Brian Micklethwait's Blog

In which I continue to seek part time employment as the ruler of the world.

Home

www.google.co.uk


Recent Comments


Monthly Archives


Most recent entries


Search


Advanced Search


Other Blogs I write for

Brian Micklethwait's Education Blog

CNE Competition
CNE Intellectual Property
Samizdata
Transport Blog


Blogroll

2 Blowhards
6000 Miles from Civilisation
A Decent Muesli
Adloyada
Adventures in Capitalism
Alan Little
Albion's Seedling
Alex Ross: The Rest Is Noise
Alex Singleton
AngloAustria
Another Food Blog
Antoine Clarke
Antoine Clarke's Election Watch
Armed and Dangerous
Art Of The State Blog
Biased BBC
Bishop Hill
BLDG BLOG
Bloggers Blog
Blognor Regis
Blowing Smoke
Boatang & Demetriou
Boing Boing
Boris Johnson
Brazen Careerist
Bryan Appleyard
Burning Our Money
Cafe Hayek
Cato@Liberty
Charlie's Diary
Chase me ladies, I'm in the cavalry
Chicago Boyz
China Law Blog
Cicero's Songs
City Comforts
Civilian Gun Self-Defense Blog
Clay Shirky
Climate Resistance
Climate Skeptic
Coffee & Complexity
Coffee House
Communities Dominate Brands
Confused of Calcutta
Conservative Party Reptile
Contra Niche
Contrary Brin
Counting Cats in Zanzibar
Скрипучая беседка
CrozierVision
Dave Barry
Davids Medienkritik
David Thompson
Deleted by tomorrow
deputydog
diamond geezer
Dilbert.Blog
Dizzy Thinks
Dodgeblogium
Don't Hold Your Breath
Douglas Carswell Blog
dropsafe
Dr Robert Lefever
Dr. Weevil
ecomyths
engadget
Englands Freedome, Souldiers Rights
English Cut
English Russia
EU Referendum
Ezra Levant
Everything I Say is Right
Fat Man on a Keyboard
Ferraris for all
Flickr blog
Freeborn John
Freedom and Whisky
From The Barrel of a Gun
ft.com/maverecon
Fugitive Ink
Future Perfect
FuturePundit
Gaping Void
Garnerblog
Gates of Vienna
Gizmodo
Global Warming Politics
Greg Mankiw's Blog
Guido Fawkes' blog
HE&OS
Here Comes Everybody
Hit & Run
House of Dumb
Iain Dale's Diary
Ideas
Idiot Toys
IMAO
Indexed
India Uncut
Instapundit
Intermezzo
Jackie Danicki
James Delingpole
James Fallows
Jeffrey Archer's Official Blog
Jessica Duchen's classical music blog
Jihad Watch
Joanne Jacobs
Johan Norberg
John Redwood
Jonathan's Photoblog
Kristine Lowe
Laissez Faire Books
Languagehat
Last of the Few
Lessig Blog
Libertarian Alliance: Blog
Liberty Alone
Liberty Dad - a World Without Dictators
Lib on the United Kingdom
Little Man, What Now?
listen missy
Loic Le Meur Blog
L'Ombre de l'Olivier
London Daily Photo
Londonist
Mad Housewife
Mangan's Miscellany
Marginal Revolution
Mark Wadsworth
Media Influencer
Melanie Phillips
Metamagician and the Hellfire Club
Michael Jennings
Michael J. Totten's Middle East Journal
Mick Hartley
More Than Mind Games
mr eugenides
Mutualist Blog: Free Market Anti-Capitalism
My Boyfriend Is A Twat
My Other Stuff
Natalie Solent
Nation of Shopkeepers
Neatorama
neo-neocon
Never Trust a Hippy
NO2ID NewsBlog
Non Diet Weight Loss
Normblog
Nurses for Reform blog
Obnoxio The Clown
Oddity Central
Oliver Kamm
On an Overgrown Path
One Man & His Blog
Owlthoughts of a peripatetic pedant
Oxford Libertarian Society /blog
Patri's Peripatetic Peregrinations
phosita
Picking Losers
Pigeon Blog
Police Inspector Blog
PooterGeek
Power Line
Private Sector Development blog
Public Interest.co.uk
Publius Pundit
Quotulatiousness
Rachel Lucas
RealClimate
Remember I'm the Bloody Architect
Rob's Blog
Sandow
Scrappleface
Setting The World To Rights
Shane Greer
Shanghaiist
SimonHewittJones.com The Violin Blog
Sinclair's Musings
Slipped Disc
Sky Watching My World
Social Affairs Unit
Squander Two Blog
Stephen Fry
Stuff White People Like
Stumbling and Mumbling
Style Bubble
Sunset Gun
Survival Arts
Susan Hill
Teblog
Techdirt
Technology Liberation Front
The Adam Smith Institute Blog
The Agitator
The AntRant
The Becker-Posner Blog
The Belgravia Dispatch
The Belmont Club
The Big Blog Company
The Big Picture
the blog of dave cole
The Corridor of Uncertainty (a Cricket blog)
The Croydonian
The Daily Ablution
The Devil's Advocate
The Devil's Kitchen
The Dissident Frogman
The Distributed Republic
The Early Days of a Better Nation
The Examined Life
The Filter^
The Fly Bottle
The Freeway to Serfdom
The Future of Music
The Futurist
The Happiness Project
The Jarndyce Blog
The London Fog
The Long Tail
The Lumber Room
The Online Photographer
The Only Winning Move
The Policeman's Blog
The Road to Surfdom
The Sharpener
The Speculist
The Surfer
The Wedding Photography Blog
The Welfare State We're In
things magazine
TigerHawk
Tim Blair
Tim Harford
Tim Worstall
tomgpalmer.com
tompeters!
Transterrestrial Musings
UK Commentators - Laban Tall's Blog
UK Libertarian Party
Unqualified Offerings
Violins and Starships
Virginia Postrel
Vodkapundit
WebUrbanist
we make money not art
What Do I Know?
What's Up With That?
Where the grass is greener
White Sun of the Desert
Why Evolution Is True
Your Freedom and Ours


