The difference of course is with fiat currency the government/central bank can "print"* money on demand and lend it to the commercial banks so they can cover their customers withdrawals.

With BTC denominated accounts if everyone tries to withdraw their BTC at once the bank has a big problem. They can try to buy BTC to cover the withdrawals but there is no guarantee they will actually be able to.

* It starts out as entries in the central banks database but if the customers are demanding their money in cash then that cash will have to be physically printed and sent to the banks.

bitcoins reside in "unspent outputs" in the blockchain. The unspent outputs are associated with an "address". An "address" is a cryptographic hash of a public key and the holder of the corresponding private key can spend the bitcoins.

A wallet is basically a collection of private keys for addresses (or sometimes just a generator seed for said keys). To an outside observer it is not visible whether two addresses are part of the same wallet or not. The only thing that distinguishes between a customer withdrawl and a move to cold storage is the internal records of the exchange. If the echange isn't keeping proper records it is unlikely to be feasible to distinguish thefts from legimitate withdrawls (and even if the exchange is keeping records do you trust those records to be honest?)

And yes if the private key for an address is lost (or someone sends bitcoins to an address that wasn't obtained by hashing a public key) the coins are gone for good. Bitcoin propoonents maintain this is not a significant issue.because of the divisibility of bitcoins, I have some reservations about that.

I would guess a software bug that wrote inappropriate values to the DAC (possiblly straight binary vs 2's complement confusion) combined with an idiot hardware designer DC coupling the audio path.

No.

QR codes encode arbitary text (in one of several character sets). There is no central registry of what that text means so QR codes in general can't "run out". The ammount of text that can be encoded depends on the size (in "modules") of the QR code, the character set and the desired error correction level.

QR codes used for taking people to websites generally encode URLs. Even a quite long URL can be encoded in a reasonable size QR code though shorter URLs are certainly preferable for more reliable scanning due to stronger error correction and/or larger "modules".

Not entirely true. the real speed of actual data devliery depends on many factors including

1: the speed of your client hardware and software
2: the speed of your local network
3: the speed of your customer premisis equipment
4: any congestion/shaping/prioritisation on your ISPs network
5: any congestion between your ISP and the server host.
6: any congestion on the server hosts network
7: the speed/congestion of the servers connection to it's hosts network
8: the ability of the server itself to keep up
9: TCP issues. Older TCP stacks had a limited window size which limited the bandwidth at a given latency. Even modern stacks have "slow start" which means it will take a while to get up to the full bandwidth on a "long fat network".

Some of these factors are under your ISPs control, many are not.

Afaict speedtest measures about the best case, it uses a nearby fast test server and it waits for the speed to stabalise to allow for TCP slow start.

I couldn't get numion to work so I can't comment on that.

Brish student loans are paid off at a rate based on your income, they are also automatically written off after a set period (the exact set period has varied, for new english and welsh* student loans now it's 30 years, prior to that it was 25 years and prior to that it was at state retirement age). In recent years both tuition fees and loan interest rates have risen sharply while the set period before the loan is written off has been shortened. Claims from different bodies as to what proportion of students will be able to replay their loans vary.

Personally this seems to some extent like an accounting trick to make the current government budget look better at the expense of running up liabilities for future governments to deal with. Rather than subsidising the university education upfront or subsidising the interest on the loans year by year they are kicking the can down the road so some future government will have to pay the cost of writing off those debts.

* Rules in scotland and northern ireland are different.

Or it could mean that in each case she was good but not quite good enough to beat the competition.

Noone knows, we only have records of the criminals who were stupid/unlucky enough to get caught. This is especially true for crimes where it is not obvious to the victim that a crime has been committed at all.

However if you cheat on your partner you risk a devorce. If you are the richer partner in the marriage that can lead to much larger losses of wealth than the relatively small tax advantages.

AIUI many greeks are withdrawing as much cash as the banks/government will let them. They know that their bank balances are at risk of a forced conversion to a new currency (and subsequent devaluation) while it's much harder to make such a forced conversion on banknotes held by individuals.

Note: the below is a UK perspective, some of it may also apply elsewhere but details are likely to vary.

Cards can be used offline and even without electricity but the fraud/overspend risk is higher and this can lead to restrictions on use or even the merchant to refuse to accept them altogether.

