SOFIA

In 2007 the Stratospheric Observatory for Infrared Astronomy finally took flight. SOFIA was designed to replace the Kuiper Airborne Observatory, a C-141 which stopped flying in 1995. Modifying a 747 SP into a flying telescope took nearly 10 years in the hangar. As recently as 2006 the project came perilously close to cancellation. On April 26 SOFIA made her first flight in this incarnation. After moving fron Waco, Texas to Dryden Flight Research Center, she completed her initial flight test phase on November 15.

Though no books have been written yet, SOFIA could someday capture the public imagination. The name and stubby appearance make her quite personable. In her first life she was christened Clipper Lindbergh by Anne Morrow Lindbergh on the 50th anniversary of the historic flight. After service with Pan Am and United, she was destined for the boneyard before being rescued by NASA as an observatory.

SOFIA will search for nebulae, dust and Black Holes in galaxies. Every galaxy yet found contains at it centre a supermassive Black Hole. Once it was thought that giant Black Holes formed from collisions between smaller objects. Galaxies recently found by the Spitzer Space Telescope show no sign of being disturbed, indicating that collisions play role in their formation. Galaxies have been found formed less than 500 million years after the Big Bang, indicating that supermassive Black Holes are primordial.

Primordial Black Holes are thought to exist by Stephen Hawking and many other physicists. They are predicted to have formed from quantum fluctuations shortly after the Big Bang. Size of a PBH would be limited by a "horizon distance," that light could travel in a given time. Previously it was thought that the speed of light would cause any PBH's to be tiny. Because c was much larger, Black Holes could have formed of enormous mass, big enough to seed formation of galaxies. A hundred billion galaxies containing massive Black Holes say that the speed of light has changed.

SOFIA's stated observation goals also include: star birth and death, formation of new solar systems, identification of complex molecules in space, planets, comets and asteroids in our solar system. Black Holes may also play a role in formation of these smaller objects. Our previous views of infant stars show twin jets like those produced by a Black Hole. Their continued presence would explain the puzzles of Earth's core heat and magnetic field. Study of asteroids is of great importance, as these objects can strike us.

2008 will be another year of seeking Black Holes in unexpected places. Happy New Year to everyone!

From the Grave

Sometimes a scientist must speak up, and that time is here again. Though we often disagreed on politics, the assassination of Benazir Bhutto is a deeply felt tragedy. Whatever men are behind the murder, they are opposed to women having education or influence. They will not win. Today women like Peggy Whitson command space stations and physicists like Angela Merkel lead nations.

Bhutto's last interview with David Frost was aired on November 2. She knew, as this scientist has found, that Osama Bin Laden has been dead 6 years. He was killed approximately December 15, 2001 during the US attack at Tora Bora. His death was hastened by diabetes and kidney failure, compounded by a location far from medical facilities.

As noted here on September 11, the recent OBL videos are transparently fake but the media treats them as real. They are composed of old footage and stills with poorly dubbed voiceover. Their crudeness is a sign of desperation, as someone with proper equipment could make much more convincing video. The image of OBL is maintained by 1) his organisation attempting to control and keep the brand name alive, 2) a news media that uncritically parrots the message, 3) intelligence agencies with a vested interest in maintaining the threat, and 4) those wishing to deny the West and its leaders a victory.

People in New York and elsewhere should be celebrating: Osama is dead! They should do as the British once did with Guy
Fawkes. Every year people could burn paper effigies of Osama. That is a useful way of facing up to fear.

The lesson of all this is to think critically while looking at the raw data. A physics education forces students to parrot data without question. Many physicists have accepted the existence of "dark energy" without examining the assumptions behind it. As with other times, the true history of our age will be written long after. The real theoretical discoveries are made with pencils and paper working in isolation. These are the best of times and the worst of times, truly an exciting time to be alive.

UPDATE: As this is written, a "new" OBL audiotape has appeared. The method used to simulate his voice is the same as Kermit the Frog.

Solar Power Satellites Closer

2007 was a year when Solar Power Satellites came closer to reality. Because of the lack of atmosphere, sunlight is about eight times more intense in orbit than on Earth's surface. SPS in geosynchronous orbit has been studied at least since Dr. Peter Glaser in 1968. This year it has been subject of a serious study by the US National Security Space Office, and a blog by Air Force Colonel "Coyote" Smith.

In September at a conference in Hyderabad, businessman Peter Reed proposed a receiving antenna on an uninhabited island in the Palau chain. At December's UN Climate Change Conference in Bali, Reed's partners described the idea further. Their plan would place an experimental satellite at 300-mile altitude, avoiding the difficulty of reaching geosynchronous orbit.

