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Re: Snarky non-responses to questions

Sat Mar 11, 2017 6:42 pm

321 wrote:So how do you know the speed measuring device has taken its readings from the same part of the vehicle?

The avg car length at 2.1metres is + or - 30mph's during the 0.3 second time period used to emit 3 laser pulses in order to calculate a speed reading.
It uses doppler, not radar. All parts of the car are moving at the same speed. It only needs to emit one pulse, although it probably makes several measurements and averages them. It does not measure the time between sending and receiving,
I'm sure the detector on the laser speed measuring device is colour blind, in that it can only detect light frequencies in a certain range close to the laser light that is emitted. In other words not detecting light in the human visible light frequency range or UV/Xray part of the spectrum, and whilst it can detect laser light in a certain frequency, its still treated by the algorithm as a binary value.

I'm also sure it can only detect light intensity (lux), and are weaker in strength than what you find in your optical disc player or supermarket checkout, so knowing that light intensity can vary due to the angle of incidence, how can we be sure the speed measuring device is accurate? Even barcode readers interpret the bars reflection within a certain range when normalised against the others it detects in a certain time frame that matches what an operator takes to scan/wave a product over the checkout.
It does not depend on light intensity for any part of the reading. Not even RADAR depends on intensity. If you get a signal back, then you get a reading. If you don't get a signal back, or don't get a sufficiently strong one, then you don't get a reading.
On top of that, how do you know the detector is working in the right time frame considering the variability of power and delay in power reaching all circuits? An example of this which everyone can see, is watching the brake lights come on from the car in front.

If you are quick enough and concentrating enough, you can see the LED central brake light come on first, followed very very quickly by the right or left brake light which ever has the shortest circuit/run inside the car, followed by the opposite side brake light at the furthest part of the circuit/run.
I guarantee that your brain is not capable of seeing the difference in time of electricity moving. It's of the order of ten billionths of a second. What you may be seeing is the time it takes to heat a light bulb. LEDs don't need to heat and lamp filaments change resistance with temperature. That will change the share of the current they each receive,
Likewise I know we have mains that is 240volts, but my little battery backup tells me, this can vary as can the current, and although batteries are used to smooth these power fluctuations in these devices, I know ambient air temperate also affects voltage, when I put flat batteries onto of a radiator to squeeze the last bit of chemical reaction out of them.
There are electronics in all devices that regulate the power they receive from the mains. Almost everything can work off any voltage 110V to 240V without manually switching anything. Dry cell batteries are theoretically capable of many times the output they actually produce but bubbles form on the electrodes that break the circuit. Heating them up reverses this effect a little.
We also know that cpu's can operate at different timings depending on their temperatures, one example being, taking the heatsink off an AMD cpu and it will freeze & crash when the cpu get too hot, ARM and Intel clock back the cpu speed to compensate and minimise damage to the CPU, even though loop based OS's when suggesting their CPU's are only x% busy are still switching away at the same rate regardless of workload. The fact CPU's can alter their clock speed just obfuscates that fact.
A CPU freezing is not the same as a CPU slowing down. You think maybe clocks and watches don't work? They all use electronics and most of them probably contain a CPU. A CPU is not a magic form of electronics anyway.
Plus we also only need a 1 degree difference in air temperature and a surface to create a heat haze, best seen on roads, and we know heat hazes affect light, so can even light then be treated as a constant when measuring speed of something on a road?
That's the one thing you've said that makes sense, but unless you're in Texas, I doubt it would make enough difference to the light path three feet above the road.
We also know light speed is not constant when passing through some objects although to be fair you wont find the most obvious one on the roads or when bolling up to space ship, but you will in a lab.
Speed guns are not rated for use underwater or through solid objects. The cops understand this.
Sometimes it pays to read the patent.
Exactly which language in the patent are you referring to?


