Almost every week, I get an email from someone asking me how they can get in touch with the Quercus Trust, the fund established by mathematician-turned-philanthropist David Gelbaum. Quercus has invested in around 47 companies by my last count and many of these investments are in companies that could almost be described as science projects. The firm is more likely to invest in piezoelectrics (energy from movement), thermoelectrics (electricity directly from heat) or atmospheric wind turbines than an energy console for your home.

But the firm doesn't do a lot of company outreach. Gelbaum rarely gives interviews and the firm does not issue press releases. Typing www.quercustrust.com into your browser sends you, magically, to Google.  It does not list its phone number. Phone numbers on SEC forms lead to its law firm. I've wanted to interview Gelbaum, but companies that have worked with him said, "Good luck." (That said, sources have also told us he reads articles about the firm's investments.) To be honest, the absolute silence is in some ways kind of refreshing. It beats those ostentatious companies that like to advertise how stealthy they are.

So how can you find him? You can't. He will come to you, so you should look for ways to promote your company in a way that might come to his attention. Here are the only three ways I can say might work:

1. Publish a paper in a peer-reviewed journal. Gelbaum reads scientific journals constantly and seeks out ideas for new companies there, according to sources. The firm's investment in Graphene Energy, an ultracapacitor company out of the University of Texas, orginated with a paper. The firm has invested in a few other professor-generated companies, like Nano Si Solar, so if you have a chair in engineering you might get a call. If anything, this is your best bet.

2. Regularly troll the 21Ventures website and the blog by partner David Anthony. 21Ventures often invests alongside Quercus and will announce a Quercus investment when announcing their own. Anthony's blog will give you some indication on areas they might find attractive.

3. Be a small, publicly traded company. Although many of the firm's investments are in small, private companies, it also holds (or has held) shares in small public companies like DayStar Technologies.