On Thu, 27 Jan 2011 16:10:50 -0800, Darren New wrote:

> Jim Henderson wrote:
>> What does surprise me is that in a moving aircraft, the GPS receiver in
>> my phone is useless.
> 
> Not all of them are. My brother has a trace from his exercize watch that
> shows him flying across country.

Well, I didn't think all of them were, after all, the plane has one 
itself. :-)

But that actually was what I wanted to try - I like playing with flight 
simulators, and it's useful to be able to get speed and altitude 
information from a GPS trace from an actual flight. :-)

>> I could as well, but then again, there are lots of wireless signals
>> flying around in open space, but I would expect something that's
>> designed to fly through the air to have some shielding against it.
> 
> Especially that in which the general public will be flying. I'm not
> surprised there are industrial settings where following the rules is
> more important than in an airplane passenger compartment.

Same here, I think (the "not surprised" bit is confusing me, but that may 
just be fatigue and the fact that I just got home from a 90 minute 
community council meeting where the primary discussion most of the time 
was "accessory dwelling units".  Yeehaw.

Jim

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On Fri, 28 Jan 2011 00:43:02 +0000, Stephen wrote:

> On 27/01/2011 11:44 PM, Jim Henderson wrote:
>> On Thu, 27 Jan 2011 23:06:53 +0000, Stephen wrote:
>>
>>
>>> That surprises me.
>>
>> It would depend on the tx strength of the signal, but it doesn't
>> surprise me.
>>
>>
> In the UK, you’re lucky if you can get reception in a park never mind a
> plane.

Well, here in Utah, that's true if you're with AT&T.  With Verizon, 
reception is pretty good everywhere I've been.

>> What does surprise me is that in a moving aircraft, the GPS receiver in
>> my phone is useless.
>>
>>
> Never tried. Any excuse to switch it off.

:-)  As I mentioned to Darren, I like to try to get that kind of data 
because it fits in with my hobby of flying in flight simulators.  Knowing 
speed/altitude data is useful when taking off (and landing) to try to get 
it right.

>> I could as well, but then again, there are lots of wireless signals
>> flying around in open space, but I would expect something that's
>> designed to fly through the air to have some shielding against it.
>>
>>
> OK these were handhelds with power to reach the horizon.

The horizon is a long ways away. ;-)

Jim

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On Thu, 27 Jan 2011 16:11:30 -0800, Darren New wrote:

> Jim Henderson wrote:
>> On Thu, 27 Jan 2011 15:31:03 -0800, Darren New wrote:
>> 
>>> Jim Henderson wrote:
>>>> There's probably nothing that prevents the cell signal from being
>>>> used, and if the plane is already doomed, turning on a cell phone
>>>> isn't likely to make things worse.
>>> The primary reason not to do this is that your phone will be in range
>>> of many more towers than you normally would be. For some cell systems,
>>> this is a Bad Thing, for performance, capacity, and possibly even for
>>> routing. It probably has nothing to do with the actual plane
>>> electronics.
>> 
>> Well, I do recall that the Mythbusters tested this myth, and it rated
>> "plausible" with relation to the electronics.  Still, I've been on
>> plenty of planes where people have not turned off their phones and they
>> all made it to their destination without incident...
> 
> Um, yeah. That's waht I was saying. It's not a problem for the airplane.
> It's a problem for the phone carriers.

Well, no, shielding against those signals is a problem for the designers 
and builders of the airplane.  They found that there were circumstances 
where cell phone transmissions did affect the instruments in the plane.

I was quite surprised by that finding, but then again, it seems when the 
myths have something to do with breaking the law (and the FARs are law), 
then the findings tend to support not breaking the law.

Jim

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>> And even today, WiFi is OK on many flights (as there are in-flight
>> WiFi services now on some flights).
>
> Funny how much less dangerous it is when they can charge you money for
> it, isn't it?

Next up: Why is it prohibited to use your phone while filling your car 
with fuel?

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> Engineers spend decades designing an LCD with a wide viewing angle, and
> then a company sells you a device to narrow the viewing angle again. :-D
> How absurd.

Well it's not like the privacy filter is installed to all LCDs 
permanently, there are still many LCD applications where you 
specifically want a good wide viewing angle.  That's why a privacy 
filter is removable or electronically switchable.

A similar story with the anti reflective and anti-glare coatings that 
engineers spent a long time developing and perfecting.  Notice how you 
can still mostly watch an LCD TV even if you have a bright window 
directly in reflection - that would be almost impossible with CRT. 
However someone decided to then market a "glossy" LCD (which is actually 
simpler and cheaper to make) and many people prefer it.

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On 28/01/2011 9:23 AM, Invisible wrote:
>>> And even today, WiFi is OK on many flights (as there are in-flight
>>> WiFi services now on some flights).
>>
>> Funny how much less dangerous it is when they can charge you money for
>> it, isn't it?
>
> Next up: Why is it prohibited to use your phone while filling your car
> with fuel?

