Category Archives: General Science

Physics Reminder

Alan Boyle has a little piece today about the elevators in the tallest building in the world. But this bit is misleading:

Imagine riding in a car going almost 40 mph (60.6 kilometers per hour). Not that impressive, right? But now imagine going that same 40 mph … straight up.

That gives you some idea how elevator riders must feel in the world’s tallest building, Taipei 101.

Actually, you can’t feel speed at all. There is no difference in sensation between a twenty mph elevator and a forty mph elevator, other than perhaps vibrations transmitted through the cables and contact with the shaft. Acceleration is what you feel, so the difference is how long it takes you to get up to speed (and back down from it), not what the top speed is.

Similarly, he writes:

The cars go faster on the way up than on the way down

Is There A Mycologist In The House?

One familiar with the southeastern Florida ecology?

Sorry, I’m still too discombobulated to be able to post pics, but I noticed when I went out to survey hurricane damage this morning that one of the changes overnight was a lawnful of mushrooms. There seem to be two varieties (I’m assuming that they aren’t variations on the same species). One is flat and gilled, and the other has a circular head. Both are white, and as the day progressed, they developed brown areas on top.

Anyone know what they are, and if having them for dinner would result in delicious nutrition, or a trip to the emergency ward?

One,Two,Many…

Via comments on a post at Crooked Timber, an article in the Globe and Mail about a tribe in the Amazon that not only doesn’t have a numbering system, they also don’t have clearly defined words for colors. Adding weirdness to weirdness, they also change their names on a regular basis. The thrust of the article is that the lack of number names interferes with their ability to count. There’s a whole literature in linguistics about this and the larger issue of how language influences thinking, though the subject has fallen into disfavor. I suspect that the truth of the matter is that language severely constrains thought, in that it’s easier to conceptualize things for which you have a word, but does not completely limit it (or where would new words come from? – the concept has to precede the word).

Incidentally, if you’re interested in this question, check out the logical langauge group. They are developing and promoting a language based on formal logic with the explicit intention of exploring the Sapir-Whorf hypothesis.

Dynamic lab notebook

I’ve been mulling the idea of keeping my lab notes on my Mac for a while, and I’ve started moving in that direction. The problem with keeping notes on a computer rather than on paper is that the computer is far less flexible. It’s much more powerful, but it’s quite constrained by the need for exactly the right software. The major advantage of a computer over a lab notebook is that you can put in a whole lot more data, and interlink the data in ways that you just can’t with paper.

The ideal lab notebook software would combine some of the functionality of a blog with some of the functionality of a wiki. The blog function would be to simply keep a log of all entries, with timestamps. The entries would consist of text, images, and tables of data. The wiki function would integrate the linear collection of entries from the blog to build up a coherent time-independent picture of the object under study. The wiki would include both information about the current state of the experiment and a set of tentative conclusions about the phenomenon under study, along with things like lists of references with comments.

Continue reading Dynamic lab notebook

How science works

Over on Technology Review there’s a good article by Richard Muller on the discovery of the K-T impact that wiped out the dinosaurs, and the history of the science behind its discovery. He makes the point that science is inherently a process of asking ever more questions, each concrete answer generating a host of new questions.

The article is worth a read on its own merits, but as soon as I read it I immediately thought of this article on global warming, written by people who claim to be conducting scientific inquiry, but then end with this astonishingly dishonest statement:

The science is settled. The “skeptics” — the strange name applied to those whose work shows the planet isn’t coming to an end — have won.

I’ll usually give people the benefit of the doubt when it comes to what they believe about global warming, since the science is complex and information is still coming in. The state of the field is rapidly evolving, so disagreement is not just reasonable, it’s mandatory for the health of the science. However here we have three people claiming scientific credibility while making utterly inane statements which to a layman might seem like solid proof, but which don’t pass even the most basic scientific smell test. Let’s take a look at the quote above in detail:

The science is settled.

Bullshit. Simple, barefaced bullshit. The science is not settled until a model exists which is consistent with all the observations. The fact that there are difficulties with a certain subset of observations (atmospheric temperature data for example) does not mean that the null hypothesis (no warming) is true: in fact, if there is other reliable data that is inconsistent with the null hypothesis, the question is very much not settled. There is ocean surface temperature data, for example, which cannot easily be reconciled with the null hypothesis.

