Raw Food

Raw food is just another form of extremism. It takes a very good idea: increased consumption of fruits and vegetables, and can take it too far. The reasons to follow an all-raw diet are just bad logic, and can cause great harm.

The Raw Foods Website I used in the video:
http://www.living-foods.com/

Echoes Of A Supernova

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The Hidden Universe (Episode 20): Cassiopeia A - Echoes of a Supernova A supernova flash echoing through surrounding dust clouds has given astronomers a virtual time machine for studying the light from the explosion that nobody saw.

This is the Hidden Universe of NASA's Spitzer Space Telescope, exploring the mysteries of infrared astronomy with your host Dr. Robert Hurt.

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It's the 17th century supernova that nobody saw, but telescopes in space and on Earth have teamed up to look back in time and study it today!

When a massive star reaches its end of days it explodes dramatically and, for a few months, can outshine anything else in the galaxy. Earlier supernovas had been seen by many, often shining brighter than the planets. Of course with no witnesses, and no records, it's difficult to tell exactly what kind of supernova it was.

A team led by astronomer Oliver Krause has, over the last few years, made a remarkable series of infrared observations of the region. These Spitzer Space Telescope images show shifting patterns of glowing dust beyond the remnant itself. These changes are so fast that they indicate motion at the speed of light!

To get what's happening we have to remember that light moves fast, but in such a vast galaxy it still takes a while for it to get anywhere. Cassiopeia A (Cas A) itself is about 11,000 light-years away, which means today we're seeing what it looked like 11,000 years ago. But that's only part of the story.

The light from a supernova can even take hundreds of years to reach surrounding dust clouds. Following the arrows of light it's clear we'll see the supernova flash first. The light echoing off of the dust clouds will later arrive at various times, delayed by hundreds of years from the original flash.

So we're not seeing the dust move, we're seeing the light from the supernova move through the dust. Out there, the flash is about as bright as the full moon, which is enough to warm the dust slightly. Spitzer detects this brief boost in its thermal infrared glow.

Now, knowing the location of the infrared light echo, Dr. Krause and his team went searching for a far more elusive visible-light echo. Using the powerful Subaru telescope in Hawaii they succeeded in measuring the very faint light of the supernova itself reflecting off the dust. The light echo has acted like an astronomical time machine, letting us study the original supernova using instruments that were beyond imagination in the 17th century.

By matching its visible spectral signature to a wellstudied supernova in a nearby galaxy, Krause and his team have now identified it as a so-called Type IIb supernova. A Type IIb is fainter than the earlier Type Ib supernovas noted by Tycho Brahe in 1572 and Johannes Kepler in 1604. Interestingly, the Royal Astronomer Flamsteed noted a star near Cas A in August of 1680 with a brightness consistent with a Type IIb supernova at that distance. So maybe it was seen after all!

But this light echo reveals more than just the supernova. The expanding flash also lets astronomers study the three-dimensional structure of the dust, illuminating it one slice at a time. If we combine the images, assigning colors to the observation dates, the result is a prismatic display of the 3D dust structure. The nearest dust is blue, and the most distant is red, while everything that stays constant is grey. We can see that interstellar dust lies in sheets and filaments, not, for instance, big, puffy clouds.

This remarkable light echo around Cas A has led to a better understanding of both supernovas and interstellar dust, which itself is made of elements forged in previous generations of supernovas. This also marks the start of the third year of our Hidden Universe podcasts. On behalf of the staff of the Spitzer Science Center, I'd like to thank all of our viewers for making this and our other podcasts so successful. And keep watching, because there's a lot more to this hidden universe just waiting to be discovered!

• http://www.spitzer.caltech.edu/

Germ Theory Denialism

A deeper look into the minds of anti-vaccination activists, HIV/AIDS denialists, and the like.

Mechanisms Of Evolution: How Does Variety Give Rise To New Species?

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Mechanisms of Evolution (Part 2): How does variety arise in the genomes of individuals and a group? How does variety give rise to new species?

Speciation is the evolutionary process by which new biological species arise. In order for continuing evolution there must be mechanisms to increase or create genetic variation and mechanisms to decrease it. The mechanisms of evolution are mutation, natural selection, genetic drift, recombination and gene flow.

