Monday, December 29, 2008

Lurking in the Dark

The wonders of life on Earth are much more interesting than "dark energy." The "Dumbo" squid, so named for its big ears, caught by another of our Oceaneering ROV's. With this year's movies, perhaps they will call it the "Despereaux" squid. Amazing things really do lurk in the dark.

We live in an age when massive amounts of information, virtually the sum of human knowledge, are available on a desktop. As a scientist I must deal with huge databases full of information. All the technology in the world can not overcome human error. Human beings are still too often guided by fear, prejudice, and mob rule. Like the Earth circling the Sun, old ideas take time to be replaced.

Over the weekend I heard a non-scientist boast proudly of what he knew about cosmology. The man was certain that the Universe was accelerating. He was smart enough to know that acceleration violates Conservation of Energy, but believed it was due to some unseen force. This man has not seen any "dark" energies, for no one has. He relied on the scientists who claimed evidence of acceleration, then breathlessly report it to the popular press.

As the year 2009 approaches, we can look forward to another International Astronomical Union meeting. Of the many symposia, none are devoted to "dark energy." However, Joint Discussion 9 will ask: Are the fundamental constants varying with Space/Time?How the world has changed in our favour!

As an example, does anyone out there remember Osama Bin Laden? At one time the press breathlessly amplified his every alleged word and videotape. The press had not seen OBL in person; no one has seen him alive since his death was reported in 2001. All that we have are suspicious recordings of his voice and transparently crude videos. As time has passed we find even Dick Cheney not sure if Bin Laden still alive. Someday the world may find that the OBL stopped breathing on December 15, 2001.

Consider the other man with a beard, St. Nicholas. Every year at this time we see many high-quality movies and video of jolly St. Nick. Many people claim to have seen him firsthand, holding court in the mall. There is much more reason to believe in St. Nicholas than to believe in Osama bin Laden. (If anyone has seen OBL alive since 2001 please leave comment here and I will happily retract this statement.)

It takes time and patience, but eventually the world will realise that neither Osama nor "dark energy" are around to bother us. That will take time, for billions of minds must change. The speed of light will continue to slow whether humans realise it or not. Despite all the challenges, science somehow advances. Like St. Nicholas, good ideas last forever.

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Wednesday, December 24, 2008

A Miniature Sleigh and Eight Tiny Reindeer

Twas a night before Christmas...when what to my wondering eyes should appear but a mini rover and eight tiny reindeer.

The Small Pressurised Rover resembles early designs for the Apollo Lunar Module, with wheels. The SPR was doing sideways maneuvers on the lawn outside Johnson Space Center Building 31. The prototype is not pressurized for Space, but can shelter two astronauts for short trips. This Fall it was tested with a crew in the Arizona desert. At this writing it is being packed up for a trip to Washington DC. On January 20 the SPR will be a memorable part of the inaugural parade, complete with a Spacesuited astronaut.

On the back are the ports where our Spacesuits will be stored externally. NASA adopted rear entry for the suits, so astronauts in the rover can just crawl inside. The suit will have removable outer layers for EVA. When astronauts are finished on the Moon they can leave the outer layers and the icky lunar regolith behind. The pressurized inner layer serves as a Spacesuit for the trip home.

The Apollo Lunar Rover was powered by 4 independent electric motors attached to each wheel. For tight spots it had on-demand 4-wheel drive. Electric cars for Earth would have a similar power system. That sideways capability would be great for parking. Perhaps this electric rover will inspire clean cars for our planet.

Johnson Space Center is also home to a small herd of deer. At night I’ve seen them run across the Building 31 lawn like silent shadows. On the evening the Rover was using the lawn, eight of them were on the other side of Building 9. Perhaps someday they will graze beneath the rectennas from a power satellite. Space age technology can coexist with nature, and help us live better with the Earth.

Happy Christmas to all, and to all a good night!