Websites


Mainstream Media

BBC
Guardian
Economist
Independent
MSNBC
Telegraph
The Sun
This is London
Times


Syndicate

RSS 1.0
RSS 2.0
Atom
Feedburner
Podcasts


Categories

Advertising
Africa
Anglosphere
Architecture
Art
Asia
Atheism
Australasia
Billion Monkeys
Bits from books
Bloggers and blogging
Books
Brian Micklethwait podcasts
Brians
Bridges
Business
Career counselling
Cartoons
Cats and kittens
China
Civil liberties
Classical music
Comedy
Comments
Computer graphics
Cranes
Crime
Current events
Democracy
Design
Digital photographers
Drones
Economics
Education
Emmanuel Todd
Environment
Europe
Expression Engine
Family
Food and drink
France
Friends
Getting old
Globalisation
Healthcare
History
How the mind works
India
Intellectual property
Japan
Kevin Dowd
Language
Latin America
Law
Libertarianism
Links
Literature
London
Media and journalism
Middle East and Islam
Movies
Music
My blog ruins
My photographs
Open Source
Opera
Other creatures
Painting
Photography
Podcasting
Poetry
Politics
Pop music
Propaganda
Quote unquote
Radio
Religion
Roof clutter
Russia
Scaffolding
Science
Science fiction
Sculpture
Signs and notices
Social Media
Society
Software
South America
Space
Sport
Technology
Television
The internet
The Micklethwait Clock
Theatre
This and that
This blog
Transport
Travel
USA
Video
War


Saturday May 26 2007

After all the excitement of this photo of Saturn, here is another.  Well, not a photo.  It’s more like a CAT scan.  Once again it is the work of Cassini.

image

This false-color image of Saturn’s main rings was made by combining data from multiple star occultations using the Cassini ultraviolet imaging spectrograph.

During occultations, scientists observe the brightness of a star as the rings pass in front of the star. This provides a measurement of the amount of ring material between the spacecraft and the star.

Cassini has given scientists the most detailed view yet of Saturn’s densely packed B ring. Cassini found that this part of the rings is densely packed with clumps, called self-gravity wakes, separated by nearly empty gaps. These clumps in Saturn’s B ring are neatly organized and constantly colliding, which surprised scientists.

The clumps in Saturn’s B ring, 30 to 50 meters (100 to 160 feet) across, are too small to be seen directly. However, scientists can map the distribution, shape and orientation of the clumps. Colors in this image indicate the orientation of clumps, and brightness indicates the density of ring particles. The formation of wakes is strongest in the bluer regions, where ring particles clump together in tilted wakes. Particles in the central yellow regions are too densely packed for any starlight to pass through.

The ultraviolet imaging spectrograph measured the flickering of the star Alpha Arae as it passed by the rings Nov. 9 and 10, 2006.

This circumstance seems to me yet one more example among many previous thousands and many more thousands to come, of the fact that the true heroes of astronomy are the instrument makers.  The theorists theorise away, on the basis of insufficient evidence.  And they are eventually proved right, or then again wrong, by the next lot of instruments.  Once the instrument guys produce their next lot of pictures, the truth is pretty much clear for all to see, and frankly the theorists might just as well not have bothered.

As it says in the press release:

“The rings are different from the picture we had in our minds. We originally thought we would see a uniform cloud of particles. Instead we find that the particles are clumped together with empty spaces in between,” said Larry Esposito, principal investigator for the Cassini ultraviolet imaging spectrograph at the University of Colorado, Boulder. “If you were flying under Saturn’s rings in an airplane, you would see these flashes of sunlight come through the gaps, followed by dark and so forth. This is different from flying under a uniform cloud of particles.”

Because previous interpretations assumed the ring particles were distributed uniformly, scientists underestimated the total mass of Saturn’s rings. The mass may actually be two or more times previous estimates.

Previous interpretations?  Just extrapolations beyond what they had learned for sure from earlier instruments.  Guesses by people who didn’t know, in other words.  And then, thanks to Cassini, they did know.  And now they will make more guesses based on what even Cassini isn’t now telling them, which will be equally worthless, even if these guesses happen to be true.  Am I missing something?

I still don’t know how proper CAT scans work, or even, really, what they are.  But I am now confused about this on a somewhat bigger scale and in greater detail.