'Cos as a bloke its very unlikely you can do two things at once. ;-)

-- 
Regards
     Stephen

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>> Next up: Why is it prohibited to use your phone while filling your car
>> with fuel?
>
> 'Cos as a bloke its very unlikely you can do two things at once. ;-)

It's true that I find it almost impossible to talk at the same time as 
playing my keyboard.

It's also true that I'm one of the few people in Laura's Rock & Roll 
class who can wave their arms at the same time as dancing with their 
feet. Most of the girls can't do it. ;-)

Also... I can play Bach? QED.

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> There's probably nothing that prevents the cell signal from being used,
> and if the plane is already doomed, turning on a cell phone isn't likely
> to make things worse.

Probably thousands of people leave their phone on by mistake (or on 
purpose) on flights daily, I've done it myself (by accident) at least 
twice.  It surely isn't much of a safety issue otherwise they would 
rigorously check every single phone on board.

I imagine also below a certain height you can easily get a signal from 
the ground based base stations, occasionally on a flight you hear 
someone's phone beep as the plane is coming in to land.

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> Next up: Why is it prohibited to use your phone while filling your car
> with fuel?

To stop you wasting time when the next customer could be already handing 
over their money.

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On 28/01/2011 11:41 AM, scott wrote:
>> Next up: Why is it prohibited to use your phone while filling your car
>> with fuel?
>
> To stop you wasting time when the next customer could be already handing
> over their money.

That sounds quite plausible.

So why do they insist you turn your engine off?

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> So why do they insist you turn your engine off?

With an engine there seems like a plausible risk that it could start a 
fire (given that it has thousands of volts specifically generated to 
make a spark to ignite fuel) under some non-so-uncommon circumstances 
(eg loose spark plug lead).

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Jim Henderson wrote:
> Same here, I think (the "not surprised" bit is confusing me, 

I'm saying that if you're in an industrial place that the general public is 
not allowed into where keying up a radio blows fuses, that's understandable, 
but you wouldn't want to design an airplane where someone from the general 
public not following the rules about their cell phone crashes the plane.

I.e., it's perfectly safe in a nuclear reactor to say "nobody turn off the 
coolant supply while the rods are out of the core." But you wouldn't put 
that control panel in reach of the public tours of the facility.

Having a cell phone in the cockpit cause troubles is more reasonable than a 
cell phone in the passenger compartment causing troubles.

-- 
Darren New, San Diego CA, USA (PST)
  "How did he die?"   "He got shot in the hand."
     "That was fatal?"
          "He was holding a live grenade at the time."

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Jim Henderson wrote:
> Well, no, shielding against those signals is a problem for the designers 
> and builders of the airplane.  

Both, then. :-)

-- 
Darren New, San Diego CA, USA (PST)
  "How did he die?"   "He got shot in the hand."
     "That was fatal?"
          "He was holding a live grenade at the time."

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scott wrote:
>> So why do they insist you turn your engine off?
> 
> With an engine there seems like a plausible risk 

They also don't want it popping out of gear and driving away with the hose 
still in it, running into the car in front, running down the attendant, etc.

-- 
Darren New, San Diego CA, USA (PST)
  "How did he die?"   "He got shot in the hand."
     "That was fatal?"
          "He was holding a live grenade at the time."

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scott wrote:
> can still mostly watch an LCD TV even if you have a bright window 
> directly in reflection 

Maybe where you are. San Diego is a bit bright to even watch with the 
reflection off the wall of the window's light. ;-)

> However someone decided to then market a "glossy" LCD (which is actually 
> simpler and cheaper to make) and many people prefer it.

It's nicer when the room is dark, yes.

-- 
Darren New, San Diego CA, USA (PST)
  "How did he die?"   "He got shot in the hand."
     "That was fatal?"
          "He was holding a live grenade at the time."

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On 28/01/2011 4:38 AM, Jim Henderson wrote:
>
> Well, here in Utah, that's true if you're with AT&T.  With Verizon,
> reception is pretty good everywhere I've been.
>

I would have thought that with either all those open spaces or canyon 
buildings, reception would be patchy. Well you live and learn.

>>>
>> Never tried. Any excuse to switch it off.
>
> :-)  As I mentioned to Darren, I like to try to get that kind of data
> because it fits in with my hobby of flying in flight simulators.  Knowing
> speed/altitude data is useful when taking off (and landing) to try to get
> it right.
>

Did I ever mention that I used to use flight simulators? I spent hours 
on FS4. So much so my wife bought me a flying lesson for my 40th 
birthday. How could I have forgotten that I suffer from acrophobia? I’ve 
not used a flight simulator since.

