This wiki page is collecting questions and statements of interest that have been expressed on the mailing lists or in person at barnraisings. Each of these could inspire a Spectral Challenge entry, so click "edit" to add yours below!

• I'm a gardener. Can i do my own soil testing? Usually i send away to a lab for a mineral profile, and to make sure there's nothing harmful in my soil before i plant food crops in it.
• I live near a refinery. How can i know what is being released in a smokestack plume?
• I'm an urbanite. When I look out over my city, i can see what i call "the smog layer". I can see that it changes on a daily, even hourly basis. Can i tell how much (and of what kind of) particles are in the atmosphere?
• I'm a surfer / fisherman / beach goer. Is this gunky stuff in the soil / on the beach just mud or is it a petrochemical spill?
• I'm a health nut. Can i test my tap water for additives?
• I love space and I have a telescope. If i add a spectrometer to the end of it, can I identify what stars are made of?
• I'm a journalist. Can i collect my own data for an expose on an overpriced consumer product like liquid soap?
• I'm into 3d printing. I would like to take plastics from the waste stream and melt them into material I can print with, but often there are unsafe additives for fire resistance or electrical insulation enhancement. How can I test if bromine or chlorine are present before i melt the plastic and breathe that stuff?
• I'm into DIYBio. My holy grail is "a low cost small sample uv spectrophotometer for the quantification of dna, like http://www.nanodrop.com/". Is this possible?
• I'm worried about dioxins in eggs - Amir Bernat posted that: "Last night it was announced in the news in Israel that eggs from several farms were found to contain Dioxins, compounds which are considered highly toxic (http://en.wikipedia.org/wiki/Dioxins_and_dioxin-like_compounds). I tried to search a bit and found a wealth of mass spectroscopy research done, but no lock with optical spectroscopy, let alone in the visual. I would like to see if our spectrometer can be used to search for Dioxsins, but I don't have any with me (unless it's in my omelette!). I would be happy if anyone could help with this, there may be a chance for some important work as well as get media coverage." Jill Schwarz responded with this review of vis/nir dioxin spectrometry: http://iopscience.iop.org/0036-021X/69/12/R03 (link to mailing list discussion)
• Monitor hydrofracking contamination Detect and measure concentration of Cl, Ba, Sr, Mg, Br in a stream or well water sample. Priority is Cl, Ba, Br > Mg, Sr.
  Cl, Mg: minimum detection limit of 1 mg/mL. Ideal threshold of detection would be 0.01 mg/mL, NYS certified lab threshold of detection. Ba, Sr, Br: minimum detection limit of 0.1 mg/mL, ideal threshold of 0.01 mg/mL. The test should be effective in water based solution in the presence of some salts (especially Cl, up to 10,000 mg/L, but also Ca, Mg, Br), petrochemical contaminants (diesel, ethylene glycol), and microinvertebrates (concentration in a healthy pond, stream, or tide water sample). Contact Jessica cassabel@gmail.com with questions.
• I live next to water and I want to know the water quality before going for a swim. We can use spectroscopy to determine how much phytoplankon, e.g. algae and potentially toxic cyanobacteria, is abundant. Check out this research note.
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