Sunday, December 21, 2008

Apollo 8's 40th

This week is the anniversary of the Apollo 8, the first crewed mission to leave Earth orbit. Friday at Johnson Space Center, a panel of original engineers remembered the flight. Most of these gentleman are in their seventies or eighties. Chris Kraft is speaking seventh from the left.

1968 was a year of worldwide strife. NASA was still recovering from the Apollo 1 fire the previous year. Apollo 2-6 were unmwnned tests. After the singularly successful Apollo 7 flight, the decision was made to send Apollo 8 into lunar orbit. Even the men in this room thought that was crazy, but somehow they pulled it off. Earth rising over the Moon is one of history's great pictures.

The original NASA engineers were mostly kids straight out of college. Today the workforce is growing, with women allowed to play. The panel was introduced by Marianne Dyson, who was a shuttle flight controller. As I wander around JSC, I meet a growing number of us girls working in Space. They come form very diverse backgrounds--I met one woman who was a curcus acrobat and another who was a Houston Texans cheerleader. This time it will be women on the Moon too.


Saturday, December 20, 2008

Earth Stands Still

A hat-tip to the wondrous Kea, who will soon be working at Oxford. In the new version of DAY THE EARTH STOOD STILL, Klaatu is deeply concerned about he mess humans have made on the planet. Again he comes across the scientist's blackboard filled with our primitive math. He begins by crossing out the "lambda" term in Einstein's field equation, which is a useless contrivance. Einstein himself called this "cosmic constant" his greatest blunder. Without it, Einstein might have predicted expansion of the Universe.

Now the equation looks like:


Klaatu then writes in the solutions of his more advanced species. Today, as was done 2 years ago, we can guess at what he wrote:

Today's physicists, trained for years in our primitive science, may raise petty objections when someone alters their equations. On the question of units, the Friedmann equations are valid in units of mass density or energy density.

The stress-energy tensor T_uv can have units of mass density ρ or energy density ρ(c^2). Removing for a moment the c^2 from Friedmann we would have:
8πGρ/3 = ⅓κρ (c^2)
4πGρ/3 = ⅙κρ (c^2)

To normalise the left-hand and right-hand sides, some physicists chose κ=8πG/(c^2). This led to decades of misconception that Relativity requires a fixed c. Some "geometrized" unit systems give κ=8πG/(c^4), which is too convoluted to describe.

If T_uv has units of energy density, we must use the same for Friedmann:
8πGρ(c^2)/3 = ⅓κρ(c^2)
4πGρ(c^2)/3 = ⅙κρ(c^2)
This is very trivial. The (c^2) on both sides simply cancels out. Einstein called constant κ "related to the gravitational constant" without mentioning c.

Now the Einstein equation becomes Ruv-½guvR=8πGTuv. The Bianchi identities become:
The world is much simpler without that pesky (c^2) factor.

Finally, the Einstein-Hilbert action becomes:
Thus we can do everything General Relativity can without a fixed c. Some problems, like the deflection of bodies by the Sun, work even better with a varying c.

In reality, a human professor would throw Klaatu out for messing with his blackboard. A Universe that can be described in a few equations just might be beyond human understanding. Humans tend to complicate their Universe with epicycles, luminiferous ether, or cosmic constants. Are humans ready for new physics? Perhaps we should ask Klaatu.


Thursday, December 18, 2008

Wilbur and Orville's 105th

December 17 was the 105th anniversary of the Wright Brothers flight. Though a local reporter wrote about the story, it took some months for governments to show interest. In September 1908, while Wilberr was in Europe, Orville demonstrated his plane for the US Army. Despite a crash which killed an observer and severely injured Orville, the Army would buy its first plane in June 1909. In 1911 the US Navy purchased its first aircraft, signalling the start of Naval Aviation. In the Great War of 1914-1918 aeroplanes played an important role. Today flight in aeroplanes is so commonplace as to be a nuisance.

