Highwaycode and pedals question

"Matt B" <[email hidden]> wrote in message
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Quoted message said:

I'm not saying that I support this particular regulation, although I can
see the conspicuity benefits of a moving light (albeit reflected), but I'm
questioning the moral aspect of picking and choosing which laws we are
prepared to obey.

How about taking into account how much desire there is that the law is
obeyed when picking which ones to ignore? There is apparently zero desire
for enforcement of the pedal reflector law in the presence of other adequate
lighting. OTOH your favourite has rather a lot of enforcement associated
with it.

clive

"Clive George" <[email hidden]> wrote in message
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Quoted message said:

"Matt B" <[email hidden]> wrote in message
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Quoted message said:

I'm not saying that I support this particular regulation, although I can
see the conspicuity benefits of a moving light (albeit reflected), but
I'm questioning the moral aspect of picking and choosing which laws we
are prepared to obey.

How about taking into account how much desire there is that the law is
obeyed when picking which ones to ignore?

Anarchy you mean?

--
Matt B

Matt B twisted the electrons to say:

Quoted message said:

You're (deliberately?) missing the point.

You seem to keep changing yours ...

Quoted message said:

The law is the law.

At the risk of of a self-inflicted Godwin's violation, wasn't that
goering's defence at Nuremberg? In any case, in this case (IMHO) the
law the being an ass and deserves to be ignored ...

Quoted message said:

but I'm questioning the moral aspect of picking and choosing which laws
we are prepared to obey.

Do you always fully obey every law in the land?
--
These opinions might not even be mine ...
Let alone connected with my employer ...

"Alistair Gunn" <[email hidden]> wrote in message
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Quoted message said:

Matt B twisted the electrons to say:

Quoted message said:

You're (deliberately?) missing the point.

You seem to keep changing yours ...

Not at all. They may get lost in the snipping and convolutions as the
threads evolve. I came into this thread with the statement: "Would you be
happy for all regulations to do with vehicle construction to be
disregarded". Same point I think.

Quoted message said:

Quoted message said:

but I'm questioning the moral aspect of picking and choosing which laws
we are prepared to obey.

Do you always fully obey every law in the land?

Possibly not. I'm not judging the rights and wrongs though, just exploring
the reasoning. I'm particularly interested in the views of those who argue
that breaking certain rules to do with road safety should be punished
regardless of its validity, consistency or lack of effect on others WRT to
that rule, yet feel perfectly justified in disregarding a road safety
regulation which, unpredictably, impacts others as well as themselves.

--
Matt B

"Matt B" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

but I'm
questioning the moral aspect of picking and choosing which laws we are
prepared to obey.

Morality is, by definition, superior to law. If you have such a question,
you have no morality.

Dave Larrington said:

Quoted message said:

The LD500 front & rear lights sitting on the table in front of me are
both marked BS6102/2. The packaging for the LD-500-R says "Reflector
meets C.P.S.C. and BS standard."

Hurrah! Then the fixer /is/ legal.

Just so long as you don't switch on the LEDs in the LD500s. The steady
mode is not certified as a BS6102/3 light, and the flashing mode is made
illegal by the presence of the steady mode. Makes them somewhat expensive
as simple reflectors really.....

Quoted message said:

No longer need I fear incarceration in Belmarsh or extradition to the
US for being a terrorist. For I have done nothing wrong, and thus have
nothing to f (cont. the Daily Mail)

Innocence has never been a bar to incarceration. Didn't your history
teacher in school tell you this? There are 60,000 year old cave
paintings protesting against being banged up without good reason!

<Churchillian voice>
Never <pause> in the field of cycling <pause> have so many laws been
passed that so few can comply with.
</C v>

Mike

Mike Causer said:

Dave Larrington said:

Quoted message said:

The LD500 front & rear lights sitting on the table in front of me are
both marked BS6102/2. The packaging for the LD-500-R says "Reflector
meets C.P.S.C. and BS standard."

Hurrah! Then the fixer /is/ legal.

Just so long as you don't switch on the LEDs in the LD500s. The steady
mode is not certified as a BS6102/3 light, and the flashing mode is made
illegal by the presence of the steady mode. Makes them somewhat expensive
as simple reflectors really.....

Surely either he has a BS6102/3 light as well and can legally have the
LD500s turned on as an additional light, or he doesn't in which case
leaving the LD500s off doesn't make him any more legal?

Alan Braggins said:

Mike Causer said:

Dave Larrington said:

> The LD500 front & rear lights sitting on the table in front of me
> are both marked BS6102/2. The packaging for the LD-500-R says
> "Reflector meets C.P.S.C. and BS standard."

Hurrah! Then the fixer /is/ legal.

Just so long as you don't switch on the LEDs in the LD500s. The
steady mode is not certified as a BS6102/3 light, and the flashing
mode is made illegal by the presence of the steady mode. Makes them
somewhat expensive as simple reflectors really.....

Surely either he has a BS6102/3 light as well and can legally have the
LD500s turned on as an additional light, or he doesn't in which case
leaving the LD500s off doesn't make him any more legal?

I have a confession to make...

