Recently people around the world have been exposed to an unfamiliar scientific term, due to the observation of a new elementary particle by physicists at CERN. The term is "boson," and the particle, the Higgs boson, completes a chapter in the modern sub-atomic description of nature. The word surely sounds odd to non-expert ears, with its echoes of a certain American TV clown, and no obvious Greek or Latin root. What is the origin of this term, and why is it worth specifying that the Higgs is not just any old supersmall particle, but a member of the particular family of fundamental physical objects grouped together as bosons? In fact this terminology goes back almost 90 years, to the dawn of the modern understanding of the atom. It stems from one of the most fortuitous episodes in the modern history of science, and involves intimately the most famous physicist of all time, Albert Einstein.
In June of 1924 Albert Einstein had become not just the best-known scientist of his era, but one of the most recognized names on the planet. The demands on his time and attention had grown exponentially due to the publicity associated with his now experimentally confirmed General Theory of Relativity. Thus when an unknown 30-year old Indian physicist, Satyendranath Bose, sent him an unsolicited manuscript to read, the chances that it would end up anywhere but the circular file were very low. "Respected Sir, I have ventured to send you the accompanying article for your perusal and opinion," the letter began, and after explaining the scientific goal of the paper, it closed with an astonishing request, that Einstein translate the English manuscript into German for publication. "Though a complete stranger, I do not feel any hesitation in making such a request. Because we are all your pupils..." Despite the long odds, in this case Bose hit the scientific lottery. At that time Einstein was deeply involved in the struggle to understand how atoms and light behaved, a 20-year quest that had begun in 1905 when had dared to suggest that light, which had been "proven" to be an electromagnetic wave during the 19th century, consisted of localized particles, which we now call photons. Bose's paper was on this topic and Einstein read it carefully, decided that it "signifies an important advance," and translated it for publication in a top German physics journal. This began a chain of events that ultimately enshrined Bose's name in the modern theory of nature.
Bose had tried to solve a longstanding problem in describing thermal radiation (the electromagnetic energy emitted by any hot object) using Einstein's photon concept. The fundamental law determining how much energy there is in thermal radiation had been found by Max Planck twenty-four years earlier, but up to that point all attempts to deduce this law from the "photon gas" picture, using thermodynamic principles had failed. Somehow Bose, in a terse document of less than two journal pages, had succeeded. But how had he done it?
The key was to count the number of states of motion that a photon can take on, when confined to a certain volume; this would determine the "entropy" of the gas, from which the Planck Law followed. However, in counting the photon states Bose had, apparently unknowingly, counted them differently from all previous physicists, including Einstein. When his new approach gave the right answer (Planck's Law), he simply wrote up the calculation, without any detailed discussion, and sent it to Einstein. Somehow, Einstein intuited that this new counting method was not simply an error by an inexperienced researcher, but represented a correct guess about the bizarre properties of the unobservable atomic domain.
How could something as mundane as an atomic accounting method actually change our view of nature? Well, as any gambler knows, the laws of statistics are also laws of nature. The reason that when we flip two coins we find a heads and a tails half the time (on average) is that the coin is equally likely to land on either side. Moreover there are two ways to get a heads and a tails (coin 1 = heads, coin 2 = tails; coin 1 = tails, coin 2 = heads) and only one way to get either of the other results. But what if we had two really identical coins, and instead of flipping them in the open we jiggled them around in a closed box, and then opened it for each trial? In this case we would not know, when we found a heads and a tails, whether it came from one or the other of the two ways. Would this change the probability that we get a heads and a tails? Absolutely not. These probabilities stem from the fact that each coin is a distinct object with independent properties. But Bose's accounting had essentially denied that this was true of micro-particles like photons.
Bose's reasoning assumes that photons are not like macroscopic coins, and that it makes no sense to ask whether photon 1 is in state 1 and photon 2 is in state 2, or vice-versa. These two states do not separately exist and hence there is only one such configuration of two photons. If we think of photons as "quantum coins," the probability of flipping two of them and getting a tails and a heads is only one third, not one half (and correspondingly the probability of heads-heads or tails-tails is now increased to one third). Note, and here's the mind-bending part, this is not because photons (or atoms) are small and we can't tell which photon is in which state. Unlike macroscopic coins, the quantum coins exist in a single fuzzy combination of heads-tails + tails-heads. While all of this was implicit in Bose's reasoning, he much later admitted that he "had no idea that what I had done was really novel."
