crwper

Or, perhaps, mono-amine oxidase? Michael

I had heard that there was a connection in scientific literature between risk-taking behaviour and low serotonin activity in the brain. I had also heard that it is not, in fact, adrenaline which we are chiefly after, but rather dopamine. I found what looks like a fairly good introductory article here, for those that are interested: http://www.nlada.org/DMS/Documents/1066920620.52/serotonin.pdf The quote below is from the article: I'm inclined not to take these things too seriously, but I am interested because it seems to offer some insight into our behaviour, and what binds our diverse community together. Michael

If you're going to the well-known valley in Switzerland, you can purchase heli rescue insurance from Air Glaciers in town. Drop by their office to inquire. I think it's about 30 Swiss francs. Michael

That reminds me of the time Spence and I spent about six hours mostly standing on the railing of a balcony waiting for traffic to clear. About midnight there was still traffic milling around, about 2 o'clock the bars closed and there was another bunch of traffic. Just as that was clearing, around 3 or 4 o'clock, people started showing up to fill the newspaper boxes. When they finally left, cabs began lining up in front of the hotel to pick up early-morning travellers. Then the sun rose, the city came to life, and we went to work. Does it still count as a long wait time even though we never got to jump? Michael

Would it be fair to say that you absorb data slower generally when it's auditory, or can you think of an audible indicator that is not rate or pitch change in a tone? One thought is the method where the device dictates the glide angle to you as a number, but I assume this would fall under the category of "pure numerical data"? A visual signal would be interesting to experiment with, but I don't think is practical for me at this point. I was looking at the techincal data on the SportVue used in the Altimaster Titan, and it looks like the LCD screen which is being projected in front of you is of the "custom-tooled" variety and not just an array of pixels. This has the advantage of higher resolution, but comes as a bit of a disappointment to me because it means less flexibility in the display. I've ordered a relatively cheap pair of Etymotic Research ER-6i earphones, which are the in-ear type. This should reduce outside noise by about 30 dB. The earphones themselves are very sensitive to voltage, which means I might be able to eliminate the amplifier from my system. I'm pretty stoked to see what these things sound like. Michael Edit to add: With the in-ear earphones, I've also considered that this will make an audible altimeter almost inaudible. I'm thinking I will have the device dictate altitude every thousand feet or so, as well as a distinctive tone at pull time. Obviously this is not the only altitude reference I use, but should help keep me from fixating on the other data.

Also, it's worth stopping by Air Glaciers when you get into town anyway. When we were there last summer, we were able to get heli rescue insurance from them for about 30 Swiss francs, I think. Michael

I think you stated your question fine, but I didn't answer very clearly. Let me know if I'm still way off the mark. Online discussion tends to focus on your beliefs. But in real life, what's usually way more important is how you represent your beliefs. If we're standing at the exit point and you won't stop telling me how you don't really like this jump as much as some other jump, then I'm likely to avoid sharing the exit point with you in the future. It's nothing personal, just that when I'm doing one thing I like to enjoy what I'm doing, not hear it compared to everything else I could be doing. Now, if this was the case, I hope you find someone who does like to share those comparisons with you. I'm just not that person. On the other hand, if we're standing on a high cliff and I'm busting my gut because you just made some crazy-ass remark, it doesn't bother me if you only like to jump high cliffs. It's a good thing to know, because I won't wake you up at one in the morning to see if you want to jump a crane with me. But I'll probably give you a shout next time I'm heading to a high cliff. Michael

I'm probably telling you something you already know, but I'm going to say it anyway. I don't think anyone's reasons for jumping are as simple as a poll with two choices, and part of me wishes we'd stop trying to sort BASE jumpers into discrete categories. You will probably share the exit point with a lot of people. Most of them, you will never know precisely what their reasons for jumping are. You'll be lucky if you can even narrow down your own reasons. Michael

Of course, it's Alti-2, not L&B. Thanks. MIchael

I was thinking about this. One thought is... I am planning to have the device log jumps as well, so you can look back later. In freefall, it seems to me that the thing you are most interested in is "does this improve things, or make them worse?" If you were optimizing your body position with a wingsuit, for example, the information which is most immediately relevant to you is relative improvement. Later on you might look back and say, "Geez, I only got 2.0 on that flight." But during the jump, the numbers may not be as helpful as I originally thought. Another advantage of beeps over words is that with beeps we can update the data every second. With words, I think it's going to have to be dictated every two seconds. One possibility is a hybrid design. What if it beeped most of the time, and every ten seconds it played an asynchronous (i.e. the beeps keep going) sound indicating your actual glide angle? It would be like you were listening to a vario and taking a peak at the dial every ten seconds. Johnny, I've thought about the wind as well. I don't think there's any way we could factor it out even if we wanted to. But the more I think about it, the more I think we don't want to. Wind is part of the environment, and it's a variable that should be experimented with. I think perhaps one advantage of using beeps instead of an actual number is that it puts you in the domain of relative change. So, while you may notice that you can't get it beeping as fast as you could previously, you will still be able to optimize your flight for the current conditions. Under canopy, this could be helpful for understanding the relationship between winds and optimal flying style.