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Burngate
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Re: Snarky non-responses to questions

Sat Mar 11, 2017 7:10 pm

DougieLawson wrote:The more important question is, "Is the cat dead?".
This has always irritated me.
Just 'cos we couldn't be bothered to look, doesn't mean the answer is a quantum-mechanical nightmare.

Change the experiment slightly.
Put a mouse in a separate compartment in the box.
After the cat has died (or not) open a door between the two compartments.

Now, is the cat dead? The mouse knows the answer, even if we don't.

When you close the fridge door, is the light off?
First experiment: Fill the fridge with sufficient alchohol and install an engineering student.
Does an inebriated student count as an observer?

Second experiment: Jury-rig two fridges, such that the light in one is only on when the light in the other is off, and vice versa. That means they're entangled in a quantum sense. Also arrange for a quantum event - e.g. atomic disintegration - to decide which is on and which is off.
Install sufficient alchohol and install an engineering student in each.
Separate the fridges by sufficient distance - send one to Mars, the other to Venus.
Now when does the spooky-action-at-a-distance information transfer from one to the other? when the Martians open the door? when the Venutians open the door?

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Re: Snarky non-responses to questions

Sat Mar 11, 2017 7:13 pm

Are we talking about the same type of speed measuring device?
In the old days, they used radar emitting ones which like the Gatso camera's could suffer from the Doppler effect, the latest one's use laser.

... Having just looked on Wiki about the Doppler effect, I can see my A-Level Physics teacher didnt tell me that Doppler worked across all waves, what he told me was it was something that affected sound waves and gave an example using sound waves.

This is my point about some teachers cant teach. Now this may be by design, ie withholding of information for different types of exams but this is where teaching is wrong, because what you get taught doesnt make sense with other observations you make throughout your life.

Hence why you lot are talking about the shift in the Red and Blue light in space, earlier in the thread and therefore how its then used to categorise stars seen in space by the light being detected and so on.

But the point still stands, how do you know you got the reading from the same part of the car, as the patent specifically stated it could get a speed reading from stationary objects?

As the laser leaves the device, there is some beam spread (radians) but not as much as you get with normal light, but enough to cover 3 lanes of road at maximum distance of operation. Its then going to get a variety of measurements back as the light is reflected back. Which measurement is the moving object? You cant tell, so you need to repeat and see what differences occur. At this point, you still havent eliminated the "noise", so you have to repeat again.

Whats with the countdown?

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Re: Snarky non-responses to questions

Sat Mar 11, 2017 7:19 pm

Burngate wrote: When you close the fridge door, is the light off?
First experiment: Fill the fridge with sufficient alchohol and install an engineering student.
Does an inebriated student count as an observer?
Isn't it easier to do my experiment? Set a video recorder recording inside the fridge. Close door. Wait long enough for the lamp to cool. Open door. Extract video camera. Stop recording. Playback experiment's results. No students, mice or beer needed.
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Re: Snarky non-responses to questions

Sat Mar 11, 2017 7:21 pm

Are you sure, I thought the laser systems use time of flight and not Doppler like the broader area radar systems?

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Re: Snarky non-responses to questions

Sat Mar 11, 2017 7:23 pm

Some people may be wondering why this thread is still going.

I suspect it is entirely for my own amusement.

Please continue (but keep the language appropriate)
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Re: Snarky non-responses to questions

Sat Mar 11, 2017 8:52 pm

For the amusement factor, and since we're talking Police/LIDAR/RADAR and Schrodinger:

Heisenberg, Schrodinger and Ohm are in a car
They get pulled over. Heisenberg is driving and the cop asks him "Do you know how fast you were going?"
"No, but I know exactly where I am" Heisenberg replies.
The cop says "You were doing 55 in a 35." Heisenberg throws up his hands and shouts "Great! Now I'm lost!"
The cop thinks this is suspicious and orders him to pop open the trunk. He checks it out and says "Do you know you have a dead cat back here?"
"We do now, idiot!" shouts Schrodinger.
The cop moves to arrest them. Ohm resists.