AIUI for chip and pin the card issuer sets a limit (which can be zero if the card issuer thinks you are a poor credit risk) for offline transactions to mitigate fraud/overspend risk and they don't usually tell you what said limit is in advance. For imprint and magstripe transactions I belive it's down to the merchant (and possiblly their bank) what transactions they are willing to risk taking offline.

If you have already eaten the meal/filled your fuel tank/got on the train then the retailers choice may come down to taking the card offline (and possiblly reverting to magstripe to get around the offline restrictions on chip and pin, I've seen that happen on a train before) or taking an IOU. The card is a lower risk than the IOU.

On the other hand a normal retailer is in a very different situation. If they decide they don't want to take cards offline and/or in a power cut either because they think the risk is too high, or for power cut scenarios because they don't want to bother stocking card imprinters and training their staff how to use them then you are SOL.

Also IIRC in the UK automated vending machines are restricted to online chip and pin transactions only. They are not allowed to do swipe and sign transactions or offline transactions.

So don't rely on your credit/debit card working in an offline/power cut scenario.

Do you have a source for your claim, because it contradicts everything I've read elsewhere.

My understanding is that Nokia sold their whole handset buisness to MS, not just the smartphones. Said sale came with limited rights for MS to use the Nokia brand and certain non-compete terms preventing nokia selling phones under their own name. Right now MS has migrated the lumia smartphones away from the nokia brand but is still selling feature-phones under the nokia brand. In the not too distant future the branding part of the deal will expire, MS will no longer be able to sell phones under the nokia name and nokia will be able to sell phones (smart or otherwise) under their own name again.

Fast long distance trains on major routes in the UK usually have sockets near some or all of the seats labeled "laptops and mobile phones only" or similar intended for passenger use. Local trains and slow trains generally do not have them. These are a relatively recent thing, first appearing on new trains in the early 2000s.

Many UK trains have sockets located at the back of the luggage racks or similar labeled with "not for public use" signs and sometimes other warnings . My understanding is that these sockets are intended for use by the cleaners, may not nessacerally meet the voltage/frequency norms for domestic power and even if they did I doubt train operators would want to encourage people to charge phones and laptops there. These have been arround a LOT longer than the sockets intended for passenger use.

Still an arrest seems OTT unless there were aggravating factors.

I think it's a solvable problem.

As long as the manufacturer has a sufficient income stream and a way of making sure that cars with known flaws are fixed there is no reason they couldn't cover the liability for all their cars and they of course have the option of taking out an insurance policy against that eventuality. The key will be ensuring that revenue stream. The nightmare situation for a manufacturer is being held responsible for a product they no longer make any income from or have any control over.

For this reason I imagine when self-driving cars first hit the market it will be on an "all-in lease" basis where the manufacturer remains in control and can therefore respond effectively to dangerous flaws before they run up too much liability. I would expect sales of self-driving cars to require some legislative moves to define the extent of the manufacturer's liability.

Prototype planes are registered as "experimental aircraft". That means that the authorities have looked at it and decided it's safe enough for a test pilot to fly it. Proper type approval comes later when the manufacturer has gathered enough evidence by (among other things) actually flying the plane.

In the USA home built aircraft are also registered as experimental aircraft (despite not being truely "experimental" in most cases) and get much the same level of scrutiny. Other countries may have different rules on homebuilts.

As for which airports it's going to depend on the type of plane. Big planes are going to be built and tested somewhere there is a big runway. Big runways are expensive and politically difficult to built so those facilities are likely to be built next to an existing one which may also form part of a fairly major airport. Airbus do their assembly and testing at tolouse international airporpot. Boeings main manufacturing facilities seem to be attatched to non-international but still reasonablly large airports. Smaller planes are obviously built and tested at smaller airports

Much as the only way you really find out how a plane copes with flying and get the snags out of the design is to perform test flights the only way you really find out how well a self driving car (or a human driver for that matter) handles real road conditions and what situations it has trouble handling is to test it on real roads. Simulations and lab tests are important but they are not a substitute for real world testing. Having experianced humans arround during that real world testing to intervene is also a good idea (again for both human drivers and manchine drivers).