If scientists in 1907 had lectured about the future of energy it would have been about coal and oil, yet someone had already written E = mc^2. 40 years later we had atomic reactors and an atomic bomb. First we must go beyond dead ends like "dark energy." The power of free thinking will lead to technological surprises.

If tiny Black Holes can be contained in an orbiting laboratory, their energy could be tapped. Even nuclear fusion converts only 0.7% of fuel into energy. A Black Hole converts matter into radiation with 2 orders of magnitude greater efficiency, approaching total conversion. The food that a human eats in a year could provide all the electricity needs of the United States! Any sort of mass could be used for fuel, even old AOL disks and issues of National Geographic.

Solar Power satellites have not been deployed because of the immense construction costs. An SPS constellation powering the US would require 30-40 satellites, each with kilometers of solar arrays. Note how much trouble it has been constructing one space station in low Earth orbit. Black Hole energy would require just one satellite without all those solar panels! The power of thought is far greater than anything humans have imagined.

Christmas Moon

Tonight all the world can share a beautiful full Moon. December 24 Mars will be at opposition, spectacularly close to the Moon. Last year we celebrated Christmas with the Earthrise photo from Apollo 8. This year, thanks to Japan's Kaguya spacecraft, we have a new Earthrise in HD.

39 years ago Apollo 8 celebrated Christmas while rounding the Moon. Thanks to a permanent presence, humans will be celebrating Christmas in Space this year and hopefully long into the future. Tonight skywatchers can contemplate the Moon, Mars and Beyond. The Vision has a goal of extending our permanent presence outward. A time is in sight when humans will enjoy Christmas ON the Moon.

Thursday December 21 the Jim Benson-founded Spacedev successfully tested a prototype lunar lander. Spacedev's hybrid rocket technology is considered safer and more reliable. (The Lunar Lander challenge earlier this year went uncollected when the only entrant blew up.) While failure is an orphan, success has many fathers and mothers. Spacedev built the engines, key parts of Spaceship One. Since their divorce Scaled Composites has tried to build engines alone, with tragic results.

Quietly, Spacedev has been built into a profitable company. Their Dreamchaser spacecraft is a good design that may reach Space before Virgin Galactic. Spacedev has partnered with the International Lunar Observatory to land a telescope on the Moon. Cost for ILO would be about 30 million US, the same amount as Google's Lunar Lander Prize. That would be a nice way to pay back the cost! (Winning the 10 million dollar X-Prize cost Scaled Composites 25 million.)

Happy Christmas to Kea, Tommaso, nige, samh, Q9 and everyone!

Big Trouble in Little Particles

The world of particle physics is getting small indeed. The UK budget is caught between Northern Rock and Southern Iraq. On December 11 the UK announced withdrawal from the International Linear Collider. One week later December 18 the US budget was finally released. It ends funding for ILC and US participation in the ITER fusion project. Fermilab is hit particularly hard, having already spent much of its budget for the year. Possibilities include laying off staff and shutting down the lab for a time. There could be very little raison d'etre for Fermilab after the Tevatron shuts down in 2009.

Remember FANTASTIC VOYAGE? Particle physics has discovered how to shrink an entire field of science! Soon physicists will be reduced to the size of electrons, and we will only perceive them only as anonymous commenters. They will forever whirl around in a wave function, muttering that the speed of light is constant and "GM=tc^3" is too simple to be right.

The 30-year decline has been documented in Smolin's THE TROUBLE WITH PHYSICS and Woit's NOT EVEN WRONG. Almost no one in the mainstream press has taken notice. Perhaps the New York Times, which usually follows physics, will write about this. Most of the taxpaying public quit caring about particle physics long ago. The decline has been happening a long time, so long that physicists have sought jobs in fields like cosmology. Key members of the Supernova Cosmology Project have no training in astronomy, which may explain their strange conclusions.

Before they all cry into their milk, we should remember that working in science is a great privilege. Most of the world, no matter how hard they work in farms or factories, will never have the opportunities that these physicists take for granted. Physics enjoyed a free ride after WW2 because of nuclear power. The people's tax dollars have lavishly supported high-energy physics for decades. After all the funding, what has particle physics given back to the public? "Dark energy?"

Quietly, out of the mainstream, some big advances in physics are being made. Predicting the speed of light may be just a first step. The product hc is to a link between the Universe of Relativity and the small-scale world of quantum mechanics. Future observations may lead to new theories of planet formation, explaining Earth's core heat and magnetic field. This may lead indirectly to sources of energy that make nuclear fusion look crude. If all this were known, funding for physics would be no problem at all. Fermilab should think about that.

