Beta

Slashdot: News for Nerds

×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

Comments

top

Damian Conway On Perl 6 and the Philosophy of Programming

multi io Re:Fourteen years? (132 comments)

Come on! In fourteen years you can develop your OS from scratch. Bearing in mind that Perl is noting more than a scripting language, what the hell have they been doing?

If I had to make a totally uninformed guess, I'd say they probably read and learnt so much about languages, interpreters and compilers and stuff that they're now totally insecure as to how to proceed.

about three weeks ago
top

Germany's Glut of Electricity Causing Prices To Plummet

multi io Re:Another misconception bites the dust (365 comments)

I don't think anybody can give you am exact date on when coal power will be phased out

Yeah, because nobody knows how you could run the grid without them. You certainly can't run it just on solar+wind+some measly storage capacities on the same scale as today's. If Germany were to run on solar+wind plants alone all the time, they'd need the ability to store one or two weeks of electricity consumption, which amounts to 10..20 TWh -- that's at least 200 (two hundred) times as much capacity as is installed nationwide today. Which means you'd need totally different storage technologies, some of which you may have to invent first. Nobody is sure how (and whether) this might work.

but the energy transition effort enjoys fairly broad support among the German public

Which doesn't change the physics. And, what actually "enjoys broad support" is getting rid of all the nuke plants. So the only date that was fixed early on in this whole effort is the day when the last nuke plant would be shut off. Because not doing that would've cost Merkel her reelection. Everything else isn't nearly as important.

about three weeks ago
top

Ask Slashdot: Communication With Locked-in Syndrome Patient?

multi io Re:As painful as it is... (552 comments)

If she can't tell you she doesn't want it unplugged then it isn't.

She is fully conscious, so she can tell him. "Telling" doesn't require verbal communication ability.

about a month ago
top

Ask Slashdot: Communication With Locked-in Syndrome Patient?

multi io Brain-Computer Interfaces (552 comments)

It's not a direct help, but I can tell you that it's certainly possible these days to communicate and control external actuators using brain activity only. What they're doing (AFAIK) is record the 2D electrical activity on the brain's surface (using EEGs on the scalp or -- for even greater accuracy -- below the skull bone), analyze it statistically and deduce what the person is thinking of doing, e.g. move a mouse pointer in some direction and choose which of several buttons to press. It requires a learning phase, but then the accuracy is quite high. I'm not sure about the actual bandwidth that you can achieve when communicating using this method only, but it's much better than what was possible only a few years ago, and it's improving further.

Brain-Computer Interface-The HCI communication channel for discovery

brain-controlled Pinball

(the links refer to a Berlin-based research group -- but that's just a coincidence because I live there a saw a presentation a few weeks ago. I'm sure there's even more research on the subject in the US).

about 2 months ago
top

Wayland 1.5 Released

multi io Re:Wayland is nothing until (179 comments)

It seems the real remote drawing / display technology these days is HTML/CSS, carried via HTTP. It even supports running client-provided code locally on the display server, as did NeWS and DPS 20 years ago, to render animations and depressed beveled buttons without incurring a server roundtrip (and Javascript is generally much nicer than PostScript -- you can even run the whole program on the display server if you want). And the protocol is a bit backwards in that the display server (aka "web browser"), rather than the client (aka "web server"), initiates the protocol requests.

[scnr]

about 2 months ago
top

Fusion Power By 2020? Researchers Say Yes and Turn To Crowdfunding.

multi io Re:I'd not trust the authors too much. (280 comments)

Tokamak power plants would use the energy of the 14MeV neutron produced by the DT fusion reaction to heat water to steam and generate it directly. `Moving charged particles' is just a plasma

Uh, a plasma contains charged particles, but is neutral overall (normally). And the particle motion is undirected. What they claim to get out it is a pulsed, directed beam of multi-MeV 4He ions (and only those -- the electrons fly away in the opposite direction), which could be converted into electricity directly (via induction).

about 2 months ago
top

Mathematical Model Suggests That Human Consciousness Is Noncomputable

multi io No it isn't (426 comments)

I hardly understand a goddamn word of TFA and have never heard of the "Integrated information theory", but I know that TFA's proposition must be false because the brain is based on the laws of physics, which are computable. Q.e.d.

about 2 months ago
top

Experts Say Hitching a Ride In an Airliner's Wheel Well Is Not a Good Idea

multi io Re:Survival rate under-estimated? (239 comments)

Yeah, at least until they hit the water at 700km/h...

Eh, terminal velocity in the lower atmosphere is abound 250 km/h. Not that it would make much of a difference though.

about 3 months ago
top

The Design Flaw That Almost Wiped Out an NYC Skyscraper

multi io Re:Math (183 comments)

You're trying to make stuff up. The probablity not being 0.5 stems from the fact that there will be some years in which more than one storm occurs, and this must be "balanced out" by there being no storm at all in more than 50% of the years (and thus, a probability < 0.5 of a storm occuring in a particular year). If storms don't happen independently, but come in "packs" as you suggest, and you're still holding up your scenario of one storm every two years on average, then the chance of a storm occuring in a particular year will be even lower than 0.393.

about 3 months ago
top

The Design Flaw That Almost Wiped Out an NYC Skyscraper

multi io Re:Math (183 comments)

what? where the hell did you pull that from? why 1/e?

if a storm hit every two years, your method would give a probability of 0.393.

