Wednesday, 26 November 2014
A Signed Book Is The Perfect Christmas Gift - Special Offer
Get a signed paperback copy of An Accident Of Birth for only £5.50 + £2.80 UK p&p. (For overseas postage, please contact me)
If you'd like me to dedicate the book to someone special, please just let me know their name, and I'll be happy to oblige.
Make someone happy this Christmas. Give them a book to read.
Twenty-year-old Francesca was born with a rare gift – fertility. In a polluted society, the government imprisons and forces her to breed children for the infertile masses. She has waited four long years for her boyfriend Dominic to rescue her. Now desperate, he hires a black market rescuer, Baron Craig Drake, a fertile who has escaped the government's clutches and thrives on exploiting others. Unbeknownst to Dominic, Drake has his own plans for Francesca. When Dominic attempts to free her from the government's prison, he finds himself struggling to keep her from becoming another victim of the ruthless Baron… and to free the woman he loves once and for all.
Wednesday, 12 November 2014
Touchdown! Rosetta's Success Story and the Philae Lander
Huge congratulations to the ESA Rosetta mission team! They have done what some said was impossible. The image above is a photo taken by the Rosetta craft of the Philae lander shortly after it was released for its descent onto comet 67P/Churyumov-Gerasimenko.
Seven hours later, this afternoon at 1603 GMT, the signal was received confirming that the Philae lander has touched down on the surface of 67P/Churyumov-Gerasimenko.
This success paves the way for ground-breaking research. The Philae lander is equipped to take images of the comet's surface, but it can do much more than that. If its battery remains serviceable and the Philae lander remains anchored to the comet, it will analyse the composition of the surface, drill for samples, and send back an analysis. It will use radio signals to probe the comet's structure, and all in all, it will provide a wealth of data about the comet.
So... why do we care?
Comets and asteroids are considered interesting because scientists believe that they are the leftover remnants from the formation of the solar system some 4.5 billion years ago. Comets are particularly interesting because they ended up in the outer reaches of the solar system, in the Kuiper belt and the Oort cloud. These places are cold - about 50 degrees above absolute zero, and because of this extremely low temperature, the composition of comets has changed little since they were formed.
Comets are well known for being made up of dust, rock and frozen gasses, including water ice. There is evidence that the water in comets could be the source of water on Earth, and this is particularly interesting because those very same comets contain a wealth of organic molecules - the building blocks of amino acids, protein, and hence, life itself.
So what we see when we get up close and personal with a comet such as 67P/Churyumov-Gerasimenko is a window into the past. So far in the past that we gain clues to the processes that took place during the very formation of the solar system. This in its turn gives us clues about our own past.
The Rosetta mission, and particularly the Philae lander, can teach us much about the early years of the solar system, and even give us clues about the formation of the Sun itself.
For so many reasons this success is a source of excitement, not only for the scientific community, but for everybody.
A Big Day for the Rosetta Team
Today is a big day for the Rosetta team. This morning, in Darmstadt, the ESA flight team gave the go-ahead to release the Philae lander on its way for an historic landing on the comet 67P/Churyumov-Gerasimenko.
This mission, which was first conceived in the 1980s, has been many years in the making. It was launched on 2nd March 2004 with the objective of visiting this comet. Over a period of ten years, Rosetta navigated a complex series of ever increasing orbits of the sun, until on 6th August this year it achieved a successful rendezvous with 67P/Churyumov-Gerasimenko.
Rosetta is the first craft to have made a rendezvous with a comet, and the success of the Philae lander is by no means certain. What happens today will be a complex and difficult landing, and the eyes of the world will be on the live feeds.
I want to wish the team success with this bold endeavour.
Image, courtesy ESA
Friday, 31 October 2014
NaNoWriMo 2014 - Here we go...
This is it. Tomorrow, National Novel Writing Month 2014 begins, and during the month of November, hundreds of thousands of people across the world will endeavour to write a 50,000 word novel in 30 days.