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EVOLUTION IS REAL SCIENCE:

1. Does The Evidence Support Evolution?
http://www.youtube.com/watch?v=p1R8w_...
2. Vitamin C And Common Ancestry
http://www.youtube.com/watch?v=SF2N2l...
3. Are We Descended From Viruses?
http://www.youtube.com/watch?v=nIsWZC...
4. Does The Fossil Record Support Evolution?
http://www.youtube.com/watch?v=QWVoXZ...
5. Where Are The Transitional Forms?
http://www.youtube.com/watch?v=kfTbrH...

FACTS OF EVOLUTION:

1. Introduction
http://www.youtube.com/watch?v=43SskX...
2. Universal Common Descent
http://www.youtube.com/watch?v=G0UGpc...
3. Good Design, Bad Design
http://www.youtube.com/watch?v=1Mtr3C...
4. Speciation And Extinction
http://www.youtube.com/watch?v=T5kumH...
5. How Fast Is Evolution?
http://www.youtube.com/watch?v=6XgeSi...
6. What Can Embryos Tell Us About Evolution?
http://www.youtube.com/watch?v=uAZmLY...
7. The Molecules Of Life
http://www.youtube.com/watch?v=nvJFI3...
8. Molecular Evolution: Genes And Proteins
http://www.youtube.com/watch?v=mA7BE3...
9. Retroviruses And Pseudogenes
http://www.youtube.com/watch?v=8ZvTmg...

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The Importance of Evolution in Biology

"Nothing in biology makes sense except in the light of evolution." -- Theodosius Dobzhansky

Evolution has been called the cornerstone of biology, and for good reasons. It is possible to do research in biology with little or no knowledge of evolution. Most biologists do. But, without evolution biology becomes a disparate set of fields. Evolutionary explanations pervade all fields in biology and brings them together under one theoretical umbrella.

We know from microevolutionary theory that natural selection should optimize the existing genetic variation in a population to maximize reproductive success. This provides a framework for interpreting a variety of biological traits and their relative importance. For example, a signal intended to attract a mate could be intercepted by predators. Natural selection has caused a trade- off between attracting mates and getting preyed upon. If you assume something other than reproductive success is optimized, many things in biology would make little sense. Without the theory of evolution, life history strategies would be poorly understood.

Macroevolutionary theory also helps explain many things about how living things work. Organisms are modified over time by cumulative natural selection. The numerous examples of jury- rigged design in nature are a direct result of this. The distribution of genetically based traits across groups is explained by splitting of lineages and the continued production of new traits by mutation. The traits are restricted to the lineages they arise in.

Details of the past also hold explanatory power in biology. Plants obtain their carbon by joining carbon dioxide gas to an organic molecule within their cells. This is called carbon fixation. The enzyme that fixes carbon is RuBP carboxlyase. Plants using C3 photosynthesis lose 1/3 to 1/2 of the carbon dioxide they originally fix. RuBP carboxlyase works well in the absence of oxygen, but poorly in its presence. This is because photosynthesis evolved when there was little gaseous oxygen present. Later, when oxygen became more abundant, the efficiency of photosynthesis decreased. Photosynthetic organisms compensated by making more of the enzyme. RuBP carboxylase is the most abundant protein on the planet partially because it is one of the least efficient.

Ecosystems, species, organisms and their genes all have long histories. A complete explanation of any biological trait must have two components. First, a proximal explanation -- how does it work? And second, an ultimate explanation -- what was it modified from? For centuries humans have asked, "Why are we here?" The answer to that question lies outside the realm of science. Biologists, however, can provide an elegant answer to the question, "How did we get here?"

• http://www.talkorigins.org/faqs/faq-i...

Expanding Crapulence: Neal Adams and the "Expanding Earth Theory"

RHYMEMAIDEN1 explores the "expanding earth theory".

Comets And Meteor Showers

NASA: Comets And Meteor Showers (Perseid Meteor Shower).

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Have you ever wondered what makes these cosmic fireworks? Meteor showers are just colorful debris of a passing comet or occasionally , the debris from a fragmented asteroid. When a comet nears the sun, its icy surface heats up. This causes clouds of gas, dirt and dust to be released, forming a tail of debris that can stretch for millions of miles.

