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Comment: Re:"You ate the poison mushroom!" reflex. (Score 1) 154

It's when I'm bending, twisting, picking up objects, etc. that I get vertigo.

Which is what's expected. You spend most of your time upright, so your brain gets a lot of experience with the chaged response of your inner ear. So it learns to interpret the modified signals more appropriately.

But when you bend down, twist, pick things up, and otherwise get into rarer positions and motions, you're in a set of conditions where the signals you're getting are not what the brain has yet figured out. Meanwhile, some of these postures also make you lose many of the visual cues of your position, throwing you into dependence on your muscle and (defective) ear signals. Bingo: Vertigo attack.

You MAY be able to reduce the amount of severity of the attacks by doing such postures as exercise, to help you learn to map more of the range of your ears' signals. Assuming, of course, you can stand the vertigo while doing the exercises, and/or can stop before the attack gets very strong.

Comment: Re:Which is why FAST flicker still causes vertigo. (Score 1) 154

Electronic ballasts don't run at line frequency, they are many times higher (1,000hz+), so that issue should be eliminated.

Electronic ballasts may indeed produce thousands of flashes per second. But they're powered by a "raw" power supply - a recitfier and filter capacitor that is in turn powered by the line, which comes and goes 120 times per second (or 100 in much of Europe).

If the filter capacitor is large enough that it doesn't discarge appreciably before it is recharged by the next half-cycle, the individual pulses produce about the same amount of light, the repitition rate of the pulses is close to constant, and thus the average brightness is close to stable over the line power cycle.

If the filter capacitor is smaller, it discharges substantially during the low-voltage parts of the cycle. The individual flashes get dimmer when the voltage droops and the repititition rate may also change. The average across several consecutive mini-flashes tends to track the input voltage.

If the capacitor is still smaller, the voltage may go so low that the high-frequency oscillator actually stops during the low voltage parts of the input cycle. The flicker may actually become substantially WORSE.

Bigger capacitors cost more. So guess what the cheap, commodty, lamps get.

Comment: Wait until you're older. B-b (Score 2) 154

There are two sets of muscles for eye movement - one for convergence, which rotates the eyes, the other for focus, which reshapes the eyes...

The latter system also reshapes the lens.

Unfortunately, as you age your lenses stiffen up and/or the muscles get weaker, and that system gradually degrades. (This "disease of age" (presbyopia) becomes significant pretty early - about mid 30s.)

(By the way: The eye rotation is actually THREE axis, although the motion around the line-of-sight is pretty limited. {Look in a mirror and rotate your head right-left to see it.} Apparently evolution found matching the image rotation by slightly rotating the eyes to be less expensive than a layer of image-rotation logic in the brain.)

Comment: Which is why FAST flicker still causes vertigo. (Score 5, Interesting) 154

I find that any kind of response time lag between my inputs and the real world, especially when it varies, is what makes me sick ...

My wife has vertigo. Her attacks can be triggered by fluorescent or high-pressure arc lights where the flicker rate is above the flicker-fusion rate of the eye. (This makes trips to warehouse stores problematic - they have to be short or she'll be down for the rest of the day. That's hard at, say, Costco.)

I used to wonder how this could be, and finally realized that the "strobe light" effect produces small, but significant, errors in observed position of the background items (shelves, etc.) that she uses for reference to balance despite the damaged inner ear.

When they first began using fluorescent lights in factories - in the days before guards over moving machinery were common - the worker injury rate went 'way up. Turns out the lights made the AC-powered motors, turning at or near an integer fraction of the line frequency, look like they were stopped or only moving slowly.

The fix was to build the light fixtures in two-tube versions, with a capacitor and an extra inductor in the balast, so the "lead lamp" and "lag lamp" would light at a quarter-cycle offset. In combination with suitably persistent phosphors this made them largely fill in each other's dim times, enough to make fast-moving parts blur and look like they were moving. For large arc lights, a similar fix was to arrange them so adjacent lamps were distributed among the three phases of the power feed, rather than having rows or patches of lights all flickering in unison.

