The OAS Word July 2013
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The OAS Word July 2013
This Month Contents OAS News – Alastair Leith FRAS .......................................................................................................... 3 OAS Group....................................................................................................................................... 4 Online Astronomy Society Academy............................................................................................... 4 Online Astronomy Society Planetarium .......................................................................................... 6 Novice Trials of Solar Imaging – by Aprill Harper................................................................................ 7 What You See Isn’t Always What You Get .......................................................................................... 9 OAS juniors – Light Pollution by Catherine Leith .............................................................................. 12 Your Images ...................................................................................................................................... 14 SPACEFEST V Tucson, Arizona. – Sam Mundell ................................................................................ 17 Cosmology – What’s That All About?................................................................................................ 21
Welcome to the following members of staff who have joined us this month Andy Paterson – Joins as a moderator in the main OAS Group Mark Woodland FRAS– Joins as writer for the mag Antonia Santiago – Joins as writer for the mag Aprill Harper – Joins as writer for the mag Gemma Lavender – Joins as associate editor
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The OAS Word July 2013
OAS News – Alastair Leith FRAS Welcome to the July’s edition of The OAS Word, apologies for the missed month, we needed to do some restructuring and changes within both the organisation and the magazine as a whole. The Online Astronomy Society continues to grow at an amazing pace, almost 250 new members a month joining the Facebook page, which is an amazing feat, no idea where they all come from. We have diversified as well with more sub-groups, which are now offered as below Astronomy for Novices This is our beginners section for people to post questions OAS Visual Astronomers Group This is run by Michael Nicholls and caters for the visual astronomer, so more sketches than images for this one. OAS Spectroscopy This group specialises in spectroscopy, very interesting field to be in, looking at what stars and stuff are made of from the light OAS Radio Astronomy Group Just as the name sounds, it looks at radio astronomy; I believe they are even looking to build their own radio telescope! More on that later OAS Astronomy Shed This group was suggested by Fred Higgingbottom (thanks Fred) and looks at the applications of DIY to Astronomy. OAS Asteroid Hunters Group Dedicated to the hunt for asteroids working with the Panstarrs project, so far, we have 5 provisional to our group! A little dormant at the moment as the next campaign does not begin until September OAS Solar Observers and Imaging Group Just started 28th June, this is our youngest group dedicated to solar astronomy, in fact anything to do with the Sun.
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The OAS Word July 2013
To many the above might seem a little eccentric, why have we done it this way? The answer is simple; it is the closest we can get to a forum on Facebook to cater for the various aspects of astronomy. Our oldest and largest group is simply too large to cater for every field of astronomy. So it’s not our way of trying to be greedy of dominate anything it’s the easiest way we can grow. Perhaps we should be called the Online Facebook Astronomy Group!
OAS Group Some of you may have seen this page, and wonder what it is all about, I mean don’t we have enough pages! Simple answer to the questions is yes, too many. Which is why we’ve invested in a new page to represent and advertise ALL the group does so it will be announced from the one conduit. This is also why we have a new website www.oasgroup.co.uk (sounds a little corporate?) but the aim of this website is to act as a central hub for all our other activities, it is where we will advertise from and blog from. Our other sites will remain, as this is where detailed information can be obtained. We wanted simple, easy to navigate sites that would simply not be possible if we merged the lot onto one. The oasgroup website is a compromise and will be the main site we use for all our corporate activities Speaking of which
Online Astronomy Society Academy GCSE Astronomy We are pleased to say that the GCSE Astronomy course by distance learning has kicked off like a dream. Some of you may remember that we teamed with Dr Johanna Jarvis of Astronomy Tuition to deliver GCSE Astronomy. Dr Jarvis, herself a professional astronomer, has been a GCSE Astronomy Tutor for many years, but now delivers her course online! We closed in June with 21 Students! We are now open to students who wish to enrol 2014/15 We are planning other courses for release around late 2013, so watch this space Do not forget we also offer our other courses Imaging with a webcam £12
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The OAS Word July 2013
This course looks at how easy it is to image with a webcam, we use a Toucam Pro 2+ and our Trusty Meade (could be any telescope though) to show how easy it is to capture and process imaging of a planet (in this case Saturn) Imaging with a PST £12 In this course, we look at capturing a solar image using a canon DSLR 1000D and a Coronado Personal Solar Telescope.
Beginning Spectroscopy £12 Looking at getting into some serious science? This course will demonstrate how to gather and analyse starlight to find out what stuff stars are made of! OR invest in a year’s passport for £30 (Passport does NOT include access to GCSE Astronomy) All courses include beginning astronomy and Cosmology plus any updates we make to either course. £45 gets you a license to Astro Photography Tool, which was featured in this month’s Sky at Night mag, cover disc Meanwhile thanks to Immersive Theatres, we have just taken delivery of a 6-inch Newtonian Reflector which we plan to use to create more training courses and run workshops.
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The OAS Word July 2013
We are now running workshops for people wishing to develop skills in astronomy here in the Midlands, please drop me a line OASAcademy@gmail.com for those interested
Online Astronomy Society Planetarium Talks are given for key stages 1-4 all in line with the National Curriculum. We offer live shows to cater for both young and old.
A setup of our dome
The dome is available for school or corporate hire, offering live presentations please email oasplanetarium@gmail.com for more details or visit our website www.oasplanetarium.com New Certification System coming out We did not want to just throw courses at you; we want to add more value to them. More on that next month!