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Re: Snarky non-responses to questions

Sat Mar 11, 2017 9:00 pm

FlexibleSigmoid wrote:For the amusement factor, and since we're talking Police/LIDAR/RADAR and Schrodinger:

Heisenberg, Schrodinger and Ohm are in a car
.
+100 :D

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Re: Snarky non-responses to questions

Sat Mar 11, 2017 9:08 pm

when the door is closed, the fridge light is definitely off.
the door hits a breaker switch and denies the light power.

when a tree falls in the woods and theres no-one to hear it, does it make a noise.
Yes. Its a bloody tree falling over.

lock a cat in an airtight box - is it dead or alive?
depends if you can hear it meowing.

philosophical questions always have an answer.

a better question would be what the hell is happening in the world, and how soon can we move to Mars.

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Re: Snarky non-responses to questions

Sat Mar 11, 2017 9:21 pm

Burngate wrote:When you close the fridge door, is the light off?
Related to Heisenberg, cats, and fridge lights, I know a cat who knows the answer about the light, but she won't tell me - when she was a kitten, she kept climbing into the fridge whenever we opened the door. One time my wife sighed and (carefully) closed the door, hoping to teach the kitten how this was a bad idea. When she opened the door a minute later, the kitten's reaction was basically, "oh good, thanks, I couldn't quite get to the next shelf up, but now I can." Completely incorrigible.

(Though we harbored suspicions for years about whether or not she was really a cat - conclusion: part cat, monkey, hobgoblin, space alien: 6lbs of muscle, brown fur, and enormous eyes, and doesn't so much meow as kvetch).

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Re: Snarky non-responses to questions

Sat Mar 11, 2017 9:23 pm

CarlRJ wrote:
Burngate wrote:When you close the fridge door, is the light off?
Related to Heisenberg, cats, and fridge lights, I know a cat who knows the answer about the light, but she won't tell me - when she was a kitten, she kept climbing into the fridge whenever we opened the door. One time my wife sighed and (carefully) closed the door, hoping to teach the kitten how this was a bad idea. When she opened the door a minute later, the kitten's reaction was basically, "oh good, thanks, I couldn't quite get to the next shelf up, but now I can." Completely incorrigible.

(Though we harbored suspicions for years about whether or not she was really a cat - conclusion: part cat, monkey, hobgoblin, space alien: 6lbs of muscle, brown fur, and enormous eyes, and doesn't so much meow as kvetch).
thats your own fault for keeping food in the fridge.

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Re: Snarky non-responses to questions

Sat Mar 11, 2017 9:25 pm

jondallimore wrote: lock a cat in an airtight box - is it dead or alive?
depends if you can hear it meowing.
If it's truly airtight, how do the sound waves emerge? Also that cat's going to die of asphixiation through breathing it's exhaled CO2. Regardless of whether the nuclear decay triggers the poisoning or radiation sickness.
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Re: Snarky non-responses to questions

Sat Mar 11, 2017 9:26 pm

jondallimore wrote:thats your own fault for keeping food in the fridge.
Get a teenager, you can never keep food in the fridge with one of those grazing every ten minutes.
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Re: Snarky non-responses to questions

Sat Mar 11, 2017 9:28 pm

DougieLawson wrote:
jondallimore wrote: lock a cat in an airtight box - is it dead or alive?
depends if you can hear it meowing.
If it's truly airtight, how do the sound waves emerge? Also that cat's going to die of asphixiation through breathing it's exhaled CO2. Regardless of whether the nuclear decay triggers the poisoning or radiation sickness.
theres air in the box, and soundwaves can propagate through whatever material the box is made from. when you hear the cat meowing its alive. when it stops meowing, its eating all the food in the fridge.