Einstein however quickly grasped the enormous implications of this change of viewpoint. By December of 1924 he had understood the meaning of Bose's new statistics and applied them to a conventional gas consisting of atoms. He discovered that at ultra-low temperatures atoms can form a new state of matter, called a Bose-Einstein condensate, which eventually was observed in Nobel prize winning experiments in 1995. Within the next few years, Werner Heisenberg, Erwin Schrodinger and others found the basic equations describing atoms and light, the theory now known as quantum mechanics. It turned out that in addition to particles that obey Bose statistics, now called bosons, there is another category of particles, called fermions, after the physicist Enrico Fermi. These particles are indistinguishable in the Einstein-Bose sense, but also cannot share the same state with each other. In the coin analogy, the states head-heads and tails-tails can't occur. Protons and electrons are fermions, whereas bosons are the force-carrying particles in nature, the Higgs being the newest member of the club. All these force-carriers carry the name of a physicist whose elevation into the physics pantheon hung on the slimmest of chances, that the great man, Einstein, would rescue his groundbreaking paper from obscurity.
A. Douglas Stone is Carl Morse Professor and Chair of Applied Physics at Yale University. His forthcoming book from Princeton University Press is titled, "Einstein and the Quantum: The Quest of the Valiant Swabian."
http://gsjournal.net/Science-Journals/Essays/View/4259
As mentioned in the article, unless physicists at CERN know which type of collisions they are basing their evidence on... they are making a speculation.
I think quantization happens because down at those dimensions there is just no room for continuous, or classical, events, so a spin points up or down because it has no other choice.
On the other hand, many years ago, when secretary pools existed, my secretary changed the word boson to bosom in my paper. I thought it was a typo, but when I asked her, she said it made more sense to her that way!
If you like, you can spend the rest of your life chasing the "Why are things as they are?" question, or you can become a physicist and explore the consequences of what things do, when things are as they are.
Einstein and Bose have decided to be physicists. It's up to you to stay a "Why?"-philosopher who can't even tie his own shoes, intellectually speaking.
:-)
Science does not ask why nature is the way it is. It asks how it is. The level of detail of those answers can vary, but at least there is a fighting chance to get answers that are deep, elegant and useful. There are no such answers to the questions of the kind why nature does certain things in certain ways. That's for religion and philosophy to answer... poorly.
When that happens, it will be as a response to "How does angular momentum get quantized?" not to "Why is it quantized?".
To physicists the former question makes sense, the latter one does not. The answer will have to include some new assumption that is broader than the assumptions underlying the explanation of nature in QM and it will have to explain more than just QM, otherwise the two explanations will be completely equivalent and you won't get a new theory, but merely a new interpretation of QM. Choice of interpretations is, as we have learned in physics over the past 80 years or so, completely arbitrary. It does not supply any new information. It may feel good to the philosophically minded, but from a scientific point of view having multiple interpretations of the same physics is, at best, a tool of convenience. Sometimes one may be easier to work with, sometimes the other, but in the end... there is no metaphysical content in switching from one to the other.
http://tableelements.blogspot.com
Wrong website, folks. You would be way better of over at YouTube, watching a couple of physics classes on the university level.
That, of course, may require a smidgen of brain plasticity, which may just not be there, any more.
:-)
Sad to say, it reflects how little progress we have made in actual understanding since the days of Bose and Einstein.
They would have asked "What is the mechanism that separates bosons from fermions?" Yes, we know the math says it, but what is the physical mechanism?
No one asks these questions anymore. We play with composite particles and build elaborate predictions around them, but the simple questions go unanswered.
Put another way, what is the difference between a force carrier particle and any other particle?
Enquiring minds want to know.
Depends on the bosons and the fermions. It can be spin, which is a necessary property of space-time based on the fact that it is relativistic, in which case your question is really what the underlying mechanism of special relativity is, in contrast to the mechanism which a world subject to Galilean invariance would be based on. There may be no answer to that, at all, especially since "classical" worlds may not even be possible, in which case expressed physics is simply self-consistent physics and relativistic worlds may be the only self-consistent ones.
