Announcing: Slashdot Deals - Explore geek apps, games, gadgets and more. (what is this?)

Thank you!

We are sorry to see you leave - Beta is different and we value the time you took to try it out. Before you decide to go, please take a look at some value-adds for Beta and learn more about it. Thank you for reading Slashdot, and for making the site better!



Tour the Vintage Radio and Communications Museum (Video)

jdagius Re:Ham Radio? (19 comments)

We seriously need a link to explain what Ham Radio is?

It's about the history of audio/visual communications over the past two centuries, not Ham Radio (though I suspect most of us nerds know what HR is).

about two weeks ago

How Alibaba Turned November 11 Into the World's Biggest Online Shopping Day

jdagius AliBaba's online outlet is called AliExpress. (115 comments)


I've found it to be very friendly, with free shipping to the States on almost every purchase. Downside is that the free shipping goes through Singapore Post and takes a month or two to arrive here.

But the prices are really cheap, and customer support surprisingly good. Amazon had better watch out!

about a month ago

Long-term Study Finds No Link Between Video Game Violence and Real Violence

jdagius Re:What? (250 comments)

| Lead has been linked to civil violence.... distribution of wealth

The violence I've read about most frequently seems to be motivated by greed, personal revenge or jihadism. I don't recall any lead-poisoned or desperately poor criminals involved. Can you list some specific examples?

But assuming you're right, does it make sense that civil violence is steadily increasing, while lead in the environment has almost disappeared?

When I was a kid we lead pipes and lead paint in our houses and the air was filled with tetra-ethyl lead from leaded gasoline. Also a lot of lead solder in those ancient TV's and radios (before integrated circuits). So the 50's and 60's should have been more violent because of all the lead in the environment.

about a month ago

Long-term Study Finds No Link Between Video Game Violence and Real Violence

jdagius Re:What? (250 comments)

Ok, please add 'graphically realistic and violent Hollywood movies' to the list of variables.

What other variables, spanning the past 50 years or so, are relevant in explaining the increase in civil violence over the years?

Cellphones, Wikipedia, microprocessors, yoghurt, micro-wave ovens? These all became popular in the last 50 years. Are these the culprits?

Guns? I really don't think so. There are more far restrictions on the sale and use of firearms today than there were a half-century ago. It's just that it's somehow "easier" (or maybe even "desirable") to pull the trigger these days. We see it all the time in the movie and video games. Right?

What say you? If it's not movies or games, what are the true causal factors here?

about a month ago

Long-term Study Finds No Link Between Video Game Violence and Real Violence

jdagius Re:What? (250 comments)

> ... assumption must be that no correlation exists.

No, that's not how statistical tests of significance are interpreted. Failure to reject the null hypothesis does not prove the null hypothesis is true.
For example, consider the null hypothesis is "all guns shoot bullets". Then if my test sample happens to contain only bullet-shooting guns, then I cannot reject the hypothesis. But it doesn't prove it either, because my sample may have overlooked legitimate counter examples. Even if the sample was drawn honestly and with no biases. But a single counter-example would be sufficient to disprove the hyposthesis.

Personally, I think the study is flawed because there is no valid control group. I would suggest comparing violence today with 50 years ago.
I grew up in the 50's and 60's. There was a lot less civil violence then. Why is that? There were nothing like "video games" then (except maybe 'cowboys and Indians'). Guns were freely available. In fact much less restricted then now. Movies and TV were much less violent and gory then now. Society had much less civil violence then.
I recall that movies started getting more 'realistic' in the 70's. I remember being at first impressed by the increasingly "realistic" violence portrayed in movies.Up to then it was all theatrics, the good guy shot the bad guy, who clutched his chest and said "you got me" and then slowly slumped over. No blood showing at all usually. Or maybe a little ketchup for 'realism'.

Now I'm no longer impressed with this realism. It sickens me. What have we gained by seeing blood and flesh ripped apart? I think it has made us much less 'emotionally sensitive' to killing. It has never taken much effort to pull a trigger. But there has always been an 'emotional resistance' which traditionally made it difficult to pull the trigger when pointing a gun at a human. That resistance now seems to be wearing off. It's 'easier' now to pull the trigger. Has nothing to do with the design or availability of guns, more with Hollywood and the game industry. IMHO.

