The significance of this is Elon Musk, who is the self-driving Uber of dot.com billionaires and is the hero of our times.
Well, I knew Steve Jobs well enough, and have met a few civilian astronauts and a bunch of other rich people. None of the others seem to have done so much for the long-term future of the human race as Musk has in leading the path to more affordable spaceflight.
Well, it beats making them into the world's most complicated airplanes as with the space shuttle. SpaceX has proven that they can do vertical landings of the first stage intact onto both land and a seagoing barge; after a trip out of the atmosphere and to about 1/5 of orbital velocity but not into orbit. They plan to do a parachute-less vertical landing of the Dragon capsule after a heat-shield re-entry. That turns out to be far less expensive and complicated than a space plane. It does turn out we need a lifting body for much larger vehicles. It still doesn't have to be a plane, though.
We don't need wings.
I am concerned about the lubrication and circuit boards (electrolytic caps, mostly) associated with hard disks over long term storage. I have found a high failure rate on my own old hard drives - old MFM drives were kind of crappily engineered, however, so the fact that an ST-251 drive from 1990 doesn't work today shouldn't necessarily be indicative of the lifespan of say, a WD Black 1TB manufactured in 2010.
In my world, we rely on practical tests of functionality *with the actual users* rather than theoretical measures of effectiveness. It seems the CDC agrees with me on this one.
As to one of your other points:
"The bottom line is that a single act of intercourse between a young couple has on average a one in 20 chance of pregnancy – this assumes the opportunity presented itself on a random day, as these things tend do when you are young."
So the answer is based on how often you fuck. The CDC numbers do not map precisely to data of this sort, however.
Last point: "measuring the effectiveness of encouraging people not to fuck" sounds like the craptastic questionnaire-based research I saw at (not to pick on them) the Lehigh psych department in the early 2000s. People lie, and they can't simulate the paths not taken effectively. There would literally be no way to know if someone decided to not have sexual intercourse based on an abstinence campaign.
Besides, my kind of abstinence campaign would be "Blowjobs for Everyone" or "Real lovers wank each other".
The only actual way to reduce teen pregnancy is to encourage them to stop fucking so much
You have figures for all the other methods. What are the figures for "encouraging them to stop fucking so much"?
The birth control available to them _does not work_.
The figures quoted say otherwise. True, the worst contraceptive you mention is successful with 72% of users across a year never having a problem, however the pill is successful for 91% of users (over a year), and the CDC includes reversible birth control measures that are more than 99% effective in the chart you mention.
It's also worth mentioning that the failures aren't necessarily a function of the devices themselves so much as user error. Condoms usually "fail" not because they break or anything else obvious, but because people who rely upon them frequently decide to chance not using them. Almost all versions of the pill can be rendered useless if combined with certain drugs - notably many antibiotics - and are more than 99% effective if used properly.
The possession of a book becomes a substitute for reading it. -- Anthony Burgess