In 1905 a patent clerk named Einstein had performed the amazing feat of publishing 4 groundbreaking papers in a very short time. If a sympathetic Max Planck had not been editor, Einstein might not have published. The first reaction was a deafening silence--by 1908 few had heard of Einstein. (During 1908 and 1909 Einstein had a fascinating disagreement with Walter Ritz on the time arrows of electrodynamics and entropy.) In 1911 Einstein would finally get an academic appointment. Not until 1919 and Eddington's eclipse expedition would Einstein become a celebrity.

We hope that in 100 years the achievements of today, like aircraft and Space flight, become commonplace.


Tuesday, December 16, 2008

Space Diving

You go girl! The close-fitting Spacesuit shows that this is a woman. The booster is based upon Armadillo Aerospace designs. This video depicts suborbital diving. There is no life-support backpack, so this is a short trip. She is shown breaking the sound barrier, like Major Joseph Kittinger in 1960.

Kittinger (2-minute video below) jumped from a balloon at 102,000 feet, a freefall record which still stands. At 43,000 feet he noticed that his glove had depressurised. Like Chuck Yeager, Kittinger neglected to tell the ground about his right side. The mission would have been scrubbed and Kittinger confined to the hospital. The hand swelled to twice its normal size and Kittinger was in pain up and down.

Human skin is airtight, and forms a natural Spacesuit. If exposed to vacuum, the body will swell from internal pressure like Kittinger’s hand. Increasing volume leads to decreasing internal pressure and decompression sickness (the bends.) A human can survive a small portions of the skin exposed to vacuum. After landing, Kittinger’s hand was back to normal in a few hours.

Our skintight suit is made of materials that behave like elastic. Direct pressure from the suit, rather than air, protects the wearer from vacuum. This allows us to build a suit that is lighter, more flexible and comfortable. A hole in the suit would cause swelling directly beneath the hole until blood clotting naturally sealed the breach. In other words, you would just get a big zit. If an astronaut developed a hole in one of today’s suits, he would get a high school named for him.

The skintight suit is a reality that Space organizations are interested in. If not via Armadillo, perhaps we could launch from a modified Spaceship Two. The practical benefits include quick emergency evacuation from a Space station. Crewmembers carrying small payloads could also be boosted directly into orbit like Iron Man. Space Diving will be a reality someday soon.


Monday, December 15, 2008

Dim Bulbs

By now everyone following astronomy has heard about the dimmest bulbs in Space, a pair of brown dwarves 17 light-years away. 2MASS J09393548-2448279 are a million times fainter than our Sun. They were discivered to be two separate objects by a team led by MIT physicist Adam Burgasser. The results appear in the December 10 issue of Astrophysical Journal Letters.

Brown dwarves occupy a spot in the mass spectrum between gas giant planets and small stars. They are too small to ignite nuclear fusion, yet they are warm by their own right. astronomers are not sure what keeps them warm at all. If the dim bulbs formed around a Black Hole, that would keep them dim but very stable. If Black Holes exist within stars, or even within Earth, dim bulbs will take a long time to discover them

Saturday, December 13, 2008

The Centres of Galaxies

More on Black Holes from the European Southern Observatory: German astronomers have made a 16-year studies of stars orbiting the galactic centre. By tracking their orbits precisely, researchers can determine the size and location of our galaxy's central Black Hole. One of the stars has a period of only 12 years, completing one orbit within time of the study. The Black Hole is now estimated to have a mass of 4 million suns.

Astronomers have found thousands of stars orbiting in the core. More than 100 OB and Wolf-Rayet stars have been found that appear to have formed just a few milion years ago. Old theories of star formation can not explain how these stars exist. The immense tidal forces and radiation of the core should have torn them apart. Perhaps someday sastronomers will discover that stars contain Black Holes too.

Another team using ESO's Very Large Telescope (VLT) has imaged the "Einstein Cross" (photo above) from 10 billion light-years away. The cross is actually 4 images of the same distant quasar, light bent into this image by gravity from a foreground galaxy. Quasars are some of the brightest objects in the Universe, powered by supermassive Black Holes. Huge singulairties formed shortly after the Big Bang is yeat another indicator of a changing speed of light.

