Over 4,000 science books now free online - Mankato Homeschooling. The National Academies Press announced this week that all PDF versions of its books will now be available free to the public. This includes more than 4,000 books on subjects such as agriculture, engineering, space, nutrition, chemistry and more. In a press release, NAP said: As of today all PDF versions of books published by the National Academies Press will be downloadable to anyone free of charge. This includes a current catalog of more than 4,000 books plus future reports produced by the Press. The mission of the National Academies Press (NAP) -- publisher for the National Academy of Sciences, National Academy of Engineering, Institute of Medicine, and National Research Council -- is to disseminate the institutions' content as widely as possible while maintaining financial sustainability. To that end, NAP began offering free content online in 1994.
Topics include: Note that many of the titles are quite advanced. Peppikins added: Stuart Firestein: The pursuit of ignorance. What is science about? PhET: Des simulations gratuites en physique, chimie, biologie, sciences de la Terre et mathématiques. Electromagnetic wave equation. Where ), and permittivity ( ), and ∇2 is the Laplace operator. In a vacuum, c = c0 = 299,792,458 meters per second, which is the speed of light in free space. The electromagnetic wave equation derives from Maxwell's equations.
It should also be noted that in most older literature, B is called the magnetic flux density or magnetic induction. The origin of the electromagnetic wave equation In his 1864 paper titled A Dynamical Theory of the Electromagnetic Field, Maxwell utilized the correction to Ampère's circuital law that he had made in part III of his 1861 paper On Physical Lines of Force.
The agreement of the results seems to show that light and magnetism are affections of the same substance, and that light is an electromagnetic disturbance propagated through the field according to electromagnetic laws. To obtain the electromagnetic wave equation in a vacuum using the modern method, we begin with the modern 'Heaviside' form of Maxwell's equations. Yields a vector. And . P. A Dynamical Theory of the Electromagnetic Field. "A Dynamical Theory of the Electromagnetic Field" is the third of James Clerk Maxwell's papers regarding electromagnetism, published in 1865. It is the paper in which the original set of four Maxwell's equations first appeared. The concept of displacement current, which he had introduced in his 1861 paper "On Physical Lines of Force", was utilized for the first time, to derive the electromagnetic wave equation. Maxwell's original equations In part III of "A Dynamical Theory of the Electromagnetic Field", which is entitled "General Equations of the Electromagnetic Field", Maxwell formulated twenty equations which were to become known as Maxwell's equations, until this term became applied instead to a vectorized set of four equations selected in 1884, which had all appeared in "On physical lines of force". Heaviside's versions of Maxwell's equations are distinct by virtue of the fact that they are written in modern vector notation.
For his original text on force, see: .
Waves. Online Reference & Tools - RapidTables.com. Science and beyond. Creating a wide variety of new holograms -- ScienceDaily. Researchers at North Carolina State University have developed techniques that can be used to create ideal geometric phase holograms for any kind of optical pattern -- a significant advance over the limitations of previous techniques.
The holograms can be used to create new types of displays, imaging systems, telecommunications technology and astronomical instruments. A geometric phase hologram is a thin film that manipulates light. Light moves as a wave, with peaks and troughs. When the light passes through a geometric phase hologram, the relationship between those peaks and troughs is changed. By controlling those changes, the hologram can focus, disperse, reorient or otherwise modify the light. An ideal geometric phase hologram modifies the light very efficiently, meaning that little of the light is wasted. Previously, researchers were only able to make ideal geometric phase holograms in a limited set of simple patterns, curtailing their usefulness for new applications. Ant colony responds to predation simulation as a 'superorganism': Ants retreat when scout removed from colony edge, flee when worker removed from nest center -- ScienceDaily.
Ants may respond to disturbances in their nest as one highly organized 'superorganism', according to a study published November 11, 2015 in the open-access journal PLOS ONE by Thomas O'Shea-Wheller from the University of Bristol, England, and colleagues. Ant colonies are incredibly complex, and at the same time, intensely cooperative, which is why they are often referred to as single 'superorganisms.' The authors of this study, interested in the extent to which ants behave as a single entity, simulated different predator attacks on 30 migrating ant colonies.
To observe the ants' responses to predation at different locations in and near the nest, they removed ant scouting at the colony periphery, and then separately, removed workers from the center of the nest. When scouts were removed from the periphery, the foraging 'arms' of the colony retracted back into the nest. Dr. Fun With Vacuum Chambers. Experience Just How Big the Universe is, in One Mind-Blowing Interactive.
