Saturday, January 30, 2010

Physics Quote of the Day (January 24 - January 30)

"Quantum phenomena do not occur in a Hilbert space. They occur in a laboratory." Asher Peres, born 30 January 1934.

"Scientific thought is the common heritage of mankind." Abdus Salam, born 29 January 1926.

"Everything with a quantum in it, with 'h' in it, was exciting." Edwin C. Kemble, born 28 January 1889.

"In reality, a theory in natural science cannot be without experimental foundations; physics, in particular, comes from experimental work." Samuel C. C. Ting, born 27 January 1936.

"We do not know the truth. But sometimes we get a glimpse of the shadow of the truth. And where there is a shadow, somewhere there must be light." Eric Mervyn Lindsay, born 26 January 1907.

"How scientists go about their job: and it's a process, it's a question of asking questions, respecting observation, respecting experiment, having tentative explanations and then testing them.... There is a problem sometimes with how we teach science at schools. Because we sometimes teach it as if it has been chiseled in stone." Paul Nurse, born 25 January 1949.

"There are many examples of old, incorrect theories that stubbornly persisted, sustained only by the prestige of foolish but well-connected scientists. ... Many of these theories have been killed off only when some decisive experiment exposed their incorrectness. .. Thus the yeoman work in any science, and especially physics, is done by the experimentalist, who must keep the theoreticians honest." Michio Kaku, born 24 January 1947.

Saturday, January 23, 2010

Physics Quote of the Day (January 17 - January 23)

"Authority in science exists to be questioned, since heresy is the spring from which new ideas flow." John C. Polanyi, born 23 January 1929.

"It is important to do everything with enthusiasm, it embellishes life enormously." Lev Landau, born 22 January 1908.

"One gets much better ideas if you talk with someone. I get ideas talking to my students even if they have suggested an idea. It’s just the process of talking with them which makes me think of things I wouldn’t have thought of otherwise, which I realize is directly a result that I’m talking with them. So, they influence you in countless ways." Charles P. Slichter, born 21 January 1924.

"Listen to learned men, but do so only with one ear !" André-Marie Ampère, born 20 January 1775.

"I can think of nothing else than this machine." James Watt, born 19 January 1736.

"You will get your difficulties with the point electron." Paul Ehrenfest, born 18 January 1880.

"I am much in the Dark about Light" Benjamin Franklin, born 17 January 1706.

Sunday, January 17, 2010

Pythagoras extended

I came across an interesting Almost Pythagoras relation at Pat'sBlog. It says that for any triangle ABC with median AM drawn from vertex A, we have the general relation:

AB² + AC² = BM² + AM² + MC² + AM².

This relation can be proven with the law of cosines.

I like the alternative proof which is derived from the fact that for any triangle ABC:

AB² + AC² = constant,

if point A is located on a circle concentric with the circle of diameter BC (see Figure 1).

A proof of this important (and practically unknown) triangle theorem is given by Nguyen Tan Tai at one of his pages.

Therefore, from Figure 1, we can draw the isosceles triangle A'BC of Figure 2 with AB² + AC² = A'B² + A'C² and median A'M = AM.

The relation A'B² + A'C² = (BM² + MA²) + (MC² + MA²) is then easily read from the Pythagorean relation on both right triangles A'MB and A'MC.

Saturday, January 16, 2010

Physics Quote of the Day (January 10 - January 16)

"Great physicists fight great battles." Jean-Pierre Vigier, born 16 January 1920.

"Physics is, hopefully, simple. Physicists are not." Edward Teller, born 15 January 1908.

"Life is made up of experiences, and the more experiences you have, the more you live." Gordon Shrum, born 14 January 1896.

"But it is not time for me to die; I have not yet finished my life's work." Jan Burgers, born 13 January 1895.

"When you recognize you may have made a mistake, admit it to yourself and go onto the next one. Don’t limit yourself to one. Don’t think this one idea is the only one you’re ever going to get and it was an epiphany." James Fergason, born 12 January 1934.

