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#1 Re: This is Cool » Spambots can BYPASS Image Verification » 2006-10-13 09:27:08

True, but Spambots smart enough to do that are rare. When MathsIsFun first put up the image verification thing, I was skeptical that it would work because it was a very basic one. I think there are only 2 possible codes that it can show!

I think that if you believe this, then you should realise that humans no longer write the best viral code. There are hackers out there who are using programs that write viral code and then instruct the user how to connect (Backdoor Trojan type programs). It is not a far cry from spambots and phisherbots. I deal a lot with computer security and know that the techniques you are describing are becoming more pervasive.
The FBI uses very simple techniques to infiltrate forums and personal computers (I will not post that technique here - Its so simple some of the clever boys and girls that inhabit this forum may get ideas, but believe me what the hackers have done is latched on to those techniques in a big way. A new generation of hacking techniques is about to emerge. I am just about to write about this on a blog that I set up for beginner level to intermediate computer users ( http://www.phibez.blogspot.com) (my blog there is in its very early stages I only started it two days ago so its a bit rough in all aspects).

#2 This is Cool » practical uses for Fibonacci series (COOL ! and FUN !) » 2006-10-12 22:10:20

cray
Replies: 0

This is a cool page that shows practical applications for the
fibonacci series
http://www.mcs.surrey.ac.uk/Personal/R.Knott/Fibonacci/fibrep.html

The page was created by
Dr Ron Knott
Ph.D, M.Sc, B.Sc (Pure Maths), C.Math, FIMA, C.Eng, MBCS, CITP
He seems to be involved in creative mathematics for young people
He has a lot more cool stuff here
http://www.mcs.surrey.ac.uk/Personal/R.Knott/

#3 This is Cool » a team is always better than an individual » 2006-10-10 05:21:09

cray
Replies: 2

I wonder if any of you can refresh my memory on who made a study of this subject:

I remember reading once that a mathematician went to a fairground and saw a stall where you had to guess the weight of a cow and, if you guessed correctly, you could keep the cow.
What he did was to total up the guesses of all the other entrants and then found the average weight
and he wrote that figure on a slip of paper. When the cow was weighed his answer was something like 1LB off the actual weight. He studied this again and again and came to the conclusion that a team of people could always form a better guess than any individual, if they used this technique. So long as the guesses were not outrageously off the target (for example it would be ridiculous to say there were only three chocolates in a jar if there were clearly more than 20).

I just wondered if anyone knew of this and who the person was that did these little tests?

#4 Re: This is Cool » I disagree with » 2006-10-10 05:04:35

It may, if the programmer chooses, round off to 1 if it gets close enough, but there again lies the human factor.

Exactly, so within say the 300 Million lines of code it will take to put a manned space craft on mars - well there is enough of a gamble to call it a risk.

However I have at last come to accept that they are one and the same,  or 1 and .999..., to be less precise.

#5 Re: This is Cool » Navier-Stokes (A Millenium Problem) Solved? » 2006-10-10 04:56:03

Why doesnt she just ask the people who designed 3DSMax and Maya, or Lightwave?, They have been solving that stuff for years

#6 Re: This is Cool » How a Water Fall Functions- The Latest Solution » 2006-10-10 04:48:37

I couldnt find any relevent info -
do you mean some kind of mathematical simulation of a waterfall?
Didnt that already get solved - I mean 3 animation software has used it for years
and not just some trickery I mean simulated waterfall mathematics
see 3dsMax, Lightwave, Maya etc

#7 Re: This is Cool » My Mind is Playing a Trick on Me! Wait, No It's Not. » 2006-10-10 04:38:36

copy and paste this link into your browser, then look at the spiral for 45 - 60 seconds then stare at the back of your hand as it rests on the mouse or keyboard
(it says 20 seconds on the website but believe me 40 - 60 is freakier !