Now get off my lawn before I call the cops.

about a month ago

Past Measurements May Have Missed Massive Ocean Warming

jdagius Re:Makes perfect sense, sort of, ... (423 comments)

> Wow, another right wing sheep spouting off about the 18-year > thing your masters keep telling you about.
FYI, most climatologists accept the "18-year thing" you speak of. They call it the "Pause", which is definitely not a term coined by skeptics.

The rest of your comment is irrelevant to the point I was trying to make. Typical of the warmist AC's who blindly follow what their leaders tell them. It is also customary, BTW, for warmists to accuse skeptics of the very things they themselves do wrong.

Skeptics have a tradition of _not_ swallowing whatever is fed to them (even though it seems to cost us mod points. Free speech?)

about 2 months ago

Past Measurements May Have Missed Massive Ocean Warming

jdagius Re:Say "No more!" to Climate Posts (423 comments)

> Just because something is not 100% does not mean we should not protect against it.

True. But you're overlooking the cost-benefit analysis.

"Buckling up" has little or no adverse cost associated with it. Yes, it slightly increases the chance you'll be trapped in a flaming wreck. But that is probably less likely than your skull crashing through the windshield in a head-on collision. So the benefits outweigh the costs.

So, if we could just wear some simple appliance like a seat belt that would mitigate, without penalty, even the most farfetched climate catastrophes (e.g. sharknado), then, yeah, why not do it? Same as 'affordable insurance', right?

But the economic and political consequences of rushing in to replace our fossil-fuel-based infrastructure with wind and solar are substantial, with threats to our political and military stability. And the benefits are negligible in the sense that the proposed replacement systems will not come close to fixing the problem as it is being described. So, not an effective 'insurance policy' at all.

[Unless you think the rabble-rousers who will benefit from our self-destruction are the "good guys".]

about 2 months ago

Past Measurements May Have Missed Massive Ocean Warming

jdagius Makes perfect sense, sort of, ... (423 comments)

... manmade CO2 warms the atmosphere. But atmosphere has not warmed as much as climate models have predicted over the past 18 years.

So there must be some 'missing' heat lurking about somewhere. If we believe the models.

Oh look at all the heat in the ocean that we have been observing for many years without really 'noticing'. (But now we really 'need' this heat, because it confirms our favorite theory of catastrophic manmade global destruction)

Hmm. Problem is that the models make the assumption that the 2nd Law of Thermodynamics is true. How does flow from a cooler body to a warmer place?

It's best to remain skeptical of reports like this until reliable mechanisms and models are presented to explain and predict it (in the past and in the future).

about 2 months ago

David Cameron Says Brits Should Be Taught Imperial Measures

jdagius Gold Weight vs Feather Weight (942 comments)

An ounce of gold surprisingly "weighs" more than an ounce of feathers because gold weights are in Troy units (1 oz=31g) whereas feathers are Avoirdupois (1oz=28g).

But a pound of feathers weighs more than pound of gold, because Troy pounds have only 12 ounces.

about 3 months ago

Developing the First Law of Robotics

jdagius In theory it's nice. In practice it's ... (165 comments)

... never going to work.

One could argue that computer viruses are merely robots without a solid body. So the First Law has already been trashed by all the big powers on the planet.

And who's going to decide what is 'harmful'? Governments again are producing semi-automated robots (drones) which harm people. But that's OK because "it's to prevent an even greater harm" they say. But who decides if 'they' got it right?

about 3 months ago

Ask Slashdot: What Are the Strangest Features of Various Programming Languages?

jdagius Quirk in MATLAB array syntax (729 comments)

MATLAB was one of the first languages to allow lists of comma-separated numbers between square brackets e.g. [1,2,3,10] to be interpreted as indexed numeric arrays or vectors. A lot of languages do that now, but MATLAB was perhaps the first to do this in 1984. A little-known quirk is that the commas are optional! [1 2 3 10] etc. This was probably introduced as a 'convenience' feature (though typing a space isn't that much faster than typing a comma). But there is a glitch ("feature") in the syntax that interprets space-separated negative numbers differently than you'd expect. So [ 1 2 -3] is interpreted as [1,2-3] (value = [1,-1]) because the precedence of arithmetic operators is higher than list operations.

