There's no way an herbalist is going to have as much medical value as a surgeon. I'm not saying she's not valuable - but applying basil to a severed artery is not going to be as effective as somebody who can sew it up.

I'm still unclear on how a surgeon without any instruments managed to sew up a bleeding artery. Because, need a curvy needle and some really strong thread -- did they unwind heavy-grade thread from around coat buttons? Do people flying from Australia even take their coats with them? I'll grant that he has the expertise to sew up a bleeding artery, but the tools are what I'm talking about.

The most useful aspect of Jack's medical expertise, right now, is psychological: everyone seems to think, "Yay, doctor," and presume a certain level of civilization safety net. Which illusion will be punctured by the first Lostite who comes down with appendicitis, because anybody watching a doctor improvise abdominal surgery outdoors, with a hunting knife, some alcohol for sterility, and no anaesthetic -- they'll change their minds about how strong the safety net feels.

You'll notice there are no diabetic Lostites, or heart patients, or anyone with a chronic ailment who needs regular medication to survive. Because, even if they had been cast, they'd be dead by now.

The obvious explanation, given all he's seen and experienced, is not that he has a faulty compass, but that there is, in fact, a significant magnetic whosit, most likely coming from the mysterious power source that must exist somewhere on the island.

Going back to the "faulty compass." Not faulty. Nor is a huge chunk of metal necessary to produce that much magnetic variation, though it could. It's one of the ways the Navy detects submarines, with a device known as MAD (Magnetic Anamoly Detector). Take a look at this map. Scroll all the way down to the bottom two maps. Take a look at the mid-Pacific Ocean and what do you see? The magnetic variation of north runs nearly parallel to the equator. Practically a full 90 degrees of declination. And then it reverses itself 180 degrees the other direction, but still parallel to what we think of as east-west. There's even finer tuned maps that pilots of P-3s use when hunting for subs using MAD. You have to know what the actually magnetic variance is at any one location to know if a huge chunk of metal, such as a sub, is throwing it off.

This is why one of my first objections to the scene was a baffled "But...but.."

Shouldn't Sayid know that the compass has deviations? He's military trained. No reason the RG would omit basic map training.

Plus? the sun does not set in the exact West unless you are on the Equator during the equinox. Almost everything else depends on your relationship with the tilt of the earth. Knowing the approximate latitude you are at, and the time of the year would help.

The magnetic variation of north runs nearly parallel to the equator. Practically a full 90 degrees of declination.

The lines of declination shown are isogonic, not directional. They don't show the direction to magnetic north, they link points where the angle between true north and magnetic north is the same.

I'm with Sayid in mistrusting Locke's compass, at least until further tests are done. If the island is near the equator, checking accurately against the stars with no reference information will be difficult.

I also mistrust Jack's estimation of west -- even if he remembered accurately where the sun had gone down the night before, the sunset azimuth varies considerably with the season. And I've learned from experience both hiking and flying that people frequently mis-estimate a ninety-degree turn when they try to measure it with the "point straight ahead, then point to the side" method. They usually end up about 20 degrees short.

So there are lots of ways errors can creep in. I think the point of the whole bit is "This place is weird. Locke is weird. Don't trust either one."

late edit: because I finally remembered the correct term is "isogonic."

sunset azimuth varies considerably with the season.

Even on the equator? My personal experience (6 degrees below) was that sunrise and sunset had very little variation. Over the course of a year, the sun inevitably rose between 6:15 and 6:30 and set around the same time. Is a 15 minute window even equivalent to a 1 degree variation in azimuth? That's not a lot of difference.

I'm talking about a difference in the position of sunset, not the time.

I'll use Singapore for an example (latitude 1° 24' North).

The planetarium progam in my Clié says that today the Sun will set there on azimuth 248°
on 15 April 2005 it will set on azimuth 279° and
on 15 July 2005 it will set on azimuth 291°

...in other words, Sayid needs to wait a year and build Stonehenge (or similar) before he can say definitively that the sun rises in the east. Even so, he needs detailed magnetic maps of the Pacific to prove that the compass's problems are Locke's fault.

Luckily, Locke will have pulled some outrageous survivalist crap by then, and Sayid will get to say "I told you so" without having to go to all that effort.

So there are lots of ways errors can creep in.

Also, Jack and Sayid are remembering general directions in a spot they are unfamiliar with. It's not like they're standing in the middle of Stonehenge where they have landmarks by which they can point to exact west.

I rewatched the compass scene. It was off by 20° from what Sayid thought was true north. I'm not sure I'd do much better than that precision estimating which way north is in my neighborhood in daylight, and I have a pretty good idea where Polaris lies in the sky.

Wow. Stonehengey x-post.

I'm talking about a difference in the position of sunset, not the time.

I understood that, I just wasn't sure how much of a difference of position it would be. From your example with Singapore, it would seem to be quite a lot. When I think about it, it makes sense. The earth still tilts, even if you are on the equator and have equal length days and nights. That tilt would be reflected in the position of sunset/sunrise at any given time and it would change quite a bit over the course of the year. Thanks for the example, it put into numbers what I couldn't quite wrap my brain around.

Aw, you guys are mathing and sciencing the pretty show with the superduper polarbearwhatchamasaurus.

You'll notice there are no diabetic Lostites, or heart patients, or anyone with a chronic ailment who needs regular medication to survive. Because, even if they had been cast, they'd be dead by now.

Yes. Maybe they've been magically healed, just like Locke? Although, sometimes Diabetes Type II and some heart conditions are intensified by comfortable, first world living. There's no endless supply of Twinkies and Marlboros. There is fruit, fish, water, and yes occasionally pork, but it's game, not some bred-to-be-fat Wilbur accompanied by buttery mashed potatoes, and drowned in gravy. The heat might be a complication for someone with cardiac or lung issues, but on the other hand, there's little-to-no polution, no Monday morning status meetings, no Friday afternoon road rage infested rush hour.