This is so cool: NASA’s twin GRAIL spacecraft (now named Ebb and Flow) have cameras on board to take images of the lunar surface, and an animation has been put together of Ebb’s view of the Moon’s far side!

Pretty neat. I love the wide-angle view; the individual images were taken while Ebb was still over a thousand kilometers from the Moon. The huge circular feature you can see on the right 30 seconds into the video is Orientale Basin, an impact so huge it must’ve lit up the solar system a few billion years ago. That basin is nearly 1000 km (600 miles) across! See the LRO image below for a clearer view, and click it for more info.

I’m really looking forward to seeing what will be done with these cameras. As Principal Investigator Maria Zuber explains in the video, they were installed specifically for educational purposes, and kids all over America will get a chance to examine the data. I love this idea, since it means these children will be invested in the project itself, and remember it for their whole lives. It’s a fantastic idea.

Image credit: NASA/GSFC/Arizona State University

There is just something wonderful when Hubble points to nearby spiral galaxies. Sprawling and detailed, we get both great resolution on smaller features as well as a jaw-dropping overview of a grand spiral… like, say, NGC 1073:

Yeah, I know. [Click to galactinate -- I had to shrink it to fit here, and it lost a lot of the coolness when I did -- or grab the 3900 x 3000 pixel version.]

NGC 1073 is a decent-sized spiral galaxy about 60 million light years away. It’s actually part of a small, tight group of galaxies many of which are far more famous (like NGC 1068). But 1073 is important because of a simple property: it looks like us.

While it’s not a perfect match, NGC 1073 does bear an interesting resemblance to our Milky Way galaxy (UGC 12158 looks more like our galaxy, but is far bigger, for example). Both have large, rectangular bars going across their centers. Bars are a bit odd, since you’d expect the arms just to wind all the way down to the center. But the gravity of a galaxy isn’t like the gravity of a solar system, with a big heavy star sitting in the center. Galaxies have their mass spread out over a long distance, so what gas and dust clouds and stars feel in the way of gravity is different, and bars are a natural outcome of that. However, they’re still not perfectly understood. Bars may form when galaxies collide, and they might be an indication of a galaxy reaching middle age. Perhaps there are other factors as well.

Studying galaxies like NGC 1073 will help us understand how bars form, and why we have one too. Remember, we’re stuck inside our galaxy and can’t see it from the outside (that picture above is an illustration based on detailed observations). It really helps our understanding of the Milky Way to observe galaxies like ours.

An important thing too is that the two galaxies are different in some ways: NGC 1073 has more open arms, for example, compared to our more tightly wound arms. Those differences are telling us something as well. What is it that makes one galaxy hold its arms closer in, and another to fling them out? Why does this galaxy have two arms, and that one three? If you can look at two galaxies that are alike except in one way, it’s easier to isolate the cause. So studying NGC 1073 is a great way to study ourselves.

It always makes me think of Nietzsche, who wrote on the nature of man, "And when you gaze long into an abyss, the abyss also gazes into you."

But on the nature of the Universe, it changes: "And when you gaze long into an abyss, your gaze falls back on yourself."

Last week, I posted an exceptional image of our home world as seen by the Suomi NPP Earth-observing satellite. The image was so popular that NASA released a second one, this time of the Eastern hemisphere, showing once again why it’s called the Blue Marble:

[Click to engaiaenate, or grab the terrestrialicious 11,500 x 11,500 pixel shot].

Like the other one, this is a mosaic, created over six different orbits — the bright north/south swaths are actually the reflection of the Sun in the ocean as the satellite passed over that area multiple times.

Although the satellite is in low Earth orbit, just a few hundred kilometers off the surface, the images have been mosaicked together to represent the view as if you were about 13,000 km (8000 miles) away. You’re seeing most of but not quite all of the entire hemisphere here. The inset image shows why; the farther you are from Earth the more of it you see.

