Teleportation Milestone Achieved
…or “Beam me up Scotty“. Well not just yet:
Scientists have come a bit closer to achieving the “Star Trek” feat of teleportation. No one is galaxy-hopping, or even beaming people around, but for the first time, information has been teleported between two separate atoms across a distance of a meter — about a yard.
Fundamentals of Physics
Fundamentals of Physics is a calculus based physics textbook by David Halliday, Robert Resnick, and Jearl Walker. It is a perfect introduction into physics, and has been well-known to science and engineering students for decades as “the gold standard” of freshman-level physics texts. It explains physics in a clear way without resulting in a ‘… for dummies’ book.
The textbook covers most of the basic topics in physics: Mechanics, Waves, Thermodynamics, Electromagnetism, Optics and Special Relativity. The extended edition also contains introductions to topics such as Quantum Mechanics, Atomic Theory, Solid State Physics, Nuclear Physics and Cosmology.
How to Learn Math and Physics
How to Become a Pure Mathematician (or Statistician)
How to Become a Good Theoretical Physicist
Wikipedia portals: mathematics – physics. Not very useful to learn math and physics, but still a nice starting point to find additional references.
And once you spend several years of dedicated study, you might want to try to solve these questions…
Any additional links would be greatly appreciated.
The Free Physics Textbook
The Free Physics Textbook, probably one of the best on the internet ! Just great !
Newton’s Cannonball
Newton was interested in two aspects of the Moon’s orbit:
1) Why, if all objects feel the acceleration due to gravity toward the Earth, doesn’t the Moon come crashing out of the sky and onto Earth?
and
2) Why, if as Galileo said, objects move with constant speed and direction until acted upon by an external force, does the Moon move in a circle rather than a straight line?
Newton’s cannonball was a thought experiment Isaac Newton used to hypothesize that the force of gravity was universal, and it was the key force for planetary motion. Learn how he uses a cannon to solve these questions.
Is there an opposite to absolute zero?
Seems like an innocent enough question, right? Absolute zero is 0 on the Kelvin scale, or −273.15 on the Celsius (centigrade) scale. Absolute zero is also precisely equivalent to 0 °R on the Rankine scale (also a thermodynamic temperature scale), and −459.67 degrees on the Fahrenheit scale.
Schrödinger’s cat
Schrödinger’s cat, often described as a paradox, is a thought experiment devised by Erwin Schrödinger. It attempts to illustrate what he saw as the problems of the Copenhagen interpretation of quantum mechanics when it is applied beyond just atomic or subatomic systems. A translation of his original paper.
The End of Cosmology?
Cosmology, from the Greek: κοσμολογία (cosmologia, κόσμος (cosmos) order + λογος (logos) word, reason, plan) is the quantitative (usually mathematical) study of the Universe in its totality, and by extension, humanity’s place in it. Though the word cosmology is recent (first used in 1730 in Christian Wolff’s Cosmologia Generalis), study of the Universe has a long history involving science, philosophy, esotericism, and religion.
A decade ago astronomers made the revolutionary discovery that the expansion of the universe is speeding up. They are still working out is implications. The quickening expansion will eventually pull galaxies apart faster than light, causing them to drop out of view. This process eliminates reference points for measuring expansion and dilutes the distinctive products of the big bang to nothingness. In short, it erases all the signs that a big bang ever occurred. To our distant descendants, the universe will look like a small puddle of stars in an endless, changeless void.What knowledge has the universe already erased? (via sciam)
Further reading
Physical cosmology : Cosmic Journey: A History of Scientific Cosmology from the American Institute of Physics
Esoteric cosmology : wikipedia
Religious cosmology: wikipedia
Secrets of the Samurai Sword
It has been said that the samurai’s sword was his soul. Perhaps this deep attachment had something to do with the perfect melding of form and function found in the katana, as the famous curved sword is known in Japan. Invented a millennium ago, the katana remains a marvel of aesthetic beauty and skillful engineering. While most bladed weapons over the centuries were designed to either pierce or slash, the katana’s two different types of steel gave it optimum qualities for both, making it a highly versatile weapon in battle. In this slide show, follow the steps that a master Japanese swordsmith takes today to craft what is arguably the most legendary of swords.—Rima Chaddha and Audrey Resutek
Learn the secrets of the Samurai Sword…
Mathematicians Design Invisible Tunnel
Call it Harry Potter’s invisible sleeve. New calculations show how to make an electromagnetic “wormhole”—a tube that is invisible from the sides but allows light to shine down the center.
The concept is a twist on a spherical cloak of invisibility proposed last year. Such a device would be made of metamaterial, a thicket of metal rings or other shapes that bends light in funny ways. A hollow shell of metamaterial could in principle channel light around its inner space without slowing the light down, rendering that hidey-hole invisible to the outside world.
More here
Hering illusion
The Hering illusion is an optical illusion due to the physiologist Ewald Hering (1861). The two horizontal lines are both straight, but they look as if they were bowed outwards. The distortion is produced by the lined pattern on the background, that simulates a perspective design, and creates a false impression of depth.
The Orbison illusion is one of its variants,
while the Wundt illusion produces a similar, but inverted effect.
The Orbison illusion is an optical illusion that was first described by the psychologist William Orbison in 1939. The bounding rectangle and inner square both appear distorted in the presence of the radiating lines. The background gives us the impression there is some sort of perspective. As a result, our brain sees the shape distorted.
