Just what is a Quark anyway?

Apart from being a character in Deep Space Nine, a "quark" is a very fundamental building block of nature. The best way to explain what they are is to tell how they came about.

It was the 1960's, and the people at SLINAC (Stanford Linear Accelerator) and CERN (Centre pour European Recherche Nuclaire) thought they had finally got the big picture of atoms, nuclei and stuff. But the machines doing this smashing suddenly produced some particles never before seen. They behaved differently from the others and were labelled "strange". They disappeared very quickly into energy according to E = mc**2. None were present in nature.

Where did they fit in? The whole kaboodle could be explained by a whole new way of thinking: that protons and neutrons themselves were made up of something even smaller. Indeed, scattering experiments (firing the particles at themselves) seemed to indicate, by the pattern alone, that there was something else inside. Electrons had nothing inside them. Scattering experiments with them told us they acted like true "point" particles.

But just what was inside the protons and neutrons? They settled on the name "quark" and the proton and neutron had three each. One had two "up" quarks and a "down" quark, and the other, two "down" and an "up". "Up" and "down" being arbitrary names having nothing to do with the normal meaning, they might as well have called them "Laurel and Hardy", or even worse,"Bill and Ted".

But what were the strange particles? They reasoned that these must have another "flavor" of quark inside (nothing to do with taste!), which they called "strange". They predicted other particles to turn up with other combinations of up, down and strange, and sure enough, as energies (accelerator energies) went up, these predicted particles turned up. Then they reasoned, "Why stop at three quarks?" - there could be more. They tentatively predicted a fourth, and they called it "charm" (!), and this would produce around 33% more new particles. The lowest energy of these was called the "Charmonium", and yes, it was found, along with all the debris. It was essentially a quark-antiquark pair, or "bare" charm.

How many more were there, and where would it stop? For reasons not appropriate to be given here, they figured out there were no more than 6 in total, and they called the last two "top" and "bottom".

These quarks were getting heavier and heavier and were very hard to produce, but the last one to be detected was bare bottom, in the mid-80's.

It has to be borne in mind that it was never the quarks they saw, just big particles with quarks inside. The question arose - why can't we get a quark on it's own. It would be pretty easy to detect, as each had either 1/3 or 2/3 of the charge on the electron. However, not one had been seen,

The reason they gave was astonishing. Up till then the forces of nature were gravity, electromagnetism, the weak force (only affects electrons and neutrinos), and the "strong" force, which keeps a nucleus together against the static electromagnetic repulsion of the protons.

They reasoned that inside the protons, the strong force was the real strong force, much stronger than had previously been thought, and it was this that was "holding" in the quarks, as if they were tied to it with elastic bands. ( see previous posts for more info). Try to pull a quark out, and the elastic gets more stretched, as it gathers energy from the "pulling", until SNAP it breaks in the middle, not with a loud noise, but a new quark-antiquark pair, matter from energy (E = mc**2). The quark goes back into the old particle, and the new antiquark makes another new particle with the quark just pulled out!

There was another problem with this scenario. It goes back to an old rule developed by Wolfgang Pauli - no two particles can have the same description and be at the same place.

But in the proton there were two "up" quarks!! They figured. that the strong force, like electricity, had the equivalent of "charge", but whereas electricity has two, plus or minus, the strong force had three, and they called these three "color" charges (nothing to do with rainbows). So, in a proton, an "up " must have a different color charge to the other "up".

Because of this "color field" they named the theory Quantum ChromoDynamics.

Believe it or not, that was an introduction. I have left much out.

There IS truth out there!

The Angry Bits

This blog has now come Full Circle (as M Palin would put it) as I am now at a similar position as I was when I started this thing. I now work at CERN again. My permanent post is at Incheon University, but I am the (silent) manager of a project at CERN called the SSA.

The SSA has nothing to do with what CERN is about however.

CERN has been operational since the 1960's, the World's biggest scientific collaboration. It is perhaps the largest telescope in the world. We use bigger and bigger telescopes to see into space, which by virtue of being far away, details are small. Similarly, CERN represents a telescope devoted to "seeing" the very small, by virtue of them actually being small. We call the largest one the Large Hadron Collider, the LHC.

It bashes bits together and has already been under scrutiny in this blog (Three jets are better than two). It makes Hadrons.

