Appelez-moi sceptique…

I came across this interesting device and had an instant gut reaction.. “Bien sûr, une ampoule d'eau stupide ne repousse pas les mouches, c'est une arnaque!”…

respiration…

OK c'est horrible scepticisme. En fait, c'est cynique et c'est juste ce que les sceptiques déteste être appelé. C'est aussi quelque chose qui arrive beaucoup trop facilement – I’m pretty convinced that ghosts don’t exist, there has been no compelling evidence, ever. But every time I hear a story of a haunting it is far too tempting to just think of a few plausible explanations and dismiss the case without a closer look. And when we do this we give fodder to the credulous investigator who will throw it back in our faces faster than a spirit-orb zipping across a room. Discovering a real ghost for the first time ever is pretty nearly impossible; yet the answer isn’t always the most obvious hypothesis and you can stumble upon a zebra every once in a while. The point is that investigation is the only real way to remain skeptical.

So in order to avoid arm-chair skepticism I will attempt to purchase and test this device. I have contacted the artist and request more information and a price (“artist” makes me worry). Barring sticker shock (of course someone could donate for the cause) – I will submit this to a decently rigorous test as soon as I gather enough flies.

Le a priori assumption is that the scattering of light created by the water sphere will scare away flies because they have very “sensitive eyes” and the movement of the light will keep them from landing (movement=danger). Not a crazy thought, at the very least this device does not claim to emit any “energy” ou “waves” or any other “b.s. stupidity”. When first approaching claims like this it is very important to ignore anecdotal evidence. In this case, that claim is that this is the “traditional way to scare flies away in most of the food markets on urban Mexico” (spelling error not my own). An argument from popularity and tradition ads zero evidence to efficacy of the device. I suppose widespread use is most likely gullibility spread on the back of a meme.

It is also critical to consider the prior plausibility of light being an effective deterrent. Flies have evolved in an environment that abounds with distractions and dangers – not to mention water. The eyes of a fly (I will assume Musca domestica for purposes of this experiment) are highly sensitive to movement and the reaction time of a housefly is famous. I will go ahead and assume that flies encounter scattered light as part of daily life. Wouldn’t being under a bush on a breezy day – especially if that bush was wet – generate roughly the same effect? It seems unlikely that a common occurrence in nature would induce an escape response the same way a dangerous object would. I conclude the plausibility of this device is low, however not totally impossible. Certain light effects may just mimic enough physical movement to scare off a fly. However is that light delivered by ce object. Par exemple, maybe a flashlight or laser is effective but not scattered light, in that case this device would just be a scam (if not just an object of art). On top of the light assumption, the user also assumes that the light is scattered not only evenly across a surface but densely enough to actually scare enough flies to make this effective for keeping your food fly-free.

Considering the above: I predict that the scattered light created from this bulb will not reduce the number of landings or the duration a fly spends on a surface (especially one with a food lure).

Now to design the experiment…

UPDATE: The artist returned my message and the device is 120 euro + shipping from europe. Too much for me…