More questions raised about Mann’s hockey stick graph

A new research paper, written by statistical scientists and to be published next month in the Annals of Applied Statistics, has found that Michael Mann’s hockey stick graph, showing a steep increase in global temperature in the last two hundred years, is statistically invalid. Key quote:

Research on multi-proxy temperature reconstructions of the earth’s temperature is now entering its second decade. While the literature is large, there has been very little collaboration with university level, professional statisticians (Wegman et al., 2006; Wegman, 2006). Our paper is an effort to apply some modern statistical methods to these problems. While our results agree with the climate scientists findings in some respects, our methods of estimating model uncertainty and accuracy are in sharp disagreement.

[We] conclude unequivocally that the evidence for a ”long-handled” hockey stick (where the shaft of the hockey stick extends to the year 1000 AD) is lacking in the data. The fundamental problem is that there is a limited amount of proxy data which dates back to 1000 AD; what is available is weakly predictive of global annual temperature. Our backcasting methods, which track quite closely the methods applied most recently in Mann (2008) to the same data, are unable to catch the sharp run up in temperatures recorded in the 1990s, even in-sample. [emphasis mine]

In other words, the temperature data going back to 1000 AD is poor, and cannot be reliably used to prove a sudden increase in global temperature in the last two hundred years. More importantly, according to this paper, Michael Mann tried to use statistics to prove his point, without consulting any statisticians.

Tour of ISS, part 4

An evening pause: Mike Finke’s tour of ISS continues in the Progress freighter, moves through the Zarya functional cargo module into the Zvezda service module at the aft end of the station, showing us a Russian crew cabin and the station’s main bathroom facilities.

Sloppy journalism from the BBC

Though solar scientists have discovered that certain recent solar behavior might help explain the long and deep solar minimum that just ended, this BBC article immediately tries to give that result credit for explaining everything. To quote:

Solar physicists may have discovered why the Sun recently experienced a prolonged period of weak activity.

NOT! The result only observed a change in solar behavior beneath the surface, whereby the meridional flow slowed down as well as lengthened significantly into the high latitudes, and that this change occurred at the same time as the weak solar minimum. The paper made no attempt to explain why this happened, nor did it provide a theoretical explanation for how these changes resulted in a weak solar minimum.

Finally, and far more important, scientists still have no good theory for explaining the solar cycle in the first place. “We think it’s the solar dynamo [that causes the solar cycle],” noted Dean Pesnell of the Goddard Space Flight Center when I interviewed him for my Sky & Telescope article, What’s Wrong with Our Sun? (August 2009). “But we don’t undertand how the dynamo works, as yet.”

The BBC should be more careful in how it reports a story like this.

Astronomers announce their recommendations for the next decade

After two years of discussion among hundreds of astronomers, the committee for the 2010 Decadal Surveyn for Astronomy and Astrophysics announced its recommendations today. The two main recommendations were

The report also called for the federal government to become a partner in one of the two giant ground-based optical telescopes now in the planning stages. In addition, the report recommended that the government increase its participation in the Laser Interferometer Space Antenna (LISA), a space telescope designed to detect gravity waves, as well as commit monies to begin the design work for a new high resolution X-ray space telescope. Other recommendations including asking NASA to increase its support for medium-sized space telescopes.

The report did not recommend any replacement for the Hubble Space Telescope.

This report follows earlier decadal surveys, for the 1970s, 1980s, 1990s, and 2000s, all of which had enormous influence on what federal agencies and astronomers built over the following decade. For example, these decadal surveys recommended the construction of the VLA, the Chandra X-Ray Observatory, the Spitzer Space Telescope, and a host of other telescopes, all of which were built.

ISS tour continues, part 3

An evening pause: Astronaut Mike Finke’s tour of ISS continues, taking us through the Unity module and into the Russian part of the station, showing us the inside of a Soyuz lifeboat, the Zarya functional cargo module, the Piers docking module/airlock, and ending looking into the hatch of a Progress freighter.

Is it a planet or not?

An object, initially announced in 1998 to be the first planet ever photographed, then rejected as a planet when data suggested it was too hot, is now being resurrected as a possible planet. Key quote by Adam Burrows of Princeton University:

[If true] this would punctuate one of the strangest episodes in the history of the emerging field of exoplanet research. If false, it would be one more warning that numerous pitfalls await the intrepid astronomer in search of planetary gold beyond the solar system.

Reporter arrested for discussing politics

Freedom of speech alert. In this post, I noted that though it seemed as if the arrest of four protesters on the University of Texas campus during a visit by President Obama seemed a violation of their rights, there wasn’t enough information in the reports to know for sure. We now have more information. Read this report also. And watch this video of the arrest of one protester, while wearing a press badge, and tell me if this isn’t an abuse of power.

NASA narrows asteroids to visit to three

NASA officials have reviewed the list of Near Earth Objects and found only three that meet all the constraints for a manned mission. Key quote:

Out of the 44 reachable asteroids, 27 were too small, and only 15 have orbits that allow for exploration between 2020 and 2050 — the timeframe NASA wants to pursue for NEO missions. The 180-day mission constraint further cuts the list to three.

It must also be noted that none of these asteroids are reachable without a heavy-lift rocket like the Ares V.

Rebuilding the American space program — the right way

In reading my post, Both for and against the Obama plan, reader Trent Waddington emailed me to say that this “is so fatalistic that it seems you don’t think it is worthwhile even spending a few minutes explaining why the policy is good. It’s easy to dismiss something a politician says as the stopped clock that is right twice a day. It’s harder to set aside your skepticism and explain why something is good policy.”

Trent is absolutely correct. What I wrote was very depressing and fatalistic. However, I think it very important to be coldly honest about things, no matter how bad they look. Once you’ve done that, you then have the right information necessary for fixing the situation.

My problem with most of the debate about the future space policy of the United States, — as well as innumerable other modern issues faced by our government — is that people don’t seem to want to face up to the reality of the problem. In the case of space and Obama, I doubt any advice, gentle or otherwise, is going to move him into putting forth a plan for NASA that has any realistic chance of getting passed by Congress. As I noted in a different post, he doesn’t play the game. He acts like the worst sort of autocrat, convinced that if he simply says what he wants to do, everyone must agree.

The reason the good part of his plan (commercial space) is not passing Congress is not because people think it is a bad idea. It is being rejected because » Read more

Diversifying your research portfolio

In this paper [pdf] adapted from a lecture he gave at an astronomy conference, Harvard researcher Abraham Loeb warns young scientists that their tendency today to take on safe research projects is unwise. Moreover, he notes the increasing “herd mentality” due to “stronger social pressure”, “more competition in the job market,” and the “growing fraction of observational and theoretical projects . . . done in large groups with rigid research agendas and tight schedules.” Key quote:

It is always prudent to allocate some limited resources to innovative ideas beyond any dogmatic “mainstream,” because even if only one out of a million such ideas bears fruit, it could transform our view of reality and justify the entire effort. This lesson is surprisingly unpopular in the current culture of funding agencies like NSF or NASA, which promote research with predictable and safe goals.

Hubble image of face-on galaxy

Another spectacular Hubble Space Telescope image was released today, showing a face-on spiral galaxy in the Coma cluster, located about 320 million light years away. Key quote:

The galaxy, known as NGC 4911, contains rich lanes of dust and gas near its center. These are silhouetted against glowing newborn star clusters and iridescent pink clouds of hydrogen, the existence of which indicates ongoing star formation. Hubble has also captured the outer spiral arms of NGC 4911, along with thousands of other galaxies of varying sizes.

NGC 4911

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