Slashdot Mirror

The Physics Dept at Exeter Univ. (UK) publishes lists of simple scientific calculators that students can (and can't) use in exams:

  http://newton.ex.ac.uk/handbook/PHY/Calculators.html

Their criteria are sufficiently similar to your requirements that it might be useful for ruling candidates in/out.

The one I looked at most closely was in the intro chapter to one of the books they linked:

http://www.thunderbolts.info/EU%20Intro%20and%20Chap1.pdf

That the shapes and spins of galaxies can be shown in simulation by collapsing parallel electric filaments ("pinch" effect), p. 26.. In contrast, from what I understand, you have to introduce a majority of dark matter & energy into such a simulation to get a stable galaxy if the stars interact otherwise with only gravity.

Something I'm looking at that's related to this:

http://en.wikipedia.org/wiki/Millennium_Run

It runs an N-body particle solver using gravitational interactions, to run the cosmic microwave background "forward" to see what kind of modern universe it should develop. This produces the pictures of the filamentary large-scale structure of the universe that I've become accustomed to seeing in recent years, but it turns out you can use the same software to model both radiative and magnetic coupling effects. Here's a variation showing how radiation changes stellar evolution:

    http://www.astro.ex.ac.uk/people/mbate/Cluster/clusterRT.html

Same basic large-scale structure, but different number of "stars", different brightnesses, speeds, etc.

I've got the GADGET code running on my MacBook Air using MacPorts, etc.. should be fun, though very slow :)

I always found the Basel problem to be the most elegant converging series involving pi (being the square root of six times the sum of the reciprocals of the squares), probably because there are so many (elegant) proofs of this (pdf), because it's so simple to understand yet not so simple to prove on a cursory inspection, and because it's the specific case that generalized to one of the most important unsolved problems in mathematics.

The wikipedia page on de Branges http://en.wikipedia.org/wiki/Louis_de_Branges_de_Bourcia is very informative

http://secamlocal.ex.ac.uk/people/staff/mrwatkin/zeta/RHproofs.htm

One month it's Healing.
One month it's Death.
One month it's Coal.

Anthracite
http://en.wikipedia.org/wiki/Anthracite
blue stone
blue flame
blue coal

a) You're clueless.

Stone Tools Reveal Humans Lived in Britain 700000 Years Ago
http://news.nationalgeographic.com/news/2005/12/1216_051216_humans_britain.html

b) They're not.

1. secnereffid suorefinobrac / suoecaterc hcaet
2. secnereffid suorefinobrac / suoecaterc thguat
3. nrub 'emalf enots eulb' a rof laoc eticarhtna
4. tnetnoc ruflus dna surohpsohp rof suonimutib
5. syenmihc evac fo mottob ta devil srotsecna
6. loac edarg hgih /w tnrub srotsecna edarg hgih
7. loac edarg wol /w tnrub srotsecna edarg wol

c) Caddo, Texas

Paleolithic 800,000-year-old Acheulian hand-axes from Homo erectus opencast Pembrokeshire Coalfield anthracite Coal cinders and South Wales Coalfield bituminous Bottom ash indicate a 100,000 years' earlier date. Homo erectus burnt 800,000-year-old Crosskeys Coal fly-ashes sampled from Pontycymer Class C - Class F bituminous South Wales Coalfield mined Paleolithic cave dates 100,000 years previous to 700,000 ya. German historian, antiquarian, dentist Doctor Garry Whilhelm Denke (1622-1699) recovered the 800,000-year-old Acheulian hand-axes and sampled the 800,000-year-old Westphalian Coal cinders and fly-ashes in 1656. All of his Stonehenge core samples ('56 Aubrey Holes, Double Bluestone Horseshoe, Centre Stonehenge, Heelstone Ditch, etc) and 800,000-year-old Pembrokeshire Coalfield (Little Haven-Amroth) Coalfield and South Wales Coalfield (Amroth Hills, Cross Keys, Seven Sisters, etc) evidence, including elder Waulsort and Wales white stone (Waulsortian, Early Carboniferous, Mississippian) collection, his crude biology (palaeontology) and hollow stem auger core drill are housed at Caddo, near Breckenridge, Stephens County, Texas, USA.

Phosphorus and Sulphur (Brimstone) means Coal burnt '56 Aubrey Holes.

