Search found 1588 matches

by idobox
Fri Sep 06, 2013 10:46 pm UTC
Forum: Science
Topic: Pound v. Foot Pound
Replies: 101
Views: 23343

Re: Pound v. Foot Pound

For one thing, it helps when idiots such as yourself toss out a "challenge" question to try to "prove" how inferior the USCS is. Do you remember any old phone numbers or addresses or friends' old phone numbers or addresses or the price of your regular lunch at your regular lunch...
by idobox
Fri Sep 06, 2013 7:33 pm UTC
Forum: Science
Topic: Pound v. Foot Pound
Replies: 101
Views: 23343

Re: Pound v. Foot Pound

What you are claiming is patently false, idobox. I have definitely talked to people who don't remember all the metric prefixes or how to convert between them. Not everyone pays for their own water, so many likely don't know that there are 1000L in a m^3. And as I said, they have no excuse but stupi...
by idobox
Fri Sep 06, 2013 2:33 pm UTC
Forum: Science
Topic: Pound v. Foot Pound
Replies: 101
Views: 23343

Re: Pound v. Foot Pound

The point is, people who use the imperial system have trouble using it. That situation can't happen with the metric system, because we have only one unit of mass, and multiplier prefixes. Nonsense. Of course people can get confused with the metric system. Plenty of people couldn't tell you offhand ...
by idobox
Thu Sep 05, 2013 4:07 pm UTC
Forum: Serious Business
Topic: How should prisoners be counted in employment rates?
Replies: 25
Views: 9595

Re: How should prisoners be counted in employment rates?

I'm from France, so I can give you French examples. In 97, the socialist party created 'emplois jeunes', or youth jobs, poorly paid part-time jobs subsidized by the state. These kids earned so little, they kept on getting unemployment money, but were not counted as unemployed. In 2008, about 700 000...
by idobox
Thu Sep 05, 2013 1:12 pm UTC
Forum: Science
Topic: Pound v. Foot Pound
Replies: 101
Views: 23343

Re: Pound v. Foot Pound

t's not the unit's fault they couldn't remember the number 14. It's certainly a strange number to have in a unit, but not really all that worse than 10, since 7 is the next bigger prime after 5. The point is, people who use the imperial system have trouble using it. That situation can't happen with...
by idobox
Thu Sep 05, 2013 12:16 am UTC
Forum: Science
Topic: Pound v. Foot Pound
Replies: 101
Views: 23343

Re: Pound v. Foot Pound

And energy (especially gas) is often billed by therm or BTU in the US, so I don't see what your problem with that or quads is. Of course, I readily admit that the mixture of measurement systems can get bizarre here. Air conditioners are often listed with the number of BTUs they can move in an hour,...
by idobox
Wed Sep 04, 2013 3:57 pm UTC
Forum: Fictional Science
Topic: Heatless transistors?
Replies: 4
Views: 4697

Re: Heatless transistors?

In my opinion, using photonics, we can make CPUs extremely efficient. Upton a point that charging our cell phone batteries will be required once per month or so. A significant part of the energy used by a smartphone is for the radio circuits, and they will keep working with electronics for quite a ...
by idobox
Wed Sep 04, 2013 3:53 pm UTC
Forum: Science
Topic: Pound v. Foot Pound
Replies: 101
Views: 23343

Re: Pound v. Foot Pound

The foot-pound (aka the foot-pound force, but not usually the "pound-foot", which is sometimes used as a unit of torque) is the equivalent of the joule (not the "Joule," who was a person). There's also the BTU, which is used for different applications. It seems idobox is simply ...
by idobox
Tue Sep 03, 2013 2:50 am UTC
Forum: Science
Topic: Pound v. Foot Pound
Replies: 101
Views: 23343

Re: Pound v. Foot Pound

I was raised with the metric system, and didn't realize that the pound.foot is the unit that makes the most sense in the imperial system. To me it just sounds like multiplying to unpractical units together, but I guess there's no equivalent of the Joule. [troll]In this regard, the BTU (I had no idea...
by idobox
Mon Sep 02, 2013 5:50 pm UTC
Forum: Serious Business
Topic: How should prisoners be counted in employment rates?
Replies: 25
Views: 9595

Re: How should prisoners be counted in employment rates?