Why do we do it?
There are almost as many answers to that question as there are participants. Some want to be published, some write only for their own pleasure, but one thing I find is common to all - we do it because we love writing.
To write a 50,000 word novel in 30 days seems like an almost insurmountable challenge until you realise that it amounts to a modest daily target of 1667 words. Many authors set themselves daily word count targets, and 2000 words per day is not uncommon.
NaNoWriMo participants come from all walks of life, and while 1667 words might be a modest aspiration, not everyone has time to reach that goal. Life gets in the way. Some people start NaNoWriMo with firm intentions, but for one reason or another, cannot reach the big goal of 50,000 words. In the end, though, every participant has thought more about writing, and most have written more than they would have done without the challenge.
That's why I say that every one of the hundreds of thousands of people who sign up for NaNoWriMo will surely be a winner.
Friday, 19 September 2014
Book Review: Relativity – The Special & the General Theory by Albert Einstein
Anyone who reads or writes science fiction gets caught up in relativity some time or other, whether it is with faster than light travel, warp drives, time travel, wormholes, the bending of space and time or any of a number of other fun concepts. Wouldn't it be nice to actually know some of the real theory behind all of this? Some people are put off reading about the subject because much of what is written is heavily mathematical. Worry no more. This book by Albert Einstein himself is aimed at those who want to understand the concepts but don't want to get bogged down in mathematics.
I have just re-read this book, and just like the last time I read it some twenty years ago, I am both impressed and grateful that a man of such awe-inspiring intellectual prowess took the trouble to explain this complex subject to me. It's almost as though he is in the room talking to a non-mathematician, and gently, one step at a time, starting with the fundamentals, building up the ideas that make this impressive set of theories.
I thought to tell you what the book is and who it is aimed at, but I cannot put it better than Albert Einstein's own words in his preface of December 1916.
“The present book is intended, as far as possible, to give an exact insight into the theory of Relativity to those readers who, from a general scientific and philosophical point of view, are interested in the theory, but who are not conversant with the mathematical apparatus of theoretical physics. The work presumes a standard of education corresponding to that of a university matriculation examination, and, despite the shortness of the book, a fair amount of patience and force of will on the part of the reader. The author has spared himself no pains in his endeavour to present the main ideas in the simplest and most intelligible form, and on the whole, in the sequence and connection in which they actually originated. In the interest of clearness, it appeared to me inevitable that I should repeat myself frequently, without paying the slightest attention to the elegance of the presentation. I adhered scrupulously to the precept of that brilliant theoretical physicist L. Boltzmann, according to whom matters of elegance ought to be left to the tailor and to the cobbler. I make no pretence of having withheld from the reader difficulties which are inherent to the subject. On the other hand, I have purposely treated the empirical physical foundations of the theory in a "step-motherly" fashion, so that readers unfamiliar with physics may not feel like the wanderer who was unable to see the forest for the trees. May the book bring some one a few happy hours of suggestive thought!”
Part I The Special Theory of Relativity
Part II The General Theory of Relativity
Part III Considerations on the Universe as a Whole
Appendix I Simple Derivation of the Lorentz Transformation
Appendix II Minkowski's Four-dimensional Space (“World”)
Appendix III The Experimental Confirmation of the General Theory of Relativity
Part I The Special Theory of Relativity
One of the great things about special relativity is you can understand it with no more than high school mathematics.
Einstein is rigorous in his approach, and argues that any definition that cannot be verified by measurement is meaningless. He begins with what he calls “the Principle of Relativity (in the restricted sense)”, which states:
If, relative to K, K' is a uniformly moving coordinate system devoid of rotation, then natural phenomena run their course with respect to K' according to exactly the same general laws as with respect to K.
