Bender

57 minutes ago, Enthalpy said:

You believe what you want.

I don't need to. I designed and built a solenoid actuator for my PhD using this formula, and the experimental data matched my model nicely.

58 minutes ago, Enthalpy said:

Hint: B²S/µ  or 0.5 B²S/µ might have been correct if B didn't depend on the gap between the magnets.

The formula does not require B to be constant. Integrating B(x)dS/mu works great, if you know B(x). S or mu can even depend on the air gap, and it would still work.

1 hour ago, Enthalpy said:

This isn't the case with permanent magnets.

This isn't the case with electromagnets either. It just gets worse with permanent because they behave like an air gap themselves.

1 hour ago, Enthalpy said:

My suggestion is that you measure magnet forces

Exactly

1 hour ago, Enthalpy said:

search for manufacturer's data and check how wrong such formulas are.

Such data is pretty worthless to check the formula.

Let's assume the disk has a diameter of about 1 m and nearly all its mass is located at the outer rim.

The outer rim would have to move slightly below light speed.

So about 300 000 000 m/s divided by a circumference of about 3, gives a rotational speed of 100 000 000 /s or 6 billion rpm

And yes, it will break long before that point. It will also require many orders of magnitude more energy than humanity ever produced.

Note that its "relativistic mass" could be much smaller than the earth's, because you would be much closer to its centre. The exact mass is not relevant, since it has absolutely no influence on my estimate above.

To know the frequency content of the signal.

This can be useful to analyse the signal in order to design appropriate signal processing or to determine characteristics of the source or to detect faults (eg damaged bearings)...

It can also be useful to filter in the frequency domain, so specific frequencies can be filtered out.

It is also useful in image processing. JPEG eg throws out the high (spacial) frequencies to compress pictures while maintaining high quality.

12 hours ago, hoola said:

check out Penrose/Hammeroff. There is reasearch going on for some years now, that the quantum is required for consciousness, as regular synaptic electrochemical loops are too slow to maintain awareness...attention is being focused on the microtubules present in the cells that seem to have a quantum function, and at around a 20mhz clock freq...

So you are serious... <facepalm>.

Besides the fact that Penrose is no neurologist, and besides the fact that his highly speculative ideas about consciousness diverge quite a bit from the mainstream, you still misread his work. Did you actually read it yourself, or have you only read some popscience article?

11 hours ago, hoola said:

try to catch a fly in your hand next time you see one.  

I rarely succeed. So my awareness must at the very least be slower than a fly.

13 hours ago, hoola said:

the 3 I refer to is the three minds, reptilian, mammalian, human.

Humans are mammals (I can't believe I'm required to point this out).

And what about fish, birds, amphibians or invertebrates? 

1 hour ago, hoola said:

the 3 I refer to is the three minds, reptilian, mammalian, human. If the awareness is a quantum function, then each of the 3 has a 20mhz QComputr and as such, due to the monogamy principle of qm, only two are capable to entangle at a time, leaving one in relative isolation, except through the normal, very much slower electochemical route. This is the reason that hope, for us 3 brained is always an unfulfilled  3 way away.., as quanta don't play that way...unfortunately. Wow, I can't believe anyone responded to this thread, let alone the interesting entries...thanks all and Bender, everything is in the math section..

Try as I may, I can't make any sense of this. If you are high or joking, please indicate so.

3 hours ago, prashantakerkar said:

1 Is

X square + Y square + 2gx + 2fy + c = 0

and

(x-a) square + (y-b) square = r square

same?

Yes

3 hours ago, prashantakerkar said:

2 What will be the general equation of the semicircle?.

Is it 

(x-a) square + (y-b) square = r square / 2 ?

No that is a circle with a smaller radius (70.7% of the original radius)

For a semicircle, you need to define a line through the centre of the circle and add the condition that the included points have to be on one side of the line.

7 hours ago, Sensei said:

e.g. Windows explorer copy files function. When it finds out file is already present in destination folder, it shows up requester asking what do it. Fine if you're copying just couple files. And have to click 1-3 times in requester what to do. But what if there is thousands or millions of files with the same names (but with different dates, different size and content) and with GB sizes.. ? It is damn annoying. User can't simply go for tea/coffee, and has to be there while copying and clicking it over and over again.. When requester is showed entire copying is stopped, increasing time of copying while human is reading what requester showed. Programmer's immediate thoughts (at least my) 1) why they didn't give option to continue copying in background (asynchronous, multi-threading) while requester is open and waiting for user action 2) why it doesn't compare byte-by-byte files to check they're binary the same file (or compare checksum of files) 3) why it doesn't queue similar requests in the list to batch process them at the end... 4) why there is no option "replace if newer date"? etc. etc.

