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

Ask Slashdot: Linux Login and Resource Management In a Computer Lab?

tibit Re:Responsability-linked quotas (67 comments)

I'd just run my own "cloud" instead, using, say KVM. With billing etc. like in the old times.

1 hour ago
top

MIT's Ted Postol Presents More Evidence On Iron Dome Failures

tibit Re:Let's talk about the article... (349 comments)

Alas, the article refers to the contrails that show mostly failed intercepts. So you have an Iron Dome engagement, as you claim, on an incoming that was determined to be a threat. It also demonstrates in terms of high school physics why such intercepts are bound to fail in the conditions listed. It's pretty much as simple as that. The king is naked, but a lot of adults have a problem acknowledging such simple truths.

On top of that, Israel-located commenters of the article seem to have a bit of a problem with discriminating successful and failed intercepts. That's because a lot of intercepts happen during the unpowered, ballistic part of the incoming's flight. Yes, the interceptor will explode, but that's immaterial. It will poke a couple holes in the expended motor case and will alter the incoming's trajectory a slight bit. Again, it's all very simple, and people somehow can't swallow the simplicity of the argument.

It's like Feynman's famous presentation of the root material cause of the Challenger disaster. All the while the bureaucratic machine of the Commission, and NASA, was expending untold resources skirting this material cause, and the root underlying organizational cause that then proceeded to kill the Columbia crew.

4 hours ago
top

Why My LG Optimus Cellphone Is Worse Than It's Supposed To Be

tibit Re:Don't buy cheap android (282 comments)

The way Bennet describes the particular phone, a $100 Tracfone ZTE sounds like a much better deal.

yesterday
top

Malaysian Passenger Plane Reportedly Shot Down Over Ukraine

tibit Re:Wait for it... (750 comments)

Interesting. One learns every day! Thanks.

4 days ago
top

Nearly 25 Years Ago, IBM Helped Save Macintosh

tibit Re:I remember the good old days of the motorola 68 (235 comments)

I'd certainly be possible to get a modern 68060 to run at 4GHz if it ran with the memory that was used for those systems back then. To run it that fast, you'd need all of the RAM to be on the die, and it'd need to be the static, cache-style, blazing fast RAM. A 68060 isn't really a 68060 anymore if you'd add three levels of cache to it.

4 days ago
top

Nearly 25 Years Ago, IBM Helped Save Macintosh

tibit Re:Pairing? (235 comments)

Algorithms and data structures. They are equally important. With the memory being so slow compared to the CPU, sometimes you can get very good performance gains just by using proper data structures and layout - you'll see the difference even in Java.

4 days ago
top

Nearly 25 Years Ago, IBM Helped Save Macintosh

tibit Re:Pairing? (235 comments)

Anyone remember the band-based printing APIs? Still makes me shudder.

4 days ago
top

Nearly 25 Years Ago, IBM Helped Save Macintosh

tibit Re:Pairing? (235 comments)

Obviously, the oil exploration people didn't get your message back then. A lot of the oil and gas we extract now comes from fields that were found and pre-developed back then on Unix workstations running very expensive Motif-based applications.

4 days ago
top

Malaysian Passenger Plane Reportedly Shot Down Over Ukraine

tibit Re:Confused. (750 comments)

I'd say that the machine is only "complex" because there are some modern CPUs in the devices carried by the passengers. The aircraft itself, without the payload, is an order of magnitude simpler, at least, than a modern multicore Intel CPU. Seriously. Even if you count the complexity of the legacy CPUs on board in the avionics and such. What I basically claim is that if you add up all the discrete parts in such a plane, and add the transistors in all of the on-board electronics, it's probably still beaten by what's in a modern PC.

Most complex machines built and operated by man go on sale, repeatedly, at a local Walmart. That's the world we live in.

4 days ago
top

Malaysian Passenger Plane Reportedly Shot Down Over Ukraine

tibit Re:Wait for it... (750 comments)

It makes no sense for UA to shoot anything down, since the separatists have no air assets. I find the other explanation - UA shooting down a civil airliner just to setup the separatists or Russia - to be way too far-fetched.

5 days ago
top

Malaysian Passenger Plane Reportedly Shot Down Over Ukraine

tibit Re:Wait for it... (750 comments)

You can't see this? Come on, they fucking brag about it.

5 days ago
top

Mt. Fuji Volcano In 'Critical State' After Quakes

tibit Re:Solution! (151 comments)

When the Yellowstone caldera blows, then everyone will have a problem. You'll have temperate temperatures around the tropics, and subtropical temperatures on the equator. Glaciers will be covering the Alps and Rockies (yes, the whole thing). And so on. Central and Northern Europe will be uninhabitable, and so will be Canada and a lot of North America. And so forth.

about a week ago
top

SpaceX Falcon 9 Rocket Blasts Off From Florida

tibit Re:In defense of NASA (112 comments)

I don't think there's anything flimsy about the SpaceX design. Structurally, it is perhaps one of the best if not the best designed system in my opinion. The tanks are stir-welded and there's simply no better welding technique out there. It's all state-of-the-art as far as I'm concerned. I highly doubt, though, that any changes would need to be made to the material thickness away from the stress concentration points. The design, as far as I can tell from public documents, has some degree of tweakability. Since it's the first stage that is subject to reusal, initially, one doesn't have to worry about interstage and such. If there'll be problems, I'd expect them at tank penetration points; in the intertank structure, and in the engine sub-structure. One really has to fly a first stage back-and-fro a couple of times to see where the problems might be, though.

