Higgs' Boson? - We Have A Discovery

[Quarky]

the sound of a higgs boson or not

It looks as though CERN can look forward to a visit from Lucy Durran with her tape recorder. Just the stuff for World Routes, I think.

[umslopogaas]

There are no doubt many books that try to explain quantum mechanics to the non-scientist, but one I found very good is 'In Search of Schrodinger's Cat' by John Gribbin (Corgi Books, paperback, publ. 1986). It was first published in 1984 by Wildwood House. It is now a bit out of date, but very clearly written. I am a scientist, but a biologist, not a physicist. At the end I sort of thought I understood it, but I wouldnt have wanted to try explaining it to any one else, even so. One major reason for becoming a biologist rather than a physicist or engineer is that my maths is weak, and biologists need less of it than physicists. OK, we need statistics, but we can usually find a statistician to help out there.

Hmm ... on re-reading the chapter on Schrodinger and his wretched pussycat, I'm not sure now that I do understand it after all ...

[Gordon]

There are no doubt many books that try to explain quantum mechanics to the non-scientist, but one I found very good is 'In Search of Schrodinger's Cat' by John Gribbin (Corgi Books, paperback, publ. 1986). It was first published in 1984 by Wildwood House. It is now a bit out of date, but very clearly written. I am a scientist, but a biologist, not a physicist. At the end I sort of thought I understood it, but I wouldnt have wanted to try explaining it to any one else, even so. One major reason for becoming a biologist rather than a physicist or engineer is that my maths is weak, and biologists need less of it than physicists. OK, we need statistics, but we can usually find a statistician to help out there.

Hmm ... on re-reading the chapter on Schrodinger and his wretched pussycat, I'm not sure now that I do understand it after all ...

That Gribbin book is very good despite being old. Brian Greene's books are also very good across the board and on the cosmology bits.

Rather than reiterate stuff from earlier posts try reading pages 67-74 of the wonderful Brian Cox book [ie Brian is wonderful - swoon - and the book is good too!!] "Everything that can happen does happen", paperback Penguin edition [my Kindle version has no pages!!]. That section explains all the stuff about things disappearing and being everywhere at once etc especially the grain of sand example. It's all about probabilities which is really what QM is at its heart. QM started as a "simple" step of quantising energy levels to explain an anomaly [the UVC]. As more people studied it it got rather more complicated [Planck must have though he'd started something monstrous]. Schrodinger and his wave packets [where is anything?] and Heisenberg and his uncertainties [there it is! Oooops, no it isn't!] are to blame!!

If you want to try the whole Cox book it is very good and avoids serious maths [which you can skip without much loss] but be warned that the "clocks" explanation, which is their quantum superposition process used more or less throughout the book, can be confusing - I found it unhelpful but others may find it otherwise.

Try some simple "quantum" arithmetic: classically 2 + 2 = 4. No doubts there. But a quantum computing machine might say: "the most probable result of adding 2 to 2 is 4 to a certainty of 99.99999....9%" - or any arbitrary certainty you want which would require some special conditions being set on the quantum machine. That is the equivalent of the grain of sand business referred above.

[umslopogaas]

Gordon #78, many thanks for that reply, the last para. in particular has sparked a few, not yet clear, thoughts. I will ponder, try to recollect my life-long battles with statistics, and hopefully return with something useful to say ... but dont bank on it.

[Gordon]

How’s about a little puzzle for a sunny summer’s morning?

Dr Planck said that material objects are made of lumpy bits of energy. People that came after him said that everything is made of this lumpy stuff. It even applies to massless objects like photons that mediate the EM force. The poor creatures are doomed, like some Wagnerian Dutchman, to sail the universe at the speed of light [unless they are rescued by bumping into something solid like a good woman that absorbs them and they disappear]. They travel at the speed of light so, as far as these photons are concerned, there is so such thing as “time”.

Further aspect of the puzzle:

Dr Planck said that the energy of a wave packet [a lump of energy] is given by the very simple equation:

E = “h” times “f”

where “h” is the Planck constant [a very, very small number whose units are “energy-seconds”] and “f” is the frequency of the wave that represents the lump and its units are “per second”. So when you do the multiplication the result E has units of energy, the seconds on the top cancelling the seconds on the bottom.

Or, because the speed of light “C” = ”f” times “w” where “w” is the wavelength [units obviously length] corresponding to the frequency “f” then we can re-write that equation as:

E = “h” times “C” divided by “w”

Now this “h” is just a number and is a constant as is "C" so the value of E is directly proportional to frequency “f” or inversely proportional to wavelength “w”. That means that say radio waves at lowish frequencies, say around FM at 100 MHz, use photons that are proportionally a lot less energetic than photons that carry X rays, say, whose frequencies are much higher than 100 MHz.