Asteroid Coming, Ready Or Not

Happy Holidays Mars! Asteroid 2007 WD5, which was just discovered November 20, will approach Mars on January 30 with a 1:75 chance of striking. If it hit Mars, the asteroid would release energy equivalent to a 15-megaton bomb and create a scar the size of Arizona's Meteor Crater. Asteroid collisions are more fun to watch on someone else's planet.

The Dawn spacecraft, which was launched September 27, has fired its ion engines for its journey to the asteroid belt. DAWN will rendezvous with asteroid Vesta in 2011 and Ceres in 2015. We are fortunate to have found meteorites from Vesta, otherwise very little is known about the composition of asteroids. More than just big rocks, the asteroids are new worlds that could even harbour life.

Bode's Law suggests that another planet should orbit between Mars and Jupiter. Ceres, the largest object in the belt, was long classified as an asteroid but recently has been promoted to minor planet. (It's bigger than Pluto.) Some theories suggest that Ceres is largely made of water, and could contain even more water than Earth.

Other observations suggest that Ceres is differentiated into core and mantle, which would mean that it was melted early in its history. Ultraviolet observations have found water vapour near the North Pole. How such a small body could be heated is a complete mystery. Ceres' 10^{21} kg mass could easily hsve coalesced around a small Black Hole.

The Constellation system and Ares V booster will create many possibilities for spaceflight. Because Mars is such a big step, some scientists are promoting a manned asteroid mission. Because of the smaller gravity well, an asteroid mission may use even less energy than landing on the Moon. An Orion could rendezvous with a near-Earth asteroid in a 2-3 month mission.

New presidents like to impose their own Vision, and an asteroid mission would be a Kennedy-like legacy. In addition to the adventure of landing on another world, the mission could easily be justified to Congress. As GHOSTBUSTERS said to the mayor, "You would be saving the lives of millions of registered voters." Are any New York City mayors listening?

Out of the Darkness

The week's news reminds us that the universe can be both violent and mysterious. Chandra X-ray Observatory images of 3C321 show that it is composed of two galaxies orbiting one together, with one galaxy firing on the other. Every galaxy yet observed contains at its centre a massive Black Hole. In this image, X-ray data from Chandra is violet, optical data from Hubble is orange, and radio data is blue. The Black Hole at one galaxy's core is obscured by dust, giving it an hourglass shape. One of the twin jets blasts out the upper right into the neighbour galaxy. Chandra Press Release.

One reason people cling to belief in "dark energy" is that 2/3 of the Universe's mass seems to be missing. The GM=tc^3 Theory predicts, and WMAP confirms that average density is a "critical" value $\Omega$ = 1. The visible galaxies, and even the dark mass surrounding them, only account for about 1/3 of this total. This has created a void in which theorists can insert fantasies of repulsive energy.

Large scale maps like the Sloan Digital Sky Survey show that galaxies are arranged in sheets with enormous voids between them. A fish in the Barrier Reef knows to avoid dark holes, because something hiding in those holes could eat her! We can only hope that scientists are more intelligent than fish. Since the "voids" contain most of the Universe's volume, they could contain many massive unseen objects.

Gamma Ray Bursts are some of the most powerful explosions in the Universe. Earlier this year GRB 070125 suddenly flared where no object had appeared before. The location in the constellation Gemini is more than 88,000 light years from any known galaxy. Searches by the Palomar Observatory and telescopes atop Mauna Kea showed no signs of surrounding dust. Something, possibly a giant Black Hole, caused the GRB. There could be many more similiar objects in the voids between galaxies. NASA press release

The jet attack of 3C321 shows us how violent the Universe can be. About 2/3 of the Universe is hidden from our eyes. This dark Universe could contain massive Big Gulp Black Holes or other exotic objects. Sometimes this dark Universe erupts into visiblity like GRB 070125. There is far more out there than meets the eye.

More about 3C321 and the anniversary of Australia's first satellite at Carnival of Space!

Moon Rising

More than 35 years ago, before most of us were born, humans walked on the Moon. With the US Vision, Japanese and other missions the Moon is again rising in public consciousness. To turn back now would be foolish. Last week NASA announced that the Lunar Surface Access Module, whose design is still undefined, will be named Altair. The original Lunar Module had no official name, but individual craft were christened Snoopy, Eagle, etc.

Many people are concerned about the "gap" between shuttle retirement in 2010 and introduction of Orion in (maybe) 2015. To keep servicing ISS, NASA would rely on the Russians or (maybe) private craft like SpaceX's Dragon. US Representative Curt Weldon, whose district includes Kennedy Space Center, has proposed to continue flying the shuttles until Orion is ready. In addition to safety concerns, his proposal would cost an additional 10 billion US.

