Green rear light

[Pandamasque]

I think it's better to discuss the green light issue outside the Lotus T127 thread.

I'd like to know the real reason it's green. The rookie driver idea by tok-tokkie is credible. The rain version isn't, IMO. Why would you change the colour of the 'rain light' for testing for selected cars?

14.5 Rear light :
All cars must have a red light in working order throughout the Event which :
- has been supplied by an FIA designated manufacturer ;
- faces rearwards at 90° to the car centre line and the reference plane ;
- is clearly visible from the rear ;
- is mounted nominally on the car centre line ;
- is mounted 300mm (+/-5mm) above the reference plane ;
- is no less than 595mm behind the rear wheel centre line measured parallel to the reference plane ;
- can be switched on by the driver when seated normally in the car.
The two measurements above will be taken to the centre of the rear face of the light unit.

The green light is said to be seen more readily in the rain/foul weather... we've seen it before(on a toyota maybe?) in testing and it has nothing to do with rookie drivers... the FIA may have just put it in place without making big deal of it... which would be kinda silly with their whole "make cars green" campaign.

Rain. Yeah right.

What? you think they switch the color when it is not raining?

2007 Valencia, Nakajima. Red for everyone else: http://www.motorsport.com/photos/select ... ing%/Day_2


Sunny Jerez later that year, not a hint of rain.

Piquet jr.

Marco Andretti.

Bahrain testing, 2007. Piquet. RAIN?

[astracrazy]

it for rookie drivers as seen here at Duxford when Renault used a rookie to do straight line testing. It is not for rain, we know this because we see it every season at grand prixs

[youtube]http://www.youtube.com/watch?v=Eyyb-14BDPg[/youtube]

Perhaps if a driver hasn't done X km's in an f1 car they must have the green light? A bit like the L plate for learner drivers in Britain (or even the green P plate would be a better example - can drive but inexperianced)

[ESPImperium]

Heres the product on the MES website: http://www.mclarenelectronics.com/Produ ... dard_2.asp

Red-Orange and Green versions are available.

I know that the FIA has been looking at a new colour for the rear of the car, and this may be what they have came up with, and decided to test it a little, get driver response, and then act on it for 2011???

There has even been a rumor that the FIA are also looking to enlarge the lighting display to have a extra 2 rows of LEDs that strobe downwards when a driver had been lapped by the driver in P1, used in conjunstion with a new strobing LED on the steering wheel to let the driver who has been lapped that he could be lapped at any moment. This LED would only glow solid blue when there is a faster car arround 5 seconds behind him at the last sector beam.

The FIA are looking at replacing the flag system with LEDs on the steeringwheel for ages, and rumor has it that 2011 will see a new system for flags and such will be implemented then with less flags on the track, the only flags that would be used are the greasy track and your car has a fault, pit in flags being the only ones used.

MES are developing the whole system, one thing that has been thought of is a standard steering wheel or two for this new system. Steering wheel 1 will look like the current Mercedes one with integrated display system, the second like the Red Bull one for teams that want the display on the monocoque. The wheel would have arround 20 switches and buttons that are team probrammable. But personally i dont see the standard wheel happening, a new integrated display and limit on wheel function, a maximum of 20 buttons and stitches as a couple of teams have many more than that.

[djones]

You only have to look at this picture you posted to show much much more visible the green light is.

Some having it and some not I'm pretty sure is just for evaluation.

Trying to read other things into this is scraping the barrel for things to talk about IMO.

[Confused_Andy]

In my opinion its not for rookie drivers...

This picture was uploaded/taken on the 19th, Sutil was driving that day:


Neither FIF1 drivers are rookies either way.

[autogyro]

I hear USF1 are using orange.
Hehe

[Giblet]

Green makes sense. Our eyes are poor in the red spectrum, and road signs are not arbitrarily green. They are in fact green because we can see that better than other colors.

Might just be a safety thing, a small improvement.

We all know THE BOSS has trouble seeing red lights.

ZING!

[Jersey Tom]

So THIS is how we're making racing 'green' ...

