imatfaal

Water and flour makes a passable glue - it's what people used to hang wallpaper for many years. I guess the milling of wheat/corn would count as processing though. I would use knobbly twigs as the axles and hope that I could use the terminal bud as an end to stop the wheel coming off. and did you say trigonometry?

Trip - Could you not use the same argument for palmistry, tarot cards, and astrology? Just because something cannot provide verifiable results does not mean that those with a financial/career investment in the techniques will not continue to claim they work.

Well it does work - I did it as a child, but we put the paper under the grill; it was all a bit charred but the writing was clear. The impression I got was that the paper had to be on the point of all burning - didn't realise you could do it just by warming it up (and sunlight?? seems like a bad idea for invisible ink). I believe it works with urine as well - perhaps it's an acid thing, but I am already out of my chemical depth so I won't speculate further. wikipedia claim Lemon, apple, orange or onion juice (organic acids and the paper forms ester under heat) This book claims that the acids break down the cellulose into sugars which then caramelize

You are begging the question - your initial assumption is not unarguable. The rabidity (is that a word?) of the reaction against both Obama and Palin in the last few years in American politics has, I think, benefited them. Undecided voters were swayed by the vitriol and moved AWAY from those espousing it - ie not so much as "I don't want to be hated" but more along the lines of "I don't want to align myself with the haters"

You Me Jeff Great Minds think alike ... unfortunately the second half of that aphorism is that ...idiots seldom differ

what basis do you claim in order to declare the textbook's shortcomings? is there an internal inconsistency or do you have empirical data? there is no basis for a truculent refusal to accept established learning on the basis of personal incredulity or lack of understanding.

Roget's spiral ---> coil, corkscrew, curlicue, gyration, gyre,helix, screw, whorl Sorry - I'll get my coat and leave

the Khan Academy - has loads of on-line self testing from the most basic ideas of arithmetics to beginnings of calculus.

Thanks for clarifying and even more so for the link to Chad Orzel's blog. I hadn't realised he had covered it and his stuff is always good.

"A quantum take on certainty: Physicists show that in the iconic double-slit experiment, uncertainty can be eased." http://www.nature.com/news/2011/110602/full/news.2011.344.html and at SciAm "New 'Double Slit' Experiment Skirts Uncertainty Principle" http://www.scientifi...ainty-principle and "it is not necessary to interpret the uncertainty principle as rigidly as we are often taught to do" from the article itself and quoted in than the editorials Does anyone have access to the article? I rather thought that the HUP was a black and white thing with no grey areas. So can you relax the HUP - or interpret it less than rigidly? Surely σxσp≥h/4π either is a principle or it isn't; if the product is less then the HUP is not universal, or if the experiment complies with the inequality and there is no need for relaxation.

Depends on their age amongst other things. You can see this by imagining (this is clearly extreme) that all who died were 75 - ie all too old in normal course of events to have children, therefore no future births were stopped in this extreme. Not sure you could ever be able to take account of every variable - and even if you did would the number really be interesting.

You can only add and subtract like terms. You can also factor out a term from an addition/subtraction to make it easy to work with. Again try it with real numbers EDIT OK I see your follow-up. No you cannot think of things being like terms that can added if their exponents are different. However you can factorise and take out most of the x term and leave something that looks like this x^2(x+3) which might help.

No - I was showing why it didn't work, I will edit my initial to make it clearer.

I think you are almost certainly correct for your own checksum, but if you had a list of 1000 passwords that were hidden with an SHA1 hash and were trying to brute force (or rainbow field etc) then I think another conclusion could be drawn - even in England you can now be prosecuted under conspiracy/je or for "going equipped" The Theft Act 1968 has the following in section 25 It would be a stretch - but not illogical or unbelievable. I am a lawyer, but not a practitioner so I would not know if this law has ever been extended (or attempted to be extended) in this manner as it wasn't mentioned when I learnt it; the law did have 'cheat' remove from the offences cos this is now covered in the Fraud Act 2006 (IIRC) which might also cover the breaking of passwords to gain unwarranted access. Going equipped is a very strange idea and can smack of arbitrary justice - I often carry enough tools to break into a car - but I would be bloody livid if I got pulled for it. My proviso was because I would not be at all surprised if other jurisdictions had similar but more technologically up to date legislation.