Now Einstein taught us that Energy, E = mass ”M” times the Speed of Light “C” squared so this can then be re-written to give a quantum packet equivalent Planck Mass, MP, as:

MP = E/”C” squared = “h” divided by “w” times “C”

This is the mass that the quantum of energy has.

OK. These energy packets are supposed to be quantised, in other words they are constrained to take certain values and not others. Now the quality of mercy in the case of “h” is not strained, it’s just a constant not a variable, just as "C" is. That means that the “f” [or the “w”] must be quantised then. But the EM spectrum is a continuum isn’t it? There are no lumpy bits or holes in it. But it has a mediating quantum that is lumpy, the photon. Observing that frequency is actually an expression of time [its units are “per second”] we are led to conclude that perhaps it is time that must be quantised for all this to work.

So at a certain level, time doesn’t flow in a continuum [macroscopically that is what it seems to do] it moves in lumps and jerks along one quantum of time at a time as it were. So deep down at the Planck level there is a “quantum” of time, the Planck Time period during which there is NO time flow, ie time is just a series of moments. In those moments everything is kind of frozen for a very, very short period and in which anything can happen and the “normal” laws of physics do not apply. So things can come and go as they please at this time scale. If there is a Planck Time then, and the speed of light is a universal constraint, there must be a Planck Length that is the distance travelled by light in the Planck Time and is the quantum of wavelength or distance. There is no linear distance smaller than the Planck Length, so space itself seems to come in little cubic boxes, the Planck Length along each side.

Now, it turns out that this Planck Length [PL] can also be written as:

PL squared = “h” times “G” divided by “C” cubed

Where “G” is the gravitational constant [that Newton would have known] and “C” is the speed of light. Strange that the PL, the smallest size of space there is, is linked directly to Gravity!! In other words gravitational energy is expressed in lumps too and that is curious and leads us to believe that there is some way of explaining Gravity using a Quantum approach. So far we’ve not done that.

Finally, the Planck Mass PM, the mass equivalent of the smallest unit of energy, can be written:

PM = “h” divided by “C” times “PL”

Which, when you work it out, is about one hundredth of a thousandth of a Gram. Now, considering that this Planck space is so incredibly small it is remarkably heavy [or energetic]. This mass is equivalent to a grain of dust.

Have look at this: http://www.youtube.com/watch?v=tEL3Amxf8eI

Who needs complicated maths to illustrate QM? Funny old world.

[Vile Consort]

Hmmm ... there is so much misunderstanding in Gordon's post that it's difficult to know where to start.

Planck was looking at black body radiation. In order to get an equation that described the observed frequency spectrum, he made the assumption that energy could only be exchanged in amounts proportional to the frequency. This does not imply the existence of photons - something he opposed all his life. He certainly did not say that material objects are made of lumpy bits of energy. Mass/energy equivalence had to wait for Einstein't theory of relativity.

Time is not quantised. In all theories that work, it is continuous. If it were not continuous, you would not be able to differentiate with respect to it, and you would be unable to do any useful calculations.

The continuous spectrum is a bit odd. When you observe a continuous spectrum (e.g. black body radiation) for a given period of time, what you have observed is a finite (but very large!) number of photons, each with a specific energy. Planck's equation for black body radiation only tells us what proportion of the photons will be in a given energy range. It's a differential equation showing the derivative of the proportion with respect to the width of the range as the range tends to zero. When we plot a theoretical energy distribution as a continuous graph, we are plotting how that derivative varies as a function of energy. When we plot an observed spectrum as a line, we are merely joining up the closely-spaced dots. The spacing is determined by how much resolution our instrument has.

Now the Plank mass/length/time etc. These have absolutely no physical significance. They are units in just the same sense that the year, second, yard, metre, kilogram, ounce etc etc etc are units. Obviously, we can pick any units we want - the inch and the metre are completely arbitrary. The constants of nature will take different values in different units - e.g. the speed of light is 300,000,000 metres per second or 186,000 miles per second or 1 light-year per year or some silly number of furlongs per fortnight. What are these Planck units then? They are the units that result in the constants of nature that keep cluttering up our equations having the numerical value of 1.

The Planck mass certainly isn't the smallest mass there can be - obviously not, as it's the size of a grain of dust, and we know atoms are a lot less massive than that.

[umslopogaas]

Phew, I'm going to abandon my promised attempt to post an explanation and leave it to you lot, you obviously know far more about this subject than me!

[Quarky]

Please don't abandon your attempt umslopogaas! It's a good way to clarify one's thoughts by putting them down in writing for all the world to examine.

Obviously QM is best understood by those with background in physical sciences, who have lived with all the underlying concepts of the ways in which sense is made of experimental data. No one can actually see an electron or a boson, i.e. hold it in the hand and have a good look at it. We have to build pictures in the mind which conform with experimental data. As Gordon said, you don't need maths - but a strong imagination is required, and some "physical intuition". That was Einstein's great strength.