The Bureau of Labor Statistics specifically has in its statement of purpose that it is meant to be impartial in both its subject matter and presentation, and it is customary for national statistical organisations to be granted political independence precisely because such organisations are only wor...
by idobox
Mon Sep 02, 2013 5:39 pm UTC
Forum: Science
Topic: Pound v. Foot Pound
Replies: 101
Views: 23343

Re: Pound v. Foot Pound

The Joule *is* a Newton-meter. And how does the calorie make any more sense than the foot-pound, in any situation where you're not talking about heating water? The N.m is actually a SI unit of torque, even if it's equivalent to J. It doesn't really makes sense to use the same unit for torque and en...
by idobox
Sat Aug 31, 2013 4:54 pm UTC
Forum: Science
Topic: why do massless photons have momentum?
Replies: 12
Views: 5049

Re: why do massless photons have momentum?

You can get to that effect classically. In Maxwell's theory, you have the Poynting vector, that tells you the strength and direction of energy propagation. If you divide it by c², you get a momentum exchange, the radiation pressure. Another way to see it is to imagine a charged particle and a plane ...
by idobox
Sat Aug 31, 2013 9:35 am UTC
Forum: Science
Topic: Pound v. Foot Pound
Replies: 101
Views: 23343

Re: Pound v. Foot Pound

It's the first time I hear about that unit, and thought it was a torque unit, like the Newton.metre
Seriously, even without entering the metric system debate, who uses such an unit rather than the Joule or the calorie?
by idobox
Sat Aug 24, 2013 9:57 pm UTC
Forum: Serious Business
Topic: How should prisoners be counted in employment rates?
Replies: 25
Views: 9595

Re: How should prisoners be counted in employment rates?

I feel important to stress again the fact that politics want good statistics, and find ways to make them say what they want. I you remove people from the count of unemployed people by changing the definition, the unemployment rate goes down, and you are more likely to get re-elected. You can also cr...
by idobox
Sat Aug 24, 2013 9:46 pm UTC
Forum: Science
Topic: Singularities and gravity
Replies: 39
Views: 10962

Re: Singularities and gravity

GR predicts reasonable behavior everywhere except at the singularity. The singularity in the Schwarzschild metric at the event horizon is a coordinate signularity. If you reparametrize the metric it goes away. In fact in a small enclosed laboratory you could not detect if you were on one side, or t...
by idobox
Sat Aug 24, 2013 4:37 pm UTC
Forum: Science
Topic: Singularities and gravity
Replies: 39
Views: 10962

Re: Singularities and gravity

we know GR doesn't work well inside a black hole. And how, pray tell, do we know this, seeing as we can never observe inside a black hole? Certainly GR seems to give the wrong result for exactly at the center of a black hole, but there's no particular reason to believe it has significant problems e...
by idobox
Fri Aug 23, 2013 9:27 pm UTC
Forum: Serious Business
Topic: How should prisoners be counted in employment rates?
Replies: 25
Views: 9595

Re: How should prisoners be counted in employment rates?

The US, and many governments in the world, twerk the definition of unemployment to make the statistics look better. If you check the wiki on unemployment in the US, you'll see they consider unemployed people only people who has been actively looking for a job in the past 4 weeks. Which means all the...
by idobox
Fri Aug 23, 2013 9:16 pm UTC
Forum: Science
Topic: Question about determining coefficient of friction.
Replies: 15
Views: 6224

Re: Question about determining coefficient of friction.

Step 1: measure grip force of your hand
Step 2: hold a rod of your material, and pull while measuring tension. When the object slips, divide pull by grip.
by idobox
Fri Aug 23, 2013 9:13 pm UTC
Forum: Science
Topic: Singularities and gravity
Replies: 39
Views: 10962

Re: Singularities and gravity

Yeah. OTOH, we will never see what's going on inside a black hole, so even when we do have a theory of quantum gravity we won't be able to verify what it says about what's going on at the centre of a black hole by direct observation. Still, it'd be pretty weird for a QG theory to say that it is act...
by idobox
Thu Aug 22, 2013 11:29 pm UTC
Forum: Science
Topic: Dark matter & black holes
Replies: 34
Views: 10067

Re: Dark matter & black holes

If DM interacts with itself only through gravity, it will not collapse easily. Particles would fall toward the center of mass, pass through it and then fly away, oscillating around it. You need something akin to friction to slow them down close to the centre and accumulate mass. Gravitational waves ...
by idobox
Thu Aug 22, 2013 11:22 pm UTC
Forum: Science
Topic: Electric guns
Replies: 30
Views: 8153