Remember that in real life, a lot of their costs are non-recurring, so there's no economical reason to make anything flimsy by cutting on material costs. They are cutting costs by integrating manufacturing of everything in-house, so that they don't have to sponsor profits of a hundred subcontractors. They also have very little corporate inertia at this point and must stay focused on their R&D and production, not in bloating up their bureaucracy. The legacy corporate structures are sometimes worse when it comes to wasting money than the governments that buy from them.

about a week ago
top

Study: People Would Rather Be Shocked Than Be Alone With Their Thoughts

tibit Re:Wow... Definitely not hunters (333 comments)

Reading the comments here, I almost think that there are two classes of people: those of think, and those who don't. I don't quite know what boredom is. Yes, I agree that it takes some mental discipline to keep going on with mental work. I don't disagree that it's easier sometimes not to think than to think. I also don't disagree that all people simply get tired of thinking after a while - after all, we all need a break; mental work is still work. But if most people who, given 15 minutes to themselves, are unable to think and use that productively - that's quite telling. Are they all so seriously tired and worn out that they are all ready to go for a vacation or something? Or can't they think? Perhaps both?

about three weeks ago
top

Study: People Would Rather Be Shocked Than Be Alone With Their Thoughts

tibit Re:How is this different from sensory deprivation? (333 comments)

Maybe I'm just skewed by my analytical approach to things, but can't you, you know, solve some problems or something? Don't you have anything to plan for etc.? Myself, I've got a backlog of things I wish to learn, so if you asked me to sit and think for 15 minutes right now, I'd be going through some structural induction proofs I meant to dig through I didn't have time. Or I'd be doing some design work for my home automation system. Or cleaning up some code. I've done a lot of my best programming just laying in bed, in the early morning hours before the alarm sounds. It really helps when you focus on something and keep relevant information immediately available for recall. Or I could be planning the hikes I want to take with the family. Etc.

about three weeks ago
top

Study: People Would Rather Be Shocked Than Be Alone With Their Thoughts

tibit Re:Sad, sad times... (333 comments)

Environment you're not familiar with? Shit, do they use some cool nanotech on their walls, or is that thing done in a blimp gondola, or in the Himalayas? I'd have thought that most university buildings are like most other university buildings. If you claim lack of familiarity with a room with a desk, what else must you be unfamiliar with?

about three weeks ago
top

Study: People Would Rather Be Shocked Than Be Alone With Their Thoughts

tibit Re:How fitting (333 comments)

If you have normal blood sugar levels, then the amount of sugar you consume is irrelevant to your mental performance, unless you posit that somehow the brain itself has a sugar intake integrator and goes hyper when the leaky integrator is past a threshold. Nothing like that has been observed AFAIK. As for caffeine, if I don't get it in the morning, I go right back to sleeping. If I consume it in the evening, nobody cares. I can fall asleep right after going through a 2 liter bottle of cola - not that I do it often, of course.

about three weeks ago
top

Study: People Would Rather Be Shocked Than Be Alone With Their Thoughts

tibit Re:How fitting (333 comments)

I don't see how being an extro- or intro-vert has anything to do with the capacity to actually sit down in fucking peace and quiet and think. I start to wonder how anyone achieves anything substantial in this world if they can't deal with 15 minutes of peace and quiet and their own thoughts.

about three weeks ago
top

Chinese Company '3D-Prints' 10 Buildings In One Day

tibit Re:No Feasible for North America (118 comments)

A conduit-shaped opening through a concrete 3D-printed structure could surely be coated from inside with a slick coating before anything is pulled through. All you'd need is to pull a spray head through it. You don't need to embed pipes in concrete.

about three weeks ago
top

Chinese Company '3D-Prints' 10 Buildings In One Day

tibit Re: Is it safe? (118 comments)

Chopped fibres aren't the same as long fibres. But I agree that having fibreglass ribbons embedded in the concrete would be a great alternative, as long as long as test coupons would pass relevant tests.

about three weeks ago

Submissions

top

MRI Magnets Cause Nystagmus

tibit tibit writes  |  more than 2 years ago

tibit writes "In an interesting twist on "it's so old it's new again", Johns Hopkins researchers led by Dale Roberts found what must have been causing much confusion for doctors the world over: strong external magnetic field can stimulate the semicircular canals, causing vertigo and nystagmus (pendular eye motion). It's a textbook case of Lorentz force in action: our angular rate gyros, the semicircular canals in the middle ear, filled with endolymph, have a ionic current flowing across. In magnetic field, the current produces a force that pushes the lymph along the channel, causing stimulation of the cupula — a pressure sensor at the end of the channel. This is interpreted by the brain as rotation of head in space, and causes a nystagmus that's supposed to stabilize the image on the retina. Of course the subject is laying down and not spinning in space, and the mismatch between inertial measurements coming from the ear and real situation causes vertigo."
Link to Original Source

Journals

tibit 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...