Little Haven-Amroth Coalfield
http://www.people.ex.ac.uk/pfclaugh/mhinf/pembs1.htm
Pembrokeshire Coalfield
Carbon content 96%
Ancient source

G-d

I'm currently second year physics in Exeter, UK. In the first year everyone covered the basics of matlab. In the second year there was a choice between an several modules including electronics and scientific programming in C with the option to do a further module, in Computational Physics. Neither of the C modules were a requirement though - I ended up doing electronics instead but I have an option to do the first C module next year (I think).

I'm currently second year physics in Exeter, UK. In the first year everyone covered the basics of matlab. In the second year there was a choice between an several modules including electronics and scientific programming in C with the option to do a further module, in Computational Physics. Neither of the C modules were a requirement though - I ended up doing electronics instead but I have an option to do the first C module next year (I think).

photonic structure in nature is not new there are many places eg http://newton.ex.ac.uk/research/emag/butterflies/downloadable_papers.html looking at structure within various insects, looking to replicate it, the beetles talked about with in the article have been studied before.

I study physics at Exeter university in the UK and several of my lecturers have been researching the structures which produce the colours in butterflies (and some other animals such as beetles). See this page on natural photonics for more details.

Indeed. Even looking at Orosz's website, his most recent publication regarding traffic that appeared in Proc. Royal Soc. London was in 2006. Sounds like this work is old, even for him.

GMD

Except the Encyclopedia of Life will be a catalogue, not an identification key.

A catalogue simply records that a species exists and is usually organised by scientific name. You can't find something unless you know its full name, or are prepared to flick through and compare your find with 1.8 million entries.

An identification key on the other hand is organised to answer the question "What is that?", a bit like trying to guess what animal someone is thinking of by asking them questions. A key allows you to specify an increasing list of characteristics and answers with a decreasing list of possible species. Here's an example key for a small number of bugs.

What do you want them to call it? PCRAM? You don't think that will confuse anyone?

Why not, that's what it's already being called, isn't it?

How is this different from "other" Phase Change RAM?

Only barters and personal favors could slip past, and it'd be hard to have a black market based on that.

"I saw seminars on Gutzwiller's work connecting the quantum mechanics of chaotic systems with the Riemann zeta function years ago."

Actually I thought that was THE link between quantum mechanics and Rimann's zeta function.
The folklore I've heard is that Dyson was introduced to Montgomery and asked him what he was doing.
Montgomery then starting explaining his work on the zeta function mentioning some particular equation he had come across at which point Dyson recognized it as an entity appearing in the theory of chaotic qm systems.
anyway, I guess that is also basically what it says in the article only using slightly different words.

In case anyone is VERY interested in this, Snaith's thesis is online at : http://www.maths.ex.ac.uk/~mwatkins/zeta/snaith-th esis.ps.
I also think Baez once mentioned it in his column although I can't find the issue.

PS: I found this account of the tale : http://www.maths.ex.ac.uk/~mwatkins/zeta/dyson.htm .

Okay, fair point. I actually do point that out elsewhere, I guess I summarised a bit too far...

Your math is off:
1. Heat capacity for egg white is less than for water or 3.1 J/g*K
2. Eggwhite coagulates at 62C
Assuming the egg achieved room temperature before experiment, dT=40K. So 50g requires:
(1) E=50g*40K*3.1J/g*K=6.2kJ
  So 4 watts of power will require at least
(2) t=6.2kJ/4W=1550s=25 min, 50s

but, the acutal power may actually higher. Both phones communicate with the tower. The base station emits power directed at the phones as well. A total of 34W would be reqired to coagulate the egg in 3 minutes. If close to the base station, this is certanly possible. I have seen birds plunge to their death immediately after perching on the feed horn on a radar at an airport,

see http://newton.ex.ac.uk/teaching/CDHW/egg/#formula for details

First off, as stated in an earlier port, 2.45GHz is NOT the resonant frequency of water molecules, otherwise only the surface of food in microwaves would be heated.

http://rabi.phys.virginia.edu/HTW/microwave_ovens. html

Cell phones work at 850MHz or 1850MHz, so it's not looking good right from the off.

Second off, as stated by the article, "For instance, a pair of mobiles each with 2 Watts of transmitter output will take three minutes to boil a large free range egg."

Four watts. Four joules per second.