Unfortunately, this lore has apparently been lost - at least outside the specialists wiring factories full of moving parts. Warehouse stores have rows and sections of arc lighting all wired to the same phase. I'm not sure, but I don't think the new electronic ballasts for flourescent lights do the lead-lag thing, OR have enough raw filtering capacitance to power the lamp through the phase reversals. (And then there's LED lamps...)

It's not a safety hazard these days, now that OSHA rules have all the fast-spinning machinery covered with guards. But for those with vertigo it's a big problem.

Comment: "You ate the poison mushroom!" reflex. (Score 4, Informative) 154

The human body has three systems for balance - Inner ears (3-axis accellerometers and "rate gyros"), visual modeling, and muscle/tendon position & stress sensors - and needs any two to balance, stand, and walk properly.

It also has a reflex: When two of them disagree (particularly visual vs. ear), it is interpreted as "You just ate a neurotoxin! Get it out NOW and we MIGHT survive it!"

Thus nausea, projectile vomiting, explosive diahrrea, and clothes-soaking sweating if the mismatch is strong. If it's smaller - nausea. ("Whatever you just ate may have been toxic or spoiled. So you're not going to like it anymore.")

Of course other things than being poisoned can trigger it:

Diseases that temporarily incapacitate or permanently damage the inner ear are one class. (For instance, Meniere's Disease, where the pressure-relef valve for the inner ear sticks, the pressure rises, and the membranes with the sensory nerves tear. Result: Sudden extremem vertigo attack - hours on the floor - followed by days or weeks of gradually reduced incapacity until the brain maps out the change to the ear - followed by another tear and repeat indefinitely. Very high suicide rate.)

Vechicles, where you may visually fixate on the accellerating inside rather than the surroundings, are another: Cars, boats, ariplanes (and the corresponding car/sea/air sicknesses) are notorious, as are carnival rides and trains. For relief, make a point of looking at the horizon or otherwise the exterior. Eventually the brain may learn "I'm in a vehicle. Ignore the weird signals from the ears. (That's why vertigo sufferers may NOT have attacks in MOVING vehicles...)

And, of course, VR mismatches - to the point that there is a term of art: "Barfogenisis" (I hear the lengths of some of the rides at Disneyland are calibrated so they end and the crowd is out into the hall just BEFORE the effect would become pronounced.)

Comment: Re:PPC macs were awful (Score 2) 235

by confused one (#47474027) Attached to: Nearly 25 Years Ago, IBM Helped Save Macintosh

Right, so this is the infamous mac os 7 era right? Powermacs? Where motorola code was emulated to work on PPC? Apple being led by non-jobs? When Macs didnt just needed a restart every 24 hours (like windows did) but would outright ruin there system install every other week? That was the most shitty Apple period ever.

The emulator was key in allowing users to use older 68k apps on the new PowerPC chips, until the software houses released versions built for the PowerPC. A lot of companies (including Apple itself) hurt the platform by delaying their PowerPC update releases. The OS did have some issues; I'm not going to sugar coat it. Apple also took a few journeys down dark alleys with poorly designed hardware during the '90s. Of course the alternative at the time was Windows 3.1, which wasn't a utopian dream either.

Comment: Our city imposes a 3% tax on utilities (Score 1) 148

by Ungrounded Lightning (#47472649) Attached to: US House Passes Permanent Ban On Internet Access Taxes

Our city imposes (suckered the voters into approving) a 3% tax on utilities - comm, power, gas, ... - and has for several years. I think that includes internet service (which is pretty steep around here). My wife and I have been fighting this law and its renewal. (It is driving businesses out of the city - they can cut their costs substantially by relocating just over the line - and thus both blighting the city and cutting other tax revenue.