You must be using an older version. My Windows Explorer does that now. I guess occasionally Microsoft does something right...

On 23/7/2018 at 5:02 PM, Enthalpy said:

Do not trust formulas like B²S/µ, they are wrong.

No it's not.

It might not accurate, usually because B isn't constant over S and because B is not easy to calculate, it can get really complicated to integrate B over S. That does not make it wrong.

4 hours ago, geordief said:

Is playfulness essential to the behaviour?

No.

You can be creative even if you know exactly what you are going to create and while knowing exactly how it will turn out.

Working out a math problem can require creativity, eg, while I have noticed not everyone experiences math problems as playful.

Or when I design a new machine, I (regularly) know the concept will work before I even make any drawings.

4 hours ago, ALine said:

A creative impulse is just the beginning stages of developing an idea which has it's basis in a desire or want to perform a certain action or basically do anything that the individual can imagine. I would not say that it is an "impulse" more like that impulse is just the desire to create something new which leads to the development of an idea. Like say you like making things then you have a desire to make something new, this desire can also be like if you want to have sexual relations with someone else, you have the desire to do it and then you have the idea to do it. Ideas derived from desires and desires derive from ideas. Best response I can think of.

Perhaps if you interpret "desire" very broadly to include eg a boss or a teacher requiring you to make something.

2 hours ago, ALine said:

so 3*(false hope) = hope - 1 

so hope = 3*(false hope) + 1

?

3*(-hope)-hope=-1

hope=1/4

Shouldn't this be in the math section?

There are a limited number of possibilities to choose from:

- point in one view is point in other: will be point in third and you have all coordinates

- point in one view is line in other: will be line in third view. Since it is perpendicular to the first view, length of the line is known

- line in one view is line in other: must be line in third. Coordinates of each end point can be determined  (see option one)

- line in one view is plane in other and line is in one of the principal directions: will be line in third. Length and position are known.

- line in one view is plane in other, and line is slanted: must be plane in third. The plane must have the same shape as in the known view, but scaled in one direction.

- plane in both views: plane or line in third view. The planes must have the same shape, but scaled. Each vertex  (point) of the plane can be projected to the third, where it will be a line or plane with the same but scaled shape.

So the tricky part is finding the corresponding points/lines/planes. With practice, you can imagine what the shape is in 3D, and it all becomes easy. Before you reach that point, start with the planes: are there corresponding lines/planes with the same width/height?

Important is that you can do this exercise for individual points, lines and planes first. There is no point in trying a 3D shape if you cannot project the constituents correctly.

6 hours ago, studiot said:

I have never heard of absement and I couldn't think of a use for the second (or even third fourth etc) integral.

Neither did I. Interesting.

While I see possibilities for absement, the higher order integrals (and derivatives beyond jerk ) look like somebody made up a bunch of words and thought it was neat to put them into a Wikipedia article.

It depends in rather nonlinear ways on the distance to the object pulled and the material and geometry of that objects and the objects around it.

Even if all those are known, it is only possible to calculate the force with a numeric finite element model, except for some specific cases.

8 minutes ago, StringJunky said:

If you covered up the drivetrain it would keep clean longer.

I guess so, but the critical part is on the wheel, which you can't efficiently cover (without sealings adding friction).

23 hours ago, John Cuthber said:

How (in)efficient is a "traditional" bike chain/ sprocket drive?

Between 80-99%, but for a single gear chain or belt drive it's probably close to the 1%.

For recreational or transportation use, it is as pointless as ceramic bearings or a carbon frame, but there are amateurs paying lots of money for those, so why not?

I wonder what happens when some dirt gets on this drive?

5 hours ago, Ten oz said:

If everyone with residency (regardless of citizenship status) received it that would go an extremely long way towards selling me. 

Now we're getting somewhere.

1 hour ago, Ten oz said:

Everyone who would receive it doesn't pay taxes.

What do you mean?

Everyone receives it.

Everyone pays taxes.

44 minutes ago, Ten oz said:

t has something to do with BUI. How can it be "universal" if it actually doesn't apply to millions?

You are the only one who keeps insisting this.

46 minutes ago, Ten oz said:

The poor are the only group I am interested in helping, yes. I am not interested is a program which would make middle class people even more comfortable while not doing anything for the millions of others.

You do realise that money-wise the net effect for the middle class would be zero?

23 minutes ago, Ten oz said:

I have not proposed a system. I have been disagreeing with BUI. 

