Recently David Friedman of the blog Ironic Sans has been posting scans of articles from the New York Times Sunday Magazine; specifically, articles from exactly 100 years ago each weekend. On Friday he posted an article, originally dated the 8th of May 1910, titled “Fears Of The Comet Are Foolish And Ungrounded“. It’s about people’s reactions of fear and panic to the imminent arrival of Halley’s Comet, which passes close to Earth every 75 years or so. The author, a popular astronomy writer called Mary Proctor, describes a letter sent to her by an eleven year-old girl:
I am in a very bad fix, in fact the whole school is. Every one says that the world will come to an end on the 18th of the month. Is it true the earth is to pass through the comet and we will all burn up? Tell me if it is true, also when shall we be able to see the comet! Please excuse this letter, but I don’t want to die.
An understandable fear of the unknown, fuelled by misunderstandings about the nature of astronomical objects, is nothing new And nor is the need for scientists to explain their work to the public, so people can avoid panic about things which pose no threat - and respond appropriately to those which do.
This is a video of the launch of Apollo 11, the rocket that placed the first human beings on the moon. It was shot at 500 frames per second, so played back at a normal frame rate it’s something like 20 times slower than real time. I definitely recommend watching it, partly for the excellent commentary by Mark Grey and partly for the sheer surreality of the process when viewed at this speed. It’s not just the natural world that can be unintentionally beautiful.
The Hubble Space Telescope turned twenty years old this weekend. In those two decades it’s produced a huge amount of scientific output, with over 8,000 peer-reviewed papers based on Hubble data. Perhaps almost as importantly, it’s brought a great many beautiful pictures to an extremely broad audience; it’s contribution to astronomers’ outreach and education efforts through these pictures and the Hubble Office for Public Outreach is incalculable.
This is a stunning picture released by NASA and ESA to celebrate the anniversary. It’s of a nebula - a cloud of gas and dust - called Carina, which is forming new stars at one of the highest rates in our galaxy. And that means that, just as I’ve said of other nebulae, it’s a pretty violent place. I’m posting this on the move, so I encourage you to go to the Hubble site for a full description.
A star-forming region in the Carina Nebula, 75,000 light-years away
Here’s a picture of the North pole of Saturn, taken by the Cassini spacecraft in 2006 from a distance of half a million miles. The colours aren’t what you’re used to because this is an infrared image, showing heat given off by the planet. The white parts are clouds which block that light - in the original image they’d have been black, gaps in the pattern of observed light, but this is essentially a negative.
But after the colour another obvious feature jumps out: clouds in the shape of a hexagon. What’s that doing there?
A hexagonal pattern of clouds at Saturn's North pole
Last week was the National Astronomy Meeting, the annual meeting of the UK’s Royal Astronomical Society. This year it took place in Glasgow. I’d never been there before, and I confess I was pleasantly surprised at how nice it was - people often speak negatively about the city, but I found it very pretty.
A Highlander Light Infantry casualty of the Second Boer War looks out towards the University building where the conference was held
Here are highlights from a couple of talks I went to.
Chris Lintott gave an interesting talk about his Galaxy Zoo project. In case you’re not familiar with the Zoo, it’s a website which allows thousands of internet users to contribute to astronomical research by classifying pictures of galaxies. I’ve previously discussed it here.
Every two to three years, the US’s National Science Foundation produces a report called Science and Engineering Indicators, on various aspects of science and technology in America. One section of the report is on the public’s level of scientific literacy, and includes a poll which asks people true-or-false questions about fairly basic scientific facts. The statements in this year’s report (available in a spreadsheet here) include things like “the centre of the Earth is very hot”; “lasers work by focusing sound waves”; and “it is the father’s gene that decides whether the baby is a boy or a girl”. On average, 64% of respondents were able to answer the questions correctly (the answers being ‘true’, ‘false’ and ‘true’ for the three above).
Worthy of comment are two statements which have been in previous reports since 1985 but were not in this year’s: “human beings, as we know them today, developed from earlier species of animals”, and “the universe began with a big explosion”. In the last report the proportion of people correctly answering that these are true* was 45% and 33% respectively, much lower than the average of 64% for the other questions.
These two questions were asked during this year’s survey and included in the original draft of the report, but removed before publication by the NSF’s oversight body the National Science Board. The rationale was that the questions are “flawed indicators of scientific knowledge because the responses conflated knowledge and beliefs.”
Courtesy of Bad Astronomy’s Phil Plait, here’s a video of Earth taken by NASA’s Deep Impact probe some 18 million kilometers away. The pictures are taken in infrared light, just outside our visible range, and shifted into visible light to make a video we can watch. The half of the planet’s surface facing the Sun is lit up; the other half, of course, is in night.
Although the whole day-time half of the Earth is lit, there’s one point on its surface which occasionally shows up with a bright flash (watch the middle of the black circle in the video). That’s caused by sunlight reflecting off water! It shows up in only one spot because the angle between Sun, water and spacecraft needs to be exactly right. (By way of analogy, imagine a small mirror being held up in a brightly sun-lit room. You can see the mirror no matter which angle its held at, but you only get blinded by a flash of reflected sunlight if it’s angled just right.) As the Earth turns a different part of its surface moves into that correctly-angled spot, which always remains in the same part of the spacecraft’s view of view.
Galaxies are gregarious creatures: many of them live in clusters. Our own Milky Way and its neighbour Andromeda are the core members of a ‘Local Group’ of some 30 smaller galaxies. But that’s small fry compared to the Virgo cluster, by far the biggest object in the nearby universe: the cluster’s about 60 million light-years away, 2 million or so in radius, and contains between 1500 and 2000 galaxies. Here’s one of them, NGC 4522. Notice how the disc seems almost to be bent upwards, with a sprinkle of blue stars above it as though they were floating off from the galaxy? As it turns out, that’s exactly what they are doing.
Here’s a nice animation demonstrating the scale of some astronomical objects (click “Play” at the bottom of the screen after waiting for it to load). Unlike some of the others I’ve posted before, it goes above planets and stars to show the sizes of galaxies, galaxy clusters, and ultimately the whole observable universe. It also goes down below astronomical scales, to everyday-sized objects like giant earthworms and eventually to the scale of subatomic particles.
And that gives me a nice excuse to segue into a discussion of particles in astronomy. You might expect that particle physics and astrophysics would have little to do with each other, dealing as they do with phenomena at opposite ends of the distance scale. But in fact they’re often very closely linked (my office, for instance, is right next to the Beecroft Institute for Particle Astrophysics and Cosmology).
My name's Olaf Davis, and I'm a PhD student in the Astrophysics group at Oxford. This blog is mainly about astronomy and mainly aimed at the layman (no physics or maths training required!) but I sometimes stray into other areas which interest me, particularly maths and science reporting and communication.