"The trouble with theorists is, they never pay attention to the experiments!" Valentine Telegdi, born 11 January 1922.

"Cosmology is a science which has only a few observable facts to work with." Robert Woodrow Wilson, born 10 January 1936.

Saturday, January 9, 2010

Physics Quote of the Day (January 3 - January 9)

"Skill can be increased with practice and the exercise of care contributes to success." Thomas T.Goldsmith, born 9 January 1910.

"If we do discover a complete theory, it should be in time understandable in broad principle by everyone. Then we shall all, philosophers, scientists, and just ordinary people be able to take part in the discussion of why we and the universe exist." Stephen Hawking, born 8 January 1942.

"Whatever the progress of human knowledge, there will always be room for ignorance, hence for chance and probability." Émile Borel, born 7 January 1871.

"I think of physics as the liberal arts of technology." Richard A. Muller, born 6 January 1944.

"Research is a matter of overcoming obstacles. That's what research is about. There are problems. There are difficulties. It's hard to make sense of a collection of information or whatever. Obstacles are the nature of research. Maybe that's why some people give up. There's always an obstacle. You overcome one to find there's another one." Alexander Dalgarno, born 5 January 1928.

"To explain all nature is too difficult a task for any one man or even for any one age. Tis much better to do a little with certainty, & leave the rest for others that come after you, than to explain all things by conjecture without making sure of any thing." Isaac Newton, born 4 January 1643.

"For we may remark generally of our mathematical researches, that these auxiliary quantities, these long and difficult calculations into which we are often drawn, are almost always proofs that we have not in the beginning considered the objects themselves so thoroughly and directly as their nature requires, since all is abridged and simplified, as soon as we place ourselves in a right point of view." Louis Poinsot, born 3 January 1777.

Monday, January 4, 2010

More FQXi essay quotes

I participated in last FQXi essay contest "What is ultimately possible in physics?". I intended to participate seriously in the discussions and read a good part of the 114 essays. However, I think I made a good start, but bad ending, as I ran out of time with exams approaching for my studies. I found that working out and discussing essays that propose whole new insights on physics is extremely time consuming (imagine the time it takes for the panel judges!). I often needed to crawl through a lot of pre- and mis-conceptions before I managed to sympathize with the subject treated. Moreover, maybe because I started participating seriously, my own essay got on the forefront (it headed at the first place for community ratings for about two weeks), so I also had to manage feedback on that. That was of course very appreciable, but diminished my ability to read and discuss more of the others, which I sincerely regret, because there were so much interesting thoughts in all the essays.

On the whole, I really appreciated participating, because the spirit of the contest was positively oriented, with much more "Why's?" than "No's!" appearing in the discussions. That's sufficiently rare in online physics forums. Generally, in online forums one gets stuck into incomprehensions and orthodoxy warnings before one manages to expose the core ideas. Personally I've benefited from all your feedback. To those who have taken the time to read, to discuss or to vote on my essay, thanks! Like all other participants, I'm awaiting the thrill of the prize announcements which probably will come in the next few weeks.

Now, here's the follow-up for the essays I started to quote last time. Please feel free to suggest others which I missed.

From "Solving the mystery of wave/particle duality---the road to a unified theory of physics", by Dennis Crossley, presenting a creative model thoroughly thought over for the whole of particle physics.
"But what is the “thing” that electrons and light are made of?"

From "Unification and Emergence in Physics: the Problem of Articulation", by Ian Durham, advocating plain language explanation for physics.
"Physics likes to strip out all the extraneous baggage of a problem before reassembling it. Physics deals with the most fundamental aspects of the universe. Thus, in that sense, it is the science of simplication. The best physical theories are both simple and elegant and provide building blocks from which we may re-assemble nature. In contemplating the explanatory limits of physics, it makes sense to keep this in mind. But in the process we also must take special care in our use of the language within which we form our ideas."

