Using the back of a different envelope, let's hypothesise some mutation to ebola that gives it a 70% mortality rate (the mean of the mortality rates you cite), and a flu-like transmission profile. Then in around 5 years of cycling through the population, we'll be down to about 2.1 billion people left on the planet. That's around the population in the late 1920s to late 1930s.

Add on your 69 years for 3 generations and we'll be back to a population situation of 1933 + 69 = 2002. In short, we'd be back to the approximate population position of today.

I see that you cite American flu rates, suggesting that you may be American. Given that, likely you live there and rarely leave (average American)? Of the last 3 years I've spent about 8-9 months (I'd have to check my pay slips) living in various countries of Africa and on my last rotation out of there an aircraft fault put us down into Abidjan airport, which borders the most recent ebola outbreak. My next rotation into Africa will see me in Gabon, in the thick of the "ebola belt". Ebola isn't a theoretical issue for me, and I'm paying close attention to the vaccine work, and would consider participating in clinical trials of one.

I have a few objections to that, as nice as it is for what it's trying to be.

The first is covered by the "Is there any kind of Âpresenter screen in Impressive?" FAQ. (Or more directly, the "No, and there is currently no proper way (or plans) to implement such a thing" answer.) There's sort of a half-assed workaround that gets some of the way there, but a half-assed workaround is still half-assed.

The second is that I don't think PDF is a good delivery medium for a lot of presentations. A lot of people (especially here) will decry things like fancy effects and animations, and when used without purpose they're distracting and obnoxious. However, they can also be used very well, to clarify relationships or show how a system transitions from state-to-state and stuff like that. I get the feeling that PDF is a bit more capable here than I give it credit for, but I still think it's pretty poor in comparison to something in the PPT/Impress/Keynote genre.

Third, it's only a viewer, which leaves open the question of what you author the PDFs in. The example slides are Beamer, and as much of a fan of Latex as I am for documents*, I think it's a pretty poor fit for most presentations. Partly this goes to my previous point, but I also think that presentations are a medium that minimizes most of Latex's strengths and maximizes its weaknesses.

(* Actually this is untrue. I hate Latex. :-) But like PPT, it stands out as being by far the best of a bad lot.)

Like you say, to each their own, but I think it's not for me.

Keynote is free now with Macs and iOS devices and free online for everyone.

Are you sure about that? I tried signing into iCloud with the credentials I use for iTunes, and it said "Your Apple ID must be used to set up iCloud on an OS X or iOS device before you can use iCloud.com."

Did I go to the wrong place? Or can I set up an account even if I don't own a machine?

Yes, I remember the Psion Organiser. I never had one myself, but a guy at work dropped his into one of the chemical storage pits (filled with an oil/ water/ salt mix), and since we were 2 weeks from getting back to shore, he asked me if I could try and bring it back to life. All I did was clean it - very carefully, inside and out, water, alcohol, water, alcohol - and then dry it very, very carefully. But it worked when I put it back together, which allowed him to back it up. And it carried on working until the next hitch on the vessel, which astonished everyone.

That stuck in my memory for 8 years later when I was looking for something better then a Nokia Communicator, and which I'd be able to take to work. I wasn't disappointed by the hardware Psion were selling then.

Sure, it was running a great OS for the time but that OS did not have the kind of app ecosystem that the iPad does.

And it didn't need it.

Writing documents - covered on the stock ROM (and you could get converters to go to Word and or Write formats too).

Spreadsheets - I could make the stock ROM's spreadsheet do the calculations for steering oil wells. Other people I knew ran their stock portfolios on their Psions. Converters available.

Drawing ... well, you could do it. The 4-shade grey screen was a limit there, but it was good enough for my purposes. Converters available.

Database - again, good enough for my purposes. I knew a mud man who did his stock control on one, so I guess that was good enough for him.

Presentations ... I think they didn't see making presentations as being a use case.

There were a LOT of other apps out there - I remember buying several, such as astronomical tools - but you could take the machine out of it's box on Xmas day and be up and running for any regular office tasks.

I used a Compaq desktop system which included a touch screen in 1989. It worked - and since I was new to computers then (I didn't actually have one at home at the time, and at work we used industrial rackmounts with teleprinter terminals and HP 9800 series systems for report writing.) The technology for touchscreens is decades old. IIRC those touch screens added about $1500 to the cost of the system, which wasn't a particular problem. If MS had agreed to include the drivers for them in Windows 3.0, then we'd probably have had the touchscreen revolution in 1991.

