E2science

All the life we ever see around us on Earth is powered by light from our local star, the Sun - either directly or indirectly. But where does the Sun get its power from?

Like all stars, our sun was born in a cold, cold cloud of gas and dust, of the sort that fills much of the space between stars. If some part of these clouds gets denser than its surroundings, usually because it's squished by a star exploding nearby, its gravitational attraction starts to pull in more and more matter, eventually forming a big ball.

All the stuff falling in to the centre squashes it together and causes it to heat up, delivering energy in the same way that anything does when it falls from a great height. If it all gets squashed enough and hot enough, hydrogen atoms start to fuse together. That releases even more energy, again for almost the same reason things release energy when you push them over a cliff - atomic nuclei are strongly attracted to each other once they get close enough, even though there are other forces working to keep them apart until they get there. Once they do get the chance to come together, the energy of their intense attraction is released as they unite.

When the hydrogen in the young star starts fusing into helium, the added heat and pressure make it easier for more hydrogen to fuse, and the process sustains itself until the hydrogen is used up. If the star is big enough, it can also fuse heavier elements together for even more energy, and keep on going a lot longer.

So almost all the energy we use here on Earth - all of our food, and most of our electricity - comes from what was left over when a vast gas cloud collapsed in on itself, and the energy that collapse then extracted from pairs of atoms collapsing into each other.

This writeup was read by Jet-Poop for the E2 Podcast Season 6, Episode 2.

Traditionally, rockets have utilized one of two general types of fuel - either solid fuel or liquid fuel. Each has its advantages and disadvantages. The former is very stable, allowing it to be stored for long periods of time in a ready rocket motor without damage or harmful environmental contamination. However, it is much more difficult to control a solid-fuel motor's thrust; practically, you're limited to deciding when to turn it off. Also, solid fuels typically can't contain as much energy as liquid fuels can.

A liquid-fuel rocket can vary its thrust by changing the rate of flow of its propellant and oxidizer, making it more suitable for more complex missions. However, liquid rocket fuel tends to be extremely volatile and/or corrosive; the more powerful types are generally toxic as all heck. This means that handling it is dangerous, and that generally it can only be loaded into the vehicle just before flight.

Efforts are underway to create a third option - that of gelled fuel. As the name suggests, such a fuel would consist of a liquid rocket fuel somehow modified or combined with another substance in order to create a gel. When in storage, the gel would behave more like solid rocket fuel, being much more easily contained, stored and handled than liquids. However, when in use, the gel would behave like a liquid fuel - being capable of variable flow to the engine, liquefying only in the combustion chamber itself.

One industry with a great deal of experience with gel handling, the food preparation industry, has been enlisted to work with more traditional aerospace engineering to learn more about how gels behave in the critical and highly specific environment of a rocket engine.

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"We have lingered long enough on the shores of the cosmic ocean.
We are ready at last to set sail for the stars."
-Carl Sagan

Inspirations for setting sail for the stars in science fiction goes back at least as far as Cordwainer Smith's The Lady who Sailed the Soul published in 1960. Arthur C. Clarke popularized the idea four years later in his short story Sunjammer, since reprinted in 1972 under the title The Wind from the Sun.

I first read about the idea of a spacecraft unfurling a huge but incredibly thin solar sail,in Larry Niven’s sci-fi novel The Mote in God's Eye . His idea was to utilize the pressure of sunlight on the sail - radiation pressure – on a craft weighing several tons that could accelerate to more than a kilometer per second within days, and then go on accelerating so long as it remained relatively close to the sun. It was one of his technological ideas I could understand and it has fascinated me ever since. Niven’s idea is similar to what Xeger discuses in the previous write up. By using giant ground based lasers that would give the craft an initial shove and it would even make it possible to tack the craft by angling the sail. By using the light of the sun which is composed of electromagnetic radiation that exerts force on objects it comes in contact with with a solar sail and lasers the combination would create the potential to send a craft anywhere within the solar system.