You need a more recent version of Adobe Flash Player. Recently, NASA scientists combined data from the Spitzer and Hubble Space Telescopes to discover the most distant galaxy known to date. The galaxy, named Abell2744 Y1, was formed around 13.2 billion years ago when the universe was extremely young. As the universe is expanding, Abell2744 Y1 is currently closer to 40 billion light years away from us, an astounding distance. Image: Galaxy cluster Abell2744 obtained by the Hubble Space Telescope (Credit: NASA) But what does that really mean? Most of us have trouble visualizing the height of buildings, or the distance it takes to get home from work, let alone things on an intergalactic scale.
Even cooler are the tidbits of information that are provided when you click on an object. 1. This is the smallest unit of scale in the universe. As you can see from the animation it takes a bit of zooming to reach this scale. 2. 3. 4. Tres-4 is the second largest planet discovered so far. 5. 6. 7. Het belang van experimenteel onderzoek. Richard Nisbett beschrijft in zijn boek Mindware het belang van het doen van experimenten. Hij zegt dat het doen van experimenten onontbeerlijk is om uit te vinden wat werkt en wat niet werkt. Onze intuïtieve beoordeling van wat werkt of niet is namelijk vaak niet juist. Hij geeft het voorbeeld van het programma Head Start voor jonge kinderen uit achterstandsgezinnen.
In het programma wordt aandacht besteed aan onderwijs, opvoeding en voeding. Hoe je kunt vergissen in of een programma werkt of niet, blijkt uit de volgende voorbeelden die Nisbett noemt: Na de aanslagen in New York in 2001 hebben 9000 traumacounselors hulpverlening geboden aan slachtoffers. Waarom programma’s als DARE, Headstart, trauma counseling en Scared straight niet goed of zelfs averechts werken, is niet goed bekend. Peer review: a flawed process at the heart of science and journals. The Placebo Effect and the Fatally Flawed Medical Studies. November 20, 2010 | 33,053 views Share A new study analyzed numerous research trials to determine the content of the supposedly "inactive" placebos used for research, but discovered that placebo disclosure is rare. Researchers examined 176 medical journal studies and found that the vast majority didn't mention the contents of the placebos at all.
The study authors argued that placebo ingredients may be important. Certain placebos could skew results in favor of the active drug. According to the Los Angeles Times: "The researchers referenced a trial for a drug used to treat anorexia linked with cancer in which a lactose placebo was used. Experimentation for Improvement. About the Course Would you like to: improve the quality of drinking water;make a stronger concrete or brick;increase the sales from your store;find the right combination of settings for your favourite recipe;improve the quality of your company's product;reduce waste;minimize energy use?
No matter what your area of interest (and there are no limits to the applications!) , it is clear: better experiments save time and money, and lead to improvement. In this course we will learn to use efficient factorial experiments, fractional factorials and response surface methods. If these terms sound intimidating, don’t fear! By the end of this 6-week course you will be able to design your own experimental program, changing multiple variables, and interpret the experimental data using simple tools, based on sound statistical principles. These tools and methods can be beneficial to solve the challenges you set for yourself above.
Verified Certificates: Link Coursework to Your Identity Course Syllabus. Understanding Research Methods. About the Course This course is about demystifying research and research methods. It will outline the fundamentals of doing research, aimed primarily, but not exclusively, at the postgraduate level. It places the student experience at the centre of our endeavours by engaging learners in a range of robust and challenging discussions and exercises befitting SOAS, University of London's status as a research-intensive university and its rich research heritage. This course will appeal to those of you who require an understanding of research approaches and skills, and importantly an ability to deploy them in your studies or in your professional lives. In particular, this course will aid those of you who have to conduct research as part of your postgraduate studies but do not perhaps have access to research methods courses, or for those of you who feel you would like additional support for self-improvement.
Course Syllabus Week 1 & 2 – What is research? E-tivity 1: Asking the right question. Scientists have invented a brain decoder that could read your inner thoughts. Scientists have figured out how to read the words of our inner monologue, a finding that could help people who cannot physically speak to communicate with the world. Image: Alex Mit/Shutterstock Talking to yourself or having mindless internal thoughts is something which most of us can admit to. But imagine if we told you that someone could eavesdrop on your private thoughts?
This sounds very creepy, but it's exactly what scientists are working towards achieving. When you hear someone speak, sound waves activate specific neurons that allow the brain to interpret the sounds as words. To learn how to translate people's thoughts, researchers from the University of California in the US looked at the brain activity of seven people undergoing epilepsy surgery. While they read the text aloud, the team built a personal ‘decoder’ for each patient, by mapping which neurons were reacting to different aspects of speech. Nervous System Intro. Humans, like all living organisms, can respond to their environment. Humans have two complimentary control systems to do this: the nervous system and the endocrine (hormonal) system. The human nervous system controls everything from breathing and producing digestive enzymes, to memory and intelligence.
