Marco Ugarte / AP file

A monarch butterfly sits on a tree trunk at the Sierra Chincua Sanctuary in Mexico.

MEXICO CITY —The amount of Monarch butterflies wintering in Mexico dropped 59 percent this year, falling to the lowest level since comparable record-keeping began 20 years ago, scientists reported Wednesday.

It was the third straight year of declines for the orange-and-black butterflies that migrate from the United States and Canada to spend the winter in mountaintop fir forests in central Mexico. Six of the last seven years have shown drops, and there are now only one-fifteenth as many butterflies as there were in 1997.

The decline now marks a statistical long-term trend and can no longer be seen as a combination of yearly or seasonal events, the experts said.

But they differed on the possible causes.

Who's at fault?
Illegal logging in the reserve established in the Monarch wintering grounds was long thought to contribute, but such logging has been vastly reduced by increased protection, enforcement and alternative development programs in Mexico.

The World Wildlife Fund, one of the groups that sponsored the butterfly census, blamed climate conditions and agricultural practices, especially the use of pesticides that kill off the Monarchs' main food source, milkweed. The butterflies breed and live in the north in the summer, and migrate to Mexico in the winter.

"The decrease of Monarch butterflies ... probably is due to the negative effects of reduction in milkweed and extreme variation in the United States and Canada," the fund and its partner organizations said in a statement.

Omar Vidal, the World Wildlife Fund director in Mexico, said: "The conservation of the Monarch butterfly is a shared responsibility between Mexico, the United States and Canada. By protecting the reserves and having practically eliminated large-scale illegal logging, Mexico has done its part.

"It is now necessary for the United States and Canada to do their part and protect the butterflies' habitat in their territories," Vidal said.

Debate over logging
Logging was once considered the main threat to the reserve, located west of Mexico City. At its peak in 2005, logging devastated as many as 1,140 acres (461 hectares) annually in the reserve, which covers 193,000 acres (56,259-hectares). But a 2012 aerial survey showed almost no detectable logging, the first time that logging had not been found in detectable amounts since the mountaintop forests were declared a nature reserve in 2000.

Lincoln Brower, a leading entomologist at Sweet Briar College in Virginia, said in a statement that "the report of the dwindling Monarch butterfly winter residence in Mexico is ominous."

"This is not just the lowest population recorded in the 20 years for which we have records," Brower said. "It is the continuation of a statistically significant decrease in the Monarch population that began at least a decade ago."

However, Brower differed on whether small-scale logging, the diversion of water resources and other disruptive activity in the reserves in Mexico are playing a role in the decline.

"To blame the low numbers of monarchs solely on what is happening north of Mexico is misleading," Brower said. "Herbiciding of soybean and corn fields that kills milkweed is a serious problem, but the historical decline over the past 19 years has multiple causes.

"All three countries need to face up to the fact that it is our collective activities that are killing the migratory phenomenon of the Monarch butterfly," he said.

Hidden problems
Environmentalist and writer Homero Aridjis praised Mexico for progress in reducing illegal logging, but added that "low intensity logging, not detected in satellite image analysis, continues unabated in and near critical overwintering habitats."

The head of Mexico's nature reserves, Luis Fueyo, said there are still some problem to be solved at the wintering grounds in Mexico, including some small-scale logging and water availability. The Monarchs don't drink any water throughout their long migration until the reach Mexico, and the mountain streams in the area have been affected by drought and human use.

The migration is an inherited trait. No butterfly lives to make the round trip. The millions of Monarchs cluster so densely on tree boughs in the reserve that researchers don't count their individual numbers but rather measure the amount of forest they cover.

This winter, the butterflies covered just 2.93 acres (1.19 hectares), down from 7.14 acres (2.89 hectares) last year.

Copyright 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed. 

Sean Kilpatrick via Reuters

Lowell Glacier rises from waters in Kluane National Park, near Haines Junction in Canada's Yukon Territory.

OSLO, Norway — Canadian glaciers that are the world's third biggest store of ice after Antarctica and Greenland seem headed for an irreversible melt that will push up sea levels, scientists said Thursday.

About 20 percent of the ice in glaciers, on islands such as Ellesmere or Devon off northern Canada, could vanish by the end of the 21st century in a melt that would add 1.4 inch (3.5 cm) to global sea levels, they said.