If you’re having a hard time picturing that, imagine taking a camera and holding it a couple of centimeters from your floor. You only see a small section of the floor, right? Now take hundreds of pictures, moving the camera each time to get a different part of the floor. If you stitch those pictures together you have a complete image of your floor, even though it was too big to see from any individual shot. It’s as if you were hovering over the floor from higher up and took one shot.

That’s how this was done as well, though the pictures couldn’t just be stitched together; they had to be warped a bit to account for the Earth being round (near the Earth’s limb you’re seeing the ground at more of an angle than what’s directly below you). That’s why the image gives you such an overwhelming feeling of perspective, of actually being over the planet from all those thousands of kilometers away.

And I wonder… someday, our children may get this view every day, just by looking out a window. Every time I think about that, I get a chill. When I was a kid, that thought was science fiction. Now it’s maybe just a few more years down the road.

[UPDATE: Right after posting this, I got a feeling of deja-vu, and suddenly realized where I've seen this view of the Earth before: Apollo 17. What I wrote in that last paragraph is literally true: humans have seen this view before, and I hope that one day it will be routine to see it this way once again.]

Image credit: NASA/NOAA.

[Note: Every week I hold a live video chat on Google+ where I answer questions from readers. I call it Q&BA, and when I get a question that stands alone, I'll make it its own video. ]

Every now and again, I hear this urban legend that pound for pound, the human body is actually hotter (or has more energy) than the Sun. I got this question in a recent Q&BA video chat session, so I tackled it. The answer is pretty interesting, and depends on how you ask the question!

I actually wrote about this legend on the blog a while back, and I show all the math. I really like this question, since it has a straightforward answer that makes it seem wrong, but then if you look at it more carefully the answer is a little trickier. And even in the video and that other post, it’s not really a complete answer; if you read the comments on the post you’ll see people arguing over it.

That’s really the best kind of question: the ones that keep on going! There’s always more stuff to figure out.

Visit the Q&BA Archive to see more videos like this one!

Over the years I have pointed out the fallacious arguments of climate change deniers when they attack legitimate climatologists like James Hansen and Michael Mann. This is, of course, like kicking at a bee hive, and whenever I do the comments section of my posts fill with lots of angry buzzing.

But now, for what I think is the first time, I find myself the target of an attack. And I have to admit, I welcome it: it’s a textbook case of denialist sleight of hand, of distraction, distortion, error, and misdirection.

Stick around for all of this. It’ll be… interesting.

Our story so far

OK, first, here’s the scoop: a few days ago, I wrote a blog post taking apart two intellectually bankrupt climate change denial articles, one in the Wall Street Journal, and the other in the UK’s Daily Mail. Both were claiming that global warming appears to have stopped in the past few years, a claim which is trivially easy to show wrong. In fact, I linked to two articles doing just that: one at Skeptical Science, and another I myself wrote. Finding actual scientists destroying that claim is not hard at all; those two links have many more links therein.

In my post about the WSJ and DM, I included a graph. It pretty clearly shows temperatures rising from 1973 to the present. And this is where the fun begins.

That’s the plot. It’s from a recent, independent study done at Berkeley, and represents actual, measured, data. Just to be clear, those points are from weather stations across the globe, and the method used to collect and analyze those measurements is described by the Berkeley team themselves (PDF). With me so far?

Apparently, William Briggs is not with me. He takes very vigorous exception to the graph in an article he wrote which he titled "Bad Astronomer Does Bad Statistics: That Wall Street Journal Editorial." I encourage you to read it, so that you can assure yourself I am not misrepresenting his arguments in any way.

I found out about this article when I saw a tweet by Dr. Briggs himself. My first thought was: Uh oh. I sure hope I didn’t make a math mistake somewhere in my WSJ post! I better read Briggs’ article and see… So I read it.

My next thought after reading his arguments was then: Ho-hum. So?

The mismeasure of an argument

Basically, Briggs accuses me of not understanding statistics, of not including error bars, of misrepresenting that points in that plot, of not displaying the plot correctly, and so on ad nauseum. His biggest claim: that those points aren’t measurements at all, but estimates.