Nerve Cells [back to top] The nervous system composed of nerve cells, or neurones: A neurone has a cell body with extensions leading off it. Numerous dendrons and dendrites provide a large surface area for connecting with other neurones, and carry nerve impulses towards the cell body. A single long axon carries the nerve impulse away from the cell body. There are several differences between axons and dendrites: The Reflex Arc [back to top] The three types of neurones are arranged in circuits and networks, the simplest of which is the reflex arc.
In a simple reflex arc, such as the knee jerk, a stimulus is detected by a receptor cell, which synapses with a sensory neurone. [back to top] Physics topics and chapters | Socratic. Scientists extract images directly from brain. Researchers from Japan's ATR Computational Neuroscience Laboratories have developed new brain analysis technology that can reconstruct the images inside a person's mind and display them on a computer monitor, it was announced on December 11. According to the researchers, further development of the technology may soon make it possible to view other people's dreams while they sleep. The scientists were able to reconstruct various images viewed by a person by analyzing changes in their cerebral blood flow. Using a functional magnetic resonance imaging (fMRI) machine, the researchers first mapped the blood flow changes that occurred in the cerebral visual cortex as subjects viewed various images held in front of their eyes.
Subjects were shown 400 random 10 x 10 pixel black-and-white images for a period of 12 seconds each. For now, the system is only able to reproduce simple black-and-white images. "These results are a breakthrough in terms of understanding brain activity," says Dr. Taboos of Science. Daily Zen List. Periodic Table of the Elements by WebElements.
Microbiology. Scientists Confirm There is a Second, Secret DNA Code That Controls Genes. 7th January 2014 By Michael Forrester Guest Writer for Wake Up World The fascinating and recent discovery of a new, second DNA code further lends credence to what metaphysical scientists have been saying for millennia — the body speaks two different languages. Since the genetic code was deciphered in the 1960s, researchers have assumed that it was used exclusively to write information about proteins. But biologists have suspected for years that some kind of epigenetic inheritance also occurs at the cellular level.
No Such Thing As Junk DNA The human genome is packed with at least four million gene switches that reside in bits of DNA that once were dismissed as “junk”. As scientists delved into the “junk” — parts of the DNA that are not actual genes containing instructions for proteins — they discovered a complex system that controls genes.
[For more information, see: 97 Percent of Our DNA Has a Higher Purpose And Is Not ‘Junk’ As Labeled By Scientists] DNA Code Controls Genes. Biophotonic Communications and Information Encoding in Complex Systems - Implications for Consciousness? How does consciousness emerge from inert matter? This may be the hardest part of the "hard problem" that is consciousness. We have developed pretty solid models for explaining how the various modules and circuits in the brain work together (often in parallel processes) to create awareness and a sense of self. But how does the brain itself, a three pound lump of fatty acids, produce consciousness?
We don't really know, but the research presented below offers the beginning of a possible explanation, but only if the various models are combined (integrated) to generate a coherent theory. Biological Photonic Communication in Cells The open access arXiv.org Quantitative Biology platform (a service of the Cornell University Library) recently posted an article on biological photonic communication and information encoding in (otherwise known as biophotons) in loach fish eggs.
Before taking a brief look at this article, here is some background on biophotonics. Amino: Desktop Bioengineering for Everyone. Inner Life of the Cell (Full Version - Narrated) Scientist creates lifelike cells out of metal. Experiments | The Lab. Scientists Discover Evolutionary Advantage For Homosexuality. PLOS | Public Library Of Science. Toezicht en de evolutietheorie - CM Web. Sexy Science. Los 13 mejores vídeos microscópicos. Reports. Science Homework Help. Geologic Time: Graphical Representation of Geologic Time. What is space? Concepts of time. Are there parallel universes? Time evolution. Measuring information and complexity. Information is noisy. Information about information. Information is surprise. Information is complexity.
Concept of entropy. Measuring information. Information is bits. Continuum Mechanics. Understanding Electricity - Learn about electricity, current, voltage and resistance. Wireless Electricity. Electrical Engineering. Ancient Technology. On How to Disagree. Translating an Essay Into an Infographic. Scientists Sign Declaration That Animals Have Conscious Awareness; Just Like Humans.
How to Criticize with Kindness: Philosopher Daniel Dennett on the Four Steps to Arguing Intelligently. Seven Warning Signs of Bogus Science. Scientific Argumentation. Persuasive essay or letter. The concept of proof. Rubber Duck Problem Solving. Scientific management. NH Field Investigation Models. 1.3.5. Quantitative Techniques. The Feynman Lectures on Physics.
More precision from less predictability: A new quantum trade-off -- ScienceDaily. Scientific Method in Action. World Science U | Thanks for signing up. Effect Size FAQs | Research that matters, results that make sense.