Governments are trying to understand every possible centimeter of sea level rise caused by global warming, to plan how to protect cities from New York to Shanghai or low-lying coasts from Ghana to Bangladesh. "We believe that the mass loss is irreversible in the foreseeable future," assuming continued climate change, the scientists, based in the Netherlands and the United States, wrote in the journal Geophysical Research Letters.

Lead author Jan Lenaerts of the University of Utrecht told Reuters that the trend seemed unstoppable because a thaw of white glaciers would expose dark-colored tundra that would soak up more of the sun's heat and further accelerate the melt.

A total melt of the glaciers would take several centuries. Climate change is warming the Arctic faster than the global average.

Most past estimates of Canada's glaciers, based on less precise data of their size and melt rates, pointed to a smaller contribution to sea level rise of perhaps three-quarters of an inch (2 centimeters) this century, Lenaerts said.

The U.N. panel of climate scientists has projected that world sea levels will rise by 7 to 23 inches (18 to 59 centimeters) this century, or more if a thaw of vast ice sheets in Antarctica or Greenland accelerates.

Canada's glaciers are little-studied and often lumped into the panel's estimates with ice in Alaska, Patagonia, Russia and Svalbard off north Norway.

"These glaciers are a significant part of the whole equation and of future sea level rise," David Vaughan, head of the ice2sea program for studying global warming based at the British Antarctic Survey in England, told Reuters. "We can't afford to ignore them." Vaughan was not among the authors of Thursday's study.

"Most attention goes out to Greenland and Antarctica, which is understandable because they are the two largest ice bodies in the world," Michiel van den Broeke, a co-author of the study at Utrecht University, said in a statement. "We want to show that the Canadian ice caps should be included in the calculations."

The experts used satellite data of the extent of Canadian glaciers over the past decade to work out a model to project their decline. The projection of a 20 percent loss of volume was based on a scenario in which world temperatures would rise by 3 degrees Celsius (5.4 degrees Fahrenheit) this century and by 8 degrees C (14.4 degrees F) in the Canadian Arctic. That's well within most U.N. scenarios.

Copyright Thomson Reuters 2013. Check for restrictions at: http://about.reuters.com/fulllegal.asp 

Egypt Ministry of Antiquities

A worker studies one of the funerary jars found inside a recently discovered burial chamber in Luxor.

Archaeologists say they have discovered a string of 3,000-year-old rock tombs in the Egyptian city of Luxor, containing the remains of wooden coffins, skeletons, furniture and canopic jars.

The tombs were dug within the funerary temple of Pharaoh Amenhotep II, who reigned from 1427 to 1401 B.C. during Egypt's 18th Dynasty. However, the newfound tombs appear to be part of a more recent cemetery. In Thursday's announcement of the discovery, Egyptian Antiquities Minister Mohammed Ibrahim said they date back to the beginning of a transitional period that lasted from 1075 to 664 B.C.

Ibrahim said a team led by Italian archaeologist Angelo Sesana made the discovery while cleaning up the site in the course of an excavation at Amenhotep II's temple, on the west bank of the Nile River.

"When we began digging, the area was only a mound of debris. We were in no way certain of what we would find." Sesana told the Italian news service ANSA.

Sesana, who has led excavations within the temple's ruins for 15 years, voiced excitement over the find: "It moves you like little else to bring back to life someone who sought immortality 4,000 years ago."

Each of the tombs consists of a pit that leads to a burial chamber. The wooden coffins found within the chambers bore decorations in red and black ink, and contained the remains of skeletons, Ibrahim said. Mansour Barek, the antiquities supervisor at Luxor, said the archaeologists found 12 canopic jars — some made of limestone, and others made of fired clay. Such jars were used in ancient Egypt to preserve the internal organs of the dead.

Barek said the lids of the jars were in the shape of the four sons of the Egyptian god Horus: Imsety, with a human head, the spirit who protects the liver; Hapi, a baboon-headed spirit responsible for the lungs; the jackal-headed Duamutef, who guards the stomach; and falcon-headed Qebehsenuef, who guards the intestines.

The discovery demonstrates that Amenhotep II's temple continued to be seen as an important site many years after the pharaoh's death, Ibrahim told Egypt's Ahram Online. Sesana said some of the canopic jars came from the tomb of an unidentified woman — and Egyptologist Wafaa El Saddik told the BBC that the jars were of good quality, suggesting that the tombs belonged to wealthy people. 

