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Nathan Myhrvold: 'Nasa doesn't want to admit it's wrong about asteroids'
Nathan Myhrvold is the former chief technology officer of Microsoft, founder of the controversial patent asset company Intellectual Ventures and the main author of the six-volume, 2,300-page Modernist Cuisine cookbook, which explores the science of cooking. Currently, he is taking on Nasa over its measurement of asteroid sizes.
For the past couple of years, you've been fighting with Nasa about its analysis of near-Earth asteroid size. You've just published a 33-page scientific paper [open, DOI: 10.1016/j.icarus.2018.05.004] [DX] criticising the methods used by its Neowise project team to estimate the size and other properties of approximately 164,000 asteroids. You have also published a long blog post explaining the problem. Where did Nasa go wrong and is it over or underestimating size?
Nasa's Wise space telescope [Wide-field Infrared Survey Explorer] measured the asteroids in four different wavelengths in the infrared. My main beef is with how they analysed that data. What I think happened is they made some poor choices of statistical methods. Then, to cover that up, they didn't publish a lot of the information that would help someone else replicate it. I'm afraid they have both over- and underestimated. The effect changes depending on the size of the asteroid and what it's made of. The studies were advertised as being accurate to plus or minus 10%. In fact, it is more like 30-35%. That's if you look overall. If you look at specific subsets some of them are off by more than 100%. It's kind of a mess.
[...] Nasa's reported response has been to stand by the data and the analysis performed by the Neowise team. Can we trust Nasa after this?
They need to have an independent investigation of these results. When my preprint paper came out in 2016, they said: "You shouldn't believe it because it's not peer-reviewed." Well, now it has been peer reviewed. How Nasa handles it at this stage will be very telling. People have suggested to me the reason Nasa doesn't want to admit that anything is wrong with the data is that they're afraid it would hurt the chances of Neocam, an approximately $500m (£380m) telescope to find asteroids that might hit Earth proposed by the same group who did the Neowise analysis.
Previously: Former Microsoft Chief Technologist Criticizes NASA
(Score: 3, Interesting) by Runaway1956 on Monday June 25 2018, @07:34AM (2 children)
Yes, the article is a mess. But, if I even begin to understand his twisted reasoning, then the complete data set can be segregated into subsets. He seems to be saying that some of those subsets have better overall accuracy, while other subsets have worse accuracy. The reasons for those differences isn't really clear. Different methods were used to estimate sizes? Different instruments were used over time? Different people did the math work? I suppose that a change in any of those would create a new subset of data. Or, maybe they simply migrated from a BSD to a Microsoft machine to do their number crunching, and things went to shit.
The most basic of claims here, is that some of the data is more reliable than some of the rest of it. That might be believable. But it's up to the claimant to communicate his claims. It's not our job to read his mind!
(Score: 2, Informative) by Anonymous Coward on Monday June 25 2018, @11:30AM (1 child)
https://www.sciencedirect.com/science/article/pii/S0019103516307643 [sciencedirect.com]
I've heard about this before. He basically claims they didn't really try when coming up with the statistical models, instead just used some default procedures So they are underestimating uncertainty between the observations (abledo, etc) and estimated size.
(Score: 0) by Anonymous Coward on Monday June 25 2018, @11:34AM
typo: