[ExI] bees again

Anders Sandberg anders at aleph.se
Tue May 21 14:25:47 UTC 2013

On 20/05/2013 18:42, John Clark wrote:
> I'll work on that, but I have another idea, splice the 7 genes that 
> rose plants use to make proteins that smell nice into E coli bacteria 
> which is ubiquitous in the human gut; then if you were to fart in a 
> elevator you'd be doing the other passengers a favor as they are 
> invigorated by the gentile fragrance of rose petals.

Actually, the first part has been done, for a wintergreen or banana smell:

And rose smell is getting characterized, even using E. coli to test the 
functions of some enzymes (but I suspect they did not smell much):

However, E. coli is apparently not as common in the gut as we tend to 
think; just 0.1% of gut flora. Apparently other groups of bacteria like 
Firmicutes and Bacteroidetesare more common and should be targeted.

> Another idea that is actually being worked on is to make 
> bio-luminescent plants. It's been estimated that if just 0.02 percent 
> of the energy a plant obtains from photosynthesis were used to make 
> Luciferase, the protein that fireflys use, a medium sized tree would 
> be as bright as a streetlamp

Hmm. Plants convert sunlight with 3-6% efficiency. So a few hundred 
Watts per square meter x 0.03 x 0.0002 = about 0.01 Watts per square 
meter - I doubt you could see anything except in very deep darkness. OK, 
maybe 0.02 percent was a typo and it is 2% - then we get somewhere 
around 0.24 Watts per square meter. That you can definitely see, but it 
is not terribly bright: a 10x10 meter tree will have a total output in 
your direction of 24 Watts. The weakest street-lights reach about 18 
Watts (a typical low pressure sodium streetlight is more like 80 Watts), 
but that light is also very directional. (a lot hinges on the wavelength 
profile and solid angle distribution, of course, but I am not great with 
telling candelas from lumens from lux).

Bioluminescent trees are a neat idea, but hardly a reliable replacement 
for street lamps. Especially in winter.

Anders Sandberg,
Future of Humanity Institute
Oxford Martin School
Faculty of Philosophy
Oxford University

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