Why is there an Uncertainty principle? Do you even have a clue as to why there is a limit to what you can measure?
Galilean invariance explains nothing. You have too many words and zero actual concepts to go with them.
Go back to the question. What is the mechanism that separates bosons from fermions, i.e. which physical manifestation CAUSES THE MATH TO BE THAT WAY?
The Universe creates the math, not the other way around.
It can also be that bosons and fermions are interchangeable. That depends on the real dimensionality of space-time. If it is exactly 3+1 dimensional, being a boson/fermion seems to be a strong symmetry. In other dimensions, this is not a strong symmetry and bosons can convert into fermions and vice versa.
I would put my money on the last one.
"No one asks these questions anymore. "
As you have seen from my little elaboration, that is not correct. All the people who actually know the math of boson and fermion states also (implicitly) know the correct answers to your semi-correct question. People do ask the correct questions in this context... it's just not the naive question that you had in mind.
Dimensions aren't an explanation, they are an excuse. You don't have an explanation for angular momentum either, so it is just more hand waiving.
The emperor has no clothes.
The emperor, is this case, is your mind. Ask questions. Then get REAL answers, not math jumbled poppycock.
Science: Testable assertions. Your response? religious dogma.
What horrible, horrible nonsense, created by a press which does not have the slightest clue about reality.
In the public consciousness, no.
Just as Tesla never got his due, or the French guy who flew before the Wright brothers, or the inventor of the first automobile, also French, or all the scientists who labored for Edison to perfect the lightbulb...the list is endless because, number one, we want all those inventions to be by Americans. And number two, the press enjoys a nice tight story, not one with a cast o thousands.
Your question made (borderline) sense about 80 years ago. Today it merely implies that you have not looked at the physics of the past 80 years.
:-)
But to answer, at least partially, your following question;
"This piece doesnt really tell us what a Boson is rather than what it behaves like";
The way an "object" behaves is what they are! The way an object behaves is what characterizes their intrinsic natures! The behavior of any given object differentiates that object from any other given object. It is by comparing these differences that distingushes any given object from other object!
No one "knows" what they really are....all we can know is our "mental constructs" which we call concepts, "Free creations of the Human mind" as Einstien put it! Wheather or not these "free creations of the human mind" actually fit reality is determined by experimental evidence that supports or deny the hypothesis which is posed!
They measure its angular momentum, which can be done in different ways. Interaction with a magnetic field, polarization of beams and targets etc..
"And whats the difference between a Higgs Boson and a regular Boson?"
Nothing. The Higgs is a specific particle. A boson is ANY particle with integer angular momentum. Your question is analogous to "What is the difference between "blue" and "sky"?"
"Are these force carrying particles then predictable in their motion?"
The free dynamics of particles of any angular momentum is the same in the absence of an external field that interacts with the spin. Fermions and bosons move the exact same way. Only once you apply a magnetic field, which breaks the symmetry of space-time, do you see a difference due to the coupling terms to the magnetic field (if there is a magnetic dipole moment associated with the spin). See Stern-Gerlach experiment.
"This piece doesnt really tell us what a Boson is rather than what it behaves like."
That's because a boson is defined by what it behaves like. EVERYTHING in science is EXCLUSIVELY defined by what it behaves like.
For a broader audience, that may not be saying much. The article is good in covering the history related to origin of the name boson, but does not answer the q "What is a boson?"
I assert that force carriers may be found with other stuff, but they are not the other stuff.
The definition of a boson is therefor simple... just look at its angular momentum. The rest follows from symmetry principles of space-time.
I didn't think so.
Your word salad of physics terms proves nothing. No organizing thought, no organizing principle.
What causes the angular momentum? Not math but actual reality?
It OK to admit you don't know.
Einstien was the first to support the quantum theory and in fact recieved a Nobel Prize for his efforts! Itwas that he always had a questioning mind and felt that their must be somthing more, behind the world of appearences that would explain the strange behavior!
And on Einstein being an atheist is blatantly wrong! He was a Pantheist
Pantheist: belief that God is everything: the belief that God and the material world are one and the same thing and that God is present in everything
Read : Ideas and Opinions by Albert Einstein and you will find this to be true!
Also you will find that he started the Phrase..."Inquiring minds want to know"..
And want to know just what the strange mechanism is behind the "God does not throw dice" is!