[raceman]

We all know THE BOSS has trouble seeing red lights.

ZING!

oh man, what an incident that was!!! plain stupidity.

[axle]

So THIS is how we're making racing 'green' ...

Yep since the failure of KERS...the FIA's latest green innovation is quite cheap!

Isn't Blue the best/most visible light, hence it's used for emergency services?!

Maybe, in bad weather, they should run Green when the track is Green and Red when they are behind a safety car? That green would IMO be a safer light to use.

[Ciro Pabón]

The most visible colour combinations for the human eye are yellow over black and white over green. Source: AASHTO study on color visibility, TRB Magazine.

On an "empty" visual space, the most visible colour is chartreuse (or so biologists argue): it's in the middle of the visible spectrum.

[myurr]

The most visible colour combinations for the human eye are yellow over black and white over green. Source: AASHTO study on color visibility, TRB Magazine.

However isn't red better at penetrating mist and fog?

Source: My dodgy memory.

[Miguel]

The most visible colour combinations for the human eye are yellow over black and white over green. Source: AASHTO study on color visibility, TRB Magazine.

However isn't red better at penetrating mist and fog?

Source: My dodgy memory.

I doubt it. Red is closer to, well, infrared. Both mist and fog have a higher amount of water, either sprayed or evaporated, and water is a good IR absorber. There is a reason why they put IR telescopes as high as possible in areas as dry as possible.

Of course, this is back of the envelope thinking, and won't be certain until I see a graph of the refractive index of water with frequency.

[autogyro]

What ever colour they choose, USF1 is going to be difficult to see.

[Ciro Pabón]

Yes, I've heard that one too. The idea is that red light, with longer wavelength, scatters less in fog. That's false: if it were true, fog would look blue.

Given the size of droplets in fog, the scattering is almost identical for any wavelength.

Europeand rear fog lights are red because stop lights are red, as far as I know. They are brighter than regular stop lights, to make them more visible. Your car has only one so they don't get confused with regular stop lights.

Yellow is in the middle of the "biological" band of wavelengths (Miguel will like this explanation): the atmosphere is transparent to the visible light and opaque to the "invisible" one. Eyes evolved to use the wavelengths that can pass through the atmosphere.

The white band, between 1 micromenter and 100 nanometers is the band where visible light is: those are the smallest wavelengths (thus, the most able to resolve small objects) to which atmosphere is transparent. Yellow colour is in the middle of that band.


Now, fog glasses are yellow because this light offers you the highest contrast, as I explained. Many fog front lights are yellow for the same reason.

Green makes sense. Our eyes are poor in the red spectrum, and road signs are not arbitrarily green. They are in fact green because we can see that better than other colors....

About why red and green for traffic lights, I've heard many theories, but I think it's simply a carryover of "traffic lights" for ships.

Ships have a red light on the left side and a green one on the right side since times of yore. The ship on the right has the right of way. This means that when you see a red light, you have to "stop" and allow the other ship to pass.

Ship lights: the ship on the right has the right of way


In truth, at sea, green doesn't mean "go": it means "caution". It's not simply "move along, don't worry", but a qualified signal. Even if you see a green light, a small vessel has to give right of way to a large vessel, and a powered vessel has to give way to a sailing vessel, for example.

I think airplanes have the same lights (red and green, left and right).

Semaphore signals for trains were invented by Joseph Stevens in the 1840's. Still, in spanish and other latin languages, a traffic light is called a semáforo or semaphore.

According to legend, he "inherited" the same light code for ships: it went like this: red/stop, green/caution, white/go.

In 1889 the british parliament passed a new legislation after the Armagh train disaster: yellow would mean that a "distant" stop was necessary (a train was far away in the track).

So, with time, it changed to red/stop, yellow/caution, green/go.

The first modern traffic light was built by William Potts in Detroit, in 1920: he used the same code as railroads.

William Potts


First modern traffic light


About why green lights for rookies, there is an apendix to regulations about traffic lights in circuits. Let me check it, I'll be back.