Higgs' Boson? - We Have A Discovery

[clive heath]

In respect of the proposition that transistor behaviour exemplifies quantum physics, here a short essay!!

n-type silicon is an impure "doped" form with an excess of electrons in the crystal lattice. These electrons are not bound to any individual atom and the material conducts, unlike pure silicon which is an insulator. The excess of electrons arises because about 1 in a 1000 atoms in the crystal are not silicon but phosphorus with one more electron in its outer shell, so the crystal structure is still essentially silicon but with excess electrons free to move. p-type silicon has a lack of electrons in the structure because about 1 in a 1000 atoms in the crystal are not silicon but aluminium, with one less electron in its outer shell, so the crystal structure is still essentially silicon but with electrons missing. An elegant experiment demonstrating the Hall Effect proves that the charge carriers in n-type material are negative as you would expect ( free electrons) and that against expectations the charge carriers in p-type material are positive. It seems that electrons persuaded by the external field to hop from an adjacent atom's outer shell to fill a nearby "hole" (i.e. where an electron should be in pure silicon) nevertheless behave as a positive flow of "holes" in the reverse direction to the electron-hopping. When you put an n-type silicon (N) sample in contact with a p-type silicon (P) sample the free electrons from the N move to fill up the adjacent holes in the P. This creates a small voltage difference (about 0.6 Volt) between the two materials which has to be overcome if current is to flow from N to P. ( A-level physics up to here including the Hall-Effect experiment) If you now sandwich a layer of P between two layers of N and cause current to flow from the first N (the emitter) to the P ( the base) and if you make the base very thin, most electrons from the emitter will have enough energy to penetrate the very thin base and are inevitably to be found in the second N ( the collector, !) and provided the collector is made positive wrto the base, current will flow. Typically the base current (i.e those electrons caught by the base) will be 500 times smaller than the collector current giving a current amplification of 500 which by the placement of resistors in the circuit can be converted into voltage amplification. Thus in a Transistor Radio of the 1960's the submicrovolt recieved signal from the aerial could be amplified ( once frequency-selected "tuned" and rectified) to produce audible output from the speakers with maybe 4 x 1.5 Volt batteries. I am not quite sure where quantum physics comes into this, but it could be in the phrase "penetrate the very thin base" but I somewhat doubt it. If this complicates the issue I apologise.

https://www.cliveheathmusic.co.uk

[teamsaint]

thanks Clive.Interesting.
It is a law of quantum physics that you cannot over complicate the issue !

[Frances_iom]

In respect of the proposition that transistor behaviour exemplifies quantum physics, here a short essay!!

catch is that such bulk effect devices were long ago replaced by MOSFET - metal Oxide semiconductor field-effect transistors in which the current thro a narrow channel of semiconductor is modified by the voltage on a gate (the metal layer) isolated from the channel by a non conducting oxide - as the device geometries become ever smaller (which is what allows todays highly integrated systems containing 100's of millions of devices) quantum effects become more and more important in modelling such devices and begin to dominate as the conventional MOSFETshrinks beyond beyond the 50-nm-technology - two of these constraints are quantum-mechanical tunneling of carriers through the thin gate oxide;and quantum-mechanical tunneling of carriers from source to drain, and from drain to the body of the MOSFET.
There are many papers on the web (+ to be honest it getting on for half a century since I was reasonably conversant with the physics!) but recognition of and modelling quantum effects are now essential in designing such devices

[Budapest]

I've had a hard day at the particle accelerator (he jokes) and am a bit cream crackered at the moment. I find this to be is a very engaging thread with lots of interesting opinions.

Lateralthinking1, the problem with our present mathematics is that it's a flawed language. Try working out Pi or the square root of 3. These, and many others, are irrational numbers that can't be resolved. Perhaps the problem with modern science is that it can only function if everything can be worked out mathematically, which of course it can't. Mathematicians come up with all sorts of weird and wonderful ways to get around this problem. One of the most amusing is how they deal with infinity, which mathematicians refer to as the 'lazy eight', because the symbol for infinity looks a bit like the number eight laid on its side. If interested, here's one of Melvyn Bragg's In Our Time programmes which deals with infinity; always a fascinating topic. Even if some folks are not overly interested in all this stuff it's well worth a listen...

http://www.bbc.co.uk/programmes/p0054927

Gordon, whilst I take on board that the incredible computational power of a fly might be a genetically embedded algorithm, honed over millions of years of evolution, there is research that shows otherwise...

Do flies have free will?

