Motorcycles and Invisibility

[Lauren_TK]

Thank you Ionbeam.

Justin: I do not argue that lights help under normal circumstances. I'm trying to dig out the facts pertaining to a question in the original post: Do lights help or hurt when the sun is at your back?

So . . . I've been running a process at work, so I've had a little time on my hands, so I've been hunting up articles on the web about Yehudi lights. From what I have gleaned, Yehudi lights work because of light intensity (brightness), not wave length (color). Specifically, intensity of lights to fool a target at a specific distance. This was an easy propostion for an aircraft whose altitude meter told them how high above sea level they were. Not so easy for tanks, as the enemy could pop out of cover at 10 meters or 1,000 meters.

OK, then. Intensity. I broke out the trusty old Handbook of Chemisty and Physics (mine is a 30 year old edition), did a quick back of the envelope, and combined it with some half-remembered lore I came up with the following:

If the object is 100 meters from the target, and the objects is no more than ~15% brighter than the background, and no less than ~30% dimmer, then object should be obscured.

So how does that apply to the original question? I'm not sure it does, as I haven't confirmed any of my assumptions. Further, while the Sun is very bright, it is also very far away. 500 lux at 50 meters might be enough to render a rider invisible.

I'm now hooked on this question, and I'm on the hunt. Stay tuned for an update from me on Sunday or Monday.

Edit: If there is further speculation from the forum, or questions, I'll see if I can facter them into my research.

 

[HotRodZilla]

Honestly, who cares. We do what we can to make ourselves seen. I don't give a crap about the hypothesis or physics behind it. Regardless of what statistics say, or how visible we are, none of that takes distracted, drunk, angry, stupid drivers into account.

What I'm trying to say is: We could could be driving a high viz carousel with every bright color known to man with horns and sirens blaring, and some preoccupied douche bag would pull out in front of us claiming he didn't see us.

Assume nothing and ride/drive as defensively as possible.

 

[Justin]

Honestly, who cares. We do what we can to make ourselves seen. I don't give a crap about the hypothesis or physics behind it. Regardless of what statistics say, or how visible we are, none of that takes distracted, drunk, angry, stupid drivers into account.
What I'm trying to say is: We could could be driving a high viz carousel with every bright color known to man with horns and sirens blaring, and some preoccupied douche bag would pull out in front of us claiming he didn't see us.

Assume nothing and ride/drive as defensively as possible.

I care :lol:

Yup, I always ride like no one sees me. But I'm going to give myself every advantage I can.

 

[Lauren_TK]

What I'm trying to say is: We could could be driving a high viz carousel with every bright color known to man with horns and sirens blaring, and some preoccupied douche bag would pull out in front of us claiming he didn't see us.
Assume nothing and ride/drive as defensively as possible.

Truth.

I do care about the physics, but then I'm a bit of a medium huge nerd. I would like to know for knowing's sake.

I would also like to maximize my chances of being seen, but I don't want to go crazy. I'd like to know how it works, and why, to make informed choices.

 

[900gc]

The most noticeable "eye catching" headlight set up I've seen lately was a new Goldwing that had a headlight modulator that worked all four headlights. It had a strobe like affect that practically yanked your eyeballs out it was so dramatic. It also left me wondering if it was legal.

 

[SoCalFJR1300]

One major issue that you can't do anything about is the size of our vehicles.

Compared to cages we're small.......and easy to not see.

I remember seeing a video years ago showing how you can block out a motorcycle in the distance that's approaching you with a pencil.

The guy held a pencil up to his eye and obscured the motorcycle with the width of the pencil.

Then there's the physcological aspect.

People are looking for cars, not motorcycles.

How many times have you sworn that the person who pulled out in front of you from that parking lot SAW you before they did it?

I've had people look right through me and pull out in front of me like I wasn't there!

They're looking for large vehicles, not small (compared to a car/truck) motorcycle, it doesn't register in their mind.

That's one reason why I'd never ride a small scooter on the street, almost invisable.

All that being said, I have a Black FJR so I wear a White helmet.

 

[bramfrank]

Another vote for headlight modulators . . . . as to whether they're legal or not - as long as they all flash at the same time, 4-6 times per second and don't actually switch from full off to full on, they are legal for daytime use (and they require ambient light detection so they switch off between duck and dawn) - the spec is clear and, while some products hit the market that were not compliant, all of the plug-and-play stuff I've seen is.

Then I also have my 4200K HID Driving lights, Hella Micro DE Xenons.

The bike's low beams are well aimed and almost invisible to oncoming traffic, especially during daylight hours. Switching to high beam aims them higher, so oncoming traffic can see them and you end up with a nominal 3200 lumens of light output. Modulating them provides the variance that the brain is looking for when scanning for the presence of something in one's field of view.

Now, add in an additional 6400 lumens of 'whiter than the flashing high beam' headlight, which supplements the basic headlight and you have a very visible daytime profile.