We had a set of hard storms come through yesterday afternoon. I was doing SkyWarn spotting with the local hams. I think (but will leave it to experts to confirm) that the structure under the smooth part of the storm (”the shelf) is a wall cloud. For a sense of scale, this is 8 photos stitched together covering above a fifth of my horizon and the leading edge of this storm when it was about five miles away.. Shortly after I shot this picture, the sirens went off. Rotation was spotted, but luckily, no funnel cloud touched down. Thankfully, while the storm blew through at 60 miles per hour, we had no significant damage… Still, it looked mean…
Addendum: I sent the picture to Greg Gust, who runs some of the SkyWarn stuff for the National Weather Service in Grand Forks. He sent me these additional comments:
Most of the structure is a classic shelf cloud on the leading edge of a line of thunderstorms… this the widespread strong to severe winds as it came through. One the south end was the feature that we believe was a wall cloud… rotating updraft… and was what prompted us to issue the Tornado Warning across the southern part of Fargo and Moorhead.
[Added August 9,2008] It appears at least two people saw this wall cloud and posted videos on YouTube. I have embedded them below.
This first video is from “bluemanhal” and contains some audio. Notice how far he has to pan the camera to see this. My photo was a panorama about 150 degrees, which loses its perspective in the image:
This second video is from “cpilotkid” and appears to have been shot from the West Acres Mall parking lot, but again notice how far he has to pan to get the entire wall cloud:
On May 29, 1919, two British expeditions, positioned on opposite sides of the planet, aimed telescopes at the sun during a total eclipse. Their mission: to test a radical theory of gravity dreamed up by a former patent clerk, who predicted that passing starlight should bend toward the sun. Their results, announced that November, vaulted Albert Einstein into the public consciousness and confirmed one of the most spectacular experimental successes in the history of science.
In recent decades, however, some science historians have argued that astronomer Sir Arthur Eddington, the junior member of the 1919 expedition, believed so strongly in Einstein’s theory of general relativity that he discounted data that clashed with it. [From Fact or Fiction: Did Researchers Cook Data from the First Test of General Relativity?]
The nice thing is this article illustrates one of the less well-appreciated challenges facing the functional scientist: distinguishing between bad data and data that conflicts with your theoretical expectations. Bad data, like other things in life, just happens. And when it happens, it can be a pain to deal with. How do you know when the data is “bad” (that is, the result of a problem at the telescope or a glitch in your software) versus when the data simply conflicts with your theory? In one case, getting rid of the data makes sense. However, being over-eager to reject conflicting data may make you reject a completely compatible alternative interpretation to your observation. Furthermore, if your data seem to support a controversial theory, you should be fairly confident your results are not the result of “bad” data. As Carl Sagan said in Cosmos , “Extraordinary claims require extraordinary evidence.” You have to be pretty confident you haven’t made a mistake if your data strays far from what you expect. Knowing the difference between “bad” data and data that supports a different theory the human part of the science I try to teach my students about. It is also the reason peer-review is such an incredibly important part of the scientific process.
By the way, the verdict of the article’s author is that Eddington and Dyson did the right thing. It turns out it was actually Dyson, who was initially inclined against Einstein’s theory, who made the decision to toss the bad data out. The final results when published[1] supported Einstein’s General Theory of Relativity, which still stands as the most well-supported model for gravitation to this day.
We live in a strange era where some presidential candidates brag about their complete absence of knowledge of science but yet admit science plays such a gigantic role in the possible improvement (or destruction) of society. Given this election climate, the Union of Concerned Scientists is asking the presidential candidates to participate in a debate focused solely on the role of science-related policy in their proposed administrations. And they want them to do it before the presidential primaries in Pennsylvania. The full text of the petition says:
Dear presidential candidate,
Given the many urgent scientific and technological challenges facing America and the rest of the world, the increasing need for accurate scientific information in political decision making, and the vital role scientific innovation plays in spurring economic growth and competitiveness, we call for a public debate in which the U.S. presidential candidates share their views on the issues of The Environment, Health and Medicine, and Science and Technology Policy.
We would like to hear how, as president, you plan to defend science from political interference, and how you plan to use science to inform your policies.
We call on you to participate in Science Debate 2008 in Philadelphia on April 18.