Lets look at this. I'll use some glaring assumptions just to get an estimate of the time taken to cook an egg with 4W (with is a factor of ten greater than you'd really expect from two mobile phone).

First off, lets assume that you want to heat the egg (70g - it's a large egg) from 20C to 100C. I'm not sure if that constitutes cooking, but it'll do for now.

Lets also assume that the energy required to heat the egg is similar to that of water (4186 J/kg).

So energy required is 4186 * 0.07 * 80 = 23kJ.

At 4W, we're talking 5860 seconds, or 98 minutes. And that's assuming 100% efficiency, which definitely won't be the case in this situation. (Not forgetting the already incorrect factor of ten for the phone output power, frequency of operation and burst nature of phone comms).

By the by, I discovered this page on egg boiling science as I finished writing this post:

http://newton.ex.ac.uk/teaching/CDHW/egg/

Perhaps someone with more patience than me can more accurately calculate the energy required to boil a 70g egg?

#5 might be closer to a solution than you guess.

I, like others, RTFA, and along with everyone else who'd like their 30 seconds of "WTF" back, here's a way that might actually work.

1) Remove batteries from phones.
2) You've got between 1 and 2 amp-hours of 12 volts to work with.
3) You need to get the yolk to around 63C for soft-boiling, and from 20C room temperature, that'll take you around 15-20kJ of energy. Yeah, I've skipped a bit.
4) ...but it's within the right order of magnitude to cook an egg, particularly because the low internal resistance of such batteries allows for very high current.

Crack one egg onto one phone - you'll cook something as you short the entire battery out through a pile of egg. If you used the battery as a swizzle stick, constantly stirring the egg mess, and constantly scraping the battery terminals free of solidified gunk, you'll generate a decent amount of heat in the gunk. (You'll also probably electrolyze some of the stuff in the egg, so I wouldn't recommend trying this at home - FSM-only-knows what kind of stuff will show up at the battery terminals beyond hydrogen and oxygen.)

At worst, you'll end up with a partially-toxic, soupy, warmed-over mess with a few chunks of scrambled egg in it.

6) If you've got enough surplus energy (like, say, 100kJ to work with), break up the battery packs, use them to power a small hot plate or peltier unit, (preferably with 12V, but if you've got even more surplus energy in the battery packs to waste on conversions, you could use a converter to turn 12VDC into 120VAC), and power your heater with that.

Crack the egg onto the hot plate, and you'll end up with a light fluffy omelette.

Either way, you're way ahead of the author of the original link.

Let me throw some more figures into thsi discussion to give some perspective on electric cars.
1 litre of fuel contains 33KJ(http://www.projects.ex.ac.uk/trol/dictunit/no tes2.htm) so at 30% efficient let's say that's 10KJ equivalent.

My tank has a capacity of 30L and I can get approx 400 miles on this - but it is a new car so lets keep it easy and say 30L = 300 Miles. so I need 1KJ to get me 1 Mile.
I'll drive up to 600 Miles in one day, so either my electric car needs to store 600KJ, or to be equivalent to my car I need to be able to re-charge whatever it's tank capacity is at a rate of 100Miles/Minute (Assuming it takes 3 minutes to fill the tank at the pump - it's faster than this but I'll be generous).
If I could plug in a 100KW to my car, I'd re-charge it's capacity in 3 seconds. 5KW would re-charge this capacity in the required 3 minues - quite doable with a 240V 3 phase supply.
But where the hell are these batteries that can store that much power that fast? Ok even if I'm generous and take a break for 1/2 an hour at a service station while my car re-charges, what kind of battery can store that much that fast? Or are there "simple technologies" to get around this?
One design I saw for this was replacable battery banks that at the service station would be slid out by machinery and replaced with new fully charged ones...

There is one more thing to worry about - the particular patent abounds with junk terms like "vacuum pressure".

This would be a problem if this particular term were "junk", but it isn't. It's a well known term in the field of quantum electrodynamics. See, for instance, this document which provides a defintion.

You know, a few moments with google would have told you this.

It already is. Scientists already define the second as follows ....

It is the length of time taken for 9192631770 periods of vibration of the caesium-133 atom to occur. http://www.ex.ac.uk/cimt/dictunit/dictunit.htm

Well, I, for one, will never enjoy a pasty ever again.

