How The Chilean Quake Moved An Entire Planet
Listen to a colleague of mine explain that we can’t measure the time or pole shift, because they’re too small.
Monthly Archives: March 2010
Lies, Damned Lies, and Forbes
Cut Pay For Government Workers
I’m going to rail against this, but it’s only partly because I’m a Federal employee. It’s mostly because the authors are being deceitful.
If this were an airline or an automaker, the solution would be a no-brainer: It would be time for a big pay cut. If the company didn’t cut pay, or increased it, creditors and investors would question the seriousness of management.
The 2010 budget has a freeze of senior staff pay, and the 2011 budget that has been drafted proposes to extend
this pay freeze to all senior political appointees throughout the Federal Government and continue the policy of no bonuses for all political appointees. This is exactly the behavior that many taxpayers wanted, and often did not get, of high-level executive pay in the private sector in businesses that were being bailed out or supported by federal money.
But here’s the biggie:
[T]otal compensation per federal worker–cash earnings plus fringe benefits–now averages twice that of the private sector. So cutting cash earnings by 10% across the board seems not only reasonable, but justified.
The basic problem here is that this isn’t an apples-to-apples comparison — the spectrum of workers in the federal government is not even close to that of the private sector. Part of the reason for this is that there are many private-sector contractors that do work for the government, and a lot of these are low-paying, unskilled jobs, such as the janitorial staff. Many government jobs require a college degree, unlike a large number of private-sector jobs. I know that my local environment is not representative, but I’d be surprised if as many as 10% of the civilian government positions in the command don’t require a college degree, and perhaps a third of the staff have advanced degrees of some sort. This kind of comparison of averages of dissimilar distributions is at best incredibly misleading and at worst an out-and-out lie, like if you were comparing the compensation of the employees of a fast-food restaurant with the architectural and engineering firm on the next block, and concluding the A&E folks were overpaid.
What would be appropriate is a comparison of similar jobs within the government and private sector. Take me (please!) The median salary for a physicist working in industry was over $100k back in 2004 (couldn’t find anything newer), which was certainly more than I was making at the time, even with my locality pay for living in the DC area. I can think of many jobs where you would take a pay cut to work for the government — lawyers, I understand, can make a nice living in the private sector, much better than government lawyers or judges. And my Google-fu tells me that the article’s authors, Brian Wesbury and Robert Stein, both had stints in the federal government. They should have no trouble reporting how their private sector salary and compensation stacks up against what they received as federal employees, but that isn’t mentioned in the article.
Shift Happens
I linked to a gravitational redshift experiment that was recently published, and have had a chance to read the paper. It’s quite cool. I had been dismayed at the first couple of popular summaries, but this one is pretty good and as I had indicated, the press release is pretty good for a press release. So there’s not a lot to add.
The original experiment was designed to measure gravitational acceleration; the two trajectories have a different potential energy, mgh, and will accumulate a phase difference as compared to the other trajectory. You can think of this as the difference in deBroglie wavelengths, where the difference in momentum leads to a slightly different wavelength, and this gives a phase difference when the atoms recombine. Since the mass and the relative trajectory are known, measuring the phase difference will allow you to determine g.
The special insight presented in this paper was the interpretation in terms of relativity. The energy, rather than being the classical kinetic and potential terms, is mc^2. The “oscillation” that allows for interference is now at a much higher frequency, and the accumulated phase will be gh/c^2, which is the gravitational redshift. To do this, you need to independently know g, which was determined using a corner-cube gravimeter.
There is also a difference in the implications by reinterpreting the results. The first measurement assumes the classical physics is correct — the phase difference is proportional to g is the result of an equation that is assumed to be true at this level of precision — and that there is a phase to measure, i.e. the atoms have a wave nature, which is an early prediction of quantum mechanics. The answer in the form of a value for g only makes sense if we assume these theories are correct. And that’s not really a problem, since we have independently tested those theories many times over the years.
But the other interpretation is a direct test of relativity — the theory predicts an answer which can be directly compared to the result. And that allows one to put limits on how “wrong” this aspect of relativity might be. You add another term onto the time dilation term, with a perturbation expansion (we already know relativity is pretty good and have results from the Vessot rocket experiment, so any deviation has to be small). So we write the time dilation as (1+B)(gh/c^2), and then assume the worst case, that all of the discrepancy in the measurement is not experimental error, but rather a flaw in the theory. And they get a result of B = 7±7 x 10^-9, which is consistent with relativity being correct (B = 0), and limits any problems with this aspect of it to a part in a hundred million.
Make Like a Tree
Hamiltonian Function: The Nissan Leaf
Energy efficiency analysis of the new electric car that’s been advertised recently.
Put the Candle Back
Weird bookshelves
Newsworthy
Several more global warming pieces have popped up on my radar recently.
Al Gore’s NYT op-ed We Can’t Wish Away Climate Change
While I have pointed out before that you should not hold out much hope for science on the op-ed page, Mr. Gore’s piece has links to actual scientific work, which is generally more than you get from the other side.
Back to the Woodshed with You
Last week I took George Will to task for his scientific illiteracy and misrepresentation of the “no statistically significant warming” statement that has given every global warming denier a naughty tingly feeling during the past few weeks.
I missed something.
I was going to include a graphical example, and I should have, because I would have found one more problem with the statement. I was reading a post over at Skeptical Science, where graphs were included, and did a mental reconstruction and realized my error of omission. I’ll grab the GISS graph from that post (slightly different slope, but the concept is the same), and add in two lines: one representing no increase in T, and one representing twice the amount slope of the best fit.
Now, one can see here that even though it’s obviously not the best fit to the data, the “no increase” line is a semi-plausible fit. It’s possible. But here’s the problem: look at the temperature in 1995 based on the two scenarios. If one is going to claim that the temperature has not increased in the last 15 years, one also has to admit that it’s about a tenth of a degree warmer than we thought it was. So all of the global warming that “didn’t happen” before is even worse, and harder to explain away.
Personally, I think not distorting the science in the first place is probably the best way to proceed.
Hard to Swallow
Rulings Restrict Clean Water Act, Foiling E.P.A.
The Clean Water Act was intended to end dangerous water pollution by regulating every major polluter. But today, regulators may be unable to prosecute as many as half of the nation’s largest known polluters because officials lack jurisdiction or because proving jurisdiction would be overwhelmingly difficult or time consuming, according to midlevel officials.
“We are, in essence, shutting down our Clean Water programs in some states,” said Douglas F. Mundrick, an E.P.A. lawyer in Atlanta. “This is a huge step backward. When companies figure out the cops can’t operate, they start remembering how much cheaper it is to just dump stuff in a nearby creek.”
Pop Goes the Weasel
Chad is having trouble with rodents chewing on the wiring in his car. It’s a problem in labs, too, where something will occasionally chew through some data cable (which was not as serious as when they chewed into the bag of M&M’s left on the lab bench, but try convincing the boss of that). I noticed one comment that was similar to my thought: float the data lines at a kiloVolt. That’ll larn them varmints.
Why?
Feynman discusses the “why” question, and why he can’t give a satisfactory explanation of magnetic attraction/repulsion.
When you explain a “why,” you have to be in some framework that you allow something to be true. Otherwise you are perpetually asking, “Why?”
I’ve pointed out before that science doesn’t really address the question of “why,” and this is the reason.
I really can’t do a good job, any job, of explaining magnetic force in terms of something else that you’re more familiar with, because I don’t understand it in terms of anything else you’re more familiar with.
In other words, you have to explain to the level of your audience.