studiot

Here is another version of the Monty Hall question. A mathematician has two children. You ask if at least one of them is a boy. She answers yes, at least one of my children is a boy. So what are the chances that she is a mother of two boys ? This version demonstrates very clearly that it depends upon what question you ask to what the chances are. @KJW if you answer this please put the answer in a spoiler.

Here is another version of the Monty Hall question. A mathematician has two children. You ask if at least one of them is a boy. She answers yes, at least one of my children is a boy. So what are the chances that she is a mother of two boys ? This version demonstrates very clearly that it depends upon what question you ask to what the chances are.

Thank you for bringing this up, although I feel it is a tad off topic. +1 I also feel it deserves a thread all of its own What do you think ? Here is a short excerpt from a recent book about statistics that may also be of interest about the nature of scientific papers in general.

Then post it if you want to discuss it. Otherwise there is nothing to discuss and this thread is done.

Otherwise there would not be big boys and little boys.

Welcome Modafinil. We have an introduce yourself thread https://scienceforums.net/topic/75313-the-official-introduce-yourself-thread/ It would be most helpful in answering your quesry if you visited this thread and gave us a pointer as to where you are coming from with this. Have you studied or are you studying Mechanics, where the difference between Matter and Energy is spelled out ? They are not exactly interchangeable, though one often leads to the other. But framing an answer is difficult wthout some idea of what you already know, especially since you equation (do you know about equations ?) is only part of the story, and you have an incomplete version of the equation.

Hello arc, welcome back. Kinda difficult to follow you graphs as they seem to cover all sorts of timescales. But I did pick this out. This shows a steady temperatiure 2010 - 2024 and entirely misses the local minimum shown by this one over the same time period.

Small bottle of acetone based nail varnish remover.

What does any idealogue want ? He wants to force his irrational ideas on others and show off to his supporters what a big boy he is.

Only 78 million years BP ? What's the big deal ? Surely there was plenty of life of all sizes on the planet from the very large to the very small at this date. So why wouldn't it have recolonised after impact ?

No, you are confusing the location of the singularity ( 90o) with the 'value' of the function at that location. The Domain is the x axis. Each element of the domain is a point on the x axis. The Codomain is the curved graph of the function. As you have already mentioned larger angles than are possible in any triangle I assume you have seen something like this. The dashed line represent the location of the singularity. Some mathematicians regard the +∞ and -∞ as two different infinities, some regard them as the same (ie only one) ∞ It rather depends what you want to do with it. But you have noticed that the graph switches from + to - at x = 90o. It is the sudden switch that is interesting. But the tangent function is only a graph drawn on paper (or screen). And involves handling infinity. The fluid examples I gave for a reason. They involve a similar switch of state and you can follow quantities like velocity, acceleration, momentum, energy, density (that you asked about) right through the singularity. Furthermore the singularity has physical existence. I have built hydraulic jumps; they also occur in nature. Their physical presence looks like (is) a step in the water surface and all the above properties change abruptly at this step. But all the properties (including the step and the water surface) remain finite throughout. There are no infinites to cope with. I also mentioend shock waves, but I have only ever studied these theoretically for the purpose of preventing explosions in high pressure gas piplines. Which is why I recommended MigL as the member to ask.

For the benefit of those who would like to continue discussing this subject here is my definition of a singularity. In order to have a function you must have a domain, a codomain and a rule which maps the elements of the domain to the elements of tyhe codomain. Once set the domain cannot be altered, although it may be restricted. The domain describes the location of a singularity which occurs in the codomain as a result of the rule. It is not the singularity itself. The singularity occupies some region in the domain, which may be a single point or a line or a curve or an area or a volume or hypersurface or hypervolume etc depending upon the number of dimensions the domain possesses. The singularity occurs where the function is discontinuous or re-entrant or infinite or is of class less than Cn where n refers to the maximum order of derivative required. Some singularities are said to be removable others are permanent. Infinite discontinuities can often be removed and are called poles in electrical engineering, where there is a lot of information to be found under the heading 'poles and zeroes'. Any function with a discontinuity cannot have an inverse. So not quite to those who said a singularity is a point in time. That point is part of the domain and describes the location of the singularity, not the beast itself.

If you really want to explore this I suggest you start with more accessible singularities, such as the Hydraulic Jump or the Acoustic Schock Wave, where we can answer some of these questions. MigL is the perfect Physicist to ask about the latter.

Addressing the issue of imagination further; I often say I distinguish two complementary processes: analysis and synthesis. Analysis is about measuring, describing and explaining what is already there. Synthesis (which I consider more difficult) is about creating something that is not yet there.

