Search found 436 matches

by lgw
Mon Nov 11, 2013 10:14 pm UTC
Forum: Science
Topic: Why do we perceive a 4-dimensional universe as 3?
Replies: 98
Views: 15825

Re: Why do we perceive a 4-dimensional universe as 3?

I still suspect that particles are somewhat more intuitive than waves from an evolutionary standpoint. I also kind of think that the problem with teaching QFT is less the quantum part and more the field theory part. I'm not sure there's a whole lot of motivation to adopt the field theory point of v...
by lgw
Mon Nov 11, 2013 9:55 pm UTC
Forum: Science
Topic: What is the smallest object that has gravity?
Replies: 65
Views: 19286

Re: What is the smallest object that has gravity?

It's hard to tell what your physics experience is, but it falls out of newtons 3rd law if you're ok with classical theory. Perhaps more intuitively, 'big' things are just collections of a whole bunch of small things, and it'd be very strange indeed if gravity only 'turned on' after a certain number...
by lgw
Thu Nov 07, 2013 6:56 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1286: "Encryptic"
Replies: 102
Views: 32559

Re: 1286: "Encryptic"

I get UTF-8 from a purely engineering point of view, most programming languages are in English after all. Except that backwards compatibility is nice, but it's kind of a big burden to put on a system that is probably supposed to last for a couple of decades, about halfway through which the old stan...
by lgw
Tue Nov 05, 2013 1:21 am UTC
Forum: Science
Topic: Speed of Propagation of a Magnetic Field.
Replies: 116
Views: 28549

Re: Speed of Propagation of a Magnetic Field.

You can define simultaneity in such a fashion that the two ends of the rope are cut simultaneously from your perspective, yes. But there will be another perspective from which they aren't. Yeah, spacelike-separated events can appear from your reference frame to have any temporal separation you like...
by lgw
Mon Nov 04, 2013 9:53 pm UTC
Forum: Science
Topic: Speed of Propagation of a Magnetic Field.
Replies: 116
Views: 28549

Re: Speed of Propagation of a Magnetic Field.

... The fact that it requires to spatially separated events to be simultaneous when simultaneity is relative demonstrates that in any relativistic setting (which, seeing as relativity (particularly SR which is relevant here) has been confirmed at many different scales over the last 100 or so years,...
by lgw
Mon Nov 04, 2013 9:32 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1284: "Improved Keyboard"
Replies: 102
Views: 20762

Re: 1284: "Improved Keyboard"

If i didn't have to pay for recieved minutes, i'd be a fool to ever have any minutes on my phone. I'd tell my friends that when the phone rings once and stops, look at the id, and call me back so I dont have to pay for minutes, since landline calls are free. Why not call them from a landline in the...
by lgw
Fri Oct 25, 2013 9:10 pm UTC
Forum: Science
Topic: Why do we perceive a 4-dimensional universe as 3?
Replies: 98
Views: 15825

Re: Why do we perceive a 4-dimensional universe as 3?

Atoms as little balls are incredibly unintuitive from the get-go, and that only seems not to be the case because you've been brought up to believe that's actually what everything is made of. The notion that normal clouds are collections of individual particles is also unintuitive, really. So why sh...
by lgw
Wed Oct 23, 2013 12:04 am UTC
Forum: Coding
Topic: Coding: Fleeting Thoughts
Replies: 9990
Views: 1999112

Re: Coding: Fleeting Thoughts

These days I'm not sure I would even consider goto harmful, if used within the body of a function. Because it's just easier to use other constructs where they fit, chances are a goto needed to be there, at least in recent code.
by lgw
Tue Oct 22, 2013 9:14 pm UTC
Forum: Coding
Topic: Superuser: "What are the Windows A: and B: drives used for?"
Replies: 38
Views: 14010

Re: Superuser: "What are the Windows A: and B: drives used f

I've used 8" floppies - to install microcode on mainframes, back in the day. I made good use of the big reel-to-reel tape drives (which far predate floppies of any size) early in my programming career. I was writing tape device drivers, and while the reel-to-reel drives were useless for most pu...
by lgw
Mon Oct 21, 2013 8:59 pm UTC
Forum: Science
Topic: Why do we perceive a 4-dimensional universe as 3?
Replies: 98
Views: 15825

Re: Why do we perceive a 4-dimensional universe as 3?