>>>
>>>
>> OK these were handhelds with power to reach the horizon.
>
> The horizon is a long ways away. ;-)
>

About 15 miles, all round. ;-)

-- 
Regards
     Stephen

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On 28/01/2011 11:14 AM, Invisible wrote:
>>> Next up: Why is it prohibited to use your phone while filling your car
>>> with fuel?
>>
>> 'Cos as a bloke its very unlikely you can do two things at once. ;-)
>
> It's true that I find it almost impossible to talk at the same time as
> playing my keyboard.
>
> It's also true that I'm one of the few people in Laura's Rock & Roll
> class who can wave their arms at the same time as dancing with their
> feet. Most of the girls can't do it. ;-)
>
> Also... I can play Bach? QED.

Well done you. :-)

It was a joke.

-- 
Regards
     Stephen

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On Fri, 28 Jan 2011 09:23:47 +0000, Invisible wrote:

>>> And even today, WiFi is OK on many flights (as there are in-flight
>>> WiFi services now on some flights).
>>
>> Funny how much less dangerous it is when they can charge you money for
>> it, isn't it?
> 
> Next up: Why is it prohibited to use your phone while filling your car
> with fuel?

It isn't, at least not here in Utah.  Used to be, a few years ago.

Jim

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On Fri, 28 Jan 2011 09:06:24 -0800, Darren New wrote:

> Jim Henderson wrote:
>> Same here, I think (the "not surprised" bit is confusing me,
> 
> I'm saying that if you're in an industrial place that the general public
> is not allowed into where keying up a radio blows fuses, that's
> understandable, but you wouldn't want to design an airplane where
> someone from the general public not following the rules about their cell
> phone crashes the plane.

I see, and yes, I agree.

> I.e., it's perfectly safe in a nuclear reactor to say "nobody turn off
> the coolant supply while the rods are out of the core." But you wouldn't
> put that control panel in reach of the public tours of the facility.
> 
> Having a cell phone in the cockpit cause troubles is more reasonable
> than a cell phone in the passenger compartment causing troubles.

Yes, and many pilots reportedly leave their cell phones on while working.

Jim

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On Fri, 28 Jan 2011 17:33:17 +0000, Stephen wrote:

> On 28/01/2011 4:38 AM, Jim Henderson wrote:
>>
>> Well, here in Utah, that's true if you're with AT&T.  With Verizon,
>> reception is pretty good everywhere I've been.
>>
>>
> I would have thought that with either all those open spaces or canyon
> buildings, reception would be patchy. Well you live and learn.

When we moved into the ASC Tower (now the Wells Fargo tower), we 
anticipated problems with cell reception, so they installed a device/
antenna system that boosted the carriers' signals inside the building.

> Did I ever mention that I used to use flight simulators? I spent hours
> on FS4. So much so my wife bought me a flying lesson for my 40th
> birthday. How could I have forgotten that I suffer from acrophobia? I’ve
> not used a flight simulator since.

I don't think you had mentioned that - I prefer X-Plane myself, but I 
need a faster computer.  And as Ken's done with college after this 
summer, I think a new computer might well be in the cards. :-)

>>> OK these were handhelds with power to reach the horizon.
>>
>> The horizon is a long ways away. ;-)
>>
>>
> About 15 miles, all round. ;-)

True, though just try walking to it. ;-)

Jim

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On Fri, 28 Jan 2011 11:31:22 +0000, scott wrote:

>> There's probably nothing that prevents the cell signal from being used,
>> and if the plane is already doomed, turning on a cell phone isn't
>> likely to make things worse.
> 
> Probably thousands of people leave their phone on by mistake (or on
> purpose) on flights daily, I've done it myself (by accident) at least
> twice.  It surely isn't much of a safety issue otherwise they would
> rigorously check every single phone on board.

If it were, they'd ask you to turn off the phone, remove the battery, and 
put it in checked baggage.  Same with laptops.

That in and of itself tells me it's not as big a danger as they want 
people to believe.

> I imagine also below a certain height you can easily get a signal from
> the ground based base stations, occasionally on a flight you hear
> someone's phone beep as the plane is coming in to land.

Yep.

Jim

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Stephen wrote:
> I would have thought that with either all those open spaces or canyon 
> buildings, reception would be patchy. Well you live and learn.

Verison uses CDMA. CDMA works better in canyons because there's lots of n
ice 
reflective surfaces to bounce the signal off to route it where it's going
.

Most verison fones have three or four antennas (well, "fingers", but thin
k 
of them as antennas) which they time-shift to make reflections add instea
d 
of cancel.

> Did I ever mention that I used to use flight simulators? I spent hours 

> on FS4. So much so my wife bought me a flying lesson for my 40th 
> birthday. How could I have forgotten that I suffer from acrophobia? I�
��ve 
> not used a flight simulator since.

