Are you Positive?

Let's make a quantum jump ("quantum" jump these days means to most people "a specific" jump) to what Paul Dirac did.

In those days, the early thirties, quantum mechanics was still in it's infancy, as was special relativity.

What Paul Dirac did was to try to marry quantum mechanics with relativity for the electron, the simplest particle.

His results were astonishing.

He wrestled with the maths involved, turned the mathematical handle, and out came the washing.....But there were TWO results, not just the one.

The one he was after, the electron, was quite clear. What was NOT clear, however, was the other answer. The maths had produced something no experimentalist had ever done!

Paul Dirac simply shrugged off the shock and said "There must be another particle out there, with the same mass as the electron, but oppositely charged".

Outrageous!

In 1932, Carl Andersson found it in his cloud chamber. The path it took had the look of an electron, but curved the opposite way. It was henceforth named the "positron".

Paul Dirac and Carl Andersson had just revealed anti-matter!

Outrageous!

The Atom - Part Three

It was the insight of the century (OPINION!).

By the time the Bohr atom had come along, everyone knew that light behaved like particles AND waves, depending on the experiment.

Prince Louis De Broglie took this concept and turned it on its head, reasoning thus:

"So, the quanta of light, which we know as waves, sometimes behave like particles. WHY CAN'T particles, sometimes behave as waves?"

He even backed this insight up with a formula for the wavelength of a particle:

wavelength = (Planck's constant) divided by (particle momentum)

His PhD thesis was one side of A4 (mine was a mini-book of 10 chapters).

This got the theorists thunking. Then two guys name Davisson and Germer successfully DIFFRACTED a stream of electrons, PROVING that the stream behaved like light.

Then the A-HA came (as Martin Gardner would have said).

If electrons behaved as waves sometimes, if they were in an atom, unless their "orbits" were whole numbers of electron wavelengths, there was no possibility of any other configuration because of destructive interference. Have you ever tried to poing a ruler on the end of a desk any other way than the notes you get?

Yes, resonance was the key. The electron waves resonated around the nucleus exactly like notes in a piano. Only certain frequencies "poinged".

So the picture that emerged was this one:





Ripples in a pond. Rulers poinging. Piano strings vibrating. If you will pardon the pun, does this ring any bells?

WAVES.

The electrons behaved as waves in the atom.

The upshot of this realisation was that Quantum Mechanics was born. (sorry Max)

Enter Erwin Shrodinger......

The Atom - Part Two

Note - all this applies to the hydrogen atom only - one electron going "round" a single proton.

So Neils Bohr came along and formulated a "theory" that explained the atom's stability.

With no theoretical justification whatsoever, he simply claimed that the electron was stable only in "allowed" orbits.

That is, it could only "circle" at certain distances, rather like the planets. This explained something that had baffled the chemists for a long time - spectral lines.

When an element is heated, it gives off light, and when it is split into it's colors, there are colored lines, unlike the continuous colors of the rainbow.

These lines were easily explained now, as it was simply an electron jumping from one allowed state to another,emitting one photon of light.

The point was, only certain differences were allowed, hence the lines. The number were easily explained by postulating that light came not in every energy, but only in little amounts, which were called "quanta". The formula for these was even simpler, sand was put forward by Max Planck. The allowed energies of these quanta was simply (a constant) multiplied by the frequency of the light.

E = hf... h is now called Planck's Constant.

There was even a formula for the allowed energy states.

Here is a picture to illustrate what they thought...
























But they still did not know WHY the electron only had "allowed" orbits. That breakthrough would come in 1928 with the next protagonist, Prince Louis De Broglie, and my personal hero.

The Number of the Base

Let's have some math for a change.

Why do we count in tens?

Simple, we have ten fingers. When we get beyond 10, we have a "handful" (technically 9, as we have ten digits, number 0 thru 9).

The Arabs invented the number zero, so 1 thru 10 became 0 thu 9.

Computers count in twos, zero and one, because their switches can only be "on" or "off".

They became "BInary digiTS" or "BITS". Someone then thought about bunching them into "handfuls" as well, in groups of eight, and these were called "BYTES".