http://www.at-bristol.org.uk/Optical/AfterEffects_main.htm

#8 Jokes » Engineer and a mathematician bet for $100 » 2006-10-10 03:59:27

cray
Replies: 1

an engineer and a physicist are at opposite ends of a football field and a nice crisp $100 is at the 50 yard line, a bell rings and they walk to half the distance, it rings again and they continue splitting the difference, eventually they're both standing a foot away from the bill. at this point the physicist says "if we keep up this pattern we'll never reach the bill", the engineer leans over and picks up the bill and says "eh, close enough".

thats one I got from here
http://ask.metafilter.com/mefi/3893

#9 Re: Dark Discussions at Cafe Infinity » infinite barbell, circle, 37777...777773 » 2006-10-10 03:39:26

For example, you would be hard-pressed to imagine an infinite circle if you're using spherical geometry - since all your points are on a sphere, there is most certainly a limit to how large a circle could get!

I wish I'd listened to my teacher more when I was at school because I would be taking a rough ride to nowhere to try and prove you wrong with my knowledge but it sure sounds like an obsfucation to bring in circular geometric planes !
I am not disputing your word, just making clear I havent a clue what youre talking about ! HA !

Anyway my simple points were that
1) I dont think that a infinite circle can exist in practice simply because by definition every aspect of it would be infinitely spaced apart - just the fact that logic alone would tell you it is impossible, as a circle would have a defined radius that cannot be infinitely long. A circle is a defined article so to speak.

2) If one were to begin the mathematical excersise of defining an infinitely large circle the definition would necessarily prove that the circle was not infinite since the implication that something is circular implies that it is also curved and to define a curve that must be done in a finite space

#10 Re: This is Cool » Apparently it is OK to say "hey ppl itz da best, k cu ltr" » 2006-10-09 13:04:33

Absolutely, these days its just a bit of fun but when the hacker organisations such as Cult of The Dead Cow, L0pht Heavy Industries, etc were on the FBI wanted list, it was a method of disguising the intention of the writer - CDC (the junior members) greet each other in forums with these words
L0  teh c0w
Hail  teh cow
B0w t0 teh C0w

note the zero in place of o   and the misspelt "the"   this is all part of the variants
in the same way that the word "owned" is now often written  "Pwned"
especially by gamers.
I (just for my own personal interests) made a study of Cult of Dead Cow and though they are now by-and-large respectable programmers earning great amounts of money from very hi-tech security ventures, they were once very anti-establishment hackers with a political edge so needed this kind of 31337 language.
I am not too sure about this bit, but I think the initial users of leetspeak were the CDC members known as Oxblood Ruffin, and Lord Digital.

Interestingly I once found a English to Leetspeak converter - I will try and find it again and post the url
A|-| |-|3r3 i7 i5 |\|0w 7|-|3 ur1 i5 |-|3r3

http://www.computerhope.com/jargon/l/leetspea.htm

microsoft also post this advice for parents and teachers
http://www.microsoft.com/athome/security/children/leetspeak.mspx

#11 Re: This is Cool » I disagree with » 2006-10-09 12:48:08

It is and it can - there is no opportunity for discussion about it, the simple fact of the matter is that 0.999... = 1

But that leaves open the possibility of ambiguity doesnt it?
Surely the computer that takes astronauts to mars is going to be programmed to define 1 as 1, isnt it ?  Else if there is a calculation where the sum turns out to be .999... it just might conflict with a backup calculation that gathers the answer 1 to be more appropriate - 
I mean you can imagine a situation where no matter how infinitely small the difference between
.999... and 1   - it could have a consequence in the physical world.
Or is that just not possible?

#12 Re: Dark Discussions at Cafe Infinity » infinite barbell, circle, 37777...777773 » 2006-10-09 12:37:03

Sure it can.  A circle with an infinite radius is a line.

I just realised you are talking about non-Euclidean Geometry arent you ?
I dont know much about that but I believe people who do know would assert that
the infinite circle could be imagined and that you would be able to imagine walking along
its perimiter, and that a circle of such magnitude, or approaching infinity would appear as a line
In the opposite sense to which two lines that are paralell appear to meet in the distance
this circle would never appear to have rounded edges

#13 Re: Dark Discussions at Cafe Infinity » infinite barbell, circle, 37777...777773 » 2006-10-09 07:50:41

So your saying it's a line, but not a circle, or are you saying
it's a line and a circle at the same time, or what are you saying?