That's one of the funnier stories I've heard lately. Thank you.

>>> OK these were handhelds with power to reach the horizon.
>> The horizon is a long ways away. ;-)
> About 15 miles, all round. ;-)

Not from in an airplane.

-- 
Darren New, San Diego CA, USA (PST)
  "How did he die?"   "He got shot in the hand."
     "That was fatal?"
          "He was holding a live grenade at the time."

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On 28/01/2011 5:47 PM, Jim Henderson wrote:

>
> When we moved into the ASC Tower (now the Wells Fargo tower), we
> anticipated problems with cell reception, so they installed a device/
> antenna system that boosted the carriers' signals inside the building.
>

What about in the street?


>
> I don't think you had mentioned that - I prefer X-Plane myself, but I
> need a faster computer.  And as Ken's done with college after this
> summer, I think a new computer might well be in the cards. :-)
>

Not that PovRay would benefit ;-)


>> About 15 miles, all round. ;-)
>
> True, though just try walking to it. ;-)
>

Who do you think I am, Jesus?
It was at sea.



-- 
Regards
     Stephen

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On 28/01/2011 5:56 PM, Darren New wrote:
> Stephen wrote:
>> I would have thought that with either all those open spaces or canyon
>> buildings, reception would be patchy. Well you live and learn.
>
> Verison uses CDMA. CDMA works better in canyons because there's lots of
> nice reflective surfaces to bounce the signal off to route it where it's
> going.
>
> Most verison fones have three or four antennas (well, "fingers", but
> think of them as antennas) which they time-shift to make reflections add
> instead of cancel.
>
Magic! :-)

>> Did I ever mention that I used to use flight simulators? I spent hours
>> on FS4. So much so my wife bought me a flying lesson for my 40th
>> birthday. How could I have forgotten that I suffer from acrophobia?
>> I’ve not used a flight simulator since.
>
> That's one of the funnier stories I've heard lately. Thank you.
>
My pleasure.

>>>> OK these were handhelds with power to reach the horizon.
>>> The horizon is a long ways away. ;-)
>> About 15 miles, all round. ;-)
>
> Not from in an airplane.
>

No an oil platform about 150 feet above sea level.

-- 
Regards
     Stephen

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On Fri, 28 Jan 2011 18:13:45 +0000, Stephen wrote:

> On 28/01/2011 5:47 PM, Jim Henderson wrote:
> 
> 
>> When we moved into the ASC Tower (now the Wells Fargo tower), we
>> anticipated problems with cell reception, so they installed a device/
>> antenna system that boosted the carriers' signals inside the building.
>>
>>
> What about in the street?

Wasn't too bad, as I recall.

>> I don't think you had mentioned that - I prefer X-Plane myself, but I
>> need a faster computer.  And as Ken's done with college after this
>> summer, I think a new computer might well be in the cards. :-)
>>
>>
> Not that PovRay would benefit ;-)

Oh, of course not. ;-)

>>> About 15 miles, all round. ;-)
>>
>> True, though just try walking to it. ;-)
>>
>>
> Who do you think I am, Jesus?
> It was at sea.

LOL

Jim

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Stephen wrote:
> Magic! :-)

Almost!

http://denbeste.nu/cd_log_entries/2002/04/Howspreadingactuallyworks.shtml

Even better: http://denbeste.nu/special/cdma_spreading.html

And that's just the digital part of getting bits from one side to the other.

-- 
Darren New, San Diego CA, USA (PST)
  "How did he die?"   "He got shot in the hand."
     "That was fatal?"
          "He was holding a live grenade at the time."

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On 28/01/2011 7:13 PM, Darren New wrote:
> Stephen wrote:
>> Magic! :-)
>
> Almost!
>

I'm still coming to terms with tropo scatter. ;-)

> http://denbeste.nu/cd_log_entries/2002/04/Howspreadingactuallyworks.shtml
>
> Even better: http://denbeste.nu/special/cdma_spreading.html
>
That is a good one.

> And that's just the digital part of getting bits from one side to the
> other.
>

LOL

-- 
Regards
     Stephen

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> They also don't want it popping out of gear and driving away with the
> hose still in it, running into the car in front, running down the
> attendant, etc.

Scary automatic transmissions :-)

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> Maybe where you are. San Diego is a bit bright to even watch with the
> reflection off the wall of the window's light. ;-)

Nah, you just need a better TV, contrary to popular belief we have some 
days with sun sometimes too :-)

>> However someone decided to then market a "glossy" LCD (which is
>> actually simpler and cheaper to make) and many people prefer it.
>
> It's nicer when the room is dark, yes.

That's a general problem too, everyone quotes the specs of their TVs 
when measured under completely dark conditions.  In reality that is not 
a very common situation for watching TV, and it is quite surprising how 
the numbers change when you add in some ambient light.

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