Drift velocity refers to electron flow, not photons. Thus, the speed of light in a mono-mode fiber is only dependent on the index of refraction. The diamonds length is insignificant compared to the fiber.
See (http://newton.ex.ac.uk/aip/physnews.415.html) where a Bose-Einstein condensate with an extremely high index of refraction is used to radically slow the spped of light.
120 km/h is a mistake, maybe the data rate is 120 bytes/second.

This reminds me of something I saw from a while back, the idea of an optical black hole.

Basically, it has nothing to do with gravitational black holes, but the semi-hysterical press stories didn't pick up on that at the time either.

I'd explain it, but follow the link, or try this one for something clearer and simpler. I got these links from this search, but not all the results look relevant. Still, you may be able to find more, at least starting there.

Applications for cryptography? Maybe. I tend to think that if there were, someone from the NSA would have already tried it. Going by the amount of time it took them with the eight, ten, and twelve digit numbers, I'm not sure how useful they'd be on 128-bit numbers. That's, what, 2^128, which is about 10^37 digits? Not sure about the math.... On the other hand, maybe it works, and there's lots of autistics on government payroll. Where'd I put that tin-foil hat?

BTW - the Sacks book is phenomenal. Some of the problems these people have - there's one person who doesn't have the concept of right (as in right v. left). For dinner, she eats the food on the left half of the plate. If a ball slowly rolls to her right, she will turn a full circle to the left to find it. If I recall, there's about 10-15 cases, each one different.

So if you want to start a flamewar you should rely on trusted methods like the metric system.

It works for me?

Look here
(Apologies for the dodgy colours - I'm stuck on a 2k machine so I saved the screenie with MS Paint :s)

Come on man. Women have been mathematically inclined for quite some time. Even Charles Babbage had help from a woman

I use this (JavaScript) code:

// Metric length measurements
lenFactor["km"] = 1000; // kilometre
lenFactor["m"] = 1; // metre (si base unit)
lenFactor["cm"] = 0.01; // centimetre
lenFactor["mm"] = 0.001; // millimetre

// UK (Imperial) length measurements
lenFactor["inches"] = 0.0254;
lenFactor["feet"] = 0.3048;
lenFactor["yards"] = 0.9144;
lenFactor["chains"] = 20.1168;
lenFactor["furlongs"] = 201.168;
lenFactor["miles"] = 1609.344;

// Convert length to metres, e.g. 200 inches to metres:
// lengthToMetres(200, "inches");
function lengthToMetres(n, strUnit) { return (n * lenFactor[strUnit]) }

// Convert metres to length, e.g. 10 metres to inches:
// lengthFromMetres(2, "inches");
function lengthFromMetres(n, strUnit) { return (n / lenFactor[strUnit]) }

And as far as I can tell, this works! (note, the code might have lost some line breaks due to slash-dot; I did my best!)

If memory serves me, it was largely based on information from A Dictionary of Measures, Units and Conversions. Again (if memory serves), all the conversion factors are set such that they should not produce any rounding errors.

The only issue here is that they're set from a UK perspective so you *might* need to change them for US measurements!

I may not agree with what you say, but I'll defend to the death your right to say it. Twice in the last year certain groups at Exeter University have tried to ban a particularly nasty political party from debates on campus. Of course this was shot down, both times, by a large majority.

Ban groups and more people support them. You fight lies with the truth, not silence.

Of course many "Socialists" in the UK think that the general populace can't be trusted not to fall into the trap of believing what the BNP et.al. say.

A cool overview of why this is such an interesting hypothesis.

If nothing else check out the animation.

mind-boggling

A cool overview of why this is such an interesting hypothesis.

If nothing else check out the animation.

mind-boggling

Seriously though, what the heck is he pointing to here ???

i totally just had a monty python moment as i was scanning through the images in the uk site pretty randomly, you know, flick flick flick ... and then suddenly oh no, whats this??? the hand of god is prodding venus!!!!

gaaah!!

phew.

i totally just had a monty python moment as i was scanning through the images in the uk site pretty randomly, you know, flick flick flick ... and then suddenly oh no, whats this??? the hand of god is prodding venus!!!!

gaaah!!

phew.

i totally just had a monty python moment as i was scanning through the images in the uk site pretty randomly, you know, flick flick flick ... and then suddenly oh no, whats this??? the hand of god is prodding venus!!!!

gaaah!!

phew.

i totally just had a monty python moment as i was scanning through the images in the uk site pretty randomly, you know, flick flick flick ... and then suddenly oh no, whats this??? the hand of god is prodding venus!!!!

gaaah!!

phew.

i totally just had a monty python moment as i was scanning through the images in the uk site pretty randomly, you know, flick flick flick ... and then suddenly oh no, whats this??? the hand of god is prodding venus!!!!

gaaah!!

phew.

