Replacing concrete as a building material

It seems strange, but the world is running out of sand (see here; there’s also a fantastic book on the topic). The problem, in particular, is that sand is used in producing concrete, but only sand with grains that are shaped in a particular way will work.

Image from NPR

Unfortunately, desert sand, which is plentiful, is weathered by the wind into a rounded shape that cannot be used for construction purposes. The kind of sand most commonly used for construction comes from a small number of places, and is increasingly rare (and hotly contested).

To turn granular sand into a useful building material, it is generally combined with cement (usually a limestone product) to produce concrete. In addition to using up vast quantities of rare sand, this also produces a lot of carbon dioxide (although there’s various work-arounds in development); construction is a significant source of this greenhouse gas.

What if we took a completely different approach to turning sand into a construction material though? One that can use any sand, even the most common of desert sands. One that does not require concrete at all.

Continue reading

The Long Computer

How long can a computer last?

There’s a few extant working examples from the dawn of the computer age, say the 1940s. And while not currently very old, there’s a working model of (part of) Babbage’s difference engine (a mechanical computer) that looks like it could last a while (but also looks pretty hard to fix if something breaks).

The Antikythera Mechanism is in rough shape, but a modern copy, made out of tougher materials, could probably last a while – but it isn’t a general purpose computer either.

The desktop or laptop computer (or phone) that you’re using probably won’t last ten years (15 or 20 if you’re lucky). Good luck replacing old motherboards (or even memory chips). Even better luck replacing that old pre-IDE non-standard hard drive controller.

Continue reading

Some Thoughts About Libra

In case you haven’t heard, Facebook is launching a “cryptocurrency”.

There’s quite a bit of hype, and an equal amount of criticism (particularly vis-a-vis Facebook’s poor reputation for privacy). It isn’t quite clear to me though whether anyone has actually read the technical documentation.

There is a white paper here, and some technical documentation here. Probably worth a read in both cases. It’s really important to note though (discussed elsewhere on the web, but not here) that they’re actually really early in the development game. It isn’t clear whether any actual code has been written yet. Editorial correction: there’s a bit of code here. It’s very early in the dev process, and only a few commits have been made so far.

The first thing that drew my attention was a tweet that was linked from another article. Key phrase “Blockchain without proof of work or value volatility“. Now, there’s a lot of different kinds of blockchains out there, but that still sounds a bit odd. I also saw the word “smart contract” mentioned all over the place, but there’s absolutely nothing in the technical documentation about those at all – and those are difficult, difficult things to implement properly.

Continue reading

Fixing Call Spoofing

The past few years I’ve received fewer spam phone calls on my cellphone than in the past, but I’ve noticed an uptick recently. It’s an irritant for me, but a severe problem for others – most of those calls are scams rather than ads, and vulnerable people do fall for them. Do Not Call registries only help to a certain extent, particularly as it is hard to enforce illicit calls when the call is done via VOIP and is coming from another country.

A potential solution to this could look something like SSL for websites. SSL (secure socket layers) is used when you access a website via “https” rather than “http”. Most modern browsers show an indicator next to the url that lets you know whether or not the website is “secure” (at least in the sense that there’s some verification of who owns the site, as well as an encrypted connection between your browser and the web server that is difficult for a third party to read).

Continue reading

A Space Elevator Would Make an Excellent Radiator

The Earth is getting hotter.

I don’t feel like having a heated (pun intended) argument over anthropomorphic climate change, so let’s just say for the sake of argument that in thirty year’s time a super-intelligent AI pops its metaphorical head out of a lab in Silicon Valley and turns the entire planet into a layered shell of computational material. Or that the price of Bitcoin goes to the moon, and humans do pretty much the same thing to our poor planet all on our own. Whatever: all of these things radiate a vast amount of heat, and the world will get hotter (especially if there’s a few extra gigatons of CO2 involved).

What do people usually do with things that generate a lot of heat? Well here’s an example, from a computer:

Harumphy at the English Wikipedia [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/)]
Continue reading

Bitcoin and Volatility

The following is, I suspect, an important point, and one that I haven’t heard anyone make so far.

Bitcoin is currently (and this changes regularly, so will be out of date shortly after this is written) hovering around the $10,000 mark, with a total market cap of around $170 billion.

The volatility of Bitcoin – both daily and intra-day – has not decreased as the price has increased. There are still 10%+ intraday moves, and 3 – 5% daily moves aren’t uncommon at all.

Let’s assume that the BTC bulls are correct, and the price goes to a million dollars in a couple of years (or “to the moon”, in BTC parlance). That implies a total market cap in the region of $10 trillion, which would be a size-able piece of the entire world economy (by comparison, global GDP is somewhere north of $100 trillion).