(Looks around for Charles Clarke)

Fixer: 1 x LD500
Speedmachine: 2 x LD500
Trike: 2 x LD500 and sometimes a third attached to the rack bag
MTB: Trek single-LED thing

(Counts eggs, interpolates into size of chicken flock)

--
Dave Larrington - <http://www.legslarry.beerdrinkers.co.uk/>
Badger Badger Badger Badger Badger Badger Badger Badger Badger Badger
Badger Badger Badger Badger Badger Badger Badger Badger Badger Badger

David Martin said:

Matt B said:

"David Martin" <[email hidden]> wrote in message
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Quoted message said:

Matt B wrote:

>>>Probably not as soon as he would have seen the pedal reflectors.
>>
>>Thus indicating a lack of knowledge on the laws of physics.. Ever heard
>>of the inverse square law?
>
>It's no to do with the intensity, but to do with the fact that the pedals
>are moving, that makes the reflected light from them more conspicuous.
>The
>effect is similar to that of flashing amber lights, like those used to
>make
>tractors and other slow vehicles more conspicuous.
>
>BTW the inverse square law also applies to the powered lights on a bike
>;-)

Very good. Now, as your follow up to show you understand how the
inverse square law applies.

Even though, As I've already mentioned, the intensity is not the only factor
influencing the conspicuity, the fact that it is moving is also important.

Quoted message said:

A car light produces 100 units of light per unit area at a distance of
1 m. A bicycle rear light 1 unit.
Taht should be about the right ratio for a 100W car headlamp to a 1W
cycle lamp.
At which distances will the cycle light be brighter than the reflected
light of the headlamps assuming the reflector is 100% efficient.?

Is this a trick question?

I'm no physicist, but I'm game for a laugh... The ratio of intensities is
100(2d)**2/d**2, as the distance that the reflected light has travelled is
twice that of the cycle lamp? Which is a constant 25:1? The reflected
light will always appear to be 25 times the intensity of the cycle lamp
light?

Quoted message said:

How much brighter will the cycle light be than the reflector at 50m?

0.04 times?

I can't help thinking I've made a fool of myself here, but, hey - who cares
;-)

Please enlighten (NPI) me David, you seemed so convinced I was barking up
the wrong tree :-)

You can treat both as point sources. It is the intensity of the source
that varies.

As both reflector and light are the same distance away they light
coming from them falls of at exactly the same rate, so at 1m, 100W
light is reflected (100% efficciency) by the reflector, and 1W is given
out by the light.

At 10m, the amount of light falling on the reflector is 100/d**2 or 1W
so the amount of light the reflector can 'produce' is 1W, the same as
the bike light.

You've missed out the gain of the headlamp's reflector.

Quoted message said:

At 20m the effective power of the reflector is 0.25W, the light still
produces 1W.

The reflector isn't isotropic either, so it also has gain (1)...

Quoted message said:

At 50m the effective power of the reflector is 0.04W, the light still
produces 1W.

which may also have gain due to its reflector, but probably less than
the gain of the reflector at(1).

Quoted message said:

There are obvious simplifications here, but the principle is
essentially correct.

It is, but missing out the three gains makes the result meaningless.

David Martin said:

Matt B wrote:

Quoted message said:

Quoted message said:

If the whole sphere of light emitted
from a point source is concentrated uniformly into a cone occupying 1/10th
of the sphere 1000/d**2 will be the formula?

No. It won't.

If you take a beam from a headlight and measure the intensity at a
distance d, this will eb equivalent to a beam from a point source at an
apparent distance p.

so the ratio between teh intensity at 1 unit distance , and the
intensity at n units distance is

p**2/(p+n-1)**2

As n becomes large, p becomes negligible. You can measure this
effective distance by looking at how rapidly the beam on your lights
spreads with respect to distance. It is still obeying the inverse
square law, but from a virtual point light source, rather than the
reflector.

The properties of the reflector are best modelled as a gain in the
direction of the observer, thus a 100W isotropic light source and a
reflector with a gain of 10 appears as a 1000W light source to the
observer.

Whatever the distance to the observer, the source will always be 10x
isotropic.

This is quite a useful effect in the Radar world, where the gain works
on both transmission and reception. See Skolnik et al for the maths.

Al.

Matt B twisted the electrons to say:

Quoted message said:

yet feel perfectly justified in disregarding a road safety
regulation which, unpredictably, impacts others as well as themselves.

Whilst more reflectors is, in general, better than fewer I really can't
see how the absence of reflectors on my 'bent affects anyone other than
me (and then only marginally).

Speeding, by way of contrast, obviously increases the level of risk that
third parties are exposed to ...
--
These opinions might not even be mine ...
Let alone connected with my employer ...

"Alistair Gunn" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Matt B twisted the electrons to say:

Quoted message said:

yet feel perfectly justified in disregarding a road safety
regulation which, unpredictably, impacts others as well as themselves.

Whilst more reflectors is, in general, better than fewer I really can't
see how the absence of reflectors on my 'bent affects anyone other than
me (and then only marginally).

You think that one specific case "proves" that the pedal reflector law is
unnecessary.

Quoted message said:

Speeding, by way of contrast, obviously increases the level of risk that
third parties are exposed to ...

If I could provide one specific case where speeding results in no extra risk
to any third party would you apply the same logic to speeding as you do to
pedal reflectors?

--
Matt B