Some guy points it out for ya in case you're nearly blind.

Why do all these pictures remind me of her ?

That's only one of a competing set of theories regarding the origin and function of the dollar sign. The etymology itself is pretty easy, but the sign has a number of possible explanations. (Scroll to the bottom.)

For instance, the theory you advanced was popularized by Ayn Rand.

here's a LINK and here's ANOTHER. I'd love to see the Video of him using the Microwave!

Because he WASN'T like the other hard line "commies." Gorby was the first of the next generation of the Communist (Bolshevik) party. Here, what follows is the birth and death dates of the rulers (since the name of the post changed a lot) of the USSR.

Lenin 1870-1924
Stalin 1879-1953 (note this period)
Khrushchev 1894-1971
Brezhnev 1906-1982
Andropov 1914-1984
Cherenko 1911-1985
Gorby 1931-????

Note that everyone up to Gorby was not only alive during the Lenin years but was policialy indoctrinated in the Stalin years. Gorby came too late for that. Born in 1931, Gorby's school years got him nearly all the way through the Stalin period.

Consequently, Gorbachev was really a product of the Khrushchev years rather than Stalin. Realize that Khrushchev's break with Stalin (as mentioned in grandparent post) was not looked upon favorably by the hard line commies you refer to and their move on power following his tenure instituted a period of reactionary extremism.

Gorbachev then, represented a fundamental ideological break with the old hard line elements in the party. If Reagan (note I'm fixing my spelling. All you ACs who bitched about it clearly didn't read the sig) had really been the deciding factor in the fall of the Soviet Union one would expect to see a re-centering of the political climate under Cherenko, Brezhnev, and Andropov all of whom held power during Reagan's first term of office. Instead, what you see is the exact opposite. These three are Stalinists they don't move to the center, but rather further to the extremes.

Reagan's evil empire musings and his overtly hostile attitude towards the Soviet Union weren't terribly helpfull in the big picture. In fact Reagan's saber rattling nearly plunged us into thermonuclear war during the Able Archer exercises, a little publicized intelligence/war-game debacle that got way out of hand.

As for the spending of the 1980s, the United States dug itself into a multi trillion dollar hole in the process. Most of that money went into the military industrial complex. While I've no real issue beefing up the military (as having the 2nd best isn't good for much) its a real pity that some of the social programs so badly needed in this country go un-funded so we can sink another billion into systems both unneeded and unwanted by the Pentagon.

Getting back to the point... Gorby did what he did because he saw the ruin being perpetuated on his country by the lies and secrecy of the Stalinists. He genuinely believed he could redeem the Soviet Government and put to rest some of the injustices done in the name of the Party under Stalin and his followers. He was wrong.

When the dust settled Bush and Reagan got to grin at the world and tell it what a great job they did because no one was left to disagree with them.

Indeed, I defended the right of the nazi-like BNP party to speak at Exeter University, even though I stand for the complete opposite of their views (left wing authoritarians close to Stalin or Hitler). Ban one view, and before long another view is banned, and another...

First they came for the Jews
and I did not speak out -- because I was not a Jew.

Then they came for the communists
and I did not speak out -- because I was not a communist.

Then they came for the trade unionists
and I did not speak out -- because I was not a trade unionist.

Then they came for me --
and by then there was no one left to speak out for me.

OK, I'll give you the benefit of the doubt you are not a troll. Hanlan's razor and all that...

Large amounts of it were invented by Arabs, but their religion doesn't permit advanced forms of banking,

Before anyone starts to believe this nonsense, the first evidence of advanced banking was invented by the babylonians.
The invention of Banking and Coinage
Origins of Banking ...but they only ever used it for fireworks to amuse the aristocrats.

And the chinese did most definately use gunpowder for
weapons.

There's more technical information about the system on the eSTAR project home page, including screenshots and more specific details about the software.