The “skeptics” — the strange name …

Apparently the authors are unfamiliar with the meaning of the word “skeptic” – it is entirely appropriate to apply it to people who doubt, who question, who disbelieve orthodox views. To be a skeptic in science is a good thing – it’s what the whole enterprise is about.

…applied to those whose work shows the planet isn’t coming to an end …

Ah yes, the signature of scientific integrity: distorting the view of your opponents beyond all recognition. The generally accepted view within the climate research community is that the world is warming and that there will be negative consequences. The difference between that and “the planet coming to an end” is the difference between a hangnail and death.

… have won.

Riiiiiiight. Questions about consistency of a subset of data completely overwhelm all of the data in favor of the hypothesis.

As I’ve said before, there’s a lot to be done before we’ll have a clear picture of what is up with global warming. There are entirely reasonable arguments that the warming is primarily natural rather than caused by humans, there’s plenty of reasonable doubt about the magnitude of the warming, there’s reasonable questions about wether the net long term effect might in fact be beneficial, and there are reasonable grounds to argue against any given policy regarding climate change. There is not even a slight amount of reasonableness to claims that the science of global warming is even close to settled, let alone settled in favor of the theory that there is no warming.

The authors of the TCS piece might have a defensible position if they were engaging is strictly political polemic, but they are not: they are brandishing scientific credentials on the one hand, and making blatantly false statements on the other. They are using scientific credentials to bolster claims which any credible scientist simply would not make. If you want to use scientific credentials to establish credibility, you have an obligation to meet a certain standard of integrity. Saying things which any scientist would know to be false, but which a member of the general public might believe, violates the most basic standards of personal and professional integrity. These guys are liars, and should be treated as such.

Alvin to be Retired

Via a story on NPR’s All Things Considered (last story on the page: audio link) the intrepid research submarine Alvin is going to be replaced with a larger sub capable of deeper dives and longer stays at depth.

Alvin is a truly storied scientific instrument, one of those few machines that almost singlehandedly revolutionize a scientific field. I’m looking forward to seeing what her successor will do.

This post isn’t entirely about the excellence of Alvin – I also have a little bit of an axe to grind. Let me point out that, in this day of submarine ROVs with ever increasing capabilities, the thing that oceanographers and deep ocean biologists want is a machine that will enable them to go in person into the depths. A dive in the new sub will take up to ten hours, cramped up in a space about the size of the interior of a VW beetle, with all manner of projections and angles to increase the discomfort. Internal temperatures during a dive hover in the neighborhood of zero celsius, and if something goes seriously wrong, you die. Much better to send a machine, don’t you think? But no: the people best equipped to make the judgement, the people who will be trading sitting in front of a computer in a climate controlled room, sipping fresh brewed coffee for a cramped, cold, dangerous machine that will put them right next to what they want to study – they choose the sub. Why? because you simply do better science on site than you can remotely, and it’s going to be that way for the foreseeable future. The lessons for space exploration should be obvious. I’m looking at you, Bob Park.

Dismounting my hobbyhorse and returning to Alvin, there’s an interesting story in the book Water Baby. When Alvin was under construction three pressure spheres were made and tested. The best (no. 2) was used on the sub, and sphere no. 1 was to be tested to destruction. The test vessel was a large oil filled tank which could be pressurized to simulate dives to various depths. The 40,000 pound lid of the vessel screwed into place on top. The crush test of sphere no. 1 was also going to be the first test of the pressure tank above 4000 psi. From the book:

At 4300 psi there was an explosion. In the next second the engineers calculated the probable trajectory of the tank’s lid, concluding that 40,000 pounds of steel were headed for the tin roof above them. They ran, all of them headed at once to the only other door at the far end of the building. “I remember the instantaneous transport of myself, like a Tibetan monk using the mind to will myself out of that building” Walsh said.
[…]
The super tank looked oddly untouched and its 40,000 pound lid, undamaged, was in place. The deadman was broken and its 40 foot cable was gone. When they removed the cover, they saw that the shrapnel had come from the upper threaded portion of the tank. The lid had shot up at least 40 feet and dropped back onto the tank, driving it about three feet deeper into the ground.

In the tank sat sacrificial sphere no. 1 undamaged.

The test tank failed at a pressure equivalent to 9600 feet, testing the sphere judged to be of the lowest quality.