Related to many gossamer dreams about space travel, solar sailing is most often read about in science-fiction tales, however using the sun to glide through space has more than just a fictitious etymology; it’s now being given more serious consideration as new materials composed of lightweight carbon fibers only a few microns thick become available. Ed Gabris, a senior engineer at NASA, notes:

"Solar sailing is more than a science fiction fantasy. NASA used solar sailing to increase the experiment time for the Mercury Mariner spaceprobe in 1974-75. The 'sail' was the spacecraft's solar panels. And by controlling the attitude of the spacecraft and the angle of the solar panels to the sun, the operations team was able to cause the spacecraft to visit Mercury several times more than would have been possible with the on-board liquid propulsion system".

The proposal of using the sun's energy to propel spacecraft across the cosmos has been around for centuries, says one expert:

Nearly 400 years ago, as much of Europe was still involved in naval exploration of the world, Johannes Kepler proposed the idea of exploring the galaxy using sails. Through his observation that comet tails were blown around by some kind of solar breeze, he believed sails could capture that wind to propel spacecraft the way winds moved ships on the oceans. While Kepler's idea of a solar wind has been disproven, scientists have since discovered that sunlight does exert enough force to move objects. To take advantage of this force, NASA has been experimenting with giant solar sails that could be pushed through the cosmos by light. There are three components to a solar sail-powered spacecraft:
• Continuous force exerted by sunlight
• A large, ultrathin mirror
• A separate launch vehicle

To give you an idea how fast (solar sailing) is, you could travel from New York to Los Angeles in less than a minute with a solar sail vehicle traveling at top speed…If NASA were to launch an interstellar probe powered by solar sails, it would take only eight years for it to catch the Voyager 1 spacecraft (the most distant spacecraft from Earth), which has been traveling for more than 20 years. By adding a laser or magnetic beam transmitter, NASA said it could push speeds to 18,600 mi/sec (30,000 km/sec), which is one-tenth the speed of light. At those speeds, interstellar travel would be an almost certainty.

Actual theories about solar sailing had their beginnings in the Russian aeronautics pioneer Konstantin Tsiolkovsky and his associate Fridrickh Tsander. In 1924 they were making notes about "using tremendous mirrors of very thin sheets" and "using the pressure of sunlight to attain cosmic velocities". It was American engineer Richard Garwin who has been attributed with coining the term in the latter part of the 1950s. Early on models included huge aluminum-coated Mylar sheets that could be aimed at the sun and "blown" toward deep space, powered by sunlight. However, such relatively heavy sails would take a very long time to go anywhere, so scientists have spent years researching and developing fresh kinds of sails and innovative techniques to thrust them into space faster and more efficiently. The promise of solar sailing in space continues, NASA has recently been in the news about awarding funds for the expansion of solar sail hardware and simulation development. The time is coming soon where we can set sail for the stars. A solar sail powered space ship is scheduled to be launched in the fall of 2002:

The Cosmos 1 mission is a joint venture of the Planetary Society and Cosmos Studios, a group of film-makers and writers set up by the widow of scientist and writer Carl Sagan.

The craft will be launched on a rocket fired from a submarine in Russian waters. The solar sail spacecraft will separate from the rocket, then unfurl and fly for a few weeks or months around the Earth pushed by the Sun.

For many space enthusiasts the modest sum of a four million dollars price tag for this Kitty Hawk moment embodies the future of practical, reasonable and quicker space travel exploration. Soaring through galaxies on sunbeams is magic and I for one can’t wait!