I think I need to do a little checking to see if they ARE taxing the internet part of the phone bill and if that's prohibited federally. Zapping them for a refund (for everybody, for several years worth) might get their attention. B-)

Comment: Future proof... (Score 1) 506

by confused one (#47462975) Attached to: Ask Slashdot: Future-Proof Jobs?

Not art.

If she's not college material, send her to trade school to learn a construction trade. Having a trade means she'll be employable. Some jobs are never going to go away -- there will always be construction jobs.

If she's college material I'd recommend two paths: lf she has a math or science bent, engineering. If STEM isn't her thing, as a first step send her to an accredited business school. Follow that with a good trade school. Having the business degree means she'll be able to operate at a higher level in the industry, handling the business with the background necessary to not screw it up.

Engineering and construction jobs will never go away. You have to keep up with new technologies, techniques and trends but you'll be able to find a job.


Comment: It has nothing to do with the target. (Score 1) 183

What about consumer electronics (washing machines, microwaves, smartphones, routers, AP's) or critical industrial systems
where I would image RTOS to be necessary (VxWorks, QNX) ? I can't imagine Windows CE dominating in those spaces.

You seem to be missing something here.

We're not talking about the target. We're talking anout the platform on which the program for the target is built.

This is where the editors, version control system, compilers, linkers, profilers, prom burners, in-circuit emulators, etc. are running. The operating system here has no more to do with the operating system on the target (other than supporting the tools that build it) than the operating system on the mainframe where Gates and Allen developed Altair BASIC had to do with the BASIC language or the guts of their interpreter.

Comment: It's a tool vendor, not a target, issue. (Score 1) 183

But you see you are in the Windows CE embedded niche. Your vision is clouded.

I'm not in a "windows CE embedded" niche and the grandparent poster is right.

It's not an issue with the target. It's an issue with the platform(s) supported by the development tool vendors and the chip manufacturers.

For instance: With Bluetooth 4.0 / Bluetooth Low Energy (BLE), two of the premier system-on-a-chip product families are from Texas Instruments and Nordic Semiconductors.

TI developed their software in IAR's proprietary development environment and only supports that. Their bluetooth stack is only distributed in object form - for IAR's tools - with a "no reverse engineering" and "no linking to open source (which might force disclosure)". IAR, in turn, doesn't support anything but Windows. (You can't even use Wine: The IAR license manager needs real Windows to install, and the CC Debugger dongle, for burning the chip and necessary for hooking the debugger to the hardware debugging module, keeps important parts of its functionality in a closed-source windows driver.) IAR is about $3,000/seat after the one-month free evaluation (though they also allow a perpetual evaluation that is size-crippled, and too small to run the stack.)

The TI system-on-a-chip comes with some very good and very cheap hardware development platforms. (The CC Debugger dongle, the USB/BLE-radio stick, and the Sensor Tag (a battery-powered BLE device with buttons, magnetometer, gyro, barometer, humidity sensor, ambient temp sensor, and IR remote temp sensor), go for $49 for each of the three kits.) Their source code is free-as-in-beer, even when built into a commercial product, and gives you the whole infrastructure on which to build your app. But if you want to program these chips you either do it on Windows with the pricey IAR tools or build your own toolset and program the "bare metal", discarding ALL TI's code and writing a radio stack and OS from scratch.

Nordic is similar: Their license lets you reverse-engineer and modify their code (at your own risk). But their development platforms are built by Segger and the Windows-only development kit comes with TWO licenses. The Segger license (under German law), for the burner dongle and other debug infrastruture, not only has a no-reverse-engineering clause but also an anti-compete: Use their tools (even for comparison while developing your own) and you've signed away your right to EVER develop either anything similar or any product that competes with any of theirs.

So until the chip makers wise up (or are out-competed by ones who have), or some open-source people build something from scratch, with no help from them, to support their products, you're either stuck on Windows or stuck violating contracts and coming afoul of the law.

"Who cares if it doesn't do anything? It was made with our new Triple-Iso-Bifurcated-Krypton-Gate-MOS process ..."