So, we have groups of 2, binary, groups of 8, octal, and groups of 10, decimal.

Then, the computer scientists, grouped two "handfuls" of bytes together into "handfuls" of 16. The was called "hexadecimal". Hexa meaning six, decimal meaning ten. They had to add new numbers to stand for 11, 12, etc. They called them A, B, etc.

So in the hexdecimal system, you have 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F.

So we have systems of "handfuls" 2, 8, 10 and 16. Mathematicians call these numbers the "base".

It does not end there. Why do we have 60 seconds in a minute and 60 minutes in an hour?

Simple, the Mayans counted using base 60.

Why do we have 360 degrees in a circle? Yet another civilisation had a base of 36.

Theoretically, you can have a base of any number.

It gets even weirder with the math guys. They have a number system whose base is actually an irrational number.

"The Devil sends this base with wrath...let him who hath understanding reckon the Number of the Base, for it is an exponentional number and it's number is 2.718281828...."

One is all You Need

This image shows just what anyone can do with a camera if they know how.....




Location, back of the Manhattan Inn, Tacloban City, Philippines, in the laundry room, overlooking the market and the decrepit wharf.

Only in this case, it looked beautiful. This was taken at dusk, at about 6 pm.

I noticed the water vapour from the rainforest forming clouds in the mountains. The shack on the left was perfect, as was the tree on the mountain to the right. So I used natural light, no filters, and waited for the fisherman in the foreground, who started off at extreme left.

17 minutes later, he was where I wanted him, and his presence made the perfect counterpoint to the perspective, as I applied the 2/3 rule to the water/mountains. The film was normal ASA 100 and i steadied the camera on the rail because the shutter speed was less than 1/60. Lens was a normal 50mm, on an aperture of f1.8, so as to get everything in focus.

The result was, as can be seen, quite stunning.

I only took the one. Sometimes you only need the one.


However....this is what the left hand side looks like in the daylight...








To myself...it is just as beautiful.


Smelly, squalid, wretched, decrepit, rancid, and quite simply POOR.


However, I love it anyway.

Beware of the Power Lines

(an extension to the post "Beware of the Phone")
I was watching an episode of "The Practice" last night (American TV drama about a Law Firm), and it got my thinking (again). One of their cases concerned harmful radiation from power lines built through the clients' neighbourhood.

There were several cases of cancer and leukaemia involved, due to, they said, the "radioactivity" from the power lines.

There are two issues here: 1. The researchers got it wrong - "radiation" and "radioactivity" are two different entities. Power lines would emit only "radiation", NOT "radioactivity". 2. If there were any adverse effects from this "radiation", we should all have cancer by now from the same "radiation" that flies around the air from TV signals, radio signals, CB signals and of course, cellphone signals, not to mention the microwave ovens we place so near to us in our homes.
To clarify:

"Radioactivity" comes from the decay of atoms that split apart. If power lines were made of this kind of material, they would have fallen down long ago because all the atoms have decayed (loosely speaking). Only one kind of radiation comes from this source, and IS quite dangerous. They are called "gamma" rays.

"Radiation", however, is far more widespread, and what is more, most of what was encountered is made by man.

This kind of radiation, some of which is purposely made to be powerful enough to get to satellites 22,000 miles above us, is widespread.

* Radio waves - these come into your radios eg KLM FM
* Television waves - these come into your TV (although most in America come via cable now)
* Cellphone waves - how cellphones communicate
* CB waves - short wave radio for Citizen's Band
* Radio Ham waves - used by long-range enthusiasts (they bounce off the atmosphere to get round the curvature of the earth)
* Microwaves - from the home microwave ovens

The point is - All these waves are man-made, and yet do not seem to harm us (after all , TV waves have been going for nearly 80 years now). And yet, waves from power lines, lines which are actually designed to reduce wave emissions, if any, seem to concern people in that they may be harmful. No-one yet has ever claimed that TV waves cause cancer!!