Today we have Japanese and Chinese spacecraft orbiting the Moon, with more nations planning to join in. Next year we can look forward to the Lunar Reconnaissance Orbiter, which will search for possible landing sites. LRO will also search for resources that humans can use on the Moon. A Lunar Crater Observation and sensing satellite will impact the South Pole to aid in the search for water.

As reported here, Monday at AGU Associate Administrator Alan Stern announced selection of the Gravity Recovery and Interior Laboratory. GRAIL will consist of two small spacecraft orbiting in tandem to intimately measure the Moon's gravity field. This will provide data on the Moon's interior, which heretofore has been only speculation. In turn that will also provide clues to the formation of Earth and other worlds. The Principal Investigator will be Maria Zuber of MIT. Sally Ride will be assisting with public outreach. NASA only wants PI's with spacecraft experience (sorry, Saul) so it it pleasing to have women in charge.

UPDATE: for those who weren't there, here are Alan Stern's answers to my other questions:

1) The Alpha Magnetic Spectrometer is permanently grounded for lack of Shuttle flights.

2) Though JWST is eating up the astrophysics budget, room was found to launch the NUSTAR Black Hole Probe in 2011.

3) Since people may not walk on Mars until after 2030, a Mars sample return mission is on the table.

Earlier exploration of the Moon yielded benefits too valuable to count. No one can forget the first Earthrise photos taken by the crew of Apollo 8. Before the internet, the entire human race shared the experience via radio and television. The Moon inspired a whole generation to study science. Finally, an anomaly in the Moon's recession is one more verification of a changing speed of light.

Sign of c Change

On the next block from Moscone Center was an art gallery with this encouraging sign. More people saw the presentation on "c change" than saw Ed Witten last month. As Peter Woit mentioned there, the world of particle physics has grown very small. Even the thousands of scientists at American Geophysical Union show little care for it. AGU was certainly more fun, with multiple parties every night. Tuesday at the Exploratorium museum the drinks had 3000-year old ice brought from Antarctica.

The biggest barrier to "c change" has been getting the word out. Most physicists won't take an opinion on something they have not been exposed to, and the mainstream press follows "dark energy" and the Concorde cosmology. The difficulty of publishing papers where c changes has not helped. Arxiv has become so corrupted that it serves little use. The Smithsonian/NASA Astrophysics Data System is far more thorough. Last week a large number of people, including NASA administrators, were very interested in a changing speed of light.

Happy 90th birthday to Sir Arthur Clarke!

News From Saturn

This week more news comes from Saturn's Rings. Perhaps humans are drawn to their beauty for a reason. They could hold secrets to how our planets formed, and may even point to future sources of energy. In the December issue of Nature scientists report discovery of an enormous ring current surrounding Saturn. Most of the plasma comes from the south pole of Enceladus. The clump of charged particles rotating in sync with Saturn is still considered a mystery. Charged particles circling the planet every 10 hours 47 minutes are like those that would be produced by an orbiting Black Hole.

Wednesday at AGU, Cassini scientists claimed that Saturn's Rings are nearly old as the Solar System. Previously it was thought that the Rings would decay within 100 million years. We would then face the anthropic question of why the Rings exist in just the right time for humans to enjoy them. Later I had the good fortune to talk with Larry Esposito, who wrote the book on Ring observations. He believes the Rings are continually replenished and recycled by icy moonlets orbiting within. These unseen bodies are held together in spite of Roche's Limit by colliding and melting into each other. Normally bodies colliding at orbital velocities should not stick together. Perhaps something else is needed to seed their formation.

Friday C.D. Murray talked about F Ring objects and embedded moonlets. The "fans" in this Ring are evidence of embedded objects. The shepherd moon Prometheus has been observed to interact with F Ring, sometimes leaving strands or jets of materiel. The "jets" are interpreted as resulting from collisions. A big question remains why F Ring precesses in the first place. The Rings would be another place to look for a Black Holes.

Afterward M. Sremcevic talked about Propellor features in the Rings. These are located in a narrow 3000 km belt at 130,000 km from Saturn. The objects that cause the propellors must be very small, for anything bigger than 1 km would open a gap in the Rings. Their behaviour is incompatible with an accretion origin, so they are considered as possible fragments of a shattered moon. I asked and Sremcevic confirmed that his computer models treated the objects as point masses (like Black Holes).

Many, many mysteries remain about the Rings. Some of these mysteries would be explained by very tiny but massive objects hidden within. Thes objects would also give off radiation, like the clump of charged particles. Saturn's rings show conditions similiar to those which formed our Solar System. Perhaps Black Holes are closer than we think.

For more news, check out the new Carnival of Space!