He then goes on to use an example of a railway train moving relative to the embankment to show that the above principle of relativity is in conflict with the statement that the speed of light is a constant in vacuum. He concludes that we must either abandon the so-called “Principle of Relativity (in the restricted sense)” or the assertion that the speed of light in vacuum is constant – or we can develop a theory that reconciles the two. That theory is the Special Theory of Relativity.
The argument of the text then proceeds towards a derivation of the Lorentz transformation. At this point he states its mathematical representation, and refers the reader to Appendix I if they want a derivation.
In essence, the Lorentz transformation shows that if we measure distance or time for an event in one reference frame, then the measured distance or time in a different reference frame (for the same event) depend on the relative velocity of the two reference frames.
This is all well and good, but it only applies if we constrain ourselves to uniform rectilinear and non-rotary motion, and that's what brings us on to Part II.
Part II The General Theory of Relativity
So, what if we remove this last constraint, and don't limit ourselves to uniform rectilinear and non-rotary motion?
Unlike the special theory of relativity, a full understanding of the general theory of relativity requires some really tricky mathematics, and is not for the faint hearted.
Einstein argues that gravity acts by means of a gravitational field, and that the law governing the field must be a “perfectly definite one.” With consideration, he concludes that “the same quantity of a body manifests itself according to circumstances as 'inertia' or as 'weight'”. This leads to the conclusion that an observer, given no other clues, cannot tell the difference between a downward gravitational field and an upward uniform acceleration.
Using an example of a rotating disc he shows that the classical propositions of Euclidean geometry cannot hold in a gravitational field. Hence the idea of a straight line loses its meaning. He overcomes this by using Gaussian coordinates rather than cartesian coordinates – leaving cartesian coordinates as simply a special case.
He goes to some trouble to demonstrate how space-time might be conceived this way. The space-time continuum of the General Theory of Relativity is not a Euclidian continuum, so instead we use four dimensional Gaussian coordinates.
Following on from this he describes space-time using a non-rigid reference body, moving and altering form in any way, and in which the time, measured at indefinitely close points, vary by indefinitely small amounts. He refers to this reference body as a “mollusc”.
I have necessarily abbreviated the description so far, and in so doing, I have probably made it sound either hokey or nonsensical. Reading this book will show that to be a shortfall of my description rather than Einstein's explanation. He goes on to formulate the General Principle of Relativity using a non-mathematical description. It would be pointless for me to attempt an abbreviated statement of his case, since his words are already just that, and presented without the aid of mathematics. The interested reader should certainly read Einstein's words.
It's fair to say that in Part II, Einstein explains the general theory of relativity reasonably well, considering that he is avoiding the mathematics, and attempting to convey the concepts to an educated layman.
The rest of Part II, and a short Part III
The rest of Part II and a short Part III offer interesting discussions of how the General Theory of Relativity helps with, for example, explaining the following:
The 43 arcsecond per century discrepancy between the observed orbit of Mercury and the predictions of classical mechanics.
The existence of a universe that is finite yet unbounded.
The structure of space. Given that the behaviour of measuring rods and clocks is influenced by gravitational fields, the distribution of matter cannot be described using Euclidean geometry with complete accuracy. He explains what the General Theory of Relativity tells us about the structure of space.
Conclusion
I sincerely hope I haven't managed to make this work sound either dry or too difficult to read. It is elegantly written, and well explained. He doesn't introduce any concepts without explaining what they mean, and in the end, the reader cannot but have an appreciation of the wonders of the special and general theories of relativity.
Tuesday, 16 September 2014
200p Prime Focus Photography With a Filter
It turns out there's a neat method to do this, and I'll illustrate it here with photos.
The 200p focusser has a choice of 1.25” and 2” eyepiece adaptors. Take the 1.25” adaptor, and unscrew the barrel from the ring:
Screw it back in on the other side of the ring, so that it would be poking into the telescope if you were to put it back in the focusser. Take the two knurled screws out of the 1.25” barrel, and replace them with M3.5 grub screws. I used stainless steel ones that are 4mm long (easily available on ebay).