Matter is obviously tiny balls of stuff, says naive intuition. So you just look at, say, cheese and you intuition goes "oh yeah, that's obviously made of quarks", does it? My intuition says "that's obviously made of stuff ". My intuition does not see it as an anti-node in the ch...
by lgw
Mon Oct 21, 2013 12:39 am UTC
Forum: General
Topic: Are high-yield online savings accounts BS?
Replies: 55
Views: 21879

Re: Are high-yield online savings accounts BS?

It's from 2008, but still. It says most stocks give about a 10% return. So, hard as it is to believe, there do appear to be more winners than losers in the stock market. You still can't draw that conclusion from the data, because the data are for the DJIA and S&P 500 and are based on the number...
by lgw
Mon Oct 21, 2013 12:13 am UTC
Forum: General
Topic: Are high-yield online savings accounts BS?
Replies: 55
Views: 21879

Re: Are high-yield online savings accounts BS?

Circling back to the original question: what's the point of a savings account? Well, below is the answer that makes sense to me (but please don't construe any of this as financial advice, this is merely my lay opinion). Don't get thrown by the specific numbers: savings accounts almost always pay les...
by lgw
Fri Oct 18, 2013 9:43 pm UTC
Forum: Science
Topic: Why do we perceive a 4-dimensional universe as 3?
Replies: 98
Views: 15825

Re: Why do we perceive a 4-dimensional universe as 3?

What's wrong with fields? You have no trouble accepting classical electromagnetism I presume? And then it turned out there was a particle-like aspect to its excitations. Why do electrons have to be tiny balls of stuff instead of packets of excitations? Word. If fields are not intuitive, cultivate y...
by lgw
Fri Oct 18, 2013 8:20 pm UTC
Forum: Mathematics
Topic: n sided polygon, n < 3
Replies: 35
Views: 6709

Re: n sided polygon, n < 3

gmalivuk wrote:And when n=cheese the sum is 180cheese - 360.

Sure, we can all string the relevant symbols together, but that doesn't necessarily imbue them with meaning.

I am fascinated by your new cheese-based geometry - tell me more! :D
by lgw
Fri Oct 18, 2013 7:47 pm UTC
Forum: Science
Topic: Why do we perceive a 4-dimensional universe as 3?
Replies: 98
Views: 15825

Re: Why do we perceive a 4-dimensional universe as 3?

"virtual particle" is a step backwards. Eschew particles, embrace fields. Yeah, perhaps I need a new word, I certainly didn't mean "virtual photons" in the sense one might model the "electric field" around an electron. But if you're talking about e.g., the "electr...
by lgw
Fri Oct 18, 2013 5:47 pm UTC
Forum: Science
Topic: Why do we perceive a 4-dimensional universe as 3?
Replies: 98
Views: 15825

Re: Why do we perceive a 4-dimensional universe as 3?

Most of the time people only ever want determinism to mean "determined by local causes," and that is the thing that is right out. Quite well put! What you can't get is underpinnings that are classical , but it's really locality that's broken, not deterministic behavior. I believe that's t...
by lgw
Fri Oct 18, 2013 12:04 am UTC
Forum: Science
Topic: Why do we perceive a 4-dimensional universe as 3?
Replies: 98
Views: 15825

Re: Why do we perceive a 4-dimensional universe as 3?

I don't think anything rules out a deterministic underpinning for quantum mechanics, if the deterministic part is far down the scale ladder (of course, you must explain spooky action at a distance, somehow). The probabilistic model in QM makes really good predictions, of course, but it's easy to ima...
by lgw
Thu Oct 17, 2013 8:24 pm UTC
Forum: Coding
Topic: New to Coding
Replies: 114
Views: 156457

Re: New to Coding

JS seems to be taking over from Scheme, not Java. You can use it to teach functional programming, and while I find its object model terrible, Scheme has no object model at all, so no loss there.

Java schools? Don't get me started on what I have to teach people we hire from Java schools.
by lgw
Thu Oct 17, 2013 8:14 pm UTC
Forum: Science
Topic: Why do we perceive a 4-dimensional universe as 3?
Replies: 98
Views: 15825

Re: Why do we perceive a 4-dimensional universe as 3?

Here's a slightly different way to think about some of the stuff that other posters have already said: An outside observer somehow looking in at our 3+1 universe would see me perceiving each moment in time I perceived. At any moment in time, they could look and see me perceiving at that time. From ...
by lgw
Thu Oct 17, 2013 7:34 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1278: "Giraffes"
Replies: 67
Views: 21537

Re: 1278: "Giraffes"

addams wrote:Can you imagine coniferous cows?
Like sharks, they would be.
Land sharks. Thanks be to the Gods.