AGU's Expanding Universe

The American Geophysical Union meeting in San Francisco has attracted a record 15,000 scientists from all over the world. The Gauge Theory and Representation Theory conference in Princeton drew barely 100, and only for Ed Witten's talk. AGU has outgrown Moscone Center West and occupied the much larger Moscone South. Those huge concrete arches supporting the roof form catenaries, like an inverted Golden Gate Bridge. Subjects at AGU range from Earth's interior to climate to the Solar System. Every year more woman scientists and students show up, for these fields have far more opportunities. There is far more here than 10 people could possibly see.

Monday morning in Moscone South Room 102 Carolyn Porco began a series of talks on Saturn moons. Jennifer Meyer made the surprise assertion that Enceladus' 6 GW of heat can not be accounted for by tidal forces. The conventional estimate from tidal heating is only 0.12 GW. The old hypothesis or "radioactive decay" does not work for these icy moons. In desperation some researchers are conjecturing a meteorite strike at the South Pole, a true deus ex machina. Enceladus' core is an excellent place to consider a Black Hole.

Monday evening Moscone West Room 3005 was standing-room only for the NASA Science Mission Directorate. Though Berkeley is just a subway ride away, not a single person from SNAP or Supernova Cosmology Project showed up at AGU. As the only astrophysicist in the room, I enjoyed a one-on-one talk with NASA Associate Administrator Alan Stern. He answered all my questions:

1) The Alpha Magnetic Spectrometer is permanently grounded for lack of Shuttle flights.

2) Though JWST is eating up the astrophysics budget, room was found to launch the NUSTAR Black Hole Probe in 2011.

3) Since people may not walk on Mars until after 2030, a Mars sample return mission is on the table.

4) NASA doesn't want Principal Investigators with no spacecraft experience (sorry, Saul).

5) A new Discovery mission was announced, GRAIL.

This huge building is crowded because people are very concerned about Earth and its problems. Many fine scientists like Kea are concerned about Earth. Even if a "dark energy" existed, it would have no conceivable use. The speed of light affects everything including the climate.

Change of Climate

The writer can't be there this week, but this was the Westin Bali in Nusa Dua. December 3-14 the attached convention centre is site of the UN Climate Change Conference. It makes one want to be involved in Climate Science, at least for the week. The shop there sold a very skimpy swimsuit. The adjacent Sheraton and Melia Bali hotels are even more luxurious. Next we will see many other scientists concerned with climate.

Flying Saucers

Our Cassini spacecraft continues to make big discoveries. New data shows that moons Atlas and Pan are surrounded by huge "spare tires," giving them the shape of flying saucers. The CG image is based upon Cassini photos. Since the plane of these bulges coincides with the Ring plane, scientists have concluded that the moons are made of Ring materiel piling up along their equators. Their rotation could not stretch them into this shape, because each moon takes a 14-hour day to revolve. The strange shape offers clues to how these worlds or our Earth formed.

Atlas and Pan both orbit within Roche's Limit, a mathematical boundary within which moons are not supposed to form. Inside this limit, tidal forces from Saturn were thought to tear liquid objects apart. The ice crystals that make up the moons form loose "rubble piles" that behave as a liquid. Being made of ice crystals with many empty spaces in between, the moons have a density much less than liquid water. The spare tires show that they are continuing to attract particles. It is odd that objects with less density than liquid exist inside Roche's Limit, within which liquid objects are not supposed to form at all.

If Pan and other moons formed around singularities, these tiny holes would explain both their formation and shape. Pan's 10^{15} kg mass could easily contain a 10^{12} kg singularity without getting sucked up. Even if you were only 3 meters from such a tiny Black Hole, you would feel no more gravitational pull than you do in Manhattan. Pan orbits within the Encke Gap of A Ring. Outer and inner boundaries of the gap correspond to Lagrangian points in the Pan-Saturn system. Inside the gap particles will be drawn toward Pan, eventually colliding to build the spare tire.

Since Saturn's Rings contain conditions similiar to our Solar System's formation, this offers clues as to how other worlds formed. The moon Iapetus displays a strange ridge around its equator, which may have a similiar origin. Scientists have suggested sending probes to tunnel through Europa's kilometres of ice. A similiar probe could someday burrow into Atlas and possibly find a Black Hole.

H.G Wells' Invisible Man was finally discovered by tracks he left in snow. Saturn's Rings are literally a field of ice in which the tracks of invisible objects can be seen. If our Solar System contains tiny Black Holes, this is a good place to look. Singularities would explain how these small moons formed and stay together. Black Holes may be the missing link to how Earth and other worlds were created.