Unscrew the barrel from an eyepiece, and hold it in place with the grub screws:
Now you're set. Add your t-ring and filter:
And you can put the whole assembly onto the camera:
And finally, mount the whole lot onto the telescope:
I hope this was helpful. Now all we need is clear skies.
Sunday, 27 July 2014
Book Review: The Sky's Dark Labyrinth by Stuart Clark
Book Review: The Sky's Dark Labyrinth by Stuart Clark
A novel of intrigue, heresy and the quest for the truth.This is the first in Stuart Clark's trilogy, including The Sky's Dark Labyrinth, The Sensorium of God and The Day Without Yesterday. Each takes a pivotal moment in the evolution of science and dramatises it in fiction.
From the back cover
At the dawn of the seventeenth century Europe is a dark and dangerous place. As war rages across the continent and men's immortal souls are traded for mortal lives, two astronomers risk everything to reveal the truth behind the universe's grand design.
When Johannes Kepler discovers that the stars and planets move not to the whims of angels but according to natural laws, Galileo Galilei proclaims his own startling discoveries. Ultimately both men become caught in a web of intrigue and face persecution as heretics in one of the darkest yet most enlightening periods of European history.
The Sky's Dark Labyrinth by Stuart Clark
An enthralling and entertaining journey through the corridors of power in Rome and the inevitable conflict between the church and the eminent scientists of the day.
Ptolemy's geocentric model, in which the Earth is the centre of the universe, had been accepted for over a millennium, and was one of the core elements of Catholic doctrine. In 1543 Nicolaus Copernicus' book On The Revolutions of the Heavenly Spheres (De Revolutionibus Orbium Coelestium) was published, offering a whole new model in which the Earth and planets orbit the Sun. This might have provoked a strong reaction from the Catholic church, since any disagreement with Catholic doctrine was considered heretical, and hence punishable. At the time of publication, however, it received no such response. This is thought to be largely due to a preface, credited to Andrew Osiander, which argued that the book relates to observations, and that it is for others to draw philosophical conclusions.
The Sky's Dark Labyrinth is set half a century later when Tycho Brahe proposes a geo-heliocentric model which ties in more closely with contemporary observations than does the Ptolemeic geocentric model, but manages not to conflict openly with current Catholic doctrine.
Johannes Kepler's wishes to use Tycho Brahe's observations to confirm his own theoretical ideas about the natural laws which dictate the motions of the heavenly bodies. His relationship with Tycho is sometimes volatile, and he has difficulty getting his hands on the data he needs.
Galileo Galilei believes that Copernicus' heliocentric model should be more widely held, and that there are inevitable philosophical implications. He does not shy away from the philosophical discussion and this brings him into direct confrontation with the church.
This is a time when heretics are punished severely, and don't always survive to tell the tale. A new science is emerging, and Kepler and Galilei are at the centre of it. The struggle between those who wish to preserve the long established Catholic doctrines and those who wish to bring on a new revolution in science, is littered with intrigue and treachery.
Stuart Clark's effortless writing style and vivid period descriptions bring to life a story that is so often related in dusty, dry academic texts. The book is a joy to read. Stuart Clark's deep knowledge, not only of the historical setting, but of the underlying science and astronomy and the lives of the scientists involved, ensures that this story is not only engaging, but it is historically accurate. This is a book which carries a considerable promise, whether your background is in science or not. I am happy to say that Stuart Clark does not fail to deliver the goods.
About Dr. Stuart Clark, from his website:
Image courtesy: Simon Wallace,
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Currently he divides his time between writing books and, in his capacity of cosmology consultant, writing articles for New Scientist. He is a consultant and writes for the European Space Agency where he was Senior Editor for Space Science for some time. Over the years Stuart has written for amongst others: BBC Sky at Night, BBC Focus, The Times, The Guardian, The Economist, The Times Higher Education Supplement, Daily Express, Astronomy Now, Sky and Telescope and Astronomy. He has written text for an issue of stamps for the Royal Mail. He writes an online blog for the Guardian called Across the Universe, read all around the world.