The Wundt illusion is an optical illusion that was first described by the German psychologist Wilhelm Wundt in the 19th century. The two red horizontal lines are both straight, but they look as if they are bowed inwards. The distortion is induced by the crooked lines on the background, as in Orbison’s illusion. (In some illustrations the Wundt illusion uses two vertical lines, but the inverted effect compared to the Hering illusion is more obvious with horizontal lines)
More of this in The Nature of Visual Illusion by Mark Fineman.
Non-Green Plants ?
Green, yellow or even red-dominant plants may live on extra-solar planets, according to scientists whose two scientific papers appear in the March issue of the journal, Astrobiology. The scientists studied light absorbed and reflected by organisms on Earth, and determined that if astronomers were to look at the light given off by planets circling distant stars, they might predict that some planets have mostly non-green plants.
Interesting. No ?
Seats Helped Ancient Greeks Hear From Back Row
As the ancient Greeks were placing the last few stones on the magnificent theater at Epidaurus in the fourth century B.C., they couldn’t have known that they had unwittingly created a sophisticated acoustic filter. But when audiences in the back row were able to hear music and voices with amazing clarity (well before any theater had the luxury of a sound system), the Greeks must have known that they had done something very right because they made many attempts to duplicate Epidaurus’ design, but never with the same success.
Researchers at the Georgia Institute of Technology (link to full news release) have pinpointed the elusive factor that makes the ancient amphitheater an acoustic marvel. It’s not the slope, or the wind — it’s the seats. The rows of limestone seats at Epidaurus form an efficient acoustics filter that hushes low-frequency background noises like the murmur of a crowd and reflects the high-frequency noises of the performers on stage off the seats and back toward the seated audience member, carrying an actor’s voice all the way to the back rows of the theater.
See also the full article in The Journal of the Acoustical Society of America — April 2007 — Volume 121, Issue 4, pp. 2011-2022 (subscribers only)
Cyclopaedia
Cyclopaedia, or, A Universal Dictionary of Arts and Sciences (folio, 2 vols.) was an encyclopedia published by Ephraim Chambers in London in 1728, and reprinted in numerous editions in the 18th Century. The Cyclopaedia was one of the first general encyclopedias to be produced in English.
The 1728 subtitle gives a summary of the aims of the author:
Cyclopaedia, or, An universal dictionary of arts and sciences: containing the definitions of the terms, and accounts of the things signify’d thereby, in the several arts, both liberal and mechanical, and the several sciences, human and divine: the figures, kinds, properties, productions, preparations, and uses, of things natural and artificial; the rise, progress, and state of things ecclesiastical, civil, military, and commercial: with the several systems, sects, opinions, &c; among philosophers, divines, mathematicians, physicians, antiquaries, criticks, &c: The whole intended as a course of ancient and modern learning.
Table of Trigonometry from the Cyclopaedia (Vol. II, Page 242):
Table of Optics from the Cyclopaedia (Vol. II, Page 667):
More interesting books at the University of Wisconsin Digital Collections.
Sugar powered batteries ?
‘Juiced-up’ Sugar-Fueled Battery Could Power Portable Electronics from PhysOrg.com
Juicing up your cell phone or iPod may take on a whole new meaning in the future. Researchers at Saint Louis University in Missouri have developed a fuel cell battery that runs on virtually any sugar source — from soft drinks to tree sap — and has the potential to operate three to four times longer on a single charge than conventional lithium ion batteries, they say.
[...]
The Genesis of Relativity at 499 GBP
New insights into the premises, assumptions and preconditions that underlie Einstein’s Relativity Theory, as well as the intellectual, and cultural contexts that shaped it, are the subject of a comprehensive study published this month by Springer.
The publication of The Genesis of General Relativity 1 marks the outcome of 10 years of research into the origins of Einstein’s General Relativity Theory, one of the most important physical theories of the 20th century. It provides a comprehensive study and in-depth analysis of how the work of Albert Einstein and his contemporaries changes our understanding of space, time and gravitation.
The ultimate boiled egg
Many cook books suggest the following for boiling eggs: 3-6 min for a soft yolk, 6-8 min for a medium soft yolk and 8-10 min for a hard yolk. If you are satisfied with this, there is no need for you to continue reading. However, if you are in search of the ultimate boiled egg, you’ve come to the right place!
Martin Lersch explains at Khymos (he holds a PhD in organometallic chemistry, so he must be right)
Exotic material fun
The New Scientist has a nice round-up post on exotic materials, including odd stuff that gets fatter when it’s stretched, frictionless superfluids, ferrofluids, and some neat and improbable dry ice stuff.
Why don’t magnets work on some stainless steels?
Stainless steels are iron-based alloys primarily known for their generally excellent corrosion resistance, which is largely due to the steel’s chromium concentration. There are several different types of stainless steels. The two main types are austenitic and ferritic, each of which exhibits a different atomic arrangement. Due to this difference, ferritic stainless steels are generally magnetic while austenitic stainless steels usually are not. A ferritic stainless steel owes its magnetism to two factors: its high concentration of iron and its fundamental structure.
Continue here
The open-access debate
Publishers are under increasing pressure to make journal papers free to all by abolishing subscriptions and making authors pay a fee instead. Rüdiger Voss welcomes the benefits that “open access” publishing brings, while John Enderby warns that this new publishing model comes at a price.
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Update: Marketing Research Group at KULeuven has blogging primeur (via)