From "On the applicability of quantum physics", by George F. R. Ellis, exposing original insight on how macroscopic behavior emerges from complex assembled systems.
"there are tantalizing hints that top-down action may play a significant role in quantum theory measurements"

From "Gravity From the Ground Up", by Don Limuti, a thought experiment about the underlying mechanisms of particles periodical motion.
"I start by saying "It seems reasonable to me"."

From "Galilei, Gold, Ren - votes for ultimate realism", by Eckard Blumschein, raising little known flaws in signal processing.
"Differential equations are not the primary relations in physics but they arose by stripping off the link to reality and hence they opened the door for ambiguity."

From "Perfect Symmetry", by Peter A. Jackson, proposing a methodology towards achieving the ultimately possible in physics.
"Complacency, and resistance to considering new insight, does itself, and perhaps even alone, create the real limit to what is ultimately possible in physics."
"The logic of claiming that all good theory will get noticed and rise to the fore is flawed in our present system. There is no proof the answer wasn't there 150 years ago and subdued."

From "Finally it is possible to understand our universe and its implications", by Gordon Kane, giving insights in how string theory has become testable.
"The physical universe is consistent. Physics does not prove its results as theorems, it tests them against the real world."

From "Ultimately, in Physics the Rational shall become Reasonable!", by Terry Padden, investigating how rationality and reasonability should articulate in an ultimate physics. This essay has the largest collection of quotable sentences I came across, so I recommend you read the whole essay.
"Experience is physically real. It actually happens to (our) bodies. We experience a dynamic universe with freedom to move in 3 spatial dimensions constrained in Time by a transient "Now". Reasonably, our Brains react to take immediate account of every experience. It is impossible to discard Naive Realism. It is the foundation of all of our communication. This includes self-communication, i.e. thought. Truth, the product of thinking, is mentally determined - when after conscious thought it is rationally acceptable to our Minds. Our conceptual models need to match our common experience. True science requires the rational becomes reasonable."

From "Towards A More Realistic Interpretation of Quantum Mechanics", by Terence Nelson, inquiring thoughts on quantum entanglement.
"Obviously, there must be some problem with Bell's assumptions."

From "Two steps back, three leaps forward", by Steven Oostdijk, pleading for a return to simple mechanical explanations in order to be able to answer what's ultimately possible in physics.
"The sort of math that physics requires is a math of rigorous definitions and transparent variables, with as little abstraction as possible."

Saturday, January 2, 2010

Physics Quote of the Day (December 27 - January 2)

"It is change, continuing change, inevitable change, that is the dominant factor in society today." Isaac Asimov, born 2 January 1920.

"I often liken the process of physics research to solving a jigsaw puzzle. As we put together pieces to form patches, a certain image of the overall picture emerges, but until the game is sufficiently progressed, we are not quite sure." Benjamin W. Lee, born 1 January 1935.

"I would insist that any proposal for a radically new theory in physics, or in any other science, contain a clear explanation of why the precedent science worked, ... the crank is a scientific solipsist who lives in his own little world. He has no understanding nor appreciation of the scientific matrix in which his work is embedded … In my dealings with cranks, I have discovered that this kind of discussion is of no interest to them." Jeremy Bernstein, born 31 December 1xxx.

"Every time we get slapped down, we can say, Thank you Mother Nature, because it means we're about to learn something important." John Norris Bahcall, born 30 December 1934.

"It must be confessed that the new quantum mechanics is far from satisfying the requirements of the layman who seeks to clothe his conceptions in figurative language. Indeed, its originators probably hold that such symbolic representation is inherently impossible. It is earnestly to be hoped that this is not their last word on the subject, and that they may yet be successful in expressing the quantum postulate in picturesque form." Herbert Stanley Allen, born 29 December 1873.

"Young man, in mathematics you don't understand things. You just get used to them." John von Neumann, born 28 December 1903.

"In the fields of observation chance favors only the prepared mind." Louis Pasteur, born 27 December 1822.