A "Hadron" ( pronounced " Hey! - dron!") is a particle bigger than a proton or neutron. It is important to remember that everything we see around us is made up of only protons, neutrons and electrons. "Hadrons" are created by smashing protons together to get "angry" bits - bits that don't belong in the real world. We called them "strange particles" at first, because we didn't know what they were.

Now we know that all the evidence fits like a jigsaw puzzle into thinking that all hadrons (protons, neutrons, plus angry bits) are made up of three new particles called "quarks" (from the book "Finnegan's Wake"). These quarks build up all the particles, except the electrons which seem to act like they have nothing inside at all.

All these particles are very small and behave unlike normal particles, ie billiard balls. It was first realised they were different by Neils Bohr. This was then made into a formula by Prince Louis De Broglie, and then finally made rigorous by Schrodinger et al. as Quantum Mechanics.

The basic concepts behind quantum mechanics are thus: 1. All particles also behave like waves of something ( they give answers that can only be explained by considering them as a stream of waves. "Waves of what?" I hear you say - the answer to that only comes when you understand the math behind statistics and wave mechanics - trust me) 2. You cannot know with infinite accuracy all things at the same time. 3. A new thing called 'spin" has to be called for to explain some of the things we have seen (It is NOT real "spin" as in going round and round, but just another number (we ran out of names to call these things early on)) 4. Some of the effects we have seen can be explained by a particle description AND a wave description , depending on the way we look at it. 5. These things only happen when the particles in question are very small.

So what does CERN do? Simple, we bash the bits together to get new ones, well, we used to. We have just about gotten sick of all the new bits we get out of our collisions, and now we refine the bashing to get the bits back in more useful ways. It's a bit like a car crash, we now know what bits to expect out of the car crash, but now, we bash them together at different "angles" to see which parts survive best at those angles.

The upshot of which is that we are continuing to refine the theory (Quantum ChromoDynamics or QCD) so as to predict next which bit of the engine will come out of our crash and which way it will go.

If it comes out the right way, we predict stuff about the wing mirrors, etc, if not, and we get more angry bits, we go back and try again with a different version of the theory to explain what happened before the prediction went wrong.

As for the SSA, it is just a tool to make the data collection easier, nothing fancy.

The final upshot is that there are no more angry bits any more.

Are you Still Uncertain?

This post is aimed at someone on the Chess site www.chess.com who told me I don't know the Uncertainty Principle.

In short it is this:

Dp.Dx >= h/(2*pi)

where

Dx is the uncertainty in the position of a particle

Dp is the uncertainty in the momentum of it

h is Planck's constant which is:

6.626068 × 10^-34 m² kg / s

pi = 3.1415926.......

and ">=" means "greater than or equal to"

The Uncertainty here is best explained with reference to my car example in the Calculus post. If the car is travelling at 30 kph, it is not travelling at EXACTLY 30 kph because of bumps in the road, uneven tire pressures, wind, etc. A more accurate statement would be "approximately 30kph", or better still, "somewhere between" 29kph and 31 kph. The speed would then be 30kph "give or take" 1 kph. The "1kph" is called the "uncertainty".

Thus Heisenberg's Uncertainty Principle says that the uncertainty in position, multiplied by the corresponding uncertainty in momentum, can be no less, even in principle, than a certain number (h/(2*pi).

The astounding thing to come out of this is that there is even a number.

Ok, so the number is very small, and has often been quoted as the "measurement" of how small quantum mechanics has to be in order to effective.

This is deeply related to the double slit video posted earlier. If you see the electron then the photon's momentum in order to see it, and it's uncertainty, is enough to raise the uncertainty in the position of the electron so as to destroy the diffraction pattern .

The uncertainty relation has its roots in wave theory, where a wave "packet", caused by many waves of similar wavelengths superimposed, results in a bunch of waves, travelling at a particle's speed (the group velocity), but the waves themselves (the phase velocity) travel at a speed much greater than that of light. It's dealt with here:

http://gnabgib.blogspot.com/2005/06/groupie-or-just-phase.html

The uncertainty in the wavelength is equivalent to the uncertainty in momentum, according to the De Broglie formula (wavelength of "particle" equals "h" divided by momentum), and the uncertainty in the position is equivalent to how "big" the "bunch of waves" is.