Why yes, I suppose it does mean 'sideways'. Michael

A couple of thoughts. First of all, I usually grab my toggles from the outside, but with my thumbs up. This is a small difference, but it seems to me your chances of accidentally letting go of the toggle when you grab it thumbs-down are somewhat higher. Second, suppose you grabbed the toggles/risers as in your proposed method, and began a correction. Suppose you then needed to move one hand quickly to the opposite front riser. I think Dwain suggested something like this for a quick riser turn. If your hand is also through the toggle, it seems to me you have increased your chances of accidentally releasing that toggle as you reach for the opposite front riser. Finally, I think even in grabbing your toggles/risers as in the proposed method, you are increasing your chances of dislodging a toggle accidentally. When I grab my rear risers, my hands come around the outside of the riser, with my fingers wrapping around the front. This keeps the toggle out of the way completely. If you start involving the toggles in your riser grab, I think you're just asking for trouble. It seems to me the whole idea of being able to move quickly from a riser to a toggle is perhaps not worth the risks. If you grab your rear risers to make a correction, you probably won't be letting go of them until you are no longer pointed at the object, right? So you'll have plenty of time to find your toggles. Michael

You know, I hadn't even though that holding the slider down with slider bumpers would make it more or less useless as a cross-connector. You'd have to tie it down pretty securely for it to be used this way. How does everyone accomplish this? As you said, a lanyard and snap probably also won't work. I'm not sure tying it down with a pull-up cord will do it, either. [Edited to remove an incorrect interpretation of the word 'lateral'. Who knew it meant 'sideways'?] Michael Edited for spelling.

I think the problem with re-mounting the display is mainly that it is very difficult to focus your eyes on a display that's that close. The heads-up systems (like on L&B's Titan) usually move the focus to infinity, if I'm not mistaken, so it's easier on the eyes. As for speed, that's one of the things I was thinking. It will be easy to have the thing indicate speed instead of glide angle. For example, a jumper might be more interested in optimizing horizontal speed, or in the case of speed skydiving, vertical or total speed. I was inspired to start this project after watching a video with some guys using an Atmonauti-style track off a big wall. What I was thinking is, how much have we actually played with tracking positions in freefall? If we had a device which gave instant feedback on the effects of a change in body position, how much fun would it be to try all kinds of different things in freefall? Surely this will at least give a more intuitive feel for what works and what doesn't. Michael

Also because it keeps the rear slider grommets away from the brakes, I think. Michael Edit to add: On second reading, it occurs to me that "so they can move..." may have been saying how you can tell if you've done it right, not why you do it. Oh well.

That's the general idea. Right. The first version calculated the altitude lost and the horizontal speed from position information, and then used this to calculate glide angle. If the glide angle was 2:1, it would say, "two point one". The new version uses velocity data coming straight from the GPS, rather than calculating velocity from position. As I understand it, this should be considerably more accurate. Calculating from position, you have (best case) about 5 metres error in position, which means your velocities are only accurate within something like 5 metres per second. Taking the velocity data from the GPS, I believe it uses something like carrier phase to measure the velocity, rather than taking differences. As a result, velocity is accurate (according to Garmin's specs) to about 0.1 knots (about 0.05 m/s, or about 100 times more accurate). My experience with the previous version was that, although the dictated data tells you exactly what glide angle you achieved, it is difficult to hear over wind noise. I can always make the output louder, but it seems to me there is a basic problem here that wind noise is similar in some important ways to the human voice. A tone, on the other hand, is quite distinct from wind noise. So, perhaps a tone would be better. Yeah. Another advantage with tones is that we have two dimensions to work with. One is the rate, and the other is the pitch. We could do something like have the rate indicate your glide angle, so as you say it is beeping like crazy when you're doing well, and the pitch could indicate change in glide angle (high pitch if your glide angle is improving, low pitch if it's getting worse). That would correspond with the "happy" and "sad" tones, right? A couple of options here would be (a) to have a continuously changing pitch, so you know just how fast you're improving or (b) just a couple of user-defined tones which indicate + or -. I have a feeling that from a human interface standpoint option (b) will be better, since (a) might just be too much information. Any thoughts? I think this happens naturally, if I follow what you're saying. I am getting east, north, and up velocities from the GPS. I use east and north to calculate a horizontal velocity which is independent of your direction. So, even in the middle of a turn you should be getting a good indication of glide angle. Michael