Here’s the thing: he’s wrong. Those point are in fact measurements, though they are not raw measurements right off the thermometers. They have been processed, averaged, in a scientifically rigorous way to make sure that the statistics derived from them are in fact solid. The Berkeley team describes in detail how that was done (PDF), and does actually call them estimates, but not because they are just guessing, or using some arcane computer model. They are technically estimates, in the sense that any measurement is an estimate, but they are really, really good ones. Greg Laden tears this use of words apart, as well as pretty much everything else Briggs wrote.

Oddly, Briggs then goes on to call them "predictions" for some reason, and that they came from "models", which is just weird. It’s as if he’s trying to use a word choice that raises doubt about the measurements. But again he’s wrong. They really are measurements, not model predictions. At Open Mind, Brigg’s word choice once again is ripped apart. [Note: Briggs has left a comment there, further verifying the fact that his use of words is incorrect.]

This reminds me of one of my favorite skeptic jokes. Question: How many legs does a dog have if you call its tail a leg?

Answer: Four. It doesn’t matter what you call a tail, it’s not a leg.

There are many other places where Briggs makes mistakes that render his arguments null; for example, the error bars (what statisticians usually call "uncertainty") are in fact made available by the Berkeley team, and are small compared to the long-term rise in temperature. For another, Briggs says I should’ve shown the plot going farther into the past, because 1973 was actually a low point. However, that’s completely wrong: it’s actually a high point! As Deep Climate points out here, this actually makes the warming trend lower. So in true contrarian fashion, Briggs is contrary even to himself. It’s bizarre.

So really, there goes Briggs’ argument. His main point is wrong, so we’re done, right?

Well, no. There’s more fun to be had here.

Beside the point

If you read Briggs’ article, you certainly get the impression that because the graph I use is statistically meaningless (so he incorrectly claims), then my whole argument about global warming is wrong.

And this is where I found myself greatly amused, though in a schadenfreude sort of way.

Think of it this way: if my argument hinged on that graph, and I removed it, my argument would have no foundation, correct? It would change the tenor of the entire blog post.

Go look at my article. If you remove that graph from it, what changes? Nothing. My main point — that the WSJ and DM articles are wrong, that we have lots of evidence the Earth is warming up, that 9 of the 10 hottest years on record occurred since the year 2000, that the DM article specifically uses scientific studies and presents them as if they say the exact opposite of what they actually say — still stands.

So even if that graph is wrong and misrepresents what I’m saying — which it does not — it doesn’t matter. In fact, I used that graph as an illustration, to show how we’re warming up. I never intended it to be the basis for the argument I was making, just a way of further showing it. If you read the actual words I wrote, including the links to many, many articles backing up my position, you’ll see that Briggs has not refuted a single actual point I made.

So even if he’s right about that graph, it doesn’t matter. And he’s not right.

But notice what he’s done. He’s taken what is clearly a minor point and blown it up as if it’s my main point. He’s used shady words (predictions, models) to cast aspersions, and to make someone (me!) look bad. Then, by "refuting" this minor issue he can then poison the well, strongly implying that all my arguments are wrong. That’s kind of a big no-no when trying to argue a point.

But it packages well. Watts Up With That, another denialist blog, has run with Briggs’ claims about me as well. He also makes the false claim that warming has stalled, and so on. Note WUWT also says the signers of the WSJ OpEd are "16 scientists", which isn’t true: not all are scientists, and only four have actually published climate science research. And don’t forget about the article the WSJ refused to print talking about the reality of global warming, signed by 255 actual scientists.

Oops.

Denialism’s dark mirror

I will admit the irony of this attack amuses me greatly; Briggs accuses me of many things he himself is doing. That is standard fare from antiscience group: creationists, global warming deniers, and alt-medders, for example, all seem to project their own tactics on the scientists with whom they disagree. Don’t like real medicine? Accuse scientists of being in the pocket of Big Pharma (and forget about the millions being made by quacks on useless "remedies"). Don’t believe in evolution? Accuse scientists of being too dogmatic. Don’t think global warming is real? Accuse scientists of misrepresenting the data.