Night at the Museum Pt. 2

Sometimes reality exceeds our dreams, and the Museum of Natural History is far larger than any movie set. In the opposite corner from Rose Center for Earth and Space is the Hall of Meteorites. This room has not been placed closer because it can't be moved. The Cape York meteorite fragment here weighs 34 tons! This rock from Space is so heavy that it is mounted on supports descending into bedrock.

Touching a big meteorite is a priceless experience. They are dense because they are made of nickel and iron forged by heat into metal. Sliced sections show the silver-grey texture of steel. Banging on a meteorite with the naked fist produces a ringing sound. Sometime in their past these rocks were exposed to intense heat, forged into a metal that survived the lesser heating of impact. For many centuries, meteorites were humanity's only supply of metals. The Cape York meteorite was mined by local Inuit for steel.

In this room are travellers from the asteroids, Mars and Beyond. the Zagami meteorite (lower photo, top) comes to us from Mars. The Camel Donga meteorite displayed below came from asteroid Vesta. How a tiny body like Vesta could have been so hot was a complete mystery. The lack of olivine in meteorites is another mystery.

The Brenham meteorite was found in a Kansas field. Farmers there in the 1880's often bumped into mysterious metallic rocks. A homesteader named Eliza Kimberly recalled a meteorite she had been shown as a schoolgirl. For five years she collected samples and wrote letters to scientists, despite teasing by her husband and neighbours. (Her work wasn't accepted by the arxiv, either.) Finally a scientist was convinced to examine her meteorites and the woman was proved right. The meteorites she found were billions of years old, dating from a time near Earth's formation.

Elsewhere in the hall is a model of Arizona's Barringer Crater. For many years this hole in the Earth was thought to be a product of volcanoes. A Princeton graduate and lawyer named Daniel Barringer became bored with the office and headed West to be a mining engineer. He tried to take geology at Harvard, but dropped the class when an instructor called his questions "childish." Gaining success in his chosen field, Barringer became obsessively interested in the crater. He spent years and most of his fortune making excavations and trying to convince the science community. Within Barringer's lifetime the world realised he was right too.

There are lessons in this room for all scientists. There have been many times (like today) when the textbooks' explanation for the Universe is lacking. Good ideas can come from outside the mainstream of science, even from a Kansas farm. These ideas may be ignored at first, even ridiculed. Determination and years of work can lead to the truth, even within a lifetime.

The books claim that Earth's nickel-iron core remains hot due to "radioactive decay." We can't get samples of the core, but meteorites like Eliza Kimberly's date from the time of Earth's formation. From their composition and what is known about Earth's density, scientists have concluded that Earth's core is also made of nickel-iron. These meteorites may be considered as samples similiar to the core.

The hypothesis of "radioactive decay" may also be tested here. Earth's core has temperatures exceeding thousands of degrees, hot enough to melt rock. The book claims that isotopes within Earth's core cause it to be hot. Since the Hall of Meteorites contains similiar samples, are any of them about to melt? If they contained even a tiny amount of radioactive isotopes, it would not be safe to go near this room. If they contained any isotopes, those would have decayed to nothing long ago. Today these rocks are cold as the New York Winter, yet Earth's core continues to produce heat.

If Earth's core formed around a singularity, that tiny object would generate heat indefinitely. Today it would have the mass of a small moon and the diameter of a grain of sand, far too tiny to suck us up. The tiny amount of Earth that it eats is far less than the mass that arrives each year via these meteorites. Presence of a singularity would also explain Earth's magnetic field and how Earth formed from dust grains in the first place. Like Eliza Kimberly and Daniel Barringer, a scientist should not be afraid of bold steps.

This week Robot Guy hosts the new Carnival of Space!

Night at the Museum

Even on sunny afternoons, one can find stars in a planetarium. A tour of New York's bright lights has included Times Square, the Christmas tree at Rockefeller Center, and Grand Central Terminal. American Museum of Natural History recently starred in NIGHT AT THE MUSEUM. The movie reminded us what an adventure this place is, for one could spend days here without seeing everything. Within the glass cube of its Rose Center for Earth and Space, a gigantic sphere marks Hayden Planetarium. The current show, COSMIC COLLISIONS, is narrated by Robert Redford and features breathtaking images of asteroids and meteors. Though New York lights drown out the stars, this place is a reminder of how Space can touch our lives.

The sphere's lower half is home to a circular Big Bang Theatre, with a show narrated by Maya Angelou. The winding exit ramp is a Big Bang Walkway with milestones of cosmic evolution marked along the tour. While "inflation" and "dark energy" are not on this guest list, Rose Center has at great expense built a model of our spherical Space/Time. Complementing this space are models of the planets, further reminders of the beauty of spheres.

