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Comment Re:Passed data with a ton of noise? (Score 1) 338 338

The question is: is the signal-to-noise ratio good enough? If so a cheap cable that passes the data is every bit as good as an expensive one, so long as the packets arrive intact at the other end.

Ethernet already does a lot to counter noise. The signals are differential pairs (so instead of having ground and signal, you have signal+ and signal-). The wire pairs are twisted, which keeps them in close proximity. Interference tends to be common mode noise (so for two wires close together it will affect the signal in each wire almost the same), and differential amplifiers are designed to only amplify the difference between the two wires and will therefore reject common mode noise. Each end also has an isolating transformer, and each end has proper termination (to avoid things like reflections which can bugger up signal integrity). It takes a significantly terrible out-of-spec twisted pair cable to make ethernet stop working.

Incidentally, the signalling for 100baseTX ethernet only has a fundamental frequency of 31.25MHz (naively people would expect 1MHz per 1Mbps but this is not so). 100baseTX uses a 3 level (in other words +1, 0, -1) non return to zero signalling (in other words, a 1 will cause the signal to change level and a 0 will cause the signal to remain at the current level - or it might be the other way around, it's a long time since I did this stuff). Each 4 bits is encoded into a 5 bit symbol designed to prevent long runs of 0s (which would cause the signal level to remain constant for too long). Lots of people call an ethernet connection a "broadband" connection, but it's not, it's baseband (hence the "base" in 100baseTX).

Comment Re: Caps Lock used to power a huge lever. (Score 1) 683 683

I'd have to question that (not that she has to do it or the reasons she was told, but the supposed reality that elders can't read normal text as well as caps). One of the pieces of research that was done here in the 1950s resulted in motorway road signs in the UK being in mixed case rather than all caps - it caused howls of anguish from old-timers resistant to change - but the thing is words with lower case text have more of a shape - for instance "Manchester" can be resolved as the word "Manchester" much faster than "MANCHESTER" - it was found you could read the mixed case before you could even resolve all the letters because you could recognise the shape of the word, given that lower case text has more features like ascenders and descenders. Hence all UK road signs ever since have been in mixed case.

Comment Re:Third Dimension (Score 5, Interesting) 1170 1170

Drones are subject to the same rules that RC aircraft are subject to.

It is however extremely hard to enforce. RC users are generally pretty responsible - they've probably spent many hours building their aircraft, and during this time it has sunk in the dangers they can pose, and usually they've joined a local club to help them learn to fly their new expensive aircraft and the club will also coach them on safely operating their aircraft.

Drone users not so much. Many of the ready-to-fly drones require pretty much zero skill to operate, so people can take off and cause mischief pretty much straight away.

Comment Re:I never would have thought of that! (Score 1) 216 216

I would have thought the answer to that is obvious: most guns with folding stocks are a lot easier to conceal, and someone wanting to do something bad with a rifle would want to take one that they can conceal en-route. An old Lee-Enfield 303 with a wooden stock isn't so easy for the school shooter to conceal on his way to committing the crime.

Comment Custom allocator (Score 3, Insightful) 58 58

This sounds awfully familiar...OpenSSL had a critical vulnerability because they had decided to write a custom allocator instead of using the one provided by the OS. You would think IE developers, with their product being WIndows-only and strongly tied to Windows would never dream of reinventing the allocation wheel, especially as Windows memory management in general has had a huge amount of work done on it in the last few years to make it harder to exploit memory allocation bugs.

Comment It really depends (Score 1) 654 654

It really depends on where you live.

I would say 'no' where I live now. Although there is a bus stop almost outside my house, it takes three times as long to get to work by bus than it does to drive - my drive being around about 20 minutes, and the bus journey (plus walk at the end) being an hour. I can actually beat the bus journey on my bicycle, and it's 12.5 miles (hilly miles, too). The bus not only goes "around the houses" taking a route much longer and slower than my direct route, it stops all the time, and it only goes within a mile of my workplace. It would be 1.2 hours every day longer on the daily route to work.

On the other hand if I lived in a big city such as Madrid I wouldn't even bother owning a car, regardless of whether public transport was free or not. The car becomes more of a liability than an asset once you live in a densely populated city.

Comment Re:Tax dollars at work. (Score 1) 674 674

We likely don't know the full story here. I suspect it could have gone like this:

* Someone has their phone plugged into a socket labeled 'Not for public use'.
* PCSO notices, says "SIr, can you unplug your phone, that socket isn't for public use".
* Man gets belligerent and argues with the PCSO and refuses to unplug.

Comment Concorde (Score 4, Informative) 238 238

No mention of Concorde in the summary, which could do this at over Mach 2?

How have the economics changed that this will be viable where Concorde wasn't? IIRC, British Airways only managed to fly it profitably because they got the aircraft for £1 each. Concorde's engines were thermodynamically very efficient when in supercruise, and the aircraft burned as much fuel as a B747 while hauling only about 1/4 to 1/3rd of the passengers. I don't think there's much that can be done to get the fuel burn down per passenger seat, and due to the nature of supersonic flight it's always going to be more of a maintenance nightmare than a subsonic airliner.

Comment Re:Paranoia (Score 1) 431 431

When I was at school (tr:US high school) we had a 2 litre coke bottle three quarters full of the stuff. Just sitting there in our study room...

We had bought the iodine at one chemists shop, then gone to another to get the ammonia (buying both in the same shop seemed like a bad idea to us) and then made it by the litre. I dread to think what it would have done if it had dried out.

Comment Re:No local intelligence (Score 1) 431 431

You also have to mix the methane with the right amount of oxygen (so you'll end up with much more than 1cu.ft gas to make an explosive mixture). The other consideration is delta-t: how quickly does the stick of dynamite's reaction complete, compared to the equivalent energy of methane/oxygen mix?

1000 pains = 1 Megahertz