As Earth passes near this dusty tail, some of the small dust particles hit our atmosphere. They burn up and create great celestial fireworks for us to enjoy.

NASA generates meteor shower forecasts to prevent potential hazards to spacecraft that are launching and orbiting Earth. NASA also monitors these showers to check the accuracy of the forecasts.

You can learn about all of NASA's missions at http://www.nasa.gov.

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Rocks and Ice in the Solar System

Our Solar System consists of the Sun, planets, and moons, but it also contains a multitude of smaller chunks of rock and ice. These objects were left over from the time when our Sun and Solar System formed.

So where are all of these small neighbors? Millions of rocky chunks called asteroids orbit in a region between the four rocky inner planets and the four outer gas giant planets. The Dawn mission is currently on its way to investigate Ceres and Vesta, two of the largest asteroids. Beyond Neptune, there is another swarm of objects made mostly of ice and dust. This is the disc-shaped region known as the Kuiper Belt, the origin of many comets. Some comets originate even farther out, from a giant shell of objects near the edge of the Solar System known as the Oort Cloud.

Our Solar System consists of the Sun, planets, and moons, but it also contains a multitude of smaller chunks of rock and ice. These objects were left over from the time when our Sun and Solar System formed.

So where are all of these small neighbors? Millions of rocky chunks called asteroids orbit in a region between the four rocky inner planets and the four outer gas giant planets. The Dawn mission is currently on its way to investigate Ceres and Vesta, two of the largest asteroids. Beyond Neptune, there is another swarm of objects made mostly of ice and dust. This is the disc-shaped region known as the Kuiper Belt, the origin of many comets. Some comets originate even farther out, from a giant shell of objects near the edge of the Solar System known as the Oort Cloud.

http://nightsky.jpl.nasa.gov/docs/08I...

The Electromagnetic Spectrum

Science@NASA: EMS (Episode 1) - An Introduction To The Electromagnetic Spectrum

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Measuring the electromagnetic spectrum

You actually know more about it than you may think! The electromagnetic (EM) spectrum is just a name that scientists give a bunch of types of radiation when they want to talk about them as a group. Radiation is energy that travels and spreads out as it goes-- visible light that comes from a lamp in your house and radio waves that come from a radio station are two types of electromagnetic radiation. Other examples of EM radiation are microwaves, infrared and ultraviolet light, X-rays and gamma-rays. Hotter, more energetic objects and events create higher energy radiation than cool objects. Only extremely hot objects or particles moving at very high velocities can create high-energy radiation like X-rays and gamma-rays.

The different types of radiation in the EM spectrum, in order from lowest energy to highest:

Radio: Yes, this is the same kind of energy that radio stations emit into the air for your boom box to capture and turn into your favorite Mozart, Madonna, or Justin Timberlake tunes. But radio waves are also emitted by other things ... such as stars and gases in space. You may not be able to dance to what these objects emit, but you can use it to learn what they are made of.

Microwaves: They will cook your popcorn in just a few minutes! Microwaves in space are used by astronomers to learn about the structure of nearby galaxies, and our own Milky Way!

Infrared: Our skin emits infrared light, which is why we can be seen in the dark by someone using night vision goggles. In space, IR light maps the dust between stars.

Visible: Yes, this is the part that our eyes see. Visible radiation is emitted by everything from fireflies to light bulbs to stars ... also by fast-moving particles hitting other particles.

Ultraviolet: We know that the Sun is a source of ultraviolet (or UV) radiation, because it is the UV rays that cause our skin to burn! Stars and other "hot" objects in space emit UV radiation.

X-rays: Your doctor uses them to look at your bones and your dentist to look at your teeth. Hot gases in the Universe also emit X-rays .

Gamma-rays: Radioactive materials (some natural and others made by man in things like nuclear power plants) can emit gamma-rays. Big particle accelerators that scientists use to help them understand what matter is made of can sometimes generate gamma-rays. But the biggest gamma-ray generator of all is the Universe! It makes gamma radiation in all kinds of ways.

http://imagine.gsfc.nasa.gov/docs/sci...