Bender

7 hours ago, Ten oz said:

if everyone worked hard

Here is your problem: not everyone can work hard for a variety of reasons:

- lack of marketable skills

- disability 

- discrimination 

- lack of work: This will get worse in the near future. I predict the problems in this respect will lift of with self-driving cars. It is absurd that this would be a problem: our hopelessly outdated economic model makes us slow down automation and technological advancement.

- voluntary work or all the useful things people do that doesn't currently clasify as "work"

As a liberal, I also have to point out that there is no freedom of work now (unless you have very good credentials). Of course people get unhappy when they are not free in such an important aspect of their life.

Will UBI solve everything by itself? Of course not, but it will solve the problems directly caused by our current system.

7 hours ago, Ten oz said:

Seeing those one deems unworthy of happiness happy when they themselves are not happy leads to multiple levels of envy and anger.

When more people are happy, this problem will decrease.

17 hours ago, Pembroke said:

If this is the case, I still think it is possible that certain people ignore rational arguments because the processes taking place in their brain is for whatever reason rejecting it. Why processes would do that is beyond the scope of what I can glean from pure reason

It is pretty simple: the cost function, usually consisting of conscious and subconscious, rational and emotional components, favoured the irrational choice.

4 minutes ago, Ten oz said:

I would vote for any politician that supports universal basic income. I wish such policies were advocated publicly. I would support those politicians in hopes in prosuit of UBI we at least get healthcare and fixes to Social Security.

That said I do not believe UBI would work. It doesn't address the nature of certain terrible people. The Nazis chanting "Jews will not replace us" won't be satiated by being able to work harder to get more wealth. To that end what percentage of wealthy people do you think got there by "working harder"? UBI doesn't address any of that. There are  people in this world wouldn't mind seeing all members of the LGBTQ community rounded up and killed. Such people would never just work harder to have more and ignore gay couples happily living their lives thanks in part to UBI. It isn't merely about competition. Feelings of hatred, envy, righteousness, superiority, and etc often lead to wanting to see others crushed. They don't merely want more money than there nemisis. They want their nemisis to be made to suffer. UBI totally ignores what is actually behind societal ills.

None of this has anything to do with UBI, which is an economic system. It's success does not depend on whether terrible people exist or not.

It does indirectly alleviate the problem by reducing envy and attitudes like "they steal our jobs". It will also reduce general insecurity which in turn reduces us vs them sentiments. Moreover, crime rates of non-caucasians will drop dramatically when they no longer face financial stress.

Lastly, criminal organisations will have a harder time exploiting the weak and desperate when there are much less weak and desperate.

Given that LGBTQ hatred is on a steep decline worldwide, Nazi's aren't as popular as 70 years ago and aggression and crime rates are significantly decreasing worldwide, I do not share your pessimism that terrible people will always spoil the party.

4 minutes ago, Ten oz said:

Humans are selfish and competitive by nature just as most predators are. Many of us have need others to lose so that we can revel is wining. Worse still is that for some the feeling can never be fully satiated. The challenge of creating equitable societies is seldom about the availability of resources or there distribution but rather is how we humans behave. How does an equitable society exist while under never ending assault from selfish, greedy, angry, often violent segments of the population who work tirelessly to undermine it? Even if it is only 1% that is enough to sow fear, distrust, discontent, and all the other things which plague societies. Obviously equitable societies can't cast out or kill agitators because that would mean they were no longer equitable. It is a bit of a catch 22 the way I see it. Refusal to stand strongly against a strongman empowers strongmen yet to stand strongly against them results in war where everyone basically becomes strongmen. 

As a kid I saw what I believe was a twilight zone episode, but could have been something else, where a scientist was wakened from some sort of cryo sleep into a Utopian future. The scientist had gone to sleep 50yrs earlier in hopes his cancer could be cured in the future. The Utopian future provided for everyone. No one was hunger, homeless, depressed, or etc. All was perfect. The Utopian govt had awoke the scientist because they needed his help to access an old weapons system he had help designed. A meteor was headed towards earth and the Utopian govt wanted to bow it up. The Scientist agreed to help and got the weapons system online for them and then he was immediately detained. Turns out there was not a meteorite. It was a U.S. military space shuttle carrying the U.S. President and numerous govt officials.  The shuttle had fled earth during a third world war many years prior and was finally returning. The Utopian govt blow it up for fear the officials would come back is destroy their perfect society. They acknowledge it was genocide but insisted it was necessary genocide. The scientist rebuked them savages. Both the scientist and the Utopians were right. 

 

None of this invalidates UBI. It does not prevent people from working harder to get more wealth. It will certainly reduce crime, given that our prisons are filled with poor people.

I hope you aren't giving too much credibility to some anti-communist episode you saw as a kid. UBI is nothing like communism.

15 minutes ago, Pembroke said:

If the income is unconditional, can I choose not to work?

Off course.

Fair warning: you could have a significantly increased risk of depression if you don't do anything useful (which is my definition of "work", as getting paid is no longer a necessity).

