Years ago, when recruiting for a tech support position, I had an agency send a bunch of 'pre-screened and qualified' candidates through. Most were fine, and we could start straight away with conversations about debugging AUTOEXEC.BAT and CONFIG.SYS (this probably dates the time period!) One candidate, however, looked like a deer-in-headlights, and was clearly out of his depth. In the end, I asked "There is a computer in this room, can you point to it?", and he sheepishly pointed to the fridge!
I felt really bad for the poor guy; it was not his fault. We finished the interview early, had a friendly chat, and I sent him on his way with some bus fares.
I then got on the phone and tore the agency a new one. They had wasted his time, and my time, by 'doctoring' the qualifications. I never used them again.
Author of article here. Thanks for kinds comments.
Yes, it's possible to stabilize bottle rockets with fins (to adjust the CP), but as the article hints, the stick is multipurpose in helping with launch, as well as stability (plus being easy to manufacture with low precision).
Aeronautics is a complex science and my articles are intended to pique interest, not oversimplify or belittle. It's a hard balance to explain things in a few hundred words. I hope you enjoy them and, if there is interest, they become the catalyst for you to learn more. It's a fascininating subject.
That is a fantastic follow-up article. Bookmarked :)
Re: the stick...
> the stick is multipurpose in helping with launch, as well as stability (plus being easy to manufacture with low precision)
True. Model rockets achieve mostly the same, except instead of keeping the stick attached to the rocket, the stick is instead attached to the launchpad, and is stuck through two (or more) holes on the side of the rocket (fancier/bigger rockets typically opt for rails, but a simple metal rod is typically good enough for smaller rockets).
Like I mentioned, if such a rocket were to be built to be disposable (i.e. with a "recovery system" that just disintegrates the rocket instead of something like a parachute), they could probably be cost-competitive and performance-competitive with mortars (probably a slightly-higher upfront cost due to the launchpad and electric ignition system instead of a traditional fuse, but not by a whole lot); that they ain't typically used for pyrotechnics seems to imply a regulatory issue with doing so.
1. Process: I keep a task list (using google tools) with a list of topic ideas. When I think of something I want to write about, or find interesting links, I place them there. There's typically about two dozen ideas at any time incubating.
2. Start: I started the blog about a dozen years ago as a way to add depth to my website that was the front-end for my consulting business. I stopped consulting shortly after starting, and am now retired, but I keep the blog up on that site; I've built a following. It was easy to start. Ideas are easy; the hard part is finding the free time to write!
3. Motivation. I love doing it. I get pleasure from writing. When I was a kid, I loved reading the works of Martin Gardner. I hope my blog could be seen some way as an homage to his works.
4. No real struggles, but I made a conscious choice to not enable comments on my site. Comments will get you down. Everyone is a critic. Jerks will say "that's not special, I could have don that" (hmmm, but you didn't). My email address is not hard to find on the site if you want to get in contact with me. Don't fret too much about publishing; do what is right for you. There is a whole spectrum of 'advice' from people saying regular rapid cadence (even if you have nothing to say), through to only publish gems. I typically average about one post a week. Some of my posts are lightweight, others are heavyweights.
I think multi-rotor is a great safety feature, especially if they're partitioned into separate power systems. It would almost require intention to design something like the Volocopter without the ability to soft land in the case of an emergency.
The link you provided mentions this in an odd way:
> With a single engine helicopter you don’t have this redundancy. However, on engine failure, the single massive disk of the helicopter is an asset. ... Close to the ground, this stored kinetic energy can be traded, through pulling up the cyclic, to allow a safe landing. This is called autorotation, and is practiced by all helicopter pilots.
The air taxi that succeeds, at any sort of scale, will not be meant or designed for skilled helicopter pilots pulling levers, at the right moment, as they speed towards the ground. They will be dumb, cheap to service, unskilled to fly, and have more than one point of failure.
There's currently about 360 articles about math, science, programming, data-mining, geekery ... in style similar to a hero of mine, the late Martin Gardner.
I make about $50-$70/month from Adsense on my blog. I use a single Auto ad unit in the middle of each article. It would be nice if it were more. They payout every couple of months when the balance gets over $100. When they payout I get a 'report' that tells me they reduced my payout because of 'invalid traffic' (with no details about what/how/when). This deduction varies from about 5-20% of the payout.
I felt really bad for the poor guy; it was not his fault. We finished the interview early, had a friendly chat, and I sent him on his way with some bus fares.
I then got on the phone and tore the agency a new one. They had wasted his time, and my time, by 'doctoring' the qualifications. I never used them again.