Re: Electric guns

Being able to adjust velocity is all very well and good, but what prevents soldiers from leaving it on the maximum velocity at all times to increase damage even at short ranges (or, alternately, decreasing velocity to make recoil less problematic)? It would be a trade off between fire rate and ammo...
by idobox
Wed Aug 21, 2013 5:56 pm UTC
Forum: Science
Topic: Singularities and gravity
Replies: 39
Views: 10962

Re: Singularities and gravity

To clarify, a singularity is a point where stuff tends to infinity or stop working normally. For example, the function 1/x has a singularity for x=0. Escape velocity is the speed you need to throw stuff so that it never falls back. On Earth, it is about 11km/s on the surface, and it goes down the hi...
by idobox
Wed Aug 21, 2013 5:35 pm UTC
Forum: Science
Topic: Electric guns
Replies: 30
Views: 8153

Re: Electric guns

I understand your point, but I find it depressing we let such things as usefulness and logistics get in the way of sci-fi sounding weapons. You may have picked the wrong subforum if you're unhappy about science getting in the way of your fiction. I went for this sub forum because I wanted actual an...
by idobox
Wed Aug 21, 2013 3:56 pm UTC
Forum: Serious Business
Topic: Children's Suffrage
Replies: 233
Views: 70576

Re: Children's Suffrage

Children are not allowed to vote because they are not considered responsible of their act, and it should remain that way. Their parents are responsible for them, and they are not allowed to drive, own guns, leave the house without permission, have jobs, sign contracts, etc. To give them the right to...
by idobox
Wed Aug 21, 2013 3:13 pm UTC
Forum: Science
Topic: Electric guns
Replies: 30
Views: 8153

Re: Electric guns

I understand your point, but I find it depressing we let such things as usefulness and logistics get in the way of sci-fi sounding weapons. I don't like guns, and have no desire to have one, but I would be tempted by a working portable rail/coil-gun. Especially if it is roughly the power of a bb gun...
by idobox
Tue Aug 20, 2013 4:28 pm UTC
Forum: Serious Business
Topic: What is the best way to deal with complexity?
Replies: 23
Views: 8918

Re: What is the best way to deal with complexity?

We have used big organizations and human experts to try to cure cancer, with mitigated results. It makes sense to try a new method. Asking oncologist to enter symptoms and other patient data (gender, weight, other conditions) in a dedicated database, as well as the treatment and results would provid...
by idobox
Tue Aug 20, 2013 3:58 pm UTC
Forum: Science
Topic: Electric guns
Replies: 30
Views: 8153

Electric guns

After some wiki-ing, I've found that common assault rifle (I used the M16) ammunition has a travel velocity around 1000m/s and energy around 1.7kJ. I also found that energy density of various explosives varies from 3MJ/Kg for common gunpowder all the way to 7.5MJ/Kg for nitroglycerine, a value that ...
by idobox
Mon Aug 19, 2013 4:24 pm UTC
Forum: Science
Topic: Is a previous spacefaring species on Earth possible?
Replies: 102
Views: 30944

Re: Is a previous spacefaring species on Earth possible?

And it's still less effective than mining solid rock deposits. Because working underwater is hard for air breathers like us. Moving large amounts of rock should be easier with buoyancy and effective cooling. You're going to have to citation this claim, because it's my understanding that many sedime...
by idobox
Fri Aug 16, 2013 10:01 pm UTC
Forum: Science
Topic: Trapping Particals in magnetic feild.
Replies: 3
Views: 1644

Re: Trapping Particals in magnetic feild.

A charged particle in a void, travelling perpendicularly to a constant magnetic field will 'orbit' for some time, but it will loose energy (and speed) through synchrotron radiation. Particle accelerators commonly do that. It might be possible to get this effect with non-uniform fields, but it's prob...
by idobox
Fri Aug 16, 2013 5:32 pm UTC
Forum: Fictional Science
Topic: The Light Saber problem
Replies: 122
Views: 64015

Re: The Light Saber problem

However, the whole "And these blast points, too accurate for Sandpeople. Only Imperial stormtroopers are so precise" business always cracked me up. Sandpeople must be REALLY bad shots. Naturally, one thing to keep in mind is that the New Hope era stormtroopers were recruits, whereas the o...
by idobox
Fri Aug 16, 2013 5:16 pm UTC
Forum: Science
Topic: Is a previous spacefaring species on Earth possible?
Replies: 102
Views: 30944

Re: Is a previous spacefaring species on Earth possible?