Is there an instrument there that indicates glide angle? I can only find varios on that website, which indicate vertical speed but do not take horizontal speed into account. Michael

The usual argument with analog gauges is that they are the best way of communicating both absolute value (and moreso position within a range of values) and change in value using one instrument. My concern with tones is that it might make it difficult to compare what you are doing now with what you did earlier, unless you're very good at distinguishing frequency. However, this may not be an issue, and at any rate tones are very good for communicating change, so it's definitely worth trying it out in freefall. Michael

I've been working on a project which is now in its second iteration. The idea is to develop a device which will dictate my glide angle every second or two during freefall. This will allow me to make adjustments to my body position and determine immediately what effect those changes have. I've seen a bunch of GPS data indicating that people are wearing GPS on skydives and BASE jumps, and later viewing the data to see what works and what doesn't. It seems to me that having this information in-flight would be a considerable improvement. Since I am a programmer, I figured the best chance for this project to get done would be if I turned it into a programming problem. My first attempt used a Garmin Geko GPS attached by cable to a Palm Tungsten. The headphone output of the Palm Tungsten went to a home-built amp, which went to a pair of earphones. On the software end of things, the program took position data from the GPS and calculated glide angle. To dictate the glide angle, it played one of thirty sound files (me saying, "0.0", "0.1", etc.) depending on that value. Problems noted: First, the cable was fussy as hell. As often as not it would come undone on jumprun or something, and I'd have to abandon the test for that skydive. Second, the audio was too quiet to be heard in freefall. Since the amp was really just acting as a voltage follower (a 1:1 amp), there is plenty of room to improve on volume. I did not get a chance to try the device using my wingsuit, which I thought would be a bit quieter than regular freefall. Successes: Even though I couldn't make out the numbers in freefall, I could hear that it was saying something, so I know that the GPS is working properly very soon out the door. The Garmin GPS has a time to first fix of something less than 10 seconds when hot, i.e. if signal is lost for 15 minutes. So, on to the second version. This one is a Garmin GPS 10 (a wireless GPS with accurate velocity output), plus the Palm Tungsten again, and the amp and earphones. I've also re-written the software to make it easier to tweak. The new version has different behaviours for freefall (>13 m/s down), under canopy (0-13 m/s down), and in aircraft (climbing). So far I only really know what I want in the freefall stage, which will be similar to the previous version. I've tested the wireless, and that works really well. I also tested the velocity walking to work this morning. The specs say it's accurate to 0.1 knots, and in fact that seems true. It was stable when I was walking a steady pace, and if I slowed down just a bit it would drop instantly by 0.1 or 0.2 m/s. The amp will be easy to change so the output is louder. Currently the interface on the software is pretty simple. It's just echoing what it gets from the GPS, and it has a button to connect/disconnect. I will likely be adding to this a page with a position/velocity readout, as well as a "satellites in view" page for checking things out on the ground. I will also be adding a position/velocity log, so you can go back later and check things out. So, why am I posting this? I think something like this would be very useful for anyone interested in optimizing their track or wingsuit flight. I will definitely be releasing the software, along with source code, for anyone who is interested. You'll need a Palm Pilot and a GPS. The amp is easy to build, but this is something I could probably build for cost if someone is not able to build it themselves. Does anyone know of a commercial alternative (i.e. a small battery-powered audio amp)? I am curious to know 1) if anyone else is interested in this kind of thing, and 2) if you are interested, what features would you like to see? Michael

I also say, leave it like it is. A purely technical forum would get boring sometimes, just like a purely chit-chat forum would get vapid. I think there's a good balance of both here. Michael

It's not Zurich, but I tried to get a ticket from Luzern to Munich last summer. Blank stare. I tried a couple more times. Nothing. "Oh, can I get a ticket to Munchen?" Sudden recognition. I never had a problem using English in Europe, which is almost embarassing, really. In Amsterdam we ran into a beggar who, after a first try in Dutch, asked us in perfect English (with no accent) if we could give him a bit of money, all the time appologizing for his English. That's humbling. However, it seems that it might be worth your while to make sure you know what your destination is called locally. Michael

Damn, that looks exciting. Are the trees a viable "alternate"? Michael

A while back, someone suggested to me: If I go in, erase the last few seconds of tape. I like this one. Inevitably my family will look for it (because that's what people do), but I really don't think they need to see it. Michael

Grain silos. Oil rigs. Michael

This reminds me of the trick of grabbing someone's retractable pilot chute and pulling it to collapse their canopy. If you had an object strike, and somehow the retractable got caught on the object, this might make a bad situation worse... It's unlikely, but I thought I'd put it out there anyway. Michael