My favorite irony is that a lot of these global warming denialists take money from fossil fuel interests, but then routinely say to "follow the money", as if it’s the climatologists who are raking in the big bucks from shady think tanks with undisclosed bankrollers. While Briggs points out he gets no money from them, he asks where my money comes from. Think on this, Dr. Briggs; how much money would I make if I suddenly turned coat and said global warming wasn’t real? I’ll guarantee you it would be a lot more than I make now, probably with a couple of zeroes added to the end. So that argument falls a wee bit flat here.

Like all the others.

Of course, given the comments I’ve seen on my blog, on Briggs’ blog, on Watts Up With That, or in any other blog discussing global warming, I know how this will go. You can bring up the major pieces of evidence supporting reality again and again, but the denialists will ignore them and go after phantoms instead. Because if they do acknowledge the actual evidence, they lose.

In 2015, NASA’s New Horizons spacecraft will zip past Pluto, giving us our first close-up view of this tiny world.

The team behind the space probe have a nice idea to help raise awareness of it: make a new US Post Office stamp commemorating it. My friend Dan Durda, both an accomplished astronomer and artist, created this lovely design of the stamp:

[Click to enhadesenate. Note: the word "Forever" means the stamp is always good for first class postage, and is crossed out here to prevent forgery.]

It shows the spacecraft going by Pluto and its (relatively) freakishly large moon Charon. I like how he didn’t go for photorealism, but instead used an oil paint-like feel for it. The stamp is meant as a followup — I might even say send-up — of a US stamp issued in 1990 about Pluto that has the label "Not Yet Explored".

I like this stamp! I’d love to see it made official, too. Alan Stern, the head guy for the mission, created a petition to help that along. It takes more than just a nice stamp design to get the PO’s notice; it has to have public support as well. I signed the petition, and if you want to, please do.

I’ll note that I expect this to raise the specter of whether Pluto is a planet or not. I have some thoughts on that, and I’ll be posting again soon on that topic.

Over the course of several hundred years – most notably in the 17th and 18th centuries — winter temperatures in western Europe were much lower than normal. Glaciers came much farther south than they had before, and a famous painting shows people ice skating on the Thames river — which hasn’t been frozen since. The period is known as the Little Ice Age, and its cause has always been something of a mystery.

However, new research by scientists at the University of Colorado-Boulder (yay team!) may have pegged it: the LIA appears to have started abruptly in the late 13th century, between the years 1275 and 1300. Radiocarbon dating of plants from Baffin Island (north of the Hudson Bay in Canada) and sediment samples from a lake in Iceland indicate that there was a rapid onset of severe cooling at that time. It’s been thought that the cooling started around then, but it’s been hard to pin down until now.

More importantly, this narrows down the cause of the LIA: four tropical volcanoes erupted violently in that period. The ash would have darkened the atmosphere, letting slightly less sunlight down. Some of the gases emitted by volcanoes also cool the air. It seems clear these volcanoes are what triggered the Little Ice Age. But why did it last so long?

That may be due to what happened after the volcanoes erupted. Most likely, the warmer temperatures would have melted the north polar sea ice. This fresh water is less dense than salty water, so it would flow on top of the oceans, and wouldn’t have mixed well with the deeper water. This would have slowed the transport of heat from the equatorial waters back up north, cooling them further. That system is what maintained colder temperatures for so long. There were variations — the Ice Age was more of as series of pulses of temperature drops than one long period — but for centuries the heating of the Earth was disrupted in that region.

For a long time it’s been suspected that the Sun played a role here, too. During the period of 1645 to 1715 there were few or no sunspots, a time called the Maunder Minimum. Sunspots are dark, but they’re surrounded by a region, a rim, that emits strongly in the UV. These faculae, as they’re called, actually more than make up for the darker regions of the spots, so in reality sunspots add to the amount of light and heat the Earth receives, by a fraction of a percent. So an active Sun, it’s thought, may warm the Earth a teeny bit more.

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