I have absolutely no idea. I have said nothing to indicate that I agree or disagree with the 'Big Bang' and I am not very interested in Cosmology or other the study of other unreachable realms. Grow up.

That was a most intriguing and thoughtful answer Thank you. +1 As to the selected quote, I am not sure what you mean by Kurdish text please elaborate. Actually no, I am not sure I have a suitable working definition of imagination. The source of my disagreement was the all embracing part. I don't know why this is but the larger part of scientific work does not involve new discovery, yet all the scientists who participate in the grunt work which is also part of Science seem to for ever remain unsung. As our body of scientific knowledge grows the scope for new discovery compared to the work of verifying, recording and collating becomes less and less. Of course, set against this, the work of imagining new applications and new correlations is expanding, due to the new knowledge. So the balance and direction of that balance is never fully determined. Just a small welcome pointer. Welcome as a new member. I see you have reached your 24 hour post limit. This is in place as a very effective antispam measure, but only lasts the first 24 hours. I look forward to further interesting posts in the future.

Maybe there is some mileage in this but it is too all embracing. What do you mean by imagination ? Fleming for instance nearly threw away the all important penecillin culture as a failure because he was looking for something else. Roengten, likewise, was looking for something else entirely when he discovered X rays.

Where exactly did I say you think you are like Einsrein ? Funny you should accuse me of this, although I did make a post at least in part supporting the sense of a quotation you attributed to Einstein, that was challenged by another member. I said absolutely zero about your intentions. I challenged a flat statement by you that 1+1 = 2 and offered some supporting evidence which you have thrown back in my face as pathetic. Have you any further rude insults you wiah to offer in return ?

I don't see what the good lady has to do with the price of bacon. But if you would like to explain what you mean you might get a better answer. Are you referring to Dirac Delta Functions ?

Oh dear, oh dear, oh dear. Once again you have ignored the questions I did ask Yet offered answers to questions I did not ask. Nowhere did I ask you to explain the mathematical reason why 1 + 1 may not equal 2. What I did say backalong was Instead of asking 'what do I mean ?' or 'how could that be ?' or somesuch You chose to not only preach your guess to me but to challenge my statement as well, without the knowledge of what I was referring to. This is what several other members have been cautioning against. As English is my first language I put a question mark at the end of any question I (unless I forget) and I have asked now on several occasions for clarification of one of your statements. for instance the one you ignored in your last response. . By contrast I cannot recall any time you have actually asked a question of one of mine. Yes your guess would have some merit if we were talking about probability or accuracy but I was not. The answer I was thinking about is 1 + 1 = 1. The electronic chip I was referring to (although the mathematical process can also be implemented in other ways) is called an AND gate. Have you heard of Truth Tables ? Yet again you refer to singularities and infinites indiscriminately. They are not the same, which perhaps is why they have different names, It is true that an infinity is one way for a singularity to occur. But there are many more types of singularity that have nothing to do with infinity. Further your statement that maths cannot handle infinity (or singularity) is just plain wrong, but I will excuse you since you need more knowledge. Once again

I don't understand this question. What does it have to do with the topic ? You have stated that you are guessing (intuition) where mathematics failed. You have also stated that you are not comfortable with mathematics, but wish to learn more. As I see it this has led to a situation where you don't know enough mathematics to actually discern whether and where mathematics has failed. Take a 'singularity'. A very simple example is density. Consider a homogeneous object such a s a ball bearing or a billiard ball. Density is defined as mass divided by volume. Now ask the question what is the density at any individual point in that ball ? An individual point has exactly zero volume. Yet we are taught from a very young age in mathematics that you cannot divide by zero. So what is the density at that point ? Ha smathematics failed ? Is there a singularity at that point ? Yet every day folks all over the world handle this mathematical conundrum ( that stopped the ancient greek philosophers in their tracks) without thinking about it because mathematics that you don't know about, can handle the situation with ease. I have already offered you another example ( 1 + 1 not equal to 2) that you have consistently ignored.

So what do you want to know about either ?

As I honestly do not know what an Orson or a Mork is I am going to do the obvious thing and ask. What is an Orson and a Mork ?

One factor not yet mentioned is that the torque/speed characteristics are very different for electric motors as compared to internal combustion ones. So one consideration is to know where you want maximum power.

Do you honestly find it uninteresting to learn that our whole IT technology rests on devices that do not make 1 + 1 = 2 ? You computer would not work without these devices. As regards infinities and singularities, you whole world is surrouinded by them but since you seem unwilling to discuss them I can only think you don't want to know more about them.