Let’s also assume, barring changes that nobody is even talking about yet, that BTC remains highly volatile, even at that stratospheric price. I’ve heard people claim over the years that eventually things will settle down, but I’ve seen no evidence of this so far.

What does that do economically? What’s the ramification of a large percentage of the economy having dramatic volatility of this nature?

The major global currencies seldom move more than a percentage point or two on any given day. The rapid appreciation of the Swiss Franc in 2015 caused serious problems in a number of countries, and required various countries to backstop their mortgage industries (some people had hedged by taking out mortgages in Francs, instead of their local currency or Euros). That was a one-time event though, and primarily limited to Europe. What would happen if this sort of move (in both directions, with little advance warning) occurred several times per month, on a much larger basis, and on a global scale?

None of this is insurmountable (although precisely how one might go about tamping down the vol of a distributed blockchain is beyond me), but people need to start thinking about this before it causes economic havoc. Because it absolutely will.

 

How to Deal with Melting Glaciers

Flickr Creative Commons – Copyright Sangudo

This one’s an exercise in scalability.

If glaciers in Antarctica and Greenland continue melting at current rates, the world is looking at a sea-level rise that will put many major cities below sea level. See here for some of the possible scenarios.

Reducing (or even removing) greenhouse gases from the atmosphere may mitigate the damage, but even so we’re looking at serious consequences over the next century, paid out in blood and treasure.

There might be something we can actually do about all that extra water though.

Mental image: Picture industrial scale desalination plants, located at the coast of Antarctica, gulping in vast quantities of sea water. Vast pipes would carry the resulting purified water deep inland, to where (even in worst case scenarios) it would still be cold enough to remain frozen. Artificial snow machines, on an enormous scale, would turn the water into snow, and deposit it into brand new glaciers, locking it away.

 

Power Laws and The Great Filter

The economist, Robin Hanson, proposed a solution to the Fermi Paradox about 20 years ago. Commonly referred to as the Great Filter, Hanson theorized a set of potential barriers to intelligent life in the universe, with the implication that at passing through at least one of the steps must be improbable, the result being that technological species are rare.

I recently read an essay by Neil deGrasse Tyson that quoted an estimate: that in the history of life on Earth, there have been around ten billion species. I’ve looked for a source for this; the estimates that I’ve found range over several orders of magnitude, but ten billion is a nice round number, and it works for the sake of the argument that I want to make (feel free to substitute your own number instead). Continue reading

The Great AI Altercation

There’s an ongoing argument in the tech community regarding whether advancements in AI are likely to be beneficial or harmful to humanity. Although they’ve previously staked out positions on the matter, in the past few days this has boiled over into a public spat between Mark Zuckerberg and Elon Musk.

While some commentators have said that this is simply a matter of the two protecting their personal brands, I don’t believe their argument is a conscious matter of marketing, and I don’t think it’s a fair evaluation of either of their points. Rather, I suspect that they’re simply looking at two sides of the same coin, through the filter of their personal experience.

From where Zuckerberg is sitting, AI is already used to make Facebook work better: to better match up content to users, to better allocate data centre resources. Every new technological advancement leads to him hiring more recent PhD graduates, better service, more efficient use of resources.  He has also made a valid point with regards to self-driving cars saving lives (an aspect of the discussion where it is likely that he and Musk agree).

From where Musk is sitting, AI is likely going to take over vast additional areas of manufacturing, ultimately finishing off the process that automation and off-shoring started. He may personally gain in the short-term from the reduced costs of building product, but he knows he also has to sell to somebody – and if that person doesn’t have a job, they’re likely not going to be buying a luxury car (or a trip to Mars, for that matter).

The take-away will be no surprise to most readers: AI is disruptive. It will (and is already) benefiting some people, while causing obvious (hopefully, but not necessarily, short-term) harm others. It is impossible to determine right now whether there will be a net benefit on the far side of whatever societal disruption occurs. Opinion of public figures with regards to AI likely rests on whether they will personally benefit (whether they realize this consciously or not), and it is probably worthwhile to interpret their remarks that way.

Bitcoin Fork: A modest proposal

There’s a lot of talk in the Bitcoin community about the possibility of a hard fork in the blockchain at some point.

The underlying issue has to do with the size limit of transaction blocks, which result in limits to the time it takes to process a Bitcoin transaction. There’s a good article on the philosophy of the two sides on QZ (link), which is worth reading if you need a primer.

Essentially, one side wants to double the size of a block from 1mb to 2mb, and the other side wants blocks to be unlimited in size. Both options have drawbacks (both technical and philosophical) that I won’t get into here.

I’d like to propose a compromise between the two options. Continue reading