We hooked those systems up to the old Motorola analogue mobile phones - we could get 2400 BPS data links from 70 miles offshore. Since the antennae for a formal radio system would have cost 10s of thousands of dollars for installation, and be repeated each time we needed to hire a vessel, then the price of the touchscreen didn't seem too unreasonable. We saved hundreds of thousands over the years that system was working!

Ahhh, memories. Xenix! X! Multiple overlapping windows! All so new then.

... Interesting.

And with an $800 BoM, you'd have been up against a £400 Psion 5 (retail cost), which included all applications necessary (was a web browser considered necessary at the time? I honestly can't remember. I know I did do some web browsing on it, because it would connect well to my Sony mobile or Nokia Communicator ; but I honestly can't remember if the web browser was built in or one I chose)., a large installed base of users with their own applications from the 3- and 5- series and an established dealer network.

Oh, hang on - you priced things in dollars. American? Then no Psion dealer network. Maybe you'd have survived.

Technologies that had to mature before the tablet computers became practical:
Wifi networking.

Useful, I'll agree. Not "necessary". I ran cables throughout the old house in the mid-1990s, and was getting a stable 100MBPS connection from any computer from about 1996 until we left in 2012. If I had a guest and I wanted to provide them with WiFi, I'd turn on the laptops WiFi card and the last time I did it, they could get half the connection speed that I had through the cable. I was considering running 1000-base, but would probably have left it until the previous cable was 20 years old before replacing it.

Capacitive Touchscreens -- Most early designs used a stylus, which sucks, and had poor resolution to boot

I used a touch screen with a stylus. You might think that they suck, but I'm perfectly happy with them. My Psion used one (and I never lost one!) and my last - or last-but-one - phone also had a stylus (which I also didn't lose, until I lost the phone itself). You might think that they suck, but that's a subjective opinion, not an objective fact.

Low power but still acceptably fast processors -- A huge sticking point, lots of early tablets had extremely poor battery life on top of being slow

Yeah ... in 2000 I objected so badly to replacing the AA cells (rechargeable or primary) EVERY DAMNED MONTH. It was such a pain in the arse having to go to any shop in the world and buy two batteries EVERY DAMNED MONTH. It's so much better having to carry a charger (and the panoply of adaptors for the 5 different sockets that I meet most months) with me and having to recharge the device several times a day.

A touch enabled OS -- WinCE is terrible to use with a finger, and really pretty bad with a stylus. Symbian was never great. PalmOS was too narrowly focused on Palm pilots

When I discovered Symbian, I never felt the need to try a WinCE machine or a Palm machine. I just got on with using the applications and barely noticed the OS. Which is how it should be.

Battery capacity -- Battery technology has come a long way inetwork speed n the past 15 years. Early attempts would use NiCad batteries, which just aren't good enough, especially with the relatively high energy consumption figures from the old chips

See above comments about the horrors of a monthly battery change (Either NiCads, NiMHs or primaries).

The technology to make effective "tablet" devices was available in the late 1990s - Psion did it. To this day, it's a mystery to the community of "Psioneers" why they stopped manufacturing them, or why they didn't sell the hardware division as a going concern when they restructured to become a software-only company. If they'd continued ... well, the world is full of "if onlys".

Because it, well, works. The older tech worked poorly when it worked at all and suffered a much higher rate of failure.

Crap resistive touchscreens were crap because they were crap. Good resistive touchscreens were good because they were good, not crap.

See up-thread for comments about the Psion 5 family. I forget who made the touchscreen - I know that the display was a Hitachi part, but I can't remember if you could get the touchscreen separately. That was a good part - and probably one of the highest cost items on the BoM to build the device. But it was also one of the major features of the device, and essential to it's success.

Capacitive touchscreens are more accurate to use with a bare finger than resistive ones, which call for a stylus

[SHRUG]

When you want accuracy from fingertips, you use an implement. Be that a dissecting needle and forceps (I spend several hours each working day at the microscope - it shows), or a stylus, or a keyboard. Fingertips weren't designed for precision work. They evolved to their current form while we were still making tools by banging rocks together. By the time we started to make needles and fabrics, our ancestors were already "anatomically modern humans".