What does it teach us? It teaches us that we cannot measure everything.

This is something that the books don't teach, and is a piece of knowledge only available through complete understanding. That means, you can find it nowhere on the web either, unless you ask Mr Feyman, who would probably say the same, but unfortunately he is rather indisposed at this time.

The fundamental obstacle that faces us all in quantum mechanics is trying to envisage "particles" as "waves". It did in 1924 and still does now.

Little Shimmy

Let's just take a sidestep for a minute.

Science is wonderful because:

1. You get liquids climbing out of their own containers (Liquid Helium does this with no help at all!)

2. You get objects with so much stuff in them, that light cannot escape (Black Holes)

3. There is a law which states that time cannot be reversed (2nd law of Thermodynamics)

4. The faster you go the heavier you get (Relativity)

5. The faster you go the more time slows down for you (Relativity again)

6. There is more energy in a grain of salt than the entire energy output the Earth has ever produced (nuclear fusion)

7. Stuff can be created out of nothing (E = mc2 and the Heisenberg Uncertainty Principle)

8. Light comes from electricity (Maxwells equations)

9. Water in a fission reactor glows blue (Cerenkov radiation from electrons)

10. DNA's sequence is actually a code for copying itself (genetic code)

11. The entire universe is made up of only 12 particles, plus the photon (only quarks and leptons exist - everything else is made up from them (Quantum Chromodynamics and ElectroWeak Theory))

12. "Science is not only more beautiful than we know, it is also more beautiful then we CAN know"

(with apologies to JB Haldane)

Dur Khaima (part four)

Luckily for our hero, he became stationed at Peshawar, a
frontier town on the borders of Afghanistan, where there
was always plenty going on, taking his mind off what had
transpired.

But he never forgot her, and often would idle the time
away disconsolately thinking about what might have been,
and the cruel fate that had been dealt to them both.

His love, in her own way, had expressed that it would be
much worse for her than for him, since she was confined
to a Palace, whereas he was still free, with time to
forget her. "Never" he would say to her, " I will never
forget, and if you ever need me, Larla, I will come. If
I am not dead, I will come. "

However, time passed, and he spent his days, fighting
campaigns, indulging in British India Society Circles,
and as a secret agent (his upbringing, swarthy
complexion, and mastery of the vernacular, allowing him
to be mistaken for an Afridi, one of the border tribes
of nearby Afghanistan).

However, he never could quite fit in with either India
society, nor British Society. Some of his "chaps" said
he was like "two people in one skin".

As a result, he was branded a "dull dog" and often
ostracised by his own, and one day, incurred the wrath
of his closest Indian friend by pretending to worship
Allah by facing Mecca and praying, a habit he had had to
learn when in Muslim disguise.

Then shortly after, he had word through the famous
Indian grapevine, from the Hakim who had once treated
the despot Rana with boils. Apparently, the younger
bride, having no faith in the Rana's doctors, had called
for him from her own country, and the Hakim, knowing the
Sahib (Indian for Englishman) well, had left him word
via his servant.

The Hakim was in a place close to an army Cantonment
only 100km, as the crow flies, from the city where his
love was. He pressed on with all dispatch to get there.

The Rana was ill, desperately ill, he was told, and the
custom of Suttee was still practiced there, but being so
far from British influence, the Laws were largely
ignored there for the same reason the Rana tried to
double-cross them in the first place.

The term "Suttee" literally means "to go within" and as
kings (Ranas) were traditionally burned on a funeral
pyre after death, Suttee decreed that their living wives
would join him there to be burned alive ("to go
within"), hence the prohibition by the "Ruling" British.
Normally widows are "put away" into seclusion as being
bad luck. It is widely held, however, that some Munshis
misinterpreted the "go within" to not mean "go within
the house" but to "go within the flames".

So, the Hakim was on his way the Rana's City, and
naturally, if any news of the elder bride could be
relayed, it would be a great relief.

The Hakim and the Sahib finally devised a method of
communication using pigeons carefully hidden in a secret
compartment below the Hakim's cage that he used to carry
live chickens, as he didn't trust the Rana's food
markets. If there was any news, a pigeon would be sent
with a message tied to its leg.

Thus satisfied, the Hakim was allowed to proceed, and
yet another anxious wait followed for any news.