Stuart Clark's website is www.stuartclark.com, where you will find more information about his writing, fiction and non-fiction, his journalism and much more.
Tuesday, 8 July 2014
Susan Kaye Quinn guest post - release of Second Daughter
NEW RELEASE
Second Daughter (The Dharian Affairs #2)
Assassins, skyships, and royal intrigue...
Kindle, Kobo, AllRomance
Second Daughter is the second book in The Dharian Affairs trilogy (Third Daughter, Second Daughter, First Daughter). This steampunk-goes-to-Bollywood (Bollypunk!) romance takes place in an east-Indian-flavored alternate world filled with skyships, assassins, royal romance and intrigue.
Reviews of the first book, Third Daughter:
"The author fuses carriages, steam trains, airships and clockwork with the rich eastern culture that underlies Bollywood storytelling..." - Cherie Reich
“Third Daughter is vividly breathtaking. Quinn delivers royal intrigue, exotic locations, and sweeping romance. Not to be missed!” - Pavarti Tyler, author of Shadow on the Wall
ON SALE - 99cents until 7/21
Third Daughter (The Dharian Affairs #1)
Kindle, Nook, Kobo, iTunes, AllRomance
(also available in print)
The Third Daughter of the Queen wants her birthday to arrive so she'll be free to marry for love, but rumors of a new flying weapon may force her to accept a barbarian prince's proposal for a peace-brokering marriage. Desperate to marry the charming courtesan she loves, Aniri agrees to the prince's proposal as a subterfuge in order to spy on him, find the weapon, and hopefully avoid both war and an arranged marriage to a man she does not love.
NEW
Both books now have a map!
Speedy Tweets to Share:
NEW RELEASE: Second Daughter (Dharian Affairs #2) Assassins, skyships, royal intrigue #steampunk #fantasy #romance http://bit.ly/SDAmazon
WIN Gift Card and PAPERBACK Third Daughter (Dharian Affairs #1) #steampunk #fantasy #romance http://www.susankayequinn.com
Skyships, saber duels, royal romance: Third Daughter (Dharian Affairs#1) ON SALE 99cents http://bit.ly/ThirdDAmaz
Thank you so much for helping me get this book out in the world!
Win
paperback copy of Third Daughter
$10 Amazon Gift Card
Monday, 24 March 2014
Course Review: Introduction to Forensic Science
Here's Jo...
What better way to avoid writing my crime novel than spending six weeks following an introduction to forensic science. The main selling point was that the course could be completed with as little as three hours study per week. I completed the course with slightly less than that. Did I enjoy it? Yes. Did I get the most out of it? No.
The course was a mixture of videos, audio commentaries and links to articles that could be read to enhance and expand the course. Each week followed a specific topic with the first and last weeks being more of an overview. The course also had a case study which was based upon a real case. This showed how the evidence was gathered and then used to reach a conclusion as to who had committed the murder of a young woman in Scotland.
There was a week looking at fingerprints, or fingermarks as they are sometimes called, a week looking a DNA, one looking at drugs and their abuse and one looking at firearms. At the end of each week there was a pop quiz which was actually quite taxing and did mean that you had to have paid attention to the information you had been given.
I took this course from the point of view that I am writing a crime novel and I am an avid CSI fan. The overview it gave me was great and meant I now know where I am going wrong when I write something but not necessarily why. The extra reading helped to make the course accessible to people of different levels of competence. The chat rooms were very busy and it did give you a chance to understand the different laws within other countries.