I used Psion 5s and 5mxs for about 10 years until supplies dried up - during the period that this device was designed. Applications and an excellent (for a pocket device) keyboard made the Psion ; the stylus wasn't a problem.

13 years ago I was using a Psion 5 pocket computer (running EPOC, later renamed Symbian). Terrible feature set - you could drop in as large a CF card as you could afford. Connectivity was by serial cable (I moved data on and off via the CF card, so didn't bother much with the cable, and often forgot to pack it.) A half-VGA 4-grey screen (internally EPOC could handle 16 colours, but the colour screens destroyed the battery life and wrecked the price point). A keyboard with good responsiveness and which you could type on for hours (I did all the time). A touch screen that worked. A suite of office applications which met my needs. And most important of all - it would run for a month on a pair of AA cells.

13 years later, the tablet market is bringing out some devices that are comparable with the Psion 5, but are all severely crippled by being hooked to an app purchase "store", instead of providing adequate functionality out of the box. I spent about 5 years after Psion stopped producing the 5s using ebaY to get spares to repair mine (the screens were not robust!) before reluctantly giving up on them. But that month of battery life ... irreplaceable.

it's easier to type "17 25 4 12" than "17 25 4 12" even ignoring row vs column-ness.

Let's try that again not making up new HTML tags: ...it's easier to type "17 [enter] 25 [enter] 4 [enter] 12" than "17 [comma] 25 [comma] 4 [comma] 12" even ignoring row vs column-ness.

I would vote Excel in that contest. To me, comparing Excel to Python/matplotlib harkens a lot of the comparison of something like Python to a compiled language. The former gives you a REPL that lets you interact with your language easily, you can make changes and see them reflected without recompiling, etc. Well, Excel takes that one step further: with it, you don't have to do anything: as you change the input data, the calculated data changes immediately. With Python and matplotlib (at least as much as I've seen it), you don't have to recompile but you do have to re-run your script or take some other action besides just changing the data to get it to regraph (or else start writing your own wrapper).

Or not everything is graphing either. For instance, suppose you're picking between different mortgages and want to compare a few different scenarios. You can have cells for the interest rate, nominal loan time, points, extra prepayments, etc. and then have cells to calculate the total interest paid, actual loan time, etc. Want to see what an additional 1% does to your rate? Change 3.5% to 4.5% and... you see the effect.

Finally, I think spreadsheets often make data entry easier as well as just looking at tables easier. You can just grab and resize columns if something doesn't fit, as opposed to go and manually respace things. Entering data going down in a spreadsheet column is about as easy as it gets because you have an enter button on your 10-key: it's easier to type "17 25 4 12" than "17 25 4 12" even ignoring row vs column-ness.

At least personally, when I use a spreadsheet instead of going to Python/matplotlib or something else, those are usually the reasons why.

Second, he for your analogy basically stood outside and asked for some secrets and the homeowner yelled them back at him.

That's like saying someone who breaks into a house by throwing a brick through the window merely lets go of a brick when it has a particular trajectory and the glass just got out of their way.

Sure there were some incremental changes that took advantage of newer technologies, some new UI changes that I am not sure if it makes things better

This is going to sound like a shill, but I promise it's not; I've actually been really impressed with the Office UI changes post-2007. (For purposes of this discussion, let's forget about whether the ribbon itself was a good idea (I am actually pretty indifferent, to be honest) and just assume it's here to stay.) A few years back I went to work on a PowerPoint presentation in 2010 on a shared computer, than later continued work using 2007 on my own. And I definitely missed some of the changes -- where 2010 made much more accessible some operations that were more buried in 2007. And recently I was doing some collaborative work in Word 2013, and there were a couple minor but still nice changes to the way comments and track-changes were displayed in comparison to what I was used to (and have reason to believe changed since 2010).

I'm by no means a heavy Office user -- there will be weeks that go by where I almost don't open any Office programs. But at the same time, (1) they are making UI improvements and (2) I definitely don't think you can dismiss UI improvements for programs like these -- in some sense, 98% of the program is the UI for something like Word. Word's not doing any heavy computation behind the scenes that's the real thing you're interested in.