Catch up on stories from the past week (and beyond) at the Slashdot story archive

 



Forgot your password?
typodupeerror

Slashdot videos: Now with more Slashdot!

  • View

  • Discuss

  • Share

We've improved Slashdot's video section; now you can view our video interviews, product close-ups and site visits with all the usual Slashdot options to comment, share, etc. No more walled garden! It's a work in progress -- we hope you'll check it out (Learn more about the recent updates).

×

Comment: Re:Not actually batteryless (Score 1) 109

by david.given (#49166525) Attached to: Ultra-Low Power Radio Transceiver Enables Truly Wireless Earbuds

I totally didn't know that! That's awesome!

Here's one I found with four components: http://solomonsmusic.net/FM_Cr...

I am curious how that tiny antenna can produce enough energy to drive even a crystal earpiece. Most crystal radios need huge antennae, don't they? And from the writeup it looks like the FM decoding more or less happens by accident as a side effect of signal interference.

If this really works, I reckon it should be possible to build a miniaturised FM crystal set into a pair of headphones. I wonder if you could do stereo?

Comment: Not actually batteryless (Score 4, Informative) 109

by david.given (#49159993) Attached to: Ultra-Low Power Radio Transceiver Enables Truly Wireless Earbuds

Apparently it uses 1.5mW at 1V.

You can get batteryless radios. Crystal radios (which don't necessarily contain a crystal) get all their power from the radio signal, and they're scarily simple. During the second world war foxhole radios were built out of a razor blade, a pencil, some wire and a set of headphones (instructions: http://www.bizarrelabs.com/fox...) Prisoner of war radios used coal

AFAIK, however, the much lower energy VHF signals for FM isn't capable of running an FM decoder, and probably not an earpiece either.

I wonder if a modern crystal earpiece could usefully pick up low-power AM transmissions from a cellphone in your pocket without spamming everyone around you with radio waves?

Comment: Re:Now they just need intensity from the actors. (Score 1) 165

by david.given (#49058695) Attached to: Star Trek Continues Meets Kickstarter Goal, Aims For Stretch Goals
The compositing of effects onto live action was laughable --- you could tell when a scene was going to have CGI in it because it would suddenly go fuzzy as they dropped the resolution.

And at least in the first season, the choreography of the space sequences was incredibly stilted (Starfury moves onto screen right-to-left. Starfury comes to a halt in the middle of the screen. Starfury does a 180 degree turn and stops. Starfury fires cannon. Staryfury does another 180 degree turn. Starfury exits screen right-to-left). But that was because they simply didn't know to use technology properly, as CGI was brand new and they were basically making it up as they went along; they learned on the job and later seasons were pretty good.

...I wonder what happened to all their digital assets?

Comment: Re:Biased Institutions FTW (Score 1) 784

by david.given (#48837849) Attached to: Parents Investigated For Neglect For Letting Kids Walk Home Alone

I just moved to Zürich from the United Kingdom. It's absolutely true --- kids will just randomly wander around on their own. Here, it would be considered weird for a six-year-old child not to go to school on their own, particularly if it were only a mile away.

One of the things that helps, I think, is that the culture here allows random adults to talk to random children. (Or, more accurately, the other way round, frequently incessantly, in Swiss German, which I don't speak.) If one gets lost, which is very unlikely given the amazing public transport system, they can just ask. This is very weird to someone from the UK, where it's pretty dangerous to even make eye contact with someone's child...

Comment: Re:Deja Vu (Score 1) 151

A rocket ought to be fairly resistant to bad weather --- they have many more times the control authority that an aeroplane has, due to sodding huge engines, and will be above it very quickly. They already have to deal with very strong winds blowing them sideways as they pass through the jetstream (at 100km/h plus), and they don't have air intakes to suck in rain.

Does anyone know whether the Falcon 9 can't take off in bad weather, or whether they won't do a launch in bad weather because they'll lose visual contact with the vehicle, which is critical for monitoring the performance of what is fundamentally a prototype?

Comment: Debian kFreeBSD (Score 2) 267

by david.given (#48429241) Attached to: Ask Slashdot: Workaday Software For BSD On the Desktop?

...is a Debian userland on top of the BSD kernel. It lets you use all the tools you're used to while also getting all the FreeBSD kernel goodness, like in-kernel ZFS, etc.

It's still a work in progress and not all packages are built for it, but it works really well and is very pleasant to use; plus you get dpkg and apt.

Of course, one possible downside is that you don't get the BSD userland, which has a flavour all of its own. Whether you think this is a good thing or a bad thing is purely a matter of personal taste.

Comment: Re:Mediocre? How about godawful? Terrible? (Score 1) 193

by david.given (#48120183) Attached to: A Critical Look At Walter "Scorpion" O'Brien

For me it was Nicholas Montserrat's The Cruel Sea. A brilliant, brilliant book, but it was clearly written as therapy after a hellish time on the WW2 North Sea convoys, and by god it shows.

Peter Grant books: awesome, waiting for Foxglove Summer to show up. The Expanse: pretty awesome, although the authors have definitely been reading their Neal Asher; who these days pretty much defines the cheerful big-things-exploding-in-space genre.

Never heard of Scorpion. Never heard of the guy in the article. Sounds like I haven't missed much. And if you'll excuse me, I need to get on with Ancillary Sword...

Comment: Re:Disabled (Score 4, Informative) 427

Android devices have a read-write partition and a read-only partition. Out-of-the-box apps go in the read-only partition. There are several reasons for this, one of which is safety --- you can nuke the entire read-write partition and be sure of (a) getting a working factory reset phone and (b) that all user data has been deleted.

If an app's in the read-only partition, then it obviously can't be removed. (Although you can install updates --- the new versions go in the read-write partition and override the read-only one.) All you can do is mark it disabled.

(Of course, if you've rooted your phone, you can remount the read-only partition as read-write and tinker with it to your heart's content. I do this to move updated apps into the read-only partition to save space in the read-write partition. But that only works on rooted phones.)

Comment: Re:BASIC vs. Z80 assembly language (Score 3, Informative) 167

by david.given (#48010685) Attached to: Why the Z-80's Data Pins Are Scrambled
If you're interested in Z80 operating systems, go look at CP/M (seriously: get an emulator, some tools, and write programs for it). It's a fascinating look into just how minimal you can make an operating system and still have something that's not just functional but which spawned, back in the day, a vast ecosystem of tools and software. You suddenly realise just how much fat there is in a modern system (and also why modern systems have all this fat).

Comment: Re:Slashdot Hate Machine (Score 2) 65

by david.given (#47959727) Attached to: New "Crescent Bay" VR Headset Revealed and Demo'd At Oculus Connect
I rather like the StackOverflow moderation system, where it costs _you_ karma to downvote someone else.

In general, I don't think Slashdot's moderation system is effective at promoting interesting discussion. I think the bulk of the problems are the moderation cap at 5, which means there's a very limited dynamic range of interestingness; and there's no visible karma score, which means there's no point in taking the long view --- StackOverflow's system of gamifying karma so that people deliberately try to post good stuff so as to improve their score is total genius.

Plus, of course, the now-ingrained culture of ultra conservatism and whiny hate which permeates the comments section, but that's largely an artifact of the above. Sheesh, even Youtube comments can be better.

I, too, miss the old Slashdot. [sad face]

Breadth-first search is the bulldozer of science. -- Randy Goebel

Working...