[amateur51]

Please don't abandon your attempt umslopogaas! It's a good way to clarify one's thoughts by putting them down in writing for all the world to examine.

Obviously QM is best understood by those with background in physical sciences, who have lived with all the underlying concepts of the ways in which sense is made of experimental data. No one can actually see an electron or a boson, i.e. hold it in the hand and have a good look at it. We have to build pictures in the mind which conform with experimental data. As Gordon said, you don't need maths - but a strong imagination is required, and some "physical intuition". That was Einstein's great strength.

A vivid imagination ok - but what is a strong imagination? Top shelf?

[Quarky]

Strong imagination? I think what I meant by that is not necessarily a vivid imagination, but an ability to make a picture in the mind, and then turn the picture over, inside out, upside down, and then modify it until it fits all the "facts".

[amateur51]

Strong imagination? I think what I meant by that is not necessarily a vivid imagination, but an ability to make a picture in the mind, and then turn the picture over, inside out, upside down, and then modify it until it fits all the "facts".

Gotcha! - thanks for the clarification and apologies for my flippancy, Oddball.

I don't have that type of imagination, sadly

[umslopogaas]

I shall respond in due course, but unfortunately my response has been prepared on my new computer, which uses later versions of all the software I employ. I cant find anything, move anything, and all the 'Edit' functions seem to have disappeared. But I'll get there, I have actually resorted to pencil and paper to make notes of things to do. If I seem to have gone quiet, its not because I have nothing to say.

Mutter, mutter, where the **** is the ****** command to *******-**** edit, oh ****!

[Budapest]

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?

Quantum superposition, which has been proven to exist in countless laboratory experiments, means that matter can exist in more than one state; ie, in theory it can exist at the same time at opposite ends of space and time (defying most of the laws that Einstein came up with about space and time, particularly that nothing can move faster than the speed of light). The really mind bending thing about quantum superposition - or perhaps the most obvious - is that it can only occur when not observed by us humans. To try and put it simply, our mathematics proves that quantum superposition takes place, but when we observe this phenomenon it can no longer take place. For me, the interesting thing about this is the link between that thing we call human 'consciousness' and the quantum world (and of course I'll hark back to my earlier point, that all brains, whether it's a fly's or a human's, work at a quantum level - there's no other way that I can see that a brain can compute so fast).

Without getting into another debate about transistors, modern computers wouldn't work without this weird thing called quantum superposition. It happens, but it only happens when us humans don't try to observe/measure/quantify it. No wonder Einstein called it 'spookey'.

I now understand why 'Higgs boson' should not be a possessive. Everytime I read it, though, it just begs an apostrophe.

[Budapest]

Phew, I'm going to abandon my promised attempt to post an explanation and leave it to you lot, you obviously know far more about this subject than me!

umslopogaas, go for it. I for one will be very interested in your thoughts.

Particle stuff is still very much in the realm of theoretical physics; ie, no one really knows what the 'f' they are talking about.

ps. In my humble opinion, Schrodinger's Cat thought experiment just muddied the water even more for the general public's understanding of quantum theory. Schrodinger's execution of his fluffy cat was an attempt to show fellow theoretical physicists how ridiculous the concept of quantum superposition is. The fluffy cat was never intended to explain QM to the general public.

[Vile Consort]

Quantum superposition, which has been proven to exist in countless laboratory experiments, means that matter can exist in more than one state; ie, in theory it can exist at the same time at opposite ends of space and time (defying most of the laws that Einstein came up with about space and time, particularly that nothing can move faster than the speed of light).

Existing in two places at once would violate the conservation of energy. And as we know, the equations of physics always conserve energy. Always, always, always. It's a consequence of their symmetry with respect to time - as the well-known theorem of Emmy Noether tells us. It would be a very brave man indeed (or a foolish one) who proposed a theory that violated the conservation of energy.

As I said, which interpretation of QM says this? Certainly the Copenhagen and many-worlds interpretations don't.

The wave function exists in a superposition of states. But not the particle. In the Copenhagen interpretation, it isn't possible to speak of the particle's position until you make an measurement of it (whatever that means), whereupon the wave function collapses so that only one state is left. This locates the particle at one and only one point in the universe at that time.

The objective collapse theories are similar but don't require the troublesome concept of measurement to cause wave function collapse.

In the many-worlds interpretation, there would be as many universes as there are superimposed states. In any given universe, the particle is on only one place.

I would be really interested to know which of the many mainstream interpretations has a particle in two places at once. It seems to me it is only the little-known Budapest interpretation.

The Neumann/Wigner interpretation is the only interpretation that requires consciousness in order to collapse the wave function. Hardly anyone thinks it is right. And even that doesn't have the particle in two places at once.

By the way, it is a well-known logical fallacy to say that one explanation must be correct because you can't think of another. By that logic, the Phlogiston theory was correct.