Weeks passed, and then more weeks, until one day, there
was a flutter of feathers at the verandah.

A pigeon.

With some haste, the Sahib removed the message and to
some relief, his girl was fine, but to his horror he learned
that the Rana was dying.

He was aghast.

This was the worst possible news. It was at that moment
he decided to go back to the City, but not as a Sahib,
but an Afridi. He hired a skilled horseman and a
knowledgeable guide, bought a fiery mare and started off
over the barren hills between them and the Rana's City,
a route never usually travelled by ordinary means.

The journey was not easy, but the guide seemed to find
paths where there appeared to be none.

Five days later, they came upon a seemingly solid wall
of rock. Without hesitation, their guide headed straight
for it. Closer inspection revealed a narrow cleft not
visible from afar, and into it they proceeded. The
passage through the rocks was so narrow, that at one
point one of the horses nearly became wedged. One hour
later, they emerged into a clear evening sky at the top
end of the very valley the bridal camp had been lured
into almost three long years ago.

Immediately they launched into their plan, that of
mingling with the adjoining local farmers, out for the
day grazing cattle and now returning eagerly for the evening
meal. Three new faces amongst many were not questioned.

The evil in the place was still as permeating as ever,
as they made their way, as unobtrusively as possible, to the
Hakim's house, entering separately so as not to arouse
suspicion.

The Hakim was extremely disturbed to see them there, as
if ever discovered it could only mean a swift death from
a convenient "accident", especially for the Sahib who
had entered secretly and not as an officer.

However, this was only part of the Hakim's deep concern.

There was far more terrible news. All four of them knew
that Suttee was still observed there, but the Hakim's
next five words cut like a knife through our hero's
heart.

"The Rana will die tonight".

Dur Khaima (part three)

After many hours of soul-searching about possible avenues for their future, the unfortunate guy reluctantly agreed (secretly, on further rides) with his love that the wedding must go ahead.

During this time, the enormous Bridal Camp was approaching the territory governed by the soon-to-be-wed Rana, and preparations far outweighed him seeing his love even secretly.

Added to this, his problems became far worse when upon their encampment deep within the Rana's influence, they found themselves virtual prisoners in a deep valley heavily guarded by manned Fortresses armed with cannon.

Then came the real blow. The Rana subsequently demanded almost twice the bride price previously agreed as compensation for the expensive ceremonies he would have to take for marrying a half-caste, the Elder Bride, as she was one-quarter Russian.

Many Official meetings ensued, during which he discovered that the Rana did not look the 40 years he was supposed to, but more like 70, owing to his opium addictions and countless other vices. Moreover he was apparently very sick.

This so outraged our gallant British Officer, not only in principle but because they had openly referred to his love by the insulting term 'half-caste', that he did all in his power to try and dissuade the Rana from any action. But the Rana didn't care about threats of being reported to the British Authorities, as his state was so far from the nearest Political Officer that it would be months before any decision, let alone reply could be made.

So the love-lorn guy did the only thing in his power : he called the Rana's bluff. In the dead of night, they all sneaked out of the valley, 500 elephants and all, risking being fired upon by the cannon.

Our guy was banking on the fact that the Rana would never risk firing upon such distinguished company, as if and when the British got to hear of it (and they would), they may leave a garrison in the city, and this was the last thing on his mind.

Even while the Rana and his subjects were debating this, the bridal camp was nearly half way out of the valley, and by morning, they had made a new camp, being politely greeted by the Rana's entourage, as if nothing untoward had happened. In fact the services of the Officer's doctor were required, as the Rana had been overcome with a serious attack of boils. The doctor was despatched and subsequently easily cured the boils, and our hero turned his mind to other things.

Once again, he tried to dissuade his girl not to go through with it, and this time he was so desperate he requested a private meeting right in front of her uncle's eyes. Only by virtue of his heroic deeds was the meeting allowed so close to the wedding. His uncle physically gasped with shock when he witnessed their manner of greeting for the last time.

He tried every argument he could possibly think of, but she would not change his mind. Her reason was simple. It was her sister, the younger bride, the 14-year old, whom would find life hell if she was companionless. This she could not allow, and no amount of pleading or anger or even emotional blackmail could reverse her decision.