We learn about the Greek Pythagoras via the straight sides of triangles, but he was also interested in spheres. He encouraged men and women to have many interests, making contributions to music and astronomy. As a musician, he is credited with the idea that “music of the spheres” described the planets. Reasoning that it was the most harmonious shape, he theorised that Earth was spherical. Today’s science seeks to explain the Universe from such principles.

To please his musician’s ear, Pythagoras sought a “cosmic harmony.” As a mathematician, Pythagoras was inspired to claim that “all is numbers,” meaning that everything in the world could be described by equations. This idea is the basis of modern physics. Pythagorean ideas began a quest that would last thousands of years, to find equations describing the Universe.

Everyone should own a book called "RELATIVITY: A Clear Explanation that Anyone Can Understand" by Albert Einstein. For about 6.95 US you will get a better view of the subject than any imitator book. In Chapter 31 Einstein dares to imagine the entire Universe. He tries to follow a Cosmological Principle that the Universe looks the same from all locations. Like Pythagoras, he reasons that the most harmonious shape is a sphere. Using General Relativity, Einstein predicts that enough mass will cause Space/Time to be curved into a sphere of 4 dimensions, of which our 3 dimensions are just the surface.

Einstein also realised that gravity would cause this spherical Space/Time to collapse, unless it were supported by some repulsive force. Taking the Cosmological Principle into 4 dimensions, he desired a Universe that looks the same at all times. Here Einstein made the blunder of introducing a "cosmological constant" to prevent the sphere from collapsing. Later Alexander Friedmann and Georges Lemaitre independently found solutions to Einstein equations indicating an expanding Universe. Edwin Hubble's observations of redshifts finally allowed Einstein to drop the cosmological constant

The simple expression R = ct predicts that the Universe expanded from a tiny point. When t was tiny, c was enormous and the Universe expanded like a Bang. Maya Angelou and a preponderance of evidence support the "Big Bang." According to one paradigm, faster-than-light inflation would have expanded the radius so much that its sphere would be to our perception flat. When pressed, even inflation theorists admit that on the largest scales the Universe must be spherical. It is not topologically possible for a tiny point to expand into flat Space. According to General Relativity, even the smallest mass will cause Space/Time to be curved.

Views of the Cosmic Microwave Background may also indicate a spherical Universe. By measuring distances between acoustic peaks, scientists hope to complete a triangle and determine curvature. When a changing speed of light is accounted for, the angles do not add up to 180 degrees and the triangle is not flat. Most telling, the scale of density fluctuations is nearly zero for angles greater than 60 degrees. Like a ship disappearing over Earth's horizon, the lack of large-angle fluctuations is smoking-gun evidence that the Universe is curved. Both lines of CMB data indicate that the curvature has radius R = ct.

According to fashion magazines, it was fashionable to believe that the Universe was flat, like the Earth. Large objects under the influence of gravity, even raindrops, tend to form spheres. The Universe is very, very large. The flat vs. sphere debate once raged about Earth, and everyone knows which side won. Even the work of mathematician Gregory Perelman and the Poincare Conjecture predict a spherical Space. The Universe model at American Museum of Natural History hints that the sphere will win again. The only missing ingredient is "GM=tc^3" written on the side.

Grand Central

Ceiling of Main Concourse in Grand Central Terminal. Depicted on this vault are the ecliptic, celestial equator, Pisces, Triangulum, Ares, Taurus, Orion, Gemini and Cancer. Brighter stars are marked with electric lights. Legend has it that once a motorised Sun moved across that ecliptic. In a city where electric lights drown out the stars, this is a very pleasant diversion.

Once upon a time people thought that stars were fixed to an enormous vault rotating overhead. In some ways this was a useful assumption. The stars are so distant that their parallax is not easily noticed. In our neighbourhood one needs only their right ascension and declination. Many scientists, including this one, keep on the shelf a clear ball with stars drawn on the surface. Even for navigation in Earth, it is safe to treat the stars as if they were fixed to a sphere.

Sharp-eyed astronomers will notice that the constellations are depicted inside out. Inspired by medieval depictions, the artist chose to depict a celestial sphere as if seen from the outside. This is quite inaccurate, for we know that the stars are varying distances from Earth and one could never see such a view. Once again the clear ball on the shelf proves useful in deciphering this picture.

Holes in grillwork over the South windows allow sunlight to pass through, showing images of the Sun at our feet. This acts as a camera obscura, allowing one to track sunspots on the floor. One can even track the Sun's rotation from the sunspots. Galileo's observation of sunspots contradict old theories. It is a mistake to allow the assumption of a celestial sphere to become canon.