I believe Ricky must mean that at any point we looked at the circle it would look like a line

I believe (and its a belief not a proof)
that an infinite circle is impossible because by definition a circle is a finite thing
If it were infinite we would not be able to define it

#14 Dark Discussions at Cafe Infinity » The absolute majesty of mathematics! » 2006-10-09 06:36:27

cray
Replies: 3

I use the media player called "Winamp" rather than the Microsoft media player
and there is a really beautiful visualisation plugin that can be used with winamp
called "Milkdrop".  I believe some of the mathematics and algorithms used to create its effects are bordering on genius (if not the real thing)
This milkdrop program is simply some of the best maths I have seen as applied to desktop entertainment.    Winamp is free and so is milkdrop
I would urge everyone to try this - Beautiful is the only word I can use but if you disagree - ah well some maths is in the eye of the beholder.
THE MAIN INTEREST IS THAT YOU CAN REPROGRAM THESE PLUGINS WITH YOU OWN MATHEMATICS
Dont judge it within the first few seconds though it seems to interpret the music better after about a minute of the track playing and then just gets more intensely interesting
milkdrop
http://www.nullsoft.com/free/milkdrop/

winamp
http://www.winamp.com/

#15 Re: Dark Discussions at Cafe Infinity » Music; What's Your Instrument? » 2006-10-09 06:25:21

One more thing...have you heard of 'Fretboard Dabbing/Tapping' on the guitar? It is actually like the piano, but it only sounds good amplified, because trying to do that without an amplifier would only give you a very quiet sound. Finger Dabbing/Tapping above the 12th fret has an extremely good effect - It is almost the equivalent of playing notes on a piano

If I remember rightly, doesnt this produce something called "harmonics" or "Mnemonics"?
I just remembe a bass player in a band I used to know did this a lot and it made quite high pitched notes that accompanied and  complimented the actual note played.

#16 Re: Dark Discussions at Cafe Infinity » Steve Irwin is Dead. » 2006-10-09 06:04:12

I think he might not have died if he had used the sunblock I use
on the side of the tube a description of the sunblock says...
"Blocks the effects of harmful rays" !!!!!

#17 Re: This is Cool » Apparently it is OK to say "hey ppl itz da best, k cu ltr" » 2006-10-09 05:46:31

just wait till leetspeak takes over
Incase you didnt know - leetspeak was started by the hacker group "Cult of The Dead Cow"
and came from the word elite.  It is gaining widespread use in forums and is seen as a very youthful persuit.
Cult of The Dead Cow are (without much doubt) very genius computer programmers (Bill Clinton, at one time travelled always with one of the members of C0DC as a computer security advisor). 

(from wikipedia)In February 2000, the cDc was the subject of an 11-minute documentary short entitled "Disinformation." Also in February 2000, cDc member Mudge briefed President Bill Clinton on internet security

elite is the name of the computer port they used on their program "Back orifice"  31337 (eleet, in leetspeak)  BO was a method of infiltrating computers. heres a typical conversation in leetspeak
74!5 !5 133+ 4/\/) !75 (001  (this is leet and its cool)   there are many variants but essentially thats it
heres a wikipedia link
http://en.wikipedia.org/wiki/Leet

edited out a reference to wikipedia - cult of dead cow
some pseudonyms they used to interact on the internet are not suitable
for polite conversation

#18 Re: This is Cool » Recurring numbers dont exist... » 2006-10-09 05:24:27

What you have to do is realize that inifinity, as of now, only exists in the math world.  It does have very many useful applications to our real world, but it doesn't exist in it.

Isnt that a theory rather than a fact? Otherwise you are saying that there are limits to the extent of space and time, and no-one can know if that is true or not unless they have absolute proof.

#19 Re: This is Cool » Navier-Stokes (A Millenium Problem) Solved? » 2006-10-09 05:18:23

It may sound like a trivial comment to some or most people, but I can see that it will also have implications in advanced computer games and simulations. The object of which is usualy to provide a more realistic virtual experience.