I had two niggles. Firstly, two or three times there were live chats which I couldn’t attend because they were in the middle of the working day and this meant I missed out on that part of the learning experience. The second was I would have liked a little certificate to say I had sat this course, and I can get one. But first I must sit an exam and this will cost me £119. There are sixty one test centres in the UK and there is actually one within ten miles of where I live, but I am guessing I am one of the lucky ones. The other thing is I can’t see what value this certificate has. It doesn’t appear to carry any academic weight but on the basis I don’t need it, I haven’t bothered finding out it’s worth.
So, on the whole, a great little course with educated me in the facts behind the TV shows. I have already signed up for the next forensics course. Weirdly though the next course is run by Leicester University and the first was run by the University of Strathclyde. Hopefully they will not be going over old ground but I doubt they will have had time to adjust their course based upon feedback received from the introduction course.
Future Learn is a great way to access free online education but at the moment the courses seem to vary vastly in their content and enjoyability. Hopefully the great courses will quickly squeeze out the not so good and as it’s free why not pick a course that sounds fun and give it a go.
Jo Jenner regularly blogs at jojenner.blogspot.co.uk or catch up with her on twitter @jojenner40 or on facebook www.facebook.com/#!/jojennerauthor
The FutureLearn course 'Introduction to Forensic Science' was delivered by the University of Strathclyde from 6th Jan to 16th Feb 2014, and and the lead lecturer was Professor Jim Fraser who is Director of the Centre of Forensic Science.
Tuesday, 18 March 2014
Book Review: Taking Time by Ellie Garratt
From the Back Cover
A collection of dark science fiction stories, where time and space are not always as they first appear to be.
The future of humanity must be decided in Next Phase. Winning the Planetary Lottery is not as lucky as it first seems in Schrodinger's Gamble. An apocalypse and its aftermath threaten to tear one couple apart in Daiker's Children. In Life As I Know It a reclusive man finds both his heart and home invaded during an alien harvest. In Taking Time a vampire seeking shelter on a distant planet finds himself facing a very different kind of demon, after answering a frontier settlement's plea for help.
Stories range from flash fiction to novelette in length.
Taking Time and Other Science Fiction Stories
This is Ellie Garratt's second collection of short stories, and after enjoying her first collection so much I had high expectations of Taking Time. I wasn't disappointed. There is a shift in this collection both towards science fiction, and towards longer stories.
Once again, the author is taking you somewhere completely different, and she's come up with a selection of original and entertaining stories. There are five stories included in this collection, and every one of them left me with something new to contemplate.
Each story will prey on different fears or moral dilemmas, delve into different parts of your mind, and with every one Ellie Garratt strikes a chord. Whether or not you are a science fiction fan, you will be drawn into these beautifully written, clever and thought-provoking stories.
*
You can find Ellie Garratt at elliegarratt.blogspot.co.uk and you will find purchase links here.
Thursday, 13 March 2014
Book Review: The Third Daughter by Susan Kaye Quinn
From the back cover
The Third Daughter of the Queen wants her birthday to arrive so she'll be free to marry for love, but rumors of a new flying weapon may force her to accept a barbarian prince's proposal for a peace-brokering marriage. Desperate to marry the charming courtesan she loves, Aniri agrees to the prince's proposal as a subterfuge in order to spy on him, find the weapon, and hopefully avoid both war and an arranged marriage to a man she does not love.
Third Daughter is the first book in the The Dharian Affairs Trilogy (Third Daughter, Second Daughter, First Daughter). This steampunk-goes-to-Bollywood (Bollypunk!) romance that takes place in an east-Indian-flavored alternate world filled with skyships, saber duels, and lots of royal intrigue. And, of course, kissing.
The Third Daughter by Susan Kaye Quinn
This book is billed as 'steampunk-goes-to-Bollywood (Bollypunk!) romance', so what exactly is it? The author fuses carriages, steam trains, airships and clockwork with the rich eastern culture that underlies Bollywood storytelling, and together with royal intrigue, treachery, love and romance she combines the rich clothes and lush settings of court life with adventure in far off places. Everything is there, and the story cracks along at a pace which kept me gripped.