The antiquities ministry said the artifacts were transferred to storage in Luxor for maintenance and restoration, in preparation for museum display.

Egypt Ministry of Antiquities

Four canopic jars are sculpted to represent spirits who guard the internal organs of the dead.

More about Egyptian archaeology:

• Egypt's oldest carvings of pharaoh found
• Egypt's largest sarcophagus is fit for a king
• 16 severed hands found in Egypt — all rights

NBC News' Taha Belal contributed to this report from Cairo.

Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

Andrew Cowie / AFP - Getty Images

David Cundall, shown here at London's Imperial War Museum, is leading a team that will search for surplus British Spitfire airplanes that were boxed up and buried in Myanmar at the end of World War II.

YANGON, Myanmar — A search team led by a British aviation enthusiast arrived in Myanmar on Sunday to begin a dig they hope will unearth dozens of rare British Spitfire fighter planes said to have been buried in the Southeast Asian country at the end of World War II.

The 21-member team, led by farmer and businessman David Cundall, will start excavations soon near the airport in the main city, Yangon.

Cundall said the aircraft were buried in wooden crates as surplus, around 30 feet (10 meters) under the surface. He estimated that the project would take about four to six weeks to complete.

"We are expecting them to be in first-class condition," Cundall said shortly after arriving at the international airport in Yangon.

The Spitfire remains Britain's most famous combat aircraft. Its reputation was cemented during the Battle of Britain when the fast-moving single-seater aircraft helped beat back waves of German bombers.

Britain built a total of about 20,000 Spitfires, although the dawn of the jet age at the end of World War II meant that the propeller-driven planes quickly became obsolete.

The planes believed to be in Myanmar were buried by American engineers as the war drew to a close. Searchers hope they are in pristine condition, but Andy Brockman, a freelance archaeologist who is part of the search team, said it was possible all they might find is a mass of corroded metal and rusty aircraft parts.

Nevertheless, he said, "I'm very confident that we'll have answers to the story of what happened ... in 1945."

EPA

This archival picture from London's Imperial War Museum shows a Supermarine Spitfire LF Mark VIII, of No. 155 Squadron RAF, about to take off from Tabingaung in Myanmar (Burma) in January 1945.

The venture is being backed by the Belarusian videogame company Wargaming.net, which is best known for multiplayer titles including "World of Warplanes" and "World of Tanks."

The search team says 36 Spitfires are believed to be buried near Yangon airport, while another 18 are in Myitkyina in northern Kachin state and six more are buried in Meikthila in central Myanmar.

More mysteries of history:

• Video seems to show debris from Amelia Earhart's plane
• Titanic's sinking: Was it more than human folly?
• Gallery: Seven deep mysteries of history

Copyright 2013, The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

The object that North Korea sent into space on Wednesday appears to be “tumbling out of control” as it orbits the earth, U.S. officials told NBC News.

The officials said that it is indeed some kind of space vehicle, but they still haven’t been able to determine exactly what the satellite is supposed to do.

In a statement, the White House said the rocket launch was a highly provocative act that threatens regional security and violates U.N. resolutions.

The United Nations Security Council on Wednesday condemned the launch, calling it a "clear violation" of U.N. resolutions. A spokesman for U.N. Secretary-General Ban Ki-moon said he "deplores" the launch.

North Korea is banned from conducting missile and nuclear tests, under the terms of U.N. sanctions imposed after a series of nuclear weapons tests in 2006 and 2009.

Missile warning systems detected the launch at 7:49 p.m. ET Tuesday. North American Aerospace Defense Command officials said in a statement that the initial indications were that the first stage fell into the Yellow Sea and the second stage fell into the Philippine Sea.

North Korea said the launch was an attempt to place a satellite into a pole-to-pole orbit. Pyongyang's official KCNA news agency said that the rocket was fired from the Sohae Satellite Launch Center on the secretive country's west coast, and that the Kwangmyongsong weather satellite went into orbit as planned.

KCNA via Reuters

North Korean scientists work as a screen shows the Unha-3 (Milky Way 3) rocket being launched at the satellite control center in Cholsan county, North Pyongan province.