With regard to Roger Penrose's 'tubules' (or whatever he called them; I can't remember now), which was basically a theory to show that quantum effects could take place in biological matter (ie, in the brains of animals), there's also been research into this in recent years:

Quantum Entanglement, Photosynthesis and Better Solar Cells

Coherently wired light-harvesting in photosynthetic marine algae at ambient temperature

I should add that I'm not up to speed with the very latest research in this field.

So, Fluffy the cat can exist at the same time at opposite ends of the universe, mathematicians can't really add-up and flies might read the Guardian.

Is it any wonder that I love all things quantum?

[Quarky]

I'm sure that Clive is absolutely correct.

My position is that I know and have known a great many electrical engineers who understand the workings of transistors inside out, but very few if any need to use the fundamentals of quantum mechanics. Once the transistor had been invented, it was very easy to visualise its operation in terms of electrons, holes, depletion zones etc. - no need for mind bending counterintuitive concepts.

Nevertheless, I don't believe Shockley, Bardeen and Brattain could have invented the transistor without an extremely thorough knowledge of quantum theory. There is a world of difference between getting something to work for the first time, when anything might go wrong, and just following in another's footsteps.

They needed to know exactly how a crystal would behave when doped, subject to electrical fields etc , and not just qualitatively, but quantitively. Thus for example they needed to use the Fermi Dirac distribution function to calculate how many electrons were in the conduction band, above the Fermi level - pure quantum mechanics.

I was just looking on the web for an electronic version of Shockley's book - Electrons and Holes in Semiconductors: Applications to Transistors. , but none was available. However it is a three part book, with the third part directed solely to quantum mechanics. These are some of the terms used in the book:
Bloch wave boundary conditions Brillouin zone eigenfunctions Fermi level group velocity normal modes number of electrons obtained periodic boundary phonon Phys positive problem produced quantum mechanics recombination relationship volts w-type wave function wave length wave-packet zero

So it is clear that Shockley was thinking in terms of quantum mechanics, even though the disseminated popular picture of a junction transistor is not.

[Gordon]

Gordon, whilst I take on board that the incredible computational power of a fly might be a genetically embedded algorithm, honed over millions of years of evolution, there is research that shows otherwise...

Do flies have free will?

Your friend the fly does flying for a living. Im sure he doesn't think about it much except perhaps as a philosophical exercise whist perched on a ceiling minding his own business and keeping an eye out for spiders. The mechanics of his flying might be aerodynamically complicated but what he has to do to land on the ceiling isn't so hard to see, it's the how to do it under control that is complex. From our point of view it is hard because we can't fly and have to calculate everything that an aircraft has to do to fly safely. A pilot does not need to have a detailed knowledge of advanced hydrocarbon oxidation chemistry to get his plane to go faster, he just nudges the throttle a bit. Neither does he worry about getting to Australia, just push the button marked "autopilot". How many flies would it take for them collectively to invent, construct and then ride a bicycle?

Anyway I'm not so bothered about how he does land ona ceiling I'd rather know how he decided that he wanted to do it in the first place, if indeed he did "decide". Was it free will on his part or was that a trait too? It's what flies do. Does he land on ceilings without knowing why? That's where a fly's brain is interesting.

[Pabmusic]

This, from Michael Quinion, my be of interest:

"Few of us have failed to be made aware this week of the subatomic particle called the Higgs boson or that it was named after Peter Higgs, a physicist at Edinburgh University who was among a group who argued in a series of papers in 1964 that it ought to exist. Fewer will know that the second part of the name also commemorates a scientist, the Indian physicist Satyendra Nath Bose, who made a key discovery about quantum statistics in 1924 that proved that a class of subatomic particles with particular properties must exist. These were given his name, modified by the conventional -on ending for such particles. The other class of particles, fermions, were named after the Italian-born American physicist, Enrico Fermi."

[amateur51]

This, from Michael Quinion, my be of interest:

"Few of us have failed to be made aware this week of the subatomic particle called the Higgs boson or that it was named after Peter Higgs, a physicist at Edinburgh University who was among a group who argued in a series of papers in 1964 that it ought to exist. Fewer will know that the second part of the name also commemorates a scientist, the Indian physicist Satyendra Nath Bose, who made a key discovery about quantum statistics in 1924 that proved that a class of subatomic particles with particular properties must exist. These were given his name, modified by the conventional -on ending for such particles. The other class of particles, fermions, were named after the Italian-born American physicist, Enrico Fermi."

Great stuff, Pabs - many thanks for this

I shall stun my friends with it at the next kitchen supper that I'm invited to

[Gordon]

#63

catch is that such bulk effect devices were long ago replaced by MOSFET - ...... - as the device geometries become ever smaller (which is what allows todays highly integrated systems containing 100's of millions of devices) quantum effects become more and more important in modelling such devices and begin to dominate as the conventional MOSFETshrinks beyond beyond the 50-nm-technology - two of these constraints are quantum-mechanical tunneling of carriers through the thin gate oxide;and quantum-mechanical tunneling of carriers from source to drain, and from drain to the body of the MOSFET.