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Re: Snarky non-responses to questions

Sat Mar 11, 2017 9:31 pm

jondallimore wrote:when a tree falls in the woods and theres no-one to hear it, does it make a noise.
Yes. Its a bloody tree falling over.
Ah, see, that depends on your definition of "sound" - the tree falling sends waves of vibration through the air and ground. What we perceive as sound is how our mind has evolved to interpret the signals from our ears when they receive those vibrations. Without a witness, it's just vibrating air. So is sound the vibrating air itself? or the thing perceived in people's heads when they are hit by that vibrating air?

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Re: Snarky non-responses to questions

Sat Mar 11, 2017 9:37 pm

ITS A BLOODY TREE. IT MAKES NOISE.

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Re: Snarky non-responses to questions

Sat Mar 11, 2017 9:38 pm

DougieLawson wrote:
jondallimore wrote:thats your own fault for keeping food in the fridge.
Get a teenager, you can never keep food in the fridge with one of those grazing every ten minutes.
I worked many years at a university where the department had a team of student helpers (first tier support for going out to dorm rooms to diagnose/fix networking problems). The accepted practice for getting rid of excess party supplies and such was to put them on a table near where the students were kept. It... was kind of like those nature films with piranhas.

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Re: Snarky non-responses to questions

Sat Mar 11, 2017 9:48 pm

Supposedly in physics, energy is never lost, therefore if a tree makes a noise in your presence then falling trees will always make a noise in the same environment.

Of course in the quantum physics theoretical world, in a parrallel universe, trees dont make a noise because the laws of physics dont exist.

Likewise, an airtight box may or may not have air in it, so if it has air in it, then soundwaves can be heard, just like a bass bin (speaker enclosure) helps some airwaves be heard more than others, whilst ignoring resonance frequencies of materials.
However if there is no air in the box, just like no one can hear you scream in space because its a vacuum, they might still be able to see you if the light waves have not lost energy between the energy source bouncing off you screaming and me who is the observer.

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Re: Snarky non-responses to questions

Sat Mar 11, 2017 9:49 pm

jamesh wrote:Some people may be wondering why this thread is still going.
I suspect it is entirely for my own amusement.
Oh, we all know that it's to distract us, so we won't find or conjure up yet another thread speculating about the new Pi 4 (which I hear will be released Real Soon Now™) solely so we can post requests thereupon for Pink Ponies And Unicorns™. This is our bread and circuses. ;)

The cat knows when the Pi 4 will come out! The Pi 4 makes no sound in a forest! The unicorn is only pink because it's red-shifted! IT'S A COOK BOOK!

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Re: Snarky non-responses to questions

Sat Mar 11, 2017 9:55 pm

Now I want pie. 4 of them.

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Re: Snarky non-responses to questions

Sat Mar 11, 2017 10:25 pm

jondallimore wrote: lock a cat in an airtight box - is it dead or alive?
depends if you can hear it meowing.
The real question is who's going to open the box to find out? Do you really want to be in the same room as an angry cat that's been locked in a box ?

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Re: Snarky non-responses to questions

Sat Mar 11, 2017 11:37 pm

The unicorn is only pink because it's red-shifted!
Oh dear now it going to get locked, you should know the rules, don't mention the U word.

Red shifted?
That means the unicorn is Magenta or Fuchsia?

Keeping it going was worth it for the "Ohm resist"

Re cat, see IBM Quantum Qubit post
QEMU can emulated other CPU's, can a Pi Zero emulate a 5 qubit quantum computer?

4 is not a good number for the Chinese market, lets skip to the Pi5
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Re: Snarky non-responses to questions

Sat Mar 11, 2017 11:41 pm

What on Earth is a "Google keyboard"?
Memory in C++ is a leaky abstraction .

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Re: Snarky non-responses to questions

Sat Mar 11, 2017 11:45 pm

Heater wrote:What on Earth is a "Google keyboard"?
An on-screen keyboard application for Android devices
Image

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Re: Snarky non-responses to questions

Sun Mar 12, 2017 12:05 am

jondallimore
...philosophical questions always have an answer.
Hmm...I guess you never understood the questions then.
Memory in C++ is a leaky abstraction .

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