w=f[z]

That makes sense. But I have to wonder then... Since one had to enter the answers online, and presumably there is not a live person at the other end checking answers (that would take a lot of effort...), what would you put in for an answer? Cheers

I'll be darned, I found a pdf of the original test: http://rooth.org/users/avfanatic/uber-IQ-test.pdf If you are skeptical of clicking on the above link, just google Haselbauer - Dickheiser Test for Exceptional Intelligence and this same link should be third on the list I believe. Cheers

To elaborate on my previous point... Suppose we assigned the values to the letters as such: a=1, b=2, c=3, ..., z=26. Then if we had a list of names such that Bohr = 43 (which matches the original incidentally...) Curie = 56 etc. If that were the case, it seems like we could find the pattern (even without a complete set) and deduce that Feynman = 78. Sure... strictly speaking, we must agree with swansont in that there is no guarantee that "y" must follow the pattern (in other words, y could be anything). But I would assume (perhaps falsely) that this question would not have that simple of an answer. I would assume that there would be a pattern. By the way... most online "IQ tests" do have this simple of answers. But this test was meant to be printed out with no time limit or restrictions on methods (e.g., computer coding this problem was perfectly fine with the rules). This test was meant to test people who are "extremely gifted" such that gifted individuals would only score average. It was supposed to test up to IQ 180+. The other questions were not easy either. As a matter of fact, I've seen two others posted here... the "breeding furbles" one, and the "maximum number of 1-in. diameter spheres that can be packed in a box 10 in. square by 5 in. deep...". (The answers to those I got by the way... 1/2 & 594.) I could re-find those if anyone wants.... Edit: The name of this test was the "Haselbauer - Dickheiser Test for Exceptional Intelligence" by the way. "Has-Dick" for short. Edit #2: Just realized I contradicted myself (sort of). The test could be printed out, and there was no time limit etc., but you had to go back to the website and enter your answers in the online version of the test. That is, it wasn't one of those "mail in with a $15 fee"-type tests. Cheers, w=f[z]

Hi Swansont, Normally I'd agree with you... "y" seems like a free parameter, but on the original test (which is no longer there...), it seems like it was looking for a number. In other words, it might be tricky to have an automated "IQ test" that can check for a phrase such as "no solution" and/or "unsolvable" and/or "underconstrained" etc., which, if you are correct, would all be correct answers. That lead me to think that we must solve for the letters that are present, and then there must be a recognizable relation in how each letter is assigned a value. Then we would have to deduce the pattern and find y's value. Missing also are j & q (and x as you mentioned). So there really are only 22 letters out of 26 to work with.... Cheers, w=f[z]

I mentioned that I attempted a "brute force" method with a computer code. The problem I had though was that it was going to take a long long time to run (something like 26^{total number of letters to check} - computations). Yeah... not a very efficient programming technique... I know.... Anyone out there handy with coding efficient computer codes? There's got to be an efficient way to brute-force this thing... a way to minimize the number of calculations that is.... Cheers

Hi Pre4edgc, I double checked with my printed version of this problem and everything seems correct (i.e., I copied it correctly). I guess the thing that really bugged me about this problem is that linear algebra should have done the trick. This makes me think there is something more to it.... Good luck, w=f[z]

Hi everyone, Here is a question I first encountered in 2002. It was from the website http://www.highiqsociety.org/. Since then, they have taken the test that had this particular question down. Here is the question: Note: At first, Planck was spelled "Plank," but the webmaster at the original website stated that "Plank" was a typo (as stated on another forum - see below). Also, there may be some dispute about the spelling of "Block" (Bloch???) and Lippman (Lippmann???). Okay... my first thought was that this is an easy problem to solve. Simple linear algebra... right? This has proven to be a real bi*ch though.... An old (2002) discussion from another forum about this problem can be found here: http://episteme.arstechnica.com/eve/forums/a/tpc/f/6330927813/m/6740938424/p/1 Note: No one there solved it either.... Apparently 13/30,000 of the people that took this test got the correct answer. I think that number is akin to the odds of getting it correct if everyone simply guessed...! Anyway, I never found a satisfactory solution, and I haven't seriously looked at it for some time now, but for some reason I thought about it last night and thought I'd post it. Some of the things I tried: (Note: I noted that "y" in "Feynman" was the only place where "y" showed up... so I thought that there must be a recognizable pattern in the way values are assigned to letters.) - Tried using linear algebra and solving a matrix - Tried using Mathematica/Maple - Tried "brute forcing" it with a computer code (until I realized that the code would run for... like a year!) - Tried equating different names, etc. - It's been so long now I can't remember what all I tried, but it seems like everything I read in the other forum that they tried, I also tried. But nothing worked for me and I never solved this one. So... Have any of you seen this before? (If so, do you have the solution?) Care to give it a shot? Cheers, w=f[z]

Hi ecoli, It doesn't quite work that way either... Infinity - infinity is indeterminate. It is interesting to note that infinity doesn't always equal infinity. There are different degrees of infinity (or so it is thought...). This has to do with something called cardinality. The cardinality of a set is just the number of elements in the set. For example {1,4,d,y,&} has a cardinality of 5. The cardinality of the positive integers {1,2,3,...,infinity} is called aleph-null. It is also the cardinality of all the integers including zero {-infinity,...,-3,-2,-1,0,1,2,3,...,infinity}. This set is what is called countably infinite. Now the reals on the other hand, are also infinite, but that set is uncountably infinite (try it!). The cardinality of the reals is called aleph-one. If you can find a one-to-one (injective) and onto (surjective) mapping [i.e., a bijection] from one set to another, then you can show that the cardinality of the two sets are equal. This cannot be done between the integers and the reals. If this stuff interests you, read up on Georg Cantor and the continuum hypothesis. Cheers w=f[z]