Once upon a time people thought that the speed of light was fixed, like the Earth. In some ways this was a useful assumption. The speed of light changes so slowly that the change is not easily noticed. In our neighbourhood in Space/Time one need only the present value of c. Many scientists, including this one, keep on the shelf a book where the speed of light is treated as a constant. Even for navigation in the solar system, it is safe to treat c as constant.

Holes in present understanding allow light to pass through, showing a changing c. Observations of high-redshift supernovae point to a past where values like c may not have been the same. We have reached the Moon and brought back rocks billions of years old, from a time when c was slightly different. Observations of the distant Universe contradict old theories. It is a mistake to allow the assumption of constant c to become canon.

Witten Notes

For the benefit of Kea and other fine mathematicians who couldn't make the lecture, here are my 6 pages of notes from Ed Witten. NEXT: We'll see a more exciting gateway.

Projection

Between Princeton and New York, the past few days have been too exciting to describe. Saturday at 11:00 AM saw the premiere of Grand Central Terminal's Kaleidoscopic Light Show. As music played, stars and fireworks were projected onto the enormous vault and columns. More about this place soon.

I spoke with Peter Woit when he showed up in Princeton Wednesday. Gauge Theory and Representation Theory are small fields, and this post will show why. He was curious how many would show up, whether they would fill the 100 seats. Next week I'll be far away at a meeting with 11,000 scientists. Woit was curious where that was.

As Woit expected, the biggest audience was Wednesday morning for Edward Witten and his collaborator Sergei Gukov. The latter's talk was more interesting, for it told what Witten is working on. Woit gives a far longer description in Not Even Wrong, which may not be long enough to please all mathematicians. An even shorter summary is recounted here, though this gets mathematical.

G is the compact Lie Group. The goal is to understand G_R representations in terms of D-branes. G_R the real form of G_C where G_C is the complexification of G. This leads to a 4-dimensional topological gauge theory. M_4 is a 4-dimensional manifold, a product of a 3-manifold and an interval I.

M_4 = $ \omega x I$

To connect this to reality, a boundary condition is to preserve topological Supersymnetry. One should note that SUSY itself is a highly speculative idea. The many particles predicted have never been detected.

If we remove one dimension, the manifold can be pictured as the ceiling of Grand Central Terminal with the additional dimension projected onto that manifold.

This all leads to a 3-dimensional Quantum Field Theory on W, where W is a Chernin-Simons theory with gauge group G. "Surface Operators" are operators in a 4-dimensional theory supported on a 2-dimensional surface D (like Grand Central's ceiling) which is a subset of M_4.

It is considered "natural" to take D = $\gamma x I$, where $\gamma$ is a member of W and I is an interval.

Next we take W = R x C, where C is a Riemann surface and R is time and $\gamma$ = R_x.

The Hamiltonian approach leads to a Hilbert space H. C is replaced by a punctured disk, leading to a representation space H.

In 4-dimensional gauge theory, M_4 = $\Sigma$ x C where $\Sigma$ = R x I and R is time. We have seen before that R = t in Planck units. In MKS units R = ct where t is time and c is the speed of light.

A 4-dimensional gauge theory on M = $\Sigma$ x C is equivalent to a 2-dimensional topological model.

$\Sigma$ leads to M_H(G,C)

For applications to gauge and representation theory, C = D* a punctured disk. Boundary conditions are specified only at the puncture. Some lively audience questions asked what happens at the puncture, whether it represents a singularity.

Next we have solutions to Hitchins equations:

M_H = T*(E/T) = N = $\Theta_reg$
$\Theta_reg$ takes the form W_i = $\alpha$, W_j = $\beta$, W_k = $\gamma$ where $\alpha$, $\beta$, and $\gamma$ are members of L, the compact Lie algebra.

Finally a Hilbert space is proposed H = hom(Bcc, B') which could be a space of open string states between two branes Bcc and B' on M_H = T*(G/T). B' is a brane supported on G/$\pi$ and Bc is the canonical isotropic brane.

As all can see, this is not just complicated but highly speculative. "Branes" are a theoretical surfaces existing in higher dimensions that intersect with ours. Strings enter the picture only as one possible way to connect the branes. While the maths are interesting, none of this leads to a single testable prediction. Projecting these speculations onto the ceiling of reality will be quite difficult.

For years the string enterprise dominated theoretical physics, pushing other promising ideas and people out. Thanks to the hammering of critics like Peter Woit, strings are rapidly falling out of fashion.Though Edward Witten was once considered a priest of the enterprise, his latest work moves away from strings. The way is open for more useful theories that make testable predictions.

Bored yet? More interesting Space news is in the new Carnival of Space!