back and who to leave out.

There are some other issues to discuss below. Such as the probable black market in the chips, and what price to charge for them...  read more »