...and due to the slashdot effect we also have a mirror.

In SI units (which most civilised counties use) M means mega which is defined as 10^6, i.e. 1000000 , it is only the computer industry that deems K (1000) to equal 1024 which it does not, then extrapolates this to give 1M = 1024 x 1024. This is absolute rubbish, a different system of quantification should be used when referring to binary powers, as the borrowing of those from SI is clearly misleading.

Bang on. I graduate from Exeter in 19 days time (get my results tomorrow :erk:).

At primary school we had a few BBC's and a few Mac's, but this was in the very early 90's. We had a 286 at home when I left. Secondary school, I went to a great school, and naturally got involved with the computer systems there. It was win 3.11/netware. They eventually upgraded to win95. We didnt learn anything apart from how to so stuff in MS Works and Publisher.

Went to uni, computer science obviously. Aside from one module in the first semester of the first year, we didnt learn anything about computer systems. That module was an introduction to computers, for everyone that had never used one before. Very basic linux commands, and how to send an email and use google (!).

After that, we didnt learn a thing. We have 4 labs, one graphics lab with NT4 and Houdini, one Windows lab (was NT, now XP), one crap lab (broken computers, a few linux ones that are set up so badly it's unbelievable), and one unix lab (was solaris, this year it's suse). No one uses the Suse lab. Most people on the course havent used a *nix system since the first year, and that was following instructions. A few people do though, and admin the union's machine, or other machines in the media.

However all the work we did was cross-platform. Java, HTML, SQL. All the servers are Linux or Irix. It is better then other uni's in many ways. We dont learn a thing about computer admin though. Most people on the course havent even heard of DNS, let alone know how it works. 5 of us did an engineering module - "computer networks", but thats it.

A friend is at Salford. They do learn lots about the admin side. They seem to do a lot more work then us too. Trouble is, they have coursework which is "write a _____ in ASP". It's almost all MS orientated.

Point is, "Computer science" doesnt mean the same from uni to uni. I learnt more about computers from using them at home, from the local LUG, from linuxnewbie (in the good old days). I learnt more about support helping my dad when the computers crashed, 2000 miles away. I learnt more about PHP from doing my own websites. I didnt learn squat from the course. Our course is great at getting computer scientists, PhD's that will invent the next generation of AI, wont teach you about computers though. You could do the course on a spectrum 48k!

Bang on. I graduate from Exeter in 19 days time (get my results tomorrow :erk:).

At primary school we had a few BBC's and a few Mac's, but this was in the very early 90's. We had a 286 at home when I left. Secondary school, I went to a great school, and naturally got involved with the computer systems there. It was win 3.11/netware. They eventually upgraded to win95. We didnt learn anything apart from how to so stuff in MS Works and Publisher.

Went to uni, computer science obviously. Aside from one module in the first semester of the first year, we didnt learn anything about computer systems. That module was an introduction to computers, for everyone that had never used one before. Very basic linux commands, and how to send an email and use google (!).

After that, we didnt learn a thing. We have 4 labs, one graphics lab with NT4 and Houdini, one Windows lab (was NT, now XP), one crap lab (broken computers, a few linux ones that are set up so badly it's unbelievable), and one unix lab (was solaris, this year it's suse). No one uses the Suse lab. Most people on the course havent used a *nix system since the first year, and that was following instructions. A few people do though, and admin the union's machine, or other machines in the media.

However all the work we did was cross-platform. Java, HTML, SQL. All the servers are Linux or Irix. It is better then other uni's in many ways. We dont learn a thing about computer admin though. Most people on the course havent even heard of DNS, let alone know how it works. 5 of us did an engineering module - "computer networks", but thats it.

A friend is at Salford. They do learn lots about the admin side. They seem to do a lot more work then us too. Trouble is, they have coursework which is "write a _____ in ASP". It's almost all MS orientated.

Point is, "Computer science" doesnt mean the same from uni to uni. I learnt more about computers from using them at home, from the local LUG, from linuxnewbie (in the good old days). I learnt more about support helping my dad when the computers crashed, 2000 miles away. I learnt more about PHP from doing my own websites. I didnt learn squat from the course. Our course is great at getting computer scientists, PhD's that will invent the next generation of AI, wont teach you about computers though. You could do the course on a spectrum 48k!