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Comment Re:Quite accurately? (Score 1) 171

No I don't get it and you are wrong.

Your example has as nothing to do with accuracy. I'll help you.

According to Oxford :

The degree to which the result of a measurement, calculation, or specification conforms to the correct value or a standard.

In other word, the accuracy of a model results tells you how good it represents the real world. What you (and all others who so kindly replied to my original comment) are referring to is precision.

So, following your example, both model A and B would be inaccurate, but model B would be more precise than model A. Using ISO terminology, model A and B would show a bad trueness, and A would be less precise than B.

Comment Re:Quite accurately? (Score 1) 171

No. If you have stable equations, you have stable equations. Period. It only means that the result will not strongly diverge with a small perturbation.

How these equations represent the real world (ie. how accurate the results are) has nothing to do with their stability. And this is exactly what the point of the whole story is... the equations, regardless if stable or not, do not represent the observed reality.

Comment Re:Quite accurately? (Score 2, Insightful) 171

To say you can calculate quite accurately an expected value makes no sense a all. I can only understand that they estimate the value using models and believe these models to be accurate. Any other signification is senseless and it would be pointless to argue over it.

Furthermore, you can't asses the accuracy of an estimation with a model. The model is, as you point it yourself out, what gives the estimated value. Only a measurement can validate the estimation and the model.
Their models gave prediction for the other elements and observations showed that the model was pretty much spot on. Using the same approach for Li, they assumed (or hope for) a similar accuracy. Observation now show that it wasn't the case.

But the point of the statement was that the believed it would be accurate (again, because any other interpretation of the sentence makes no sense at all). If it is not based on other results using the same model or technique, how do you believe they would have that confidence on the accuracy of their expectation?

Comment Re:Quite accurately? (Score 0, Troll) 171

Correct wording would have been "Astronomers believe they can calculate quite accurately how much lithium they expect to find in the early Universe based on their experience with other elements."

or something along those lines. The second part, i'm not sure, but the "believe they" really makes the whole point.

Comment Re:Graphical calculator in schools (Score 1) 359

I'm not nostalgic. I went in university in 1999. There were no slide rules anywhere to see, I can assure you of that. But there was a lot of students quickly typing numbers on their calculator without taking a second to think if the order of magnitude even made sense.

Thing is, I doubt that a single type of calculator can be assumed as "the right one". As AC posted just before you, graphical calculator enables the resolution of complex calculus problems and can be a very powerful tool. It doesn't answer the question if it is really needed or the best for the learning process.

But back to your point, I wasn't thinking about your generation in general, but rather about engineers (and maybe physician) of your generation. Whether you consider the whole ensemble or just this particular subset, makes a huge difference. And I can assure your that engineers of your generation have a much better intuition with order of magnitudes. Sure, experience also plays a role (they are older after all), but I doubt this is the whole story. They work and think numerical problem through in a totally different way than anyone I studied with. They may also take more time to solve problems, but they mostly always get them right the first time. This is based on my professional experience and observation of a particular group of people.

Comment Graphical calculator in schools (Score 2) 359

I never understood why a graphical calculator is needed in school. We had them too in 10th and 11th class. It brought me pretty much nothing. Plus I was already used to RPN at the time, so I hate the TI calculators. It would have been a fail investment had I bought one. It was our luck that the things were part of the school material and not our own.

In my opinion, graphical calculators do not belongs in school classes any more than smartphones. It's really not the way to go to promote understanding of concepts, which is as important as learning concepts. The understanding part seems to be systematically ignored by the school system... and its getting worse with every modernisation of schools (at least from what I saw in two different countries where I lived).

But I doubt I'm the right person to ask; I have a rather odd view of this on this topic. I would go as far as to suggest to ban calculators from engineering schools and re-establish the use of slide rule. At least students would perhaps regain some notions of order of magnitude and intuition for it.

Comment Re:RPN FTW (Score 1) 359

I've been using RPN since grade 9, to the great distress of my teachers. With the time collected what I would call a small stockpile of HP RPN calculators (35, 15C, 32S, 42S to name just a few). Although I love the 2 line display of the 42S, I mostly use the 15C, regardless of the speed. I find it a shame that the "landscape" format was not further explored.

Comment Re:ITT... (Score 1) 312

Yes, its obvioue that laws regulating taxi services in Gemany have been in fact thought out to block business of american companies. And obviously, New York managed admirably to achive the same goal.

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