Sources:

How Stuff Works:
http://www.howstuffworks.com/solar-sail1.htm

SPACE.com Exclusive: Breakthrough In Solar Sail Technology:
www.space.com/businesstechnology/technology/ carbonsail_000302.html

Space News:
www.cosmiverse.com/news/space/space05150202.html

Turns of Phrases
http://www.quinion.com/words/index.htm

Autotuning has become a mainstay of popular American music production. It gives musicians and music producers control over their sound in a way that they have never before had. They can remove noise, or add it, turn a bad singer good, or a good singer into a robot. The Symphony of Science is a work using music editing on audio that was not previously set to music. In 1980 Carl Sagan's Cosmos Television series set a new gold standard for science popularization. State of the art effects and narrative clarity allowed Sagan to clearly state the majesty of the universe and the humble art of its observation. To explore important conceptual subjects in a way which is accessible for all ages. More recently the composer John Boswell obtained the boxed DVD collection of Cosmos and splitting from his other R&B auto-tune project Colorpulse he created a mash-up of his own composed work and scenes and audio from Cosmos in the first video in the series A Glorious Dawn.

Each video composition uses piano and synthesizer music as a foundation for auto-tune singing audio from Cosmos and other works by a variety of important science popularizers: Richard P. Feynman, Stephen Hawking, Neil deGrasse Tyson, Richard Dawkins, David Attenborough, Michio Kaku, Bill Nye and Jane Goodall. Each work is created around some important point brought forward in Cosmos and from that point Boswell incorporates a variety of statements related to it from other documentaries or video.

I believe our future depends powerfully
On how well we understand this cosmos
In which we float like a mote of dust
In the morning sky

In A Glorious Dawn the theme is the future. Sagan's quotes expound upon the mystery and awesome qualities of our universe which we and our descendants will explore and how it will affect us. The major point is that our understanding of the universe has reached the point where we can see a future of its exploration. This first video offering garnered acclaim across the span of geekdom, generating renewed interest in Sagan and Cosmos and gained a good deal of support from Ann Druyan and the rest of Sagan's family.

We are a way for the cosmos to know itself

The second offering We are All Connected incorporates a number of different voices, Feynman, Tyson, and Nye into a work that is much more of an artificial conversation. Tyson describes the connectedness of the universe and ourselves, Feynman reflects upon nature and its complexity. Nye shrinks himself into a speck on a speck on a speck and finally Sagan draws everything together poetically by pointing out that the beauty of life is not in its components but their whole. This video is also notable as its beat is provided by Feynman himself.

The exploration of the cosmos
Is a voyage of self discovery

Our Place in the Cosmos explore the point made by Nye in the second video. For all that humanity has accomplished our greatest achievement is perhaps the acknowledgment of how small we are compared to the universe as a whole. Here the voices of science describe our species and its minuscule planet in comparison to the vast stretches time and space. Sagan's voice, however, brings another point out, that we as thinking beings have the opportunity to take from this knowledge a place in that cosmos.

Our planet, the Earth, is as far as we know
Unique in the universe; it contains life

The latest video, The Unbroken Thread, explores the biological universe that we each carry within us. In this work, Sagan seems to differ, more than anything else, to Attenborough to describe evolution. Sagan provides the chorus to the piece and its title. Where in the third video our place in the universe is described as relatively small, here the theme is inverted, the stage of life exists at levels that are as small to us as we are to the rest of the universe. The explanation of life on Earth describes our connection with those first simple organisms. The beauty of life, the triumph of natural selection is counted trillions of times within us. The video ends with Attenborough's establishment of our responsibility for this unique, life-filled world.

With each new video Boswell takes the work of many science popularizers, takes their voices and makes them sing. He uses music and rhythm to give their statements force and nuance and poetry. Each video is unique, containing distinct musical and contextual themes but all of them point to a set of central ideas; that the universe is a vast and interesting place and that our understanding of it is our greatest achievement and greatest goal. My words cannot do justice to these videos or their message, so I highly encourage everyone to go and watch.

Our obligation to survive and flourish
Is owed not just to ourselves
But also to that cosmos
Ancient and vast, from which we spring

UPDATE: The fifth video is currently up, I suggest everyone watch it.

I am not the best resource for hip-hop/R&B criticism. If anyone has a follow-up which explores the Symphony of Science from a musical perspective that would be most welcome.