I don't see how you do. You only discuss some perverted variant of UBI.

23 minutes ago, Ten oz said:

Everyone except people who could actually use it like immigrants which there are millions of living and working in this country. 

Nobody here excluded those, except you. Illegal immigrants are an issue, but they are free to get registered and either get asylum, with all the benefits, or get a free ride home. The conditions for getting asylum are open for discussion, but have nothing to do with UBI.

26 minutes ago, Ten oz said:

That group isn't one care about when at the voting both. Too many people have graver concerns that general dissatisfaction with their upper class life.

Too bad wealth is your only criterion. Do you think these upper class folk are all living a happier, more satisfactory life then those immigrants?

7 hours ago, Ten oz said:

I simply cannot envision that as the outcome. With other programs politicians at both the local and federal levels constantly tweek who is eligible. We can say the word universal all we want but it won't be universal. It include everyone. Some combination of green card holders, undocumented workers, visa holders, felons, people on probation, and etc will be denied. Which means tens millions will be shut out forced to work harder than everyone else doing the jobs others will have no need for. Those shut out will be overwhelming immigrant and minoriy. While you envision BUI freeing people of burden empowering them to pursue education and entrepreneurship I see something far uglier where a caste system is created that does the opposite. 

None here is advocating your system.

An actual UBI would benefit nearly everyone, which is way higher than your 50/50 tipping point. It is well known that rich people are happier when the poorest are less poor. Everyone profits from less crime, less sickness, less depression, more community work, better education... (except perhaps for some power hungry religious conservatives, but who cares about those?)

Even if you don't want to count the indirect effects, at least consider the large group who are "well off" but stuck in a job they hate or feel insecure about the future financial situation of themselves or their children.

PS: I don't live in the US, so I'm not primarily interested in the current political situation there.

It depends on the surface it is dropped on. If a significant part of the kinetic energy is absorbed by the impacted surface, a more massive case would slow down slower and anything inside will experience less acceleration and less damage.

On a concrete surface, the shock absorbing qualities of the outer case become more important if it is more massive.

It could also help to improve how we appraise economies. GDP counts a lot of things we don't want and doesn't count what we do want.

Inefficient healthcare, dangerous roads and vandalism all increase the GDP, so are currently great for our economy.

3 hours ago, swansont said:

If the BUI is $10k (and the numbers here are only for an example) and the tax rate is 40%, then anyone making under $25k would get some net BUI, because 0.4 * 25,000 = 10,000) but everyone over $25k would not.

I know this is just an example, but there are better and more creative ways to raise taxes. I favour taxes on income that is not earned/deserved and/or impacts our society negatively. Examples are: resources, inherited wealth, real estate, most of the financial and marketing sectors, weapons, fuel, alcohol, meat...

Another example that is not particularly popular is a tax on (excessive) savings. Once you realise that the need for savings is significantly reduced when your income and that of your children is guaranteed, then this becomes a lot less unspeakable.

Note that none of these are directly linked to UBI, but are merely suggestions for where to get the required money.

I don't see why you wouldn't give it to the wealthy. It would require paying for a control system which negates the "unconditional /universal " part and might end up costing more than what is saved, since the wealthy are a minority.

On 9/7/2018 at 8:34 PM, YaDinghus said:

I love dark turns ;-)

"Arbeitsbeschaffungsmaßnahme" is a real thing in Germany. People create a problem for someone to solve just to make them do something. It's like an empty reference joke: the reference itself is the joke and doesn't depend on the content. 

Not only in Germany. In Belgium 14% of the people say their job is utterly useless. Since people tend to like seeing purpose in what they do, I'm guessing the amount of jobs that is actually useless is even higher.

This phenomenon masks the underlying problem that there simply isn't enough work to do. We can discuss all we want about pros and cons of UBI, but in the end it is the only reasonable answer to a structural (as in: does not depend on how well the economy does) job shortage.

8 hours ago, Ten oz said:

Anyone with a registered business which produces for sale any agriculture product is a Farmer and would receive a guaranteed salary. Anyone who is employed by a Farmer would also receive a guaranteed salary. How much is produced and sold doesn't matter. Farmers would keep the different. 

Ok, so all one needs to do is register a farming business. Sounds like something that requires conditions to be met.

How many carrots do I need to grow in my back yard to register such a business? Now I can pay my friends to pull a couple of carrots some afternoon. How many carrots do they need to pull to get the income?

Any smartphone?

As far as I know, Arduino is easy to get started, but Raspberry pi has more versatility and computing power.