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Wednesday, December 10, 2008

Bright Cluster, Dark Centre

From the European Southern Observatory in La Silla, Chile. Omega Centauri is 17,000 light years away in the constellation Centaurus. This is the most massive of the globular clusters surrounding our Milky Way. The cluster is 150 light-years across and contains about 10 million stars. In our southern sky it appears nearly as big as the full Moon.

Recent observations with the Hubble Space Telescope and Gemini Observatory indicate that the Omega Centauri contains a Black Hole with the mass of 40,000 suns. The cluster is thought to be 12 billion years old. Astronomers have long wondered how globular clusters could have formed before the galaxy's oldest stars had formed. The Black Hole provides an answer. The cluster could have been seeded by a Black Hole like a pearl forming around a grain of sand.

Below is Globular Cluster M13 as imaged by the Hubble Space Telescope. Early formation of massive Black Holes is one more indication that the speed of light was once much higher.

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Monday, December 08, 2008

Chief Miles O'brien

Miles O'brien has been inexplicably cut loose from CNN. The sinking network is dismantling its entire science, space, environment and technology unit. They will continue to report on wars, senseless crimes and vapid celebrities. Last month Aviation Week magazine closed its Cape Canaveral Bureau, sacking longtime reporters Dave Hughes, Craig Covault, and Dave Collogan. This May we heard Miles speak at the ISDC Dinner. Some out there may recall the enormous media attention when humans first reached the Moon. The future will be very exciting with a "c change" in physics. Our generation may finally reach the Moon. Private Space is already selling tickets. Technology changes our lives by the minute. Earth's environment is a continuing concern. Who will report on Space now?

Saturday, December 06, 2008

New Ride

Though fish are happy to frolic in oil rigs, humans are very concerned about the environment. We must be careful not to overuse nature’s gifts. We did such a good job with the Prius that they are now difficult to buy. During the oil shock of 2008, many people discovered the advantages of saving petrol. This new Space age may also finally be the era of the electric car.

Elon Musk, who made a big success with Paypal, developed the Tesla electric car. This Tesla dealership in Menlo Park, California is one of only two. (General Motors has over 7,000 dealers.) To get a Tesla, I must put down half the cost or about 60,000 US. I must wait about a year for my car to be ready. Though going overseas is a big temptation, Elon has chosen to make cars in the US. The big US automakers ruined the environment with SUV’s and are now begging for help. Without a handout, Elon’s car is doing quite well.

To make a small fortune in Space, one should start with a large fortune. Elon’s other big project is SpaceX. On September 29 their Falcon 1 rocket finally reached orbit on the fourth attempt. On November 22 the larger Falcon 9 had a successful ground test in Texas. Thursday the Falcon 9 first stage was trucked out of El Suegundo on its journey to the Cape. Early next year Falcon 9 will be launched from Kennedy Space Center.

Both Falcons use the Merlin regeneratively cooled engine. Fuel is circulated around the combustion chamber for cooling, so there is still fuel in the pipes when the first stage separates. On the third flight of Falcon 1, the first stage continued accelerating after separation. It bumped into the second stage, sending Falcon 1 spinning out of control. This problem did not occur on ground tests because sea level does not have the low pressures of Space. A ground test does not always translate into a successful flight.

The Shuttle system was due for retirement in 2010. The STS-134 flight that I suggested for the Alpha Magnetic Spectrometer may push that date into 2011. A report issued by the Congressional Budget office November 3 estimates that, with the AMS flight, chances are only 5 to 30 percent of finishing by September 2010. NASA is currently aiming for a September 2014 flight of Ares 1. This leaves at least a 3-4 year gap between US spaceflights.

If all goes well, 2010 will also see an unmanned Dragon dock with ISS. A crewed version will have maximum commonality. SpaceX is already lining up scientific customers for their Dragonlab. Elon and SpaceX employees point out that Falcon/Dragon are all-American systems. Like the Tesla, they are built of US parts in US plants. A manned Dragon may be the best hope for the US closing the “gap,” and they are not asking for handouts.


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