I don't think coniferous cows would be anything like land sharks, but I want one for my yard! It needs more greenery in the winter.
by lgw
Tue Oct 15, 2013 8:37 pm UTC
Forum: Coding
Topic: C - Int question
Replies: 9
Views: 3208

Re: C - Int question

I think I still have a ways to go to grasping C. Lots of googling ahead, I've searched about arrays and how they're handled and touched on malloc and other memory related functions but if you guys know of any solid write-ups on these subjects, or indeed C as a whole, please do let me know. Thanks, ...
by lgw
Tue Oct 15, 2013 5:31 pm UTC
Forum: Science
Topic: Physics charged plates
Replies: 5
Views: 1801

Re: Physics charged plates

To answer what I think the OP is asking: capacitors are all about surface area, volume doesn't really come into it.
by lgw
Tue Oct 15, 2013 5:23 pm UTC
Forum: Science
Topic: Why do we perceive a 4-dimensional universe as 3?
Replies: 98
Views: 15825

Re: Why do we perceive a 4-dimensional universe as 3?

Well, obviously we perceive one dimension as "time". It is mathematically different from the space dimensions, of course, thus the (+ + + -) signature, or however that goes - time is imaginary. Nevertheless our perception in the time dimension leaves something to be desired: "it's a p...
by lgw
Mon Oct 14, 2013 8:38 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1277: "Ayn Random"
Replies: 534
Views: 81278

Re: 1277: "Ayn Random"

Kit. wrote:
Mikeski wrote:...has an I.Q. generated by a fair random number generator*.
...
* - specifically, 12d6.

Mean 42, std.dev.<6? That's not a lot of people.


So you'd think, but have you ever read YouTube comments? Somebody's math must be off somewhere.
by lgw
Mon Oct 14, 2013 8:11 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1277: "Ayn Random"
Replies: 534
Views: 81278

Re: 1277: "Ayn Random"

For me, Objectivism has always fallen down at the stage of "first, find a perfectly rational and objective human being" - an entity which exists only in the same realm as the ideal gas, the frictionless surface, the perfect black body, etc etc. Which is, of course, pretty much exactly wha...
by lgw
Fri Oct 11, 2013 10:28 pm UTC
Forum: Coding
Topic: I made a Java test. Can you beat it? Also can you hack it?
Replies: 6
Views: 3261

Re: I made a Java test. Can you beat it? Also can you hack i

My work filter is sure that's a pron site. Either way this seems a bit spammy.
by lgw
Fri Oct 11, 2013 9:24 pm UTC
Forum: Fictional Science
Topic: Replacing the Moon with a Black Hole
Replies: 29
Views: 9253

Re: Replacing the Moon with a Black Hole

I was just pointing out that they would run out if they were the source of all the meteors that hit the planets all the time... IIRC they are more like 10%, at least of the big impacts. And well, it was big impacts we were talking about. Shoemaker-Levy did hit Jupiter recently. For some reason I no...
by lgw
Fri Oct 11, 2013 9:07 pm UTC
Forum: Fictional Science
Topic: "Zombie" Apocalypse
Replies: 61
Views: 26794

Re: "Zombie" Apocalypse

Zombies That was possibly the most entertaining post I've read on these forums. Thanks. Not all maces are morning stars. And appropriate firearms shouldn't have trouble delivering sufficient damage. The drawbacks are the requirements for precise aiming, noise and the need for suitable ammunition. B...
by lgw
Fri Oct 11, 2013 7:34 pm UTC
Forum: Fictional Science
Topic: A (Simple?) Physics Problem
Replies: 39
Views: 16163

Re: A (Simple?) Physics Problem

This scenario involves considerable leaps of fantasy, so let's assume: ⋅ The magic force stopping the Earth in its orbit affects the planet's whole volume evenly. It doesn't "grab" the core or anything like that; it stops the entire Earth. I'm making this assertion because the q...
by lgw
Thu Oct 10, 2013 7:42 pm UTC
Forum: Science
Topic: Net Positive Fusion Reaction?
Replies: 18
Views: 4876

Re: Net Positive Fusion Reaction?