The Cronula disturbances made it into the news in England - how can you have not heard of them in Oz?

You need to be a little clearer in what you are asking. You can multiply two terms to give a product term [math] 4x . 3y = 12xy [/math] With exponents (ie the 2 in [math] x^2 [/math]) you can only only really work on them if the base (ie the x in [math] x^2 [/math]) are the same and you are multiplying (dividing is the same with negative exponent) ie [math] x^2 . x^3 = x^5[/math] but [math] x^2 . y^3 \neq xy^5 \neq (xy)^5 [/math] whenever you are unsure of stuff like this sub in simple numbers and check it still works (or fails) [math] 2^2 . 2^3 = x^5 [/math] [math] 4 * 8 = 32 [/math] but [math] 2^2 . 3^3 \neq 6^5 [/math] [math]4 * 27 = 108\[/math] but [math]6^5=7776[/math]

Sorry - not my scene. You can search for projects with distributables that run on GPUs and use absolutely enormous look up tables - you might get lucky (any non standard ascii character will mean complete failure) and longer messages will not be crackable. Fair warning - you need to generate the look up tables and they weigh in at around half a terra-byte each. Also bear in mind that what you are doing may be illegal where-ever you are, and the use of the data that you obtain will again possibly be illegal

SHA1 is very secure - there are theoretical exploits that may lower the brute force search by production of disturbance vectors to be used in collision attacks- simplistically it lowers use of hash function calls to around 2^51 up to 2^57 down from pure brute force of 2^80. To actually crack a SHA1 - unless it is poorly implemented is very time consuming unless you have access to serious computing power. As with most cryptanalysis wikipedia and the net are a great source of info - even if some of it is a little too excitable. For rough ideas of times involved SHA0 which was superceded by SHA1 has the following info in wikipedia: (nb SHA0 now has lowerfaster algorithms in the order of 2^39 calls) So even if the best algorithms results are correct for SHA1 you are looking at a similar amount of computing time

A Freudian post? Perhaps you wish to believe you had something else on your mind - but the subconscious action of in fact posting demonstrates the true nature of your thoughts without the consciousness filtering out un-acceptable notions. Now get comfortable on the couch and, in your own words, tell me about..... In case of misunderstanding and to avoid offence - I am joking

Captain P is correct - you have a typo Should read, if I am understanding correctly And the answer is

I thought the HUP was pretty sacrosanct - no matter how you try to get around it you will always run into another instance of it (ie its mathematically axiomatic).

If it can be settled, let alone with an observation is it really a philosophical dispute? No, but if it disagrees with the experimentation or the maths, it doesn't need to be explained; it can be ignored as it is irrelevant. It doesn't matter how much the lack of apparent simultaneity and rejection of absolute space and time violate philosophical ideals, the theories that correctly model the universe show these things to convenient human-scale crutches that are incorrect in cosmological terms. in post-modern discourse analysis this would be a highly debated point. You might be interested in foucauldian work on discourse - ie the Archaeology of Knowledge. It is a bit weird and disjointed in places - but a great, if difficult, read. The post-modern conception of the discourse as a normative structure designed to trammel knowledge, exclude exterior interference, protect and promote those within the discourse, and control access to, use of and understanding of information/knowledge is, of course, exemplified by the refusal of the scientific establishment to recognize non-scientific critiques. The fact that the philosophical model fits observation, does not mean that it has validity or predictive power; because firstly it is a philosophical model and not a scientific one (and yes I realise this is recursive) and secondly because it is not really a model but more a non-disinterested charactature.

The original question that arose, once we understood that the universe was not steady-state, was whether there was enough mass to cause the universe to reverse its expansion. This was a book-keeping problem - we just didn't know exactly enough how much mass was in the volume. A critical mass-energy density was calculated; ie if a galaxy at x distance is moving at y speed then if the mass-energy density is greater than z the galaxy will not have escape velocity and if it is less than z the galaxy will have escape velocity. The theories did not concern changing mass or changing gravity - just how much there actually was. Dark energy has complicated this picture