Couldn't agree more Frances!!

#65

They needed to know exactly how a crystal would behave when doped, subject to electrical fields etc , and not just qualitatively, but quantitively. Thus for example they needed to use the Fermi Dirac distribution function to calculate how many electrons were in the conduction band, above the Fermi level - pure quantum mechanics.

So it is clear that Shockley was thinking in terms of quantum mechanics, even though the disseminated popular picture of a junction transistor is not.

I spent the best part of my career in electronics using transistors as such and then in ICs made up of them [Germanium, Silicon, Gallium Arsenide, junctions and FETs] and I did not for one second ever have to think about quantum mechanics to make them do what I wanted. They didn't come and go in front of my very eyes because of quantum uncertainty, neither did I have to do probability sums over paths. I did get exposure to a device called a tunnel or Esaki diode at one time which is not possible to understand without learning something about QM. Similarly lasers. Unlike the laser a tunnel diode is queer device that has little widespread use, certainly not that on the scale of transistors.

As far as we know, everything in the material world does what it does according to a description provided by QM [OK, we’re having a bit of local difficulty with gravity but let’s not worry about that]. An electron doesn’t need a PhD in QM to do what it does, QM merely describes it. On another planet far, far away some being may have another perfectly good explanation of the electron [assuming he has some] that works for him – is that explanation necessarily QM? Penrose thinks that QM isn’t broken, but it’s not complete yet. As OB says the real value of the theory is that it is precise and gives a way of quantifying behaviour so that materials can be manipulated with such confidence that they will do what we design them to do and do so consistently.

Shockley worked in materials research for a commercial telephone company, Bell, and would certainly have had to know something of the behaviour of electrons in the solid state in order to come up with the transistor. Insofar that QM, through the Dirac equation for the electron, etc, gave him this then yes he was familiar with QM but I doubt he had to do sums of probabilities over all paths to come up with the transistor. Any macroscopic description of the solid state that worked would provide this knowledge. A bit of material with excess charge like a doped N type or P type slab of Germanium is just a curiosity, like a material capacitor. So what? That excess charge arises because of chemistry and the deliberate presence of alien dopant atoms in the Germanium lattice, as has been described by Clive above.

Placing two bits of treated Germanium - one N and the other P - in contact makes a diode, useful in electronics in general for rectifying alternating waveforms eg in radios using Amplitude Modulation. Such a solid state device was already known in early radios using crystal detectors - cat's whiskers in "crystal sets". It was a miracle it worked at all and so no one worried much about why. Was a cat's whisker a QM device? Well, yes it was. Whilst Germanium [and subsequently Silicon and other exotic semiconductors] diodes have their uses they are limited. A more interesting and significant question would be: could a device in the solid state emulate a triode valve that could be made to amplify waveforms in a similar fashion? This would be very handy for the Bell telephone system.

Make a sandwich of either a P between two Ns or vice versa and you have an interesting structure, Clive and others have described this, two diodes back to back in fact, and, what do you know, it amplifies currents and becomes a powerful rival to thermionics!!! Bingo, massive commercial value to Bell Labs, Nobel prizes!! What has QM to do with all this? QM does not predict the transistor or cause it to be, it just describes the material basis which allows a transistor to exist. Someone had to invent the transistor. We don’t make a fuss about QM making triode valves amplify audio signals do we? Valves are QM devices too but understanding them is easier but does not need the insights or Dirac equations of QM.

The part of all this that I’m interested in, given the scope of this thread and linking to the deeper, strange significance of the statistical nature of QM, is what was the contribution from the QM inside Shockley’s head? What was going on when he said to himself: “I wonder what would happen if we put two diodes back to back and apply voltage across it all and then waggled the voltage on the meat in the sandwich?” What if he had not had that idea? Like any other QM phenomenon it had to happen sometime?

Is QM at the root of invention, just as it may be at the root of free will? Invention is nothing but one expression of free will isn’t it? If nothing can change we get stasis and no free will. QM and its root uncertainty is there to propel change and change needs the phenomenon of time.

According to QM [and the wonderful Brian Cox] a grain of sand will not suddenly disappear but it does have the potential to do so. All the energy packets in it are constantly exploring the universe being everywhere at once but their aggregate state, described by probability sums over all possible paths, is to stay put because the probability of the whole grain being elsewhere is as near zero as isn’t worth knowing. But it isn’t zero. One day that rare event will happen and the grain of sand will disappear, it’ll just take a very long time, longer than the age of the universe. Very tiny energy packets, at the Planck energy, do disappear and appear often. Bigger things will also disappear sometime it just takes a lot longer than a grain of sand. So the universe is here to say then?