Right.

what sense does that make?

Imagine you're throwing a 100-sided dice 100 times in two years (i.e. 50 times a year). Then you statistically throw a particular number (say, 1) once every two years. The chance of throwing that number in one year (i.e. in 50 throws) is 1-(99/100)^50=0.395 (=the inverse of not throwing that number 50 times in a row). There you go. If you transition from discrete to continuous probabilities, the number of dice sides and throws approaches infinity, and lim_{x->infinity} (1-1/x)^x = 1/E.

about 3 months ago
top

The Design Flaw That Almost Wiped Out an NYC Skyscraper

multi io Math (183 comments)

LeMessurier calculated that a storm powerful enough to take out the building hit New York every 16 years." In other words, for every year Citicorp Center was standing, there was about a 1-in-16 chance that it would collapse."

Umm, actually that would be p=1-(1/E)^(1/16)=0.0605869 (about 1-in-16.5052).

about 3 months ago
top

Heartbleed Coder: Bug In OpenSSL Was an Honest Mistake

multi io Re:Not malicious but not honest? (447 comments)

Why does the heartbeat request even contain the length of the heartbeat block?

The real question is, why even have the whole heartbeat TLS RFC in the first place, when the underlying TCP layer already checks for timeouts all by itself (you can run TLS over UDP, but hardly anybody does, and then you'd specify the heartbeat stuff only for that use case).

about 3 months ago
top

UN Report Reveals Odds of Being Murdered Country By Country

multi io Re:I've made a decision (386 comments)

In order to live as long as possible, I have decided to have gender reassignment surgery to become a woman, and I will move to Antarctica and start a utopian lesbian society, since there are no murders there. I haven't worked out the details yet, but it seems like a no-brainer.

You could start with killing somebody else -- the odds of *two* murders occuring would be even lower!

about 3 months ago
top

Stephen Colbert To Be Letterman's Successor

multi io Genuine? (193 comments)

"Simply being a guest on David Letterman’s show has been a highlight of my career"

Wait...he really meant that. It's kinda creepy when Colbert makes out-of-character statements. And now there's gonna be a whole show full of those? Ugh...

about 3 months ago
top

OpenSSL Bug Allows Attackers To Read Memory In 64k Chunks

multi io Re:ASLR anyone? hype? (303 comments)

Unless the mmap/malloc combo on the O/S you're using was able to purposely put guard pages after mmaped blocks so many malloced objects would end in such guard pages. Unfortunately...

Apparently OpenSSL uses its own allocator on top of the libc's (malloc). I.e. it only occasionally allocates a large chunk of memory from the C heap and then does its own allocations/reallocations in that (without anything like ASLR or guard pages of course). And apparently the particular sequence in which the OpenSSL library code allocates bits of memory using this allocator leads to a situation where the private key is always deterministically located behind the heartbeat packet space in memory. AFAICT this is why this bug is so remarkably portable and "works" reliably on all platforms.

about 3 months ago
top

Navy Creates Fuel From Seawater

multi io Re:Reading between the lines (256 comments)

By the time you're going to all of this trouble to turn electricity into fuel, it is unlikely that you'd want to run a car on it - you'd rather just have an electric car.

Not sure about that. Electrical energy can't be stored easily -- you need some high-tech battery with all kinds of electrolytes and complicated chemicals, and still the capacity is relatively measly. Electricity works much better if it can be consumed right after it is produced, without storing it (but if this can be achieved, electricity is otherwise very flexible -- it can be scaled up and down easily, and it can be transported quickly over long distances). HC fuels OTOH work well for storing energy -- they already store it, you just have to pour them into any airtight vessel, and they'll stay there until you burn them. So electricity and HC fuels might compliment each other quite well if the right technologies are in place. Any process that can convert electricity into fuel (and also happens to consume and thus neutralize the byproduts of burning the fuel) should be almost like a gold mine, if it can be scaled up sufficiently. So if this water-to-fuel conversion or similar processes can be made to work efficiently, chances are liquid fuels will continue to be the preferred method for large-scale mobile energy consumption needs.

about 3 months ago
top

Engine Data Reveals That Flight 370 Flew On For Hours After It "Disappeared"

multi io Re:Turns out, no. (382 comments)

Authorities quickly debunked this story this AM.

Denied, not debunked. Big difference.

about 4 months ago
top

Sulfur Polymers Could Enable Long-Lasting, High-Capacity Batteries

multi io 1,225 mAh (131 comments)

Batteries using this copolymer had an initial storage capacity of 1,225 mAh per gram of material.

At what voltage? mA*h isn't a unit of energy. V*mA*h is.

about 5 months ago

Submissions

multi io hasn't submitted any stories.

Journals

multi io has no journal entries.

Slashdot Account

Need an Account?

Forgot your password?

Don't worry, we never post anything without your permission.

Submission Text Formatting Tips

We support a small subset of HTML, namely these tags:

  • b
  • i
  • p
  • br
  • a
  • ol
  • ul
  • li
  • dl
  • dt
  • dd
  • em
  • strong
  • tt
  • blockquote
  • div
  • quote
  • ecode

"ecode" can be used for code snippets, for example:

<ecode>    while(1) { do_something(); } </ecode>
Create a Slashdot Account

Loading...