He had lost her. To an ugly husband who didn't love her, and a prison in the Zenana quarters in a place full of corruption and vice.

He turned away, looked back with one long, last look, and left the tent.

Being a British Officer, the next day he had to put all this behind him, and watch dispassionately, as the Love of His Life was married to someone else right before his eyes.

However, as he was later to find out, had he known the Rana better, it may have been better for them to take their chances and run away after all.

He wants to leg it but can't

A guy has been banned from the olympics because without legs he is better.

Story here

http://news.bbc.co.uk/sport1/hi/olympics/athletics/7141302.stm

Where is Steve Austin when you need him?

This guy does not need him. I myself would be happy at my victory!

The mere ruling means he is superior to us. Good for him, I say!

Dur Khaima (part two)

From then on his heart was in turmoil..until fate, in the greatest Hindu tradition, dealt them both a cruel blow...

It was on one of their daily rides, after making camp, that the bridal entourage, consisting of three Royal relatives, the Brides, and their Guide, our hapless Englishman that the inevitable happened.

It was a normal evening, when the younger Bride having been safely hidden in a Ruth, escorted by her uncle and a horse master, and the elder Bride (to all intents and purposes an 'ugly' woman for an Indian high-born Bride) given to riding alone on ahead with our hero, that circumstances nearly overtook them all.

Almost without warning, a dust-storm arose, and the two parties were separated by the choking clouds.

Fortunately, the younger Bride was hastened away back to camp just in time, but our hero was left alone with his forbidden love in a post-Dante hell. With her wit and quick thinking, she guided the frightened horses through a low gully and located a long-vacated cave-dwelling. In the darkness they suddenly lost each other, and then, just as suddenly, found each other, and from that moment, two hearts became one.

After a breathtaking night, during which all sense of time was lost, the storm left, but explanations had to be made.

By good fortune, the camp was half-wrecked by the storm, and almost all were relieved on two counts.....that the younger bride was returned before the storm, and that our hero had protected the elder bride during it. Nothing else mattered. Nothing else was said.

Except inside two beating hearts that were now one.

What was to be done? How could they go on? With almost divine wisdom the elder bride decided that there was no choice. Condemned to a life inside a palace she didn't know, married to a husband she didn't love, the decision was made to carry on as if nothing had happened, as any other recourse would have meant disaster for them both.

He took it very hard, but his strength came from her as she made him realise that for one night, her dreams had come true, her guy had at last returned and had loved her. Knowing was enough.

It was more than he could bear. He now had to go through with a ceremony that meant nothing to either, as she was to be married to a husband who only wanted the pretty Bride, and there was no way to avoid it. As a British Officer it was his Duty to see it through.

And see it through he did............never imagining what was to come next.....

Dur Khaima (part one)

Once upon a time, 160 years ago, there was an Englishman whose father was a traveller in India. Unfortunately, both his parents died when he was but a babe, and at 5 years old witnessed the atrocities of the Indian Mutiny in 1857.

Fearing the worst, as he was English, his Indian nurse brought him up as a Hindu and with his naturally dark features enhanced by Kohl, was passed of as a Hindu until he was 12. Being brought up the Indian way, he thought himself a Hindu and spoke fluent Pushtu, Hindi and Urdu.

Again tragedy struck and his nurse died in his arms within sight of the Ganges, after having been pursued by enemies from a corrupt Citadel where he had been friends to a young Raj (king) and the Raj's small half-sister, having prevented the formers' assassination.

His only way to live now being in his hands, he took the package left by the nurse, which contained a huge amount of money and a letter in strange writing, to the nearest Cantonment of the ruling British Army.

The package contained proof of his birthright but unfortunately was also his passage from freedom to subservience, as the British shipped him back to England to be 'educated'.

He despised it, but the powers that be encouraged him to use his Indian language skills for the 7 years in Belait (England).

In time, he naturally wanted to return to his native India, and was shipped back there to be a part of the Army. His grasp of the cultures and languages soon elevated him far above most of his peers.

His first major task was to be the sole Angrezi (Englishman) in charge of a bridal camp to escort two young Princesses to their wedding, being aged 14 and 17.

After having saved the lives of the Princesses, and the face of the State, in a dangerous river crossing, they became indebted to him and his fast friends, removing their saris to reveal their faces as a sign of gratitude during his evening visits to the Royal tent.

