I did hear about this, but I hadn't thought about writing a filter after receiving spam. That's a cool idea.
The only part that makes me slightly wary is that since so many use gmail, you'd think that spammers would automatically remove the +slashdot part pretty soon.
I don't even use spam blockers. Instead I've purchased a domain, which is quite affordable nowadays. I have a catch-all redirect, so I any mail addressed to *@mydomain.com.
Then, I give a unique username to each organisation. e.g. firstname.lastname@example.org. If I receive spam at this address, I inform them, then kill the username. I can also just create email@example.com if I want to keep dealing with their company.
Now, I receive only a few spam emails each year, so I need to do zero automated filtering. I also don't have to deal with the worry of false positives at all.
Also, now I think about it a bit more, I think the phase difference between ears is also enough to make this unfeasible for higher frequencies. But yes, I agree that it should be possible (and useful) to cancel the low-frequency engine noise.
Okay, so we've a got a proposal. Where do we pitch it?
But the engine vibrations occur at a known spot at a fixed distance from every seat and are essentially constant for long periods.
That's a good point. I imagine that could work for gross cancellation of noise, especially at lower frequencies, but I still think there'd be too much variability at higher frequencies. For example, at 2 kHz, the wavelength is about 17 cm. Hence, if you are 9 cm away from the 'optimal' position, you'd be totally out of phase, and the noise would be worse. Obviously this precision is even more important for higher frequencies.
If you haven't seen it, it's a great satire on Hollywood. The opening scene in fantastic in its own right (8 minute, single take), and features writers pitching ideas to a producer, including the sequel to The Graduate. The conclusion is that Hollywood cannot find a new idea.
You make good points about the research on cancer. I am by no means a specialist in this area, but this appears to be consistent with what I know. Also, good things to remember for grant applications, no doubt!