#20 Re: This is Cool » Quantum Teleportation » 2006-10-09 05:03:09

I think it is more about the future of computing than transport, but one can always hope

Why do you say that?  Surely this is a major breakthrough. I had heard about the quantume entanglement study in which they teleported a light beam, but until this experiment was conducted (unless its a hoax or mistake) scientists had thought matter transport no matter how small was centuries away

#21 Re: Introductions » hello » 2006-10-09 04:54:07

.sometimes i get  a headache when i am stuck on a problem which i don't get

I know exactly what you mean, and the worst thing is it doesnt go away even if you take Asprin. Still those problems are entertaining - Its like not knowing a foreign language and then suddenly you realise you are beginning to work out what some of it means

#22 Re: Introductions » Im not a mathematician, ... however! » 2006-10-09 04:36:50

I havent visited there yet but, yes it certainly looks like it from the URL, wow this is going to be a trip down memory lane !
Ha ha ha - thanks !

Edited in later

Oh yes that was the one, but I must say I didnt remember much about it, considering I must have typed up many thousands (perhaps 10's of thousands) of those cards while I was a mainframe operator. Ah the good old bad old days of computing when Microsoft was only a nightmare and not a recurring reality.

#23 Re: This is Cool » I disagree with » 2006-10-09 04:01:49

zero is a useful concept, which means "nothing", "not any".
It is particularly useful when it comes to negative numbers. I guess the first time a negative number occurred was the time when people had property and trade with debts. Hence zero played an important role as the cancelled-out. I owe you 5 pigs, I have 5 from you, but then I give you 5, I have -5 from you, thus due.

Interesting - I must read  up on the history of math more ! I mean I was always under the impression the Romans didnt have a symbol for 0, and I heard they were also fantastic at bartering domestic animals etc.  It maybe a mistake I have made in thinking that some cultures did not understand either the concept of zero (at least I thought they didnt have a term for it)

But 0.999... do cause some trouble. Perhaps 0.9999999999 in practice. For example, NASA can reduce the chance of accident by having one more check. Are you confident that after many checks no accident? Infinite checks??? Come on...

This comment blew me away, I just realised that a mathematical problem like this seems trivial and like a minor puzzle, but in actual fact it could have very serious consequences. My immediate response was to realise that the NASA mathematicians and programmers must
surely "engineer" problems like this out of their systems by using a more precise definition of terms, its safe to say my knowledge of mathematics runs out at being awe inspired by the simple qualities of a sum like   3/3 = .999... 
it shook me up to realise that there must be programmers out there who dont realise this crucial simple peice of mathematics might have serious implications unless they understand the problem properly - in the aviation business for example.
This problem has done my head in !  I thought maths was totally absolute and could be defined always in absolute terms Infinity has a lot to answer for and we should ban it !  LOL ha ha ha

Just one more line of questioning from me and then I really have to stop thinking about infinity - mainly because it makes my poor little brain hurt!

Does the concept of infinity only produce problems ?   Is infinity a major problem for mathematics?

#24 Re: Introductions » Im not a mathematician, ... however! » 2006-10-09 03:28:41

Wow! Did you know JCL? I remember hearing "if you want to program in JCL, find something already written and copy it"

Ha ha ha !    I like the JCL comment - Only the other day I was remembering what a hassle JCL was when all the batch jobs had to be rescheduled because of JCL errors etc. Also I started at the age of 16 and they used to make me type up a lot of the JCL cards, (and they wonder why ever since then I've had a bored expression on my face!)  Dont remember a single thing about JCL in detail.

#25 Re: This is Cool » I disagree with » 2006-10-05 23:58:49

Ok then I accept that but I just feel the solution is something to do with the idea of zero.
except incase it isnt I'll  put that on hold , though I have another question !
Is the reason why  this is wrong
1/3 = .333...
2/3 = .666...
etc etc
because  1/3 is not a number but an idealisation of a perfect fraction ?
after all  3/3  would literaly mean  3 divided by 3   equals 1
but a third of 1 is a lot more complex in reality than we think?
so it acts more like a label than a  actual  number
whereas .333...   is an actual number?

maybe its to do with that ?

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