Seriously, solar panel manufacture requires lots of energy and some rather unpleasant industrial processes, they're expensive (being partially paid for by the government doesn't mean they're actually cheaper), and the output sucks. Fusion could actually provide enough power to replace current sourc...
by lgw
Wed Oct 09, 2013 11:16 pm UTC
Forum: Science
Topic: Net Positive Fusion Reaction?
Replies: 18
Views: 4876

Re: Net Positive Fusion Reaction?

Depends on how you define "net positive". I'm sure others have done it, for some milliseconds at a time within a long power-hungry process. These guys are going for a more credible goal, but are still some ways from "self-sustaining". I find this work more interesting personally....
by lgw
Wed Oct 09, 2013 8:12 pm UTC
Forum: Serious Business
Topic: Bitcoin : Where can it fail ?
Replies: 326
Views: 177965

Re: Bitcoin : Where can it fail ?

A brief summary of bitcoin "mining" that's neither an infographic nor a crypto paper: ⋅ When you "spend" bitcoin you transfer it from your wallet to someone else's. ⋅ For that to work, some third party must do significant computation to prove the transaction w...
by lgw
Wed Oct 02, 2013 11:54 pm UTC
Forum: Science
Topic: Miscellaneous Science Questions
Replies: 2958
Views: 719860

Re: RELATIVITY QUESTIONS! (and other common queries)

Through matter, that is indeed what happens. Prisms make rainbows because blue light goes through glass more slowly than red light, and bends at a different angle. I've never thought of that in terms of momentum and turning a corner before. That's neat! Heck, that's so neat I don't even care if the...
by lgw
Wed Oct 02, 2013 11:50 pm UTC
Forum: News & Articles
Topic: Silk Road -- The Amazon.com of drugs
Replies: 85
Views: 20477

Re: Silk Road -- The Amazon.com of drugs

Even more fun, the founder apparently kept all sorts of transaction records around indefinitely, unencrypted, on the seized equipment. The follow-on busts will paint an interesting picture, assuming the DEA follows up on this.
by lgw
Tue Oct 01, 2013 8:12 pm UTC
Forum: Science
Topic: Miscellaneous Science Questions
Replies: 2958
Views: 719860

Re: RELATIVITY QUESTIONS! (and other common queries)

The light doesn't actually decelerate, it's just that its interactions with the medium it's travelling through make it appear that way. This is one of those cases where that whole particle/wave duality thing makes it hard to come up with a single description that works with our intuition, so I'll g...
by lgw
Mon Sep 30, 2013 5:30 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1271: Hilighting
Replies: 120
Views: 23592

Re: 1271: Hilighting

Is it just me, or does this spelling (misspelling?) of "highlight" make anyone else cringe? Is this a regional thing? (Or did I miss something?) I'm guessing that you assiduously avoid reading anything before the late 1700s, or maybe even the early 1800s, when English ...
by lgw
Fri Sep 27, 2013 11:42 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1269: "Privacy Opinions"
Replies: 118
Views: 26046

Re: 1269: "Privacy Opinions"

I never got the national security argument in seemingly democratic countries. Well, even benevolent democracies do need to keep some secrets. The nuclear launch codes. Realtime troop movement information. The way the latest superweapon works. The problem is: that a quite small set of legitimate sec...
by lgw
Fri Sep 27, 2013 11:29 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1270: Functional
Replies: 171
Views: 47142

Re: 1270: Functional

Many people have posted that a computer is naturally an iterative state machine. However, one of the coolest things ever in computer science was Guy Steele's Rabbit compiler (also his thesis), where he showed that a clean functional language like Scheme needs only a series of mathematical transforms...
by lgw
Wed Sep 25, 2013 9:42 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1268: "Alternate Universe"
Replies: 200
Views: 33490

Re: 1268: "Alternate Universe"

A study recently showed that tap water in Prague is healthier that any bottled water on the market. People are still buying it though. A study recently showed that tap water in Louisiana has brain-eating amoebas. Local water officials seemed unalarmed by this, saying it will take a couple of weeks ...
by lgw
Wed Sep 11, 2013 11:27 pm UTC
Forum: Science
Topic: why do massless photons have momentum?
Replies: 12
Views: 5358

Re: why do massless photons have momentum?

I like Feynman's general-purpose answer: that's a "why" question - you can't really answer a "why" question except in terms of something else you just accept to be true. Anyone with children the right age knows that the answer to a "why" question can always bring the re...

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