But U.S. officials say the launch was a thinly veiled attempt to test a three-stage ballistic missile capable of carrying a nuclear warhead as far as the U.S. West Coast.

ANALYSIS: 'Spoiled child' North Korea snubs China

Russia added its voice to the condemnation of the launch and also called on other nations to refrain from further escalating tensions.

"The new rocket launch carried out by North Korea flaunts the opinion of the international community, including calls from the Russian side," it said.

China, North Korea's only major diplomatic ally, said officials had urged Pyongyang not to go ahead with the launch, and expressed regret that it had taken place.

Japan and South Korea voiced concern as well. "The Japanese government regards this launch as an act compromising the peace and stability of the region, including Japan," said Osamu Fujimura, Japan’s chief cabinet secretary. South Korean President Lee Myung-bak convened an emergency meeting of his national security council.

The liftoff came as a shock to many South Koreans because they thought it would not take place until after South Korea's presidential election on Dec. 19.

Only a day earlier, North Korea hinted that the launch time might have to be readjusted due to weather or a technical problem.

"It was a surprise in terms of the timing," Bruce Bennett, a senior defense analyst with the RAND think tank, told The Associated Press. "They had talked about postponing for a week. To recover so quickly from technical problems suggests they have gotten good at putting together a missile."

This was North Korea's fifth test launch of a long-range rocket or ballistic missile – and the second launch since North Korean leader Kim Jong Un came to power in the wake of his father’s death a year ago. Experts say none of the previous attempts was successful, although Pyongyang says otherwise.

The last rocket was launched in April but fell apart shortly after being fired.

One U.S. official, speaking on condition of anonymity, told NBC News that Kim was under pressure to launch a success.

"He knows the stakes are high either way, and it is really what he does next that matters," the official said.

Jim Miklszewski is NBC News' chief Pentagon correspondent. Alan Boyle is NBC News' science editor. This report includes information from NBC News' Julie Yoo in Seoul and Arata Yamamoto in Tokyo, as well as Reuters and The Associated Press.

More world stories from NBC News:

• Pope Benedict sends his first tweet
• ANALYSIS: 'Spoiled child' North Korea snubs key ally China with rocket test
• ANALYSIS: Egypt is rapidly approaching its own 'cliff'
• Nelson Mandela suffers recurrence of lung infection
• Banking giant HSBC to pay record $1.9 billion in money-laundering case
• Suspect in US envoy's killing in Libya arrested in Egypt

Follow World News from NBCNews.com on Twitter and Facebook

AFP/Getty Images file

Panda bear Bao Bao plays in his indoor enclosure at the Berlin Zoo in 2007.

MAINZ, Germany -- Bao Bao, one of the world’s oldest giant pandas, died at the age of 34 early Wednesday, officials at Berlin’s zoo told NBC News.

The animal's health had been deteriorating over the past months, zoo officials said. Bao Bao had not been eating well and had shown a gaunt face, zoo officials say. The cause of death is being determined in an autopsy.

In 1980, Bao Bao was given as a gift by China to Helmut Schmidt, who was the West German chancellor at the time. Bao Bao was the only remaining Panda at the Berlin zoo after the death of Yan Yan in 2007.

More world stories from NBC News:

• Trayvon Martin case: How might it be treated abroad?
• Israelis fret over 'lynching' of Palestinian
• Video: Poaching surge threatens survival of rhinos
• Anti-tanning 'Facekinis' cause stir on China beach
• Reports: Kim Jong Un will travel to Iran
• Slideshow: Migration in the Americas
• Reports: Olympic sprinter drowned when migrant boat sank
• With wife's conviction, what is next for China's Bo Xilai?

Follow World News from NBCNews.com on Twitter and Facebook

U.S. Attorney's Office

This photo, attached as an exhibit to the complaint filed by federal attorneys, shows the tyrannosaur skeleton that has stirred up an international legal dispute.

Federal attorneys today filed a civil lawsuit that seeks to wrest a tyrannosaur skeleton valued at more than $1 million away from its sellers and return it to the Mongolian government.

The skeleton was sold at a New York auction last month for $1.05 million to an unidentified buyer, even though a federal district judge in Texas issued a restraining order to hold up the sale. The auction house behind the offering, Texas-based Heritage Auctions, made the sale contingent on the outcome of Mongolia's court challenge — and since then, the skeleton has been held in legal limbo.