Aniri is faced with a dilemma. Should she follow her heart or do what is expected by the Queen, her mother. Indeed, what the Queen asks of her is no less than to secure the future security of the kingdom. The plot twists leave no-one unscathed, and we wonder just who can be trusted.
Aniri, is a plucky young lady, full of adventure and love. She has her flaws, though, and the result is endearing. If you enjoy a gripping, tense plot, lush settings and plenty of intrigue then this book is for you. I thoroughly enjoyed it, and very much look forward to the next book in this series.
Finally I have to mention the layout and formatting. The overall presentation of the book is awesome. Every page is more a work of art than merely a page of text. The presentation of this book is about as good as it gets.
*
You can find Susan Kaye Quinn at www.susankayequinn.com where you will also find purchase links.
Thursday, 6 March 2014
Analyzing The Universe - Blow by Blow
Week 1
In week 1 we have an introduction to the history of optical images and their nature, what it takes to make an astro-image, what information they provide and how they are formed. Light, energy and refraction. Lenses and optics.
We see how an x-ray image is formed and why this is different from optical image formation. How we perceive images when we look at them, and how this impacts the kind of images we want and the information we can get from them.
Finally we get an introduction to the free tool DS9, its features and use.
Week 2
In week 2 we begin an in-depth tour of DS9. We look at the supernova CAS A, which was the 'first light' observation from the Chandra X-Ray observatory, and the Coma cluster of galaxies. We look at how to use DS9 to compare the x-ray image with an optical image of the same object. CAS A and Coma are used to demonstrate some of the useful functionality of DS9 such as analysing the energy spectrum of an interesting area of the image.
Getting a bit more theoretical we look at how statistics can be used to add to the knowledge gained from our observations.
Next we look at atomic spectra, black body radiation and the Stephan-Boltzmann law relating luminosity, radius and temperature. We look at cosmic distances, using parallax for measurements, and how Cepheid variables can help us measure distances.
Week 3
In week 3 we look at the Hertzsprung-Russel diagram, how it helps us to classify stars and what it tells us about stellar evolution. We look in some detail at how stars evolve with time, and what different kinds of stars are out there.
We take an in-depth look at GK-Per, which is a double star in the Persesus constellation which went supernova in 1901. We use this as the basis for a discussion of white dwarves, and some periodic phenomena associated with their spectral properties.
Week 4
In week 4 we derive some of the useful formulae for describing circular motion. We go on to the Doppler shift and its detection when we observe binary stars whose orbital motion is aligned to make such observation possible.
We study the nature of pulsars using DS9 to analyse x-ray data from Cen X-3, observing and quantifying the periodicity of the luminosity in the x-ray data. We analyse the possible causes of the periodicity and what it can tell us about the nature of the pulsar. We observe the Doppler shift in the signal from Cen X-3, and together with our other conclusions this leads us to an understanding of Cen X-3 as an x-ray source orbiting a companion star.
We then go on to figure out what exactly Cen X-3 might be. Using our knowledge of the laws of circular motion we determine the mass of the object, and try to gain an insight into how big it is. We conclude that if it was a white dwarf, it is spinning so fast that it's gravity couldn't hold it together, but if it's a neutron star, its gravity would be sufficient.
We then go on to investigate what mechanism leads to the periodicity we've observed, in the process learning much more about the nature of Cen X-3, and pulsars.
We compare observations made at different periods in history to see that the behaviour of the object has changed over a period of tens of years. We analyse the data to seek an explanation for this.
In week 4 we learn a great deal about neutron stars and pulsars, and we fortify that knowledge with our own observations.
Week 5
In week 5 we look at what makes a star shine. We look at the x-ray object Cas-A and analyse optical spectra from different parts of the object. These observations help us towards a model of Cas-A as a type II (core collapse) supernova remnant in which the movement of material shows evidence of the shock waves resulting from the explosion.