It doesn't quite work that way... Try to think of something that can be infinite, and then think if that (whatever it is) can take on negative values. Keep trying until you come up with something. cheers

Hi BT, In short, yes. So here's a little homework for you: can you think of an example...? Cheers

Since (I guess) this is the place for "crappy simple answers"... Would any of you happen to be able to give me a crappy simple answer about the post-asymptotic giant branch star ZNG1 located in the globular cluster M5 (l=4,b=47.7, d=7.5 kpc). (This is my research project...) Specifically, I'm working on a (future) publication in ApJ (I think... maybe MNRAS). Anyway, we observe material moving at high velocities (between -160 & -90 km/s relative to the local standard of rest (LSR)) that show absorption in OVI, CIV, SiIV for the high-ions and various low-ions. There seems to be various physical processes responsible for the ionization since the gas resides in multiple phases. Turbulent mixing layers (Slavin & Cox 1993) seeming to be the predominant culprit, but there is most likely some hodge-podge mixture of processes going on. Radiative cooling and collisional ionization equilibrium (CIE) (Gnat 1997) seem to be ruled out as we are unable to match the column densities where the column density ratios of the model match the observations. Conductive interfaces (Borkowski et al. 1990) seems to be ruled out due to the N(CIV)/N(NV) ratio and shock ionization (Dopita & Sutherland 1996) predictions doesn't match observations either [N(CIV)/N(OVI) ratio]. I still have to check the possibility of supernova remnants (Slavin & Cox 1992; Shelton 1998). I also still have to compare various properties with other observed HVCs to see if there is any systematic similar properties, etc. Abundance measurements (from the OI/HI ratio) reveals that this gas is slightly super-solar in metallicity ([O/H]=+0.17 +/-0.09 +/- 0.05, where the last error is just a repitition of the uncertainties of the oxygen abundance of the sun). This super-solar abundance may, in part, be explained by the Galactic metallicity gradient (Smartt & Rolleston 1997; Rolleston et al. 2000). (Note that the ratio N(OI)/N(HI) is a good indicator of the metallicity since OI and HI have nearly identical ionization potentials and are strongly coupled through charge-exchange reactions (Field & Steigman 1971).) Since ZNG1 is a pAGB star, this begs the question, "... is this material associated with the star, or is it a highly-ionized high velocity cloud (HVC) located in the Milky Way?" These high velocities get even higher relative to the photosphere (~-200 km/s) which seems quite high for a PN (typically 30-40 km/s). Preliminary work with the photoionization code CLOUDY (Ferland et al. 2003; Ferland 2003) suggests that (in order to match the electron density (0.27-0.86 cm^-3)) this gas must be located at least 5 kpc away from the star, and that this gas must be several kpc thick - thus ruling out the planetary nebula (PN) hypothesis for the most part since it is too far away from the star and too thick to be a PN. It would seem that this gas is a HVC located in the Milky Way - perhaps associated with a nuclear Galactic wind. If so, this would be the first evidence that highly-ionized HVCs may be found near the Galactic disk. So... the question is... what is this "stuff" I'm seeing and what is the origin of it? I need a crappy simple answer! I don't want to get a "C." If I don't get quick answers I'll become very very mad. Note: This is a tongue-in-cheek type of post.... Cheers, w=f[z] P.S. Manta - I'm just having fun... no hard feelings. Okay?

I think (good) note taking is sort of an art. Some students try to write everything verbatim. That is a sure sign of a lack of understanding - like Genecks said, you spend more time writing than listening and learning. The best approach for me was to only write down the key concepts, or a key term to remind me to study that particular topic in greater detail outside of class. It is an art to be able to write down the important stuff and not waste time with the rest. Outside of class is another story... but while in class, it would seem that the focus should be to learn from the professor - hard to do if you don't give yourself time to think about what's being said. Cheers

I've met Mario by the way... he co-authored some papers with a former professor of mine. As far as pop-sci goes, I enjoyed "Bridges to Infinity" by Ian Stewart. Seems like there was another few that I enjoyed too... but it's been a long time now since I read them. I still think the Boas book is really good for a coverage of the important aspects of a lot of different areas. You might check out the table of contents on Amazon if you're interested. Cheers

Hi macdave, What is your math background (e.g., precalculus, calc I, calc II, etc.)? That is, what is the highest level of math you have taken? And what is the highest level of math you are comfortable with? Cheers

Hi macdave, I think the book "Mathematical Methods in the Physical Sciences" by Mary Boas is a very handy book to have around. Cheers, w=f[z]

Hi astrocat, This may not be true for the universe... Isotropy (the property of being the same in all directions) and homogeneity (the property of being uniform) of the universe leads to the cosmological principle (any observer, in any galaxy, would see the same general features of the universe). Think about this for a while... The conclusion is that there can be no edge to the universe. And if there is no edge, then there can be no center. If the universe is infinite, then there is no edge-center problem. But what if the universe is finite? The edge-center problem is addressed by the topology (curvature) of space-time. Depending on the topology, we may very well be living in a finite universe, yet still have no center. Cheers, w=f[z]