Unconditional basic income.

Everything else will follow.

25 minutes ago, John Cuthber said:

It is precisely because of the large time constant that people use PID controllers.

The large time constant will cause the D-action to react almost exclusively to sensor and digitisation noise.

Any significant I-action is likely to cause an overshoot, which is exactly what he doesn't want, especially since he can't actively cool it down again.

So a proportional control: sure. It will be slower, noisy and take more effort, but could be slightly more accurate.

7 hours ago, studiot said:

 

I wonder if you have, perhaps, misunderstood the original description.

 

There are two beams not one.

 

These two have a common bearing at the intermediate post and probably some loose connection.

 

There is therefore maximum shear acting at this post, on both these beams which should be considered as simply supported.

 

Do you agree with this?

 

 

I do wonder what this piece of timber is actually supposed to support. Perhaps only itself?

 

 

 

 

How I understood it, he now has two beams with 16' and 4' span and a post in between. He wants to connect the two and remove the post to get a single beam with 20' span.

Edit: I suppose the beams carry crossbeams which support the roof.

4 hours ago, J.C.MacSwell said:

On thing to consider is run out of the reinforcement, It might not be the point of maximum moment but it would still be higher than the maximum in the original case, and the bolts would add stress rises in that area from both the bolt holes and loads transferred from the steel reinforcing through the bolts themselves. It might be better to reinforce a fair bit past the centre point rather than stop short.

Indeed an important point to consider if the original 16' beam was not dimensioned for a 20' span.

Check out welding helmets.

On 27/6/2018 at 6:55 AM, Pembroke said:

When people generally consider free will on the level of consciousness, they are relating it to our conscious operations, which includes things like conscious perception, and listening to reasoned arguments, etc. but there is not guarantee that those things will influence an unconscious process. Through studies in psychology, certain triggers are discovered which, on average, activates the behaviour of most or many people in a certain way, and so we could say that our wills can be influenced through those triggers, but it is less certain that we can be influenced through perception of things we think are rational, or through the arguments of rational people. I think that latter claim (about rational arguments) holds up to observation, haven't you in the past seen people ignoring rational arguments and wondered why?

I think the distinction between conscious and subconscious decisions is rather fuzzy as both influence each other constantly. This is why I consider such distinctions irrelevant in the context of free will.

The fact that people choose to ignore rational argument, consciously or not, is at best an illustration of that.

I sometimes wonder whether people actually want to be in control. Some people give me the impression that they find comfort in having some subconscious flaws to blame . 

1 hour ago, studiot said:

There is currently zero moment at the post to be removed. 

Which is why it is useless to consider that part of the beam in a strength calculation, as it won't fail there.

Moment will be biggest in the middle (since we don't have info on the load, I assume uniformly distributed load), and that is where such a beam fails. 

But the load situation considered here is with the post removed. In that case there is definitely a moment to be transmitted at that location. It is true that this position is not critical, so the connection can be considerably weaker than the beam without failing. I would strive to make it equally strong anyway to be on the safe side.

Shear stresses are required to transmit the moment (and negligible shear force) from one part to the other, but overall in a beam which is more than 5+ times as long as it is high, nobody calculates shear forces.

1 minute ago, John Cuthber said:

PID controllers have been widely used for a long time; rather longer than PWM has been common.

If you use an arduino, doesn't it have PWM built in?

PID is horrible to control temperature which usually has a large time constant and no means to actively cool after an overshoot. Just P will work but requires a voltage regulator. An Arduino does that with PWM, which is supported on only some of the outputs. It is not that difficult to implement, but for what is likely to be a first-time user, I'd stick to bang-bang for quick success. 

In this case I'd use bang-bang myself, and only look for alternatives if necessary.

1 hour ago, John Cuthber said:

A bang bang temperature controller is (usually) easy to implement, but a proportional one will give  much better control.

Proportional control requires implementing PWM, and I doubt the possible gain would matter for a school project. The noise can also be annoying.

- Shear is negligible for such a beam. Only the moment matters. (Failure modes in wood can be complicated and can be caused by shear stress, but this stress is indirectly caused by the moment and not the shear force)

- The new structure could very well be as strong as one with a single wooden beam, because steel is much stronger than wood. Depends on thicknesses.

- relying on friction is quite common and reliable and has the additional advantage of less stress concentrations. 

You also need some heating resistor to put inside (if it is water resistant) or wrap around the tube. Arduino can control relay to switch heater on and off. Usually you use a dead band: switch on at eg 49.5 and switch off at 50.5. (That is called a hysteresis controller or a bang-bang controller.)

6 hours ago, J.C.MacSwell said:

It made sense when I wrote it...I better try again +1

It made sense when I first read it. Can be confusing. 

On 23/6/2018 at 9:49 AM, vortix2950 said:

is it possible to launch air balloons carrying a large mirror and than point a telescope  at the position the mirror would proximity be in , and see a reflection of earth?  