Ok, now for the physics. These are all part of the "Electromagnetic Spectrum" - which is a bit like a normal spectrum but a lot larger. Here it is (notice how small the visible light region is)
















For those of you who do not know:


UV - UltraViolet (beyond violet -invisible)
IR - InfraRed (before red - invisible)
UHF - Ultra High Frequency
VHF - Very High Frequency
SW/HF - Short Wave/High Frequency
MW/MF - Medium Wave/Medium Frequency
LW/LF - Long Wave/Low Frequency
LW/VLF - Low Frequency/VeryLow Frequency
ELF - Extra Low Frequency
SELF - ??? (never heard of that one!)

Notice one thing - the high frequencies have short wavelengths, the low frequencies have long wavelengths (broadly speaking). This is because of the simple wave equation for light, frequency x wavelength = the speed of light. Common sense really. If the wavelength is short, say, 10 cm, more of them pass you by in one second (high frequency) than a wave that is 1.6 km long (low frequency) because they all travel at the speed of light.

For the math, the E represents how many zeroes to add to get the number eg, 1E2 is simply "100" whereas 1E-3 simply means "(0).001".

The most important word in the whole picture is "IONISATION" on the right. This is the dangerous part.

Yes, it is quantum mechanics again, and it means that there is so much energy in the radiation that each quanta of it behaves like a particle and can knock electrons from out of atoms. This is what "ionisation" is. If you get electrons knocked out of YOU, it is called radiation sickness.

However, look where it happens, not in the cellphone region (the yellow), nor in the TV region (the UHF/VHF orange-yellow), nor even in the microwaves region (bright yellow) and certainly NOT in the power lines region (the red). Why? Simply because there is not enough energy in those regions to cause damage. Think of it like a cork on a deep ocean. Deep ocean waves are too big to affect a cork (They are at least 10 meters long), but put a cork in a puddle and stamp your foot in the same puddle nearby, the cork invariably jumps right out of the puddle.

This is because the "waves" are about the same size as the cork, and is the same reason ionisation occurs.

In other words, apart from nuclear physicists, we are all safe from everyday radiation, simply because there is not enough energy in them to cause damage.

The Atom - Part One

Everybody knows what an atom looks like, right? Wrong! Apart from the latest fuzzy electron microscope images of Uranium, no-one has ever seen an atom.

All we had were "models" of it, "models" as in a realistic idea of what we thought atoms would look like.

JJ Thomson discovered the electron, and his model of the atom looked rather like a currant bun:



He thought electrons were "embedded" inside a large positively charged ball.

Then Earnest Rutherford came along and fired helium nuclei (alpha particles - two protons and two neutrons, although they were only known as alpha particles at the time, with a double positive charge) at a thin film of heavy atoms. Thus was born particle physics.

To his consternation, he found that every so often, an alpha particle came straight back at him.

If you do the statistics on the Thomson model, this was absolutely impossible.

Rutherford was quoted as saying: "It was as if you had fired a bullet from a gun into a layer of tissue paper, and the bullet came right back at you" (sic).

The only way to explain this phenomenon was to conjecture that the Thomson model was wrong, and, that somehow, virtually all the mass and all of the positive charge of the atom was concentrated into a very tiny space, with electrons "circling" around it, rather like a minute solar system.

That way, if an alpha particle hit the heavy atom "head on", the electrostatic repulsion would send it back on virtually the same path.

This was born the Rutherford Atom, as depicted in the top picture.

There was a snag, however, with this model. Maxwell's equations, formulated years before, predicted that accelerated charged particles would radiate electromagnetic energy. And according to standard mechanics, all things in circular motion were in constant acceleration.

Thus if the Rutherford model was correct, the electrons would radiate, lose energy, and spiral inward toward the nucleus, and the atom would collapse in something under 1/1000,000,000,000,000 of a second.

Clearly, this was not the case.

Then along cam Niels Bohr, with another model......but even he was wrong, even though his idea DID "explain it away"

Requiem - Pie Jesu

This is for all those who need our prayers.

For those who have lost their jobs.

For those in danger.

For those incomprehensible injustices in life.

For my "friend" Dave Harris, and I am not being sarcastic, Dave, I really mean this. May God`help you find your way.