We are material objects and are governed by QM. Deep inside every one of us there are untold numbers of tiny energy packets coming and going all the time. Am I the same person that started this post and where have bits of me been whilst I’ve been typing? Are bits of me really exploring the whole universe all the time? There’s a conundrum.

[Budapest]

Very interesting posts here, from which I've learned a lot. Thank you.

The debate about transistors aside, all electrical equipment, whether it be computers or TVs or vacuum cleaners use quantum phenomena; by which of course I mean sub-atomic particles called electrons flowing through conducting material (aka electricity).

Gordon said: We are material objects and are governed by QM. Deep inside every one of us there are untold numbers of tiny energy packets coming and going all the time. Am I the same person that started this post and where have bits of me been whilst I’ve been typing? Are bits of me really exploring the whole universe all the time? There’s a conundrum.

There's a line of arguement that runs something like: creatures like flies, with much smaller brains and less likelihood of a nervous breakdown, can exist in different points of the universe at the same time (under QM theory). More sophisticated creatures like us humans, who think too much, who are way too conscious, can't deal with such a reality. Thus we get completely mad concepts like the Higgs (shouldn't that be a possessive apostrophe) boson, which doesn't have much to do with 'science' and has everything to do with humans avoiding a nervous breakdown.

Just a thought (ha!).

[Pabmusic]

...Thus we get completely mad concepts like the Higgs (shouldn't that be a possessive apostrophe) boson...

No. 'Higgs' is the name of that particular boson. It's not a possessive.

[Vile Consort]

Very interesting posts here, from which I've learned a lot. Thank you.

The debate about transistors aside, all electrical equipment, whether it be computers or TVs or vacuum cleaners use quantum phenomena; by which of course I mean sub-atomic particles called electrons flowing through conducting material (aka electricity).

Why stop at electrical equipment? All radiation is a quantum phenomenon. It was explaining black body radiation that led Planck very reluctantly to introduce the quantum. Photosynthesis is a quantum phenomenon whereby an interaction between a photon and an electron in a chlorophyll molecule results in the conversion of carbon dioxide and water into glucose and oxygen. In fact, all chemistry is a quantum phenomenon involving the interactions of electrons and photons and hence so is all biology.

Gordon said: We are material objects and are governed by QM. Deep inside every one of us there are untold numbers of tiny energy packets coming and going all the time. Am I the same person that started this post and where have bits of me been whilst I’ve been typing? Are bits of me really exploring the whole universe all the time? There’s a conundrum.

There's a line of arguement that runs something like: creatures like flies, with much smaller brains and less likelihood of a nervous breakdown, can exist in different points of the universe at the same time (under QM theory). More sophisticated creatures like us humans, who think too much, who are way too conscious, can't deal with such a reality.

Thus we get completely mad concepts like the Higgs (shouldn't that be a possessive apostrophe) boson

No, it should not be a possessive. The man is called Higgs, hence the Higgs boson: similarly we have the Planck mass, the Dirac equation, the Poisson bracket, the Fourier transform, the Hall effect and the Einstein summation convention.

I wish you would get it out of your head that anything can be at two points in the universe at the same time. Which interpretation of QM says that?

Creatures like flies are far too large to exhibit quantum uncertainty. You don't see a dead fly jumping around all over the room, never mind all over the universe.

which doesn't have much to do with 'science' and has everything to do with humans avoiding a nervous breakdown.

Can you explain that further?

[JohnSkelton]

You don't see a dead fly jumping around all over the room, never mind all over the universe.

You do if you've taken something that hasn't ... agreed with you .

[teamsaint]

The waters around this scientific research are, sadly, too often muddied by the need of scientists to keep the funding coming in. That isn't a criticism, they have a living to earn.

A central problem in this kind of area is how the ordinary non scientist can learn something useful about our world(and universe) while not being manipulated by those with knowledge and agendas.

For those with little knowledge and an interest, I would recommend
this

http://www.amazon.co.uk/Punk-Science-Inside-Mind-God/dp/1905047932

no doubt some scientists will dispute some of it, and certainly some of the later chapters seem to veer into what seems to be speculation. But for all that, it serves as an interesting introduction to QM, as well as suggesting some really eye opening connections between matter and conciousness.
No doubt it should be read with scepticism intact,(although there is plenty of "hard science" in here as far as I can tell) but in any case , its a good read.

[aka Calum Da Jazbo]

the sound of a higgs boson or not