Looking at the spectra from different parts of the object we also draw conclusions about what chemical elements are present and how they are distributed in the remnant.
We use DS9 to create an RGB image from the remnant in which red, green and blue each represent an energy band. By adjusting the energy bands and the bias and contrast for each colour we have considerable control over how we visualise the image. This gives us scope for a lot of experimentation in DS9.
In week 5 we learn a great deal about core collapse supernovae and supernova remnants, and we fortify that knowledge with our own observations. Week 6
In week 6 we begin with Cepheid variable stars – how and why they may be used to determine the distance to astronomical objects. With an accurate measure of distance it is possible to determine the size of an object from its angular size. We learn about Hubble's discovery that the further an object is from us the faster it is moving away from us – leading us to a determination of the Hubble constant for the expansion of the Universe and how this can be used to determine the age of the Universe. We see the relationship between red-shift and distance to an object.
We learn how this led to the discovery of quasars, which are more luminous than the brightest galaxies. We see also that quasars are only seen as distant objects, meaning they are a feature of the young Universe, and we consider why that might be.
We use DS9 to analyse data from the closest quasar, 3C 273, which is 2200 million light years from Earth. We see from our analysis that it is a trillion times more luminous than our sun, and we determine its size.
We see that some material appears to be moving at many times the speed of light, and we look at the explanation for the phenomenon.
We see the evidence of gravitational lensing, and the fact that it suggests that there is much more mass in the Universe than we can observe. We look at the evidence that the expansion of the Universe is accelerating, and we see that dark energy is one theory put forward to explain the evidence.
In week 6 we learn much about galaxy clusters and black holes.
Note
For a review of the course, and my conclusions, please see the previous article.
I took this course from 28th January to 25th February 2014
Monday, 3 March 2014
Book Review: Passing Time by Ellie Garratt
From the back cover
Nine dark fiction stories that may just give you nightmares. Dare you enter the world of the strange and macabre, where the passing of time is not always as straightforward as it seems?
A man lives to regret Passing Time. A father will do anything to save his son in Expiration Date. An author finds out her worst nightmare is back in The Devil’s Song. A woman gets more than the claim fee when she takes out vampire insurance in Luna Black.
In Dining in Hell, the Death Valley Diner becomes the wrong place to stop.
A serial killer adds another file to his collection in The Vegas Screamer. In Eating Mr. Bone, an undertaker could meet an unfortunate end. A con man meets his first ghost in Land of the Free, and will truth finally be set free in The Letter?
Nine stories originally published between 2010 and 2011. Stories range from very short to novelette.
Passing Time: Nine Short Tales of the Strange and Macabre
I only occasionally dip into short stories, preferring to get stuck into a full length novel rather than skip from story to story. However, when I do venture into the shorter, I sometimes come up trumps, and this book is one of those occasions.
The first thing that strikes me as a lover of books is the quality of the publication. I only wish all publishers would set such a high standard. Everything from the cover design to the internal formatting are a high quality showcase for the high quality writing it contains.
It is, as the subtitle suggests, a collection of nine short stories, and they certainly live up to their billing as strange and macabre. I have to say that the author has come up with some wonderfully twisted and bizarre ideas, all of which are executed in a thoroughly engaging style.
These are memorable stories. I highly recommend this book to any reader, and look forward to more from the same author.
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You can find Ellie Garratt at elliegarratt.blogspot.co.uk and you will find purchase links here.
Thursday, 27 February 2014
Analyzing The Universe – Course Review
Thursday, 6 February 2014
Steampunk With A Heart: Steampunk FAQ
Today I have the pleasure of hosting the Steampunk With A Heart blog tour with the Steampunk FAQ by authors Rie Sheridan Rose and Cindy Spencer Pape.
Then of course, there are the give-aways. There are books, M&Ms, steampunk jewellery and more, so read on...