And I'll repeat, again, that except around the black smokers, there is little in terms of unique resources in the deep ocean that is interesting to exploit. Abyssal plains are BORING. And again, the challenges in sustaining a livable environment in the deep ocean are significantly different from do...
by idobox
Wed Aug 14, 2013 5:38 pm UTC
Forum: Science
Topic: Is a previous spacefaring species on Earth possible?
Replies: 102
Views: 30944

Re: Is a previous spacefaring species on Earth possible?

When you survey an area with a resolution of 10km, there are a bunch of things you might miss, for example stone buildings a few tens of meters long. So, we don't do much on the ocean floor except lay cables across it, drill into it, and heavily trawl the ocean at large for food. Gotcha. Except dril...
by idobox
Wed Aug 14, 2013 3:46 pm UTC
Forum: Fictional Science
Topic: Humanity dividing into high-tech and low-tech
Replies: 11
Views: 5008

Re: Humanity dividing into high-tech and low-tech

You don't need sci-fi to get such a divide. We already have Amish people and similar groups. We also have places where people still use animals to till the land, get water from a well, and have no electricity. So mostly middle age technology, with a few gizmos (like cell phones) from more technologi...
by idobox
Wed Aug 14, 2013 3:41 pm UTC
Forum: Fictional Science
Topic: Oblivion: Handwavium necessary for an autonomous ionocraft
Replies: 8
Views: 6366

Re: Oblivion: Handwavium necessary for an autonomous ionocra

Don't arcjet engines require that you carry a reaction mass? Or am I missing something? Arcjets use arcs to heat a reaction mass. You can take any type of engine that uses hot gases and uses arcs to replace combustion. It includes air breathing engines and rocket engines. They are not used for air ...
by idobox
Wed Aug 14, 2013 3:27 pm UTC
Forum: Science
Topic: Is a previous spacefaring species on Earth possible?
Replies: 102
Views: 30944

Re: Is a previous spacefaring species on Earth possible?

It's just curious that you're so willing to fit this hypothetical creature into the niche of 'hard to detect' but also biologically able to reach the stars, but also not dependent upon any of the technologies or industries that would let them reach the stars. For example, these colossal crabs eatin...
by idobox
Wed Aug 14, 2013 3:12 pm UTC
Forum: Science
Topic: Electrical induction in water
Replies: 6
Views: 2380

Re: Electrical induction in water

Distilled water contains H+ and OH- ions, although not a lot (10^-7 mol/l if I remember well).
It will behave lie a ionic conductor with a large resistance.

The frequency of the induced current will also be limited by ion mobility, but I have no idea how to do the math.
by idobox
Wed Aug 14, 2013 3:09 pm UTC
Forum: Science
Topic: Moon falling
Replies: 19
Views: 7265

Re: Moon falling

With reference to the "edge of the moon's gravity", traditional physics suggests there isn't one, but I'm guessing that the accelerating expansion of spacetime means there's a "horizon" where a dropped object would never hit the surface even as time tends toward infinity? Or am ...
by idobox
Fri Aug 09, 2013 6:55 pm UTC
Forum: General
Topic: Nudity and Lighting Yourself on Fire
Replies: 94
Views: 26905

Re: Nudity and Lighting Yourself on Fire

I'm thinking along the lines of that classic experiment with the jellybaby heated the glass tube with Potassium Chlorate in the bottom. Scale it up so you can stand in the tube, connect a tank of pressurized Oxygen to the bottom and have it taper to a nozzle at the top so you shoot up to the sky in...
by idobox
Fri Aug 09, 2013 6:40 pm UTC
Forum: General
Topic: Fantasies about moving
Replies: 35
Views: 7629

Re: Fantasies about moving

I'm from Marseille (nno idea why you put an s in English), and I love the place, but it might not be for everybody. Poor city with a lot of immigration, it often feels like North Africa or Southern Italy which not everybody likes. That being siad, there are a bunch of smaller and richer cities aroun...
by idobox
Fri Aug 09, 2013 6:19 pm UTC
Forum: Fictional Science
Topic: The Light Saber problem
Replies: 122
Views: 64015

Re: The Light Saber problem

You would still have to explain why shots bounce of light sabres but not off spaceship force fields. If we went with the forcefield-contained-plasma theory, perhaps the force fields require a source of energy inside them in order to deflect? Then again, how do we know they DON'T bounce off spaceshi...

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