MATLAB hasn't fixed this 'feature' yet, because it would undoubtedly break a jillion apps around the world. So you must be careful to type [1 2 (-3)] if you are allergic to commas.

BTW it's been fixed by default in OCTAVE, MATLABS free-software clone, but you turn 'quirks' on, if you want to preserve the quirky behavior.

about 3 months ago

Does Learning To Code Outweigh a Degree In Computer Science?

jdagius Does Learning Mechanical Engineering Outweigh ... (546 comments)

... learning to operate a rivet gun or steam shovel? A bridge or building could be more cheaply built by skilled operators with little or no knowledge of stress and strain, but how long would these structures stand?

The same could be said for computer programmers, who may be skilled in coding, but have little or no knowledge of the best methodologies for constructing robust and reliable software systems and structures.

about 3 months ago

Sand-Based Anode Triples Lithium-Ion Battery Performance

jdagius Re:Structure preserving? (60 comments)

@tsa > I don't think it suggests that at all.

Did you read TFA? It says. "In this very simple process, the salt acted as a heat absorber while the magnesium removed oxygen from the quartz, resulting in pure silicon. "

So the article does indeed 'suggest' that Mg is removing O. My question was concerning how is this oxygen removal related to creating porosity. Or not.

In any case, it seems likely that some formerly filled space must be vacated to create porous openings.

Does anyone know how this happens?

about 5 months ago

Sand-Based Anode Triples Lithium-Ion Battery Performance

jdagius Structure preserving? (60 comments)

The article suggests that making nano-scale silicon by using magnesium to remove oxygen solves the usual degrading issues. Why is this? Does the quartz lattice have optimal conduction geometry, which is somehow preserved after the oxygen is removed?

about 5 months ago

"Eskimo Diet" Lacks Support For Better Cardiovascular Health

jdagius Elephant in the room... (166 comments)

... lipid hypothesis http://en.wikipedia.org/wiki/L...
So I get that the "Eskimo Diet" doesn't improve cardiovascular health. But then it doesn't degrade it either. Then why all the "heart smart" low-fat, no-fat, low-cholesterol propaganda we're constantly bombarded with?
It seems Uffe Ravnskov may be right. Dietary cholesterol very likely has little or no bad effects on health. It is probably "good" for you. In fact, statin drugs used to treat CAD are far worse for your health.
Proof: If statins actually were effective against CAD, then the ads on TV could make that claim. If you listen carefully, they don't make any claim that they lower the incidence of CAD. Their sole claim for "effectiveness" is that they lower your blood cholesterol numbers. It would be more compelling if they could claim health benefits of course, but their is no compelling evidence for this.

about 6 months ago

Satellites Providing Internet To the 'Under-Connected'

jdagius Re: In space ... (50 comments)

Objects "in orbit" around the Earth are actually falling freely to the Earth. But thanks to the very large horizontal component in their motion, orbiting objects always overshoot the horizon and thus stay in orbit.
Such objects have no "weight", because weight is defined as, F=mg, a force F exerted by an object with mass m in a gravity field g, resting on a surface preventing the object from falling freely.
The mass of an object is thus independent of gravity, but it's "weight" is just an artifact imposed by surface constraints, and can vary greatly.

about a year and a half ago



Big Meteor to Strike Earth Tonite

jdagius jdagius writes  |  more than 6 years ago

jdagius writes "Don't panic! The Minor Planet Center at the Smithsonian Astrophysical Observatory is responsible for monitoring the solar system's small planetoids, comets and other space rocks, including those which might be heading our way. They have detected a meteor, several meteors wide, which will impact Earth tonite at 0246 UTC in northern Sudan. http://blog.wired.com/wiredscience/2008/10/meteor-predicte.html No biggie, these kinds of meteors hit the Earth every few months. But this is first one which has been predicted by the MPC and validates the notion that they might catch a bigger one which could cause a lot of damage. This one is expected to burn up harmlessly in the atmosphere, but will nevertheless be equivalent in energy to a small nuclear weapon, roughly a 1 kiloton blast."


jdagius has no journal entries.

Slashdot Login

Need an Account?

Forgot your password?