However, this is especially for Kim.

May you rest in piece, Child of Heaven.

Who is the Best Scientist?

I was recently asked this completely inane question by a really gullible guy called classic_katana@yahoo.com. He was absolutely convinced there was an answer.

Michael Faraday

He was totally unable to comprehend that there is no "best" scientist, as all are specialists in their respective fields.

Some people have no idea about science at all. Or that this is a very subjective issue.

I have two words to say:

"popcorn" and "gruntwibbly"

Little Neutral One

Way back in the 1930's, there was something strange about radioactivity. We knew it came in three types, called alpha, beta and gamma radiation.

Alpha is made up of helium nuclei (two protons and two neutrons, which paper can easily stop), Beta is electrons, which can be stopped by foil, and gamma is electromagnetic waves, which need lead to stop them .

The problem was Beta, because the electrons were emitted at lots of different energies. This was trouble because we could not work out why. The answer lay in two different directions.

Either the conservation of energy was being violated (unthinkable), OR the energy was being carried away by some new particle not previously seen.

Enrico Fermi reasoned it must be very light, and electrically neutral. He called it the "neutrino", meaning "little neutral one".

Years later, it was actually detected, and we now know that gadzillions of them pass through you every second.

But they are so unfriendly, they pass through everything.

To illustrate how elusive they are, physicists use a term call "mean free path", which is a measure of how far something goes before it hits anything, an "average" distance.

For example, the mean free path of an electron in a metal is about a centimeter. For an alpha particle in air, it is about 4-5 centimeters. Beta particles manage about 15 centimeters.

It is a measure of how unfriendly neutrinos are when it is realised that their mean free path IN LEAD is about three light years.

That is, they will, on average, travel through up to three light years of lead (the densest stable element) before hitting any of it.

There was for a while, a huge debate about their mass. They were thought, just like the photon, to be massless, but the problem was their helicity. Helicity is simply put, spin, but there are two ways to spin, clockwise and anticlockwise.

Massless particles travel at the speed of light, and if neutrinos were indeed massless, they never stopped and should always spin either one way or the other. Never both.

We discovered both helicities, which simply means, they would have to have stopped and started again.

Logically, this therefore meant that they HAD to have mass.

Sure enough, years later it was given an upper limit. The lightest particle we knew of up till then was the electron.

The neutrino almost does not exist, as it is 512,000 times lighter than even the electron.

Nothing messes with the neutrino.

Check Mate???

This is the piece I have been looking for ..... The Chess Chorale from the Musical.

What makes this piece so fascinating is that the Chorale, are "placed" on a large Chessboard, with equal numbers of "players" in "black" or "white" robes. The "piece" begins with a recital of the names of every single World Chess Champion to make a "move".

Tal, Steinitz, Lasker, Botvinnik, Petrosian, Smyslov, Alkehine, Morphy, Spassky, Fischer, Capablanca, Korchoi, Karpov, Kasparov . Check out the names NOT in the Intro!!


The first two minuets of CHESS - ENDGAME !!!

NO going back now....NONE

This is the final scene in "Phantom of the Opera"

I have seen the London show several times.

I am Christine, Raoul is Ben, Mme Giry is my Mom, the conductor is my Dad, and the Phantom is the Phantom.

Phase...er??

Has anyone ever wondered what a LASER is?

I think not because all you people do is use them

Light

Amplification

(of)

Stimulated

Emission

(of)

Radiation.

L A S E R

It's Quantum Mechanics again

Einstein is the Father of Quantum Mechanics.

We all use lasers, in the disk drives on our computers. But what are they?

It is just a beam of light, but a little bit different. All the things in there jiggle at the same "jiggliness". Physics term is "resonate".

When you get these things doing it all at the same time, It is called "LASER".

ALL the atoms do it at once!! Star Trek renamed it as "Phaser", But Lord Gene basically got it right.

Without the LASER, no computers would exist, nor the machines calling you to inform you of your latest court cases, nor of the money you do not have.

Makes me think digitally sometimes, but only sometimes, and only on the thirty-third floor!