You would only see a small part of Earth. Assuming an appropriately concave mirror, at the max height you can get a balloon, most of Earth will still be hidden behind the horizon.

On 25/6/2018 at 12:52 AM, J.C.MacSwell said:

Need more info...

Stick yourself underwater on a scale, adding weight if necessary to hold you in place and get a reading. Then stick the part of your arm out of the water that you wish to weigh. The difference will be the weight of that part of the arm, plus the weight of the displaced water. So then deduct the weight of the displaced water and you have the weight of that part of the arm.

How would you differentiate between a lead or a flesh arm? Both will continue to weigh down on the scale and the Archimedes force only depends on the displaced water, which is equal in both situations.

5 hours ago, StefanLazic said:

1) I was not planning of making one

2) I did not know about the german prototype before starting this thread

Apply whatever I said to any generic invention you want to make. You will need some proof of concept before you start a potentially successful kickstarter. Luckily it was never cheaper or easier to make one.

10 hours ago, Pembroke said:

To be clear, I understood what you were saying and on one level I can agree with it, the only reason I take issue with it is because when you say there is no conflict with free will, I think you are redefining what people generally think of as free will when you place the will on the level of unconscious processes rather than in consciousness, which is how people generally conceive of free will.

The problem with "how people generally conceive free will" is that want to be super-special with consciousness as some mystical property granting us that super-specialness.

Often the unconsciousness is seen as not part of us and completely out of our control. That is complete nonsense. Our unconsciousness can be trained or reprogrammed, and obviously takes our preferences into account. I disagree with the notion that it is separate from us.

10 hours ago, Pembroke said:

Let's say I felt a sense of ennui, existential angst, or something like that. If I wanted to feel satisfied with the world as it is - perhaps I had listened to some scientist speaking who said that asking if there is a meaning to life in an objective sense is a meaningless question, so all there is are natural processes. Say I would then understand or believe that, but the sense of ennui or existential angst continues. On a conscious level, I want (referring to what Bender said above) to accept this fact and simply act in life according to it, but though I do not understand the feeling, the sense of ennui or angst continues to rise to my consciousness. Is there not then a conflict between free will as it is generally understood (the ability to decide our fate) and the process in our brain which causes us to react, and potentially even act (let's say, for example, I further engage in activity to assuage the feeling of ennui or angst, despite knowing consciously they are meaningless, futile, or potentially harmful)?

Our unconsciousness can be flawed and reprogramming can be difficult. The fact that there are boundaries does not invalidate free will entirely.

Personally, I have eg completely lost my existential angst through reason. Some other examples are my fear of heights which is almost entirely gone and the fact that at one point during my early twenties I decided that I can eat and enjoy all food. Before that most vegetables and several other dishes made me convulse. I don't know why other people can't make such decisions, but I refuse to accept that I am special that way.

13 hours ago, Scott of the Antares said:

Perhaps so, but any anomalous ancient site that seems incongruous with our understanding of the development of civilisation can be more easily explained by a as today unknown civilisation rather than aliens.

Examples would include;

Gobekli Tepi; purposefully buried complex carbon dated to over 10,000 years old when buried.

Twin cities in the Gulf of Cambay under 100 feet of water; last above sea level also around 8-10,000 years ago.

Mountain of Light at Gunung Padang, core samples carbon dated to around 20,000 years ago.

Drilled and grooved blocks at Puma Punku.

Just saying that there are sites around the world that show signs of previous human civilisation that we have little knowledge of, and that some people will wrongly cite these as evidence of aliens.

Fair enough. My Atlantis alarm got triggered, but in retrospect, you didn't mention technology level.

6 hours ago, StefanLazic said:

The germans built a functional one in 1943

If you have nothing new to add, why even bother making one at all?

On 23/6/2018 at 11:18 AM, Scott of the Antares said:

I think a lot of evidence that ancient alien subscribers cite can more easily be explained by a previous civilisation that is lost to history.

And even more easily by civilisations not lost to history and human ingenuity.

On 19/6/2018 at 11:12 PM, StefanLazic said:

I think that the germans made hundreds of prototypes before making a successful jet engine. I have to risk about 1 year of savings to build a prototype that may or may not work... I guess that I'd have to build at least 10 prototypes before having a viable commercial engine, thus I believe that a jet engine is out of my reach. And unfortunately in switzerland it's impossible to get financial help to build a prototype of an invention (from the govt). Maybe I should try a kickstarter.com project...

You don't have to make a fully functional prototype; you have to build a proof of concept. With present 3D printing technology, you can probably make one for less then 1000€ , which shouldn't be a problem for an automation engineer.

Is the pressure drop over the heat exchanger specified in the data sheet? That is the pressure difference you are aiming for. 

Besides a valve, there are other ways to get a pressure difference. Bernouilli is an option, if you use a very large diameter (slow flow speed) T for the input and a small diameter (large flow speed) for the output.

Another option could be that you direct the output of the exchanger to another part in your circuit where the pressure is lower, or the input to where it is higher.