It was at this point he recognised one of the Princesses. The younger one being such an exceptional Eastern beauty that no man could possibly resist looking at her unveiled face. However, he could not take his eyes off the other one, the elder, for she was the very half-sister of the Raj he had saved in childhood, and she was the epitome of Western beauty, being half-Russian.

She didn't recognise him as he was an Angrezi, but he immediately knew her as he had been her only friend during her unhappy childhood.

Even looking upon a high born Indian woman in 1870 was unthinkable, let alone falling in love with one, especially as she was also a Princess and was now on her way to marry a King she had never met.

And yet........it had just happened to him......

"Even in your own house?"

To me , I am startled that the West has not yet "grasped" the mere rudiments of the East.

I refer to the taking off of the shoes when entering a house.

I do it automatically.

People in the Uk (bless them) seem to think it is ok if I just "wipe my feet" on the "Welcome" mat provided.

After that, I still take my shoes off, leave them on the mat, and only then I bow.

In all the places I stay, I do this.

The question has arisen for me thus: "what about your own house?"

My answer is the same, hence the title. I take off my shoes when I go inside.

The point? When will Westerners learn to have this amount of respect for Us?

American Tourists in Japan have to take off their shoes because they are there, out of respect ( very often begrudged). We just take off our shoes in the USA because we are Japanese.

At least I choose to.

The difference is clear.

Travelling Families - Solution

The problem is a paradox, or a seeming paradox. How can a twin possibly be older then her twin brother?

Moreover, why is it the guy the one who ages faster? After all, it's relativity, is it not?

Relativity says there is no difference in the points of view of either twin, since Chere can always say that is her brother who is moving very fast away from her.

So who is right?

It was just this kind of thing that led Einstein to realise that having Inertial Frames was not enough. An Inertial Frame is a point of view that conforms to all laws of physics in a consistent manner. Einstein said that all these are equivalent.

It is like saying that you cannot detect absolute motion

This is true, except when there are accelerations or gravity are present (they are equivalent). This so hard, it took Einstein 11 years to formulate it. He called it General Relativity.

This is how we resolve the paradox. If we realise that for Special Relativity, accelerations are not invloved, so the twins Inertial Frame (points of view) are NOT equivalent

Why? Because in order to return, Chere has to slow down, stop, turn around and speed up again.
That means we can actually TELL who is moving, and it is Chere, so she stays younger.

More details can be found here....

http://math.ucr.edu/home/baez/physics/Relativity/SR/TwinParadox/twin_gr.html#sr_vs_gr

Travelling famillies - a lesson for all would-be relativists

There now follows a demonstration of what Special Relativity (SR) can get up to given it's wicked way. In particular, the misunderstanding of the term "Inertial Frame".

Suppose we had a brother and sister on earth, in fact identical twins. We will call the brother "Mahal", and the sister "Chere".

Chere, the rocket scientist, invents a powerful rocket capable of near light speeds, and plans a trip to Proxima Centuri , the nearest star. Mahal, however, does not like flying, so decides to stay at home.

On their 25th Birthdays, Chere blasts off attaining a speed of 86.6% the speed of light. As the distance to promima Centuri is 4.2 light years, it takes her 4.86 years to get there. She stops, turns around, and blasts back, taking another 4.86 years to get to earth, making the trip time about 9.72 years. The equation used can be seen in the following LINK (equation 1)

The point is, because Chere has been travalling much faster them Mahal, her time has slowed down a bit, and when she gets back, here own "twin" is much older than she is! There is a better example of this HERE

All things being equal. this has been exprimentally proved, and that this is what happens. However, if relativity is right, we could just as well say that from Chere's point of view, it is Mahal who rushes away from her at 0.866c, so it would be him who is the younger when the trip ends? So who is right? They can't both be!

It is exactly this type of question that stumps those who tell us "Oh, I know all about Relativity".

Is anyone able to tell how to figure it out ( you would need a thorough understanding of the subject to be correct!)? I have left a clue - the second sentence.

This is a subject very dear to me, hence the character names. "Mahal" is "dear" in Tagalog (chosen because the twin who stays is (M)ale), "Chere" is "dear" in French (chosen because "Chere" is the French feminine adjective).