Earlier this month, a panel of paleontologists declared that the skeleton represented a Tyrannosaurus bataar, also known as a Tarbosaurus bataar, which was probably smuggled out of Mongolia sometime in the past 15 years or so. Today's complaint, filed by the U.S. attorney for Manhattan in New York federal district court, follows up on that determination and lays out the authorities' version of a tangled tyrannosaur tale.

"The skeletal remains of this dinosaur are of tremendous cultural and historical significance to the people of Mongolia, and provide a connection to the country's prehistoric past," Manhattan U.S. Attorney Preet Bharara said in a statement. "When the skeleton was allegedly looted, a piece of the country's natural history was stolen with it, and we look forward to returning it to its rightful place."

Mongolia has had laws on the books forbidding the export of dinosaur fossils since 1924. The complaint says the nearly complete skeleton was brought into the United States illegally, and thus should be forfeited by the sellers and returned to Mongolia.

James Hayes, a special agent-in-charge for the U.S. Immigration and Customs Enforcement's Homeland Security Investigations, said the complaint alleges that "criminal smugglers misrepresented this fossil to customs officials."

When the skeleton was imported into the United States from Britain in 2010, the country of origin was listed as Britain — even though, according to the paleontologists, nearly complete tyrannosaur skeletons of this type have been found only in Mongolia. The experts cited a dozen features of the bones, as well as their light color and even the dirt stuck in the cracks in the fossils, as characteristic of Tyrannosaurus bataar rather than the larger T. rex or other members of the tyrannosaur tribe.

Federal attorneys said that the importers set the skeleton's value at $15,000, but that a value of $950,000 to $1.5 million was listed in this year's auction catalog. They also said the 8-foot-tall (2.4-meter-tall), 24-foot-long (7.3-meter-long) skeleton was incorrectly listed on customs forms as consisting of assorted fossilized reptiles and skulls.

The complaint names Florida Fossils as the ultimate consignee for the imported goods, and notes that the company was owned at the time of importation by Eric Prokopi. The skeleton was shipped from Florida to Texas, and then on to New York in preparation for the May 20 sale. Soon after word spread that a million-dollar tyrannosaur was coming up for auction, representatives of the Mongolian government became interested and sought unsuccessfully to stop the sale.

The dinosaur skeleton is currently in the custody of Cadogan Tate Fine Art in Sunnyside, N.Y. In the weeks since the controversial sale took place, the auction house has let paleontologists and representatives of the Mongolian government examine the fossil.

"I thank and applaud the United States Attorney's office in this action to recover the Tyrannosaurus bataar, an important piece of the cultural heritage of the Mongolian people," Mongolian President Tsakhia Elbegdorj was quoted as saying in the U.S. government's news release about the case. "Cultural looting and profiteering cannot be tolerated anywhere, and this cooperation between our governments is a large step forward to stopping it."

My efforts to contact Prokopi today were unsuccessful, but representatives of Heritage Auctions issued this statement from the company's co-chairman, Jim Halperin:

"We auctioned the Tyrannosaurus bataar conditionally, subject to future court rulings, so this matter is now in the hands of lawyers and politicians. We believe our consignor purchased fossils in good faith, then spent a year of his life and considerable expense identifying, restoring, mounting and preparing what had previously been a much less valuable matrix of unassembled, underlying bones. We sincerely hope there will be a just and fair outcome for all parties."

More about the tyrannosaur:

• May 18: Auction stirs up a tussle over tyrannosaur
• May 21: Despite challenge, fossil sells for $1 million
• May 24: Auctioned dino skeleton believed to be smuggled
• June 8: Experts say tyrannosaur is definitely from Mongolia

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

Jugend Forscht

Sixteen-year-old Shouryya Ray, a student from Dresden who was born in Calcutta, submitted a paper proposing analytical solutions to two problems in particle dynamics.

A research paper that claims to fill in a gap in Isaac Newton's formulas for the physics of falling objects has drawn worldwide attention to a 16-year-old student in Germany, but physicists are reserving judgment until they've seen the proof.

The focus of the buzz is Shouryya Ray, an Indian-born student who won second prize this month in the math and informatics category for Germany's Jugend Forscht student science competition. Ray tackled a couple of longstanding puzzlers for physics students: How do you account for air resistance in calculating the trajectory of ball thrown out at an angle? And precisely how does a ball thrown against the wall rebound?

The first question relates to Newton's law of universal gravitation: In his Principia Mathematica, published in 1687, Newton laid out how a gravitational field would affect a thrown object — but he didn't account for the effect of air resistance. Through the centuries, physicists have used numerical approximations to take drag into account, and when computers come into play, those approximations can be incredibly precise. But Ray said he wanted to come up with a set of formulas that could calculate the effect directly, even though his instructors said that had never been done.

"I asked myself: Why can't it work?" he told the German newspaper Die Welt.

That's what Ray tried to do in his prize-winning paper, titled "Analytical Solution of Two Fundamental Unsolved Problems of Particle Dynamics" ("Analytische Lösung von zwei ungelösten fundamentalen Partikeldynamikproblemen"). In addition to the falling-ball problem, Ray took on a puzzler of more recent vintage, having to do with the description of a particle's collision with a wall, as described by 19th-century theory. But it was the "kid-trumps-Newton" angle that really stirred up a buzz.

Die Welt's report came early in the game: The Daily Mail and The Sunday Times of London picked up the story, adding to the sensation. The idea that a teenager could figure out something that Newton didn't is irresistible — particularly when the teen is an immigrant from Calcutta who says he's no genius. But the story just sparked more questions among inquiring minds in such online hangouts as Physics Forum, Slashdot and Reddit: What exactly did Ray do? And were these problems really such mysteries to solve?

That's a challenge, because Ray's paper was a school project submitted for a contest, and thus not subject to the publication process and peer review that professional work typically goes through. For that reason, the experts are reluctant to weigh in.

"This story seems rather suspicious," Richard Fitzpatrick, a physicist at the University of Texas in Austin, told me in an email. "None of the news reports give any details of the calculation. None of the people who hailed Shouryya Ray as a genius are scientists, and none of them give the impression that they have seen the calculation in question. It is impossible to gauge the scientific merit of the calculation until it is made public."

Syracuse University physicist Simon Catterall said in an email that calculating the trajectories of falling objects hadn't been seen as a particularly grand puzzle of physics. "The background given in the article seems genuine enough, so it may indeed be true, but I haven't heard anything about a new solution to a Newtonian problem on the grapevine," he told me.

Based on what's come out about the work so far, the consensus seems to be that Ray has done amazing work for his age — and if he had to choose between his passion for science and his passion for soccer, he'd be well-advised to pick math and physics. His paper putting forth an "analytical solution to two fundamental unsolved problems" may not be the breakthrough that some of the reports have made it out to be, but that doesn't take anything away from the teenager's achievement.

"What Ray has worked out, almost certainly independently, would definitely put him in the 99th percentile amongst his peers and maybe even more," one Redditor observed.

By the way, the first-place winner in the math and informatics category, Julius Kunze, wrote a paper on relativistic ray tracing. But that's a different story... 

Update for 5 p.m. ET: Other experts on Newtonian physics have replied to my follow-up queries via email:

Oxford University physicist James Binney: "Doesn't sound too interesting to me. The resistance of air to the ball won't be susceptible to simple analytic formulae — if the ball is of ordinary size, [greater than a centimeter] radius — the flow around it will be in the high Reynolds-number regime and involve a thin boundary layer. Such flows were extensively studied from the last part of the 19th century, so it's true that they lie beyond Newton's knowledge. A good approximation will be to take the drag force as pi r^2 rho v^2, where r is the radius of the ball, v its speed and rho the density of air. I'm unaware of a puzzle regarding bouncing balls. In detail the bounce will depend on the physical properties of the ball — as any squash player knows. Usually one adopts a coefficient of restitution. To be impressed we need to know details."

University of Bristol physicist Michael Berry: "Without seeing the details of what Ray has claimed, it's impossible to comment intelligently. It depends crucially on how he has modeled the air resistance. But a falling body with air resistance (however modeled) is hardly a 'fundamental unsolved problem,' as he seems to think. There's a powerful aroma of hype."  

More about physics:

• Laws of physics get bent to produce ... coneheads!
• Subatomic discovery pushes the limits of physics
• The fish that nearly sank Newton's career
• Cosmic Log archive on physics

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or adding Cosmic Log's Google+ page to your circle. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for other worlds.