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The OAS Word July 2013
Novice Trials of Solar Imaging – by Aprill Harper Like most amateur astronomers in the UK and being new to the hobby the first summer is a struggle. We look longingly at the clear skies and beautiful sunsets, and then realise we need to get all our stuff together for the following morning’s trek to work and get to bed. In the UK, summer daylight and astronomy are not normally good bedfellows. I can see how it would be easy to pack the equipment away until the winter and in the meantime other can hobbies creep in and take over our lives. This could effortlessly replace your focus and make astronomy a forgotten dusty interest with equipment taking up space in the spare room / garage / loft. For exactly this reason we acquired the scope we have. I however, took this as an opportunity to switch to solar astronomy – after all the Sun is up for longer in summer. This does require some modifications. Unlike the purpose built solar scopes, which have all the appropriate filters the standard astronomical scope, requires a solar filter; we do get all the warnings (and here again to remind you): Permanent eye damage can result from looking at the Sun directly, or through a camera viewfinder, or with binoculars or a telescope even when only a thin crescent of the Sun is visible. Never look at the Sun unless you have adequate eye protection! Homemade and on a budget, the first mission was to then make the solar filter – in two parts, using good old fashioned “Blue Peter” methods. The 1 st stage was to make the head of the filter made with the Baader photographic filter film (not suitable for visual observation as it does not attenuate the lights as much - they do also manufacture visual filter film) and cardboard. I used the instructions supplied with the film. The second stage was to make the cardboard ring which sat around the circumference of the scope, and to which the head of the filter was attached. My first images, even using the maximum shutter speed and minimal ISO were over exposed. I had worked this image through Photoshop and was able to identify a few sunspots so was initially pleased, but this would not suffice in the long term. Clearly – I needed to reduce the amount of light that was getting through. It can be said that for looking at the night sky (local or deep) buying as big a scope as you can afford is the way to go….but now I can see why it is advocated that for solar imaging, smaller could be better. 7
The OAS Word July 2013
It was recommended to me that I should consider a front-end aperture reduction device made of cardboard. Really simple device and just attached to my solar filter (interference fit), that obscured a majority of the scopes light capturing ability. I set up in the garden, running the scope though a dummy alignment (the Meade needed to be aligned, even if this is not a true or accurate alignment so that I could use its tacking facility). It can be a bit tricky to “find” the Sun, so tracking is a real aid for imaging. And Meade DO NOT include the Sun in their Autostar suite (for obviously safety reasons) – so initial alignment to the Sun is done manually. This is the took that reduction spotted identified; further
last image I evening. A of glare; spots and and with no processing.
The overall cost of this solar filter was less than £60 and about 2½ hours – a low budget solution. Depending on your scope type there are pre-made filter available (common for 6” and 8”). It is rewarding to observe for yourself and validate your observations; subsequently once you have captured your image (with spots) you can get more information regarding your observations from such websites as: http://sohowww.nascom.nasa.gov/sunspots/ and: http://sidc.oma.be/LatestSWData/LatestSWData.php Maybe we will see your images too.
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The OAS Word July 2013
What You See Isn’t Always What You Get – by Antonia Santiago As we gaze out into the night sky with the naked eye we can easily admire a panorama littered with twinkly diamonds. There are some celestial bodies that we have come to know well. Our Sun, Orion’s Belt and the Big Dipper are familiar to us. This is why it always astounds me to think that, although I can see objects in the sky, in actuality, some may no longer be there. The appearance of light when we flick on a switch seems instantaneous to us and yet in space, it’s anything but. The speed of light has a finite number of 299,792,458 meters per second. The distance between your eyes and the light bulb is relatively small. Light traveling at this high speed, through such a short distance, seems to appear instant. Not so when light travels across the enormity of space. A light year is equal to 9.4605284 × 10 meters. That is the distance light travels through a vacuum in one year. It’s easier for us to speak in terms of years when referring to light travel in space because the distances are incredibly vast. Now, when I tell you that M16, otherwise known as the Eagle Nebula, measures 70 light years by 55 light years, you can get a better idea of, not only scale, but of distance as well. Incidentally, the Eagle Nebula itself is about 7,000 light years away from Earth. If you could travel at light’s blazing speed, it would still take you approximately 7,000 years to reach the Eagle Nebula. The Pillars of Creation
Within the Eagle Nebula is found the Pillars of Creation. The Pillars of Creation are easily recognizable by their characteristic finger like appearance. First photographed in 1995 by the Hubble telescope, these protrusions consist of dense molecular hydrogen gas and dust, with portions being dense enough for star formation. It is believed that one of these stars has already gone supernova. A new infrared image shot by the Spitzer Telescope in 2007 revealed a previously unseen wave of fast traveling scorched dust headed towards the pillars. It is believed that this wave was caused by the supernova blast and had already reached the pillars thus destroying them. The supernova blast is thought to have happened around 6,000 years ago. If this is true, it means that it would take approximately another 1,000 years for the light from the pillars to reach us and confirm our suspicions. As of right now, if you look through a decent telescope and point it towards the Eagle Nebula, you will see the Pillars of Creation intact in their beauty.
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The OAS Word July 2013
The Universe cannot, all at once, be seen as it is at this very moment. What we actually see is a view at some point in the past. Even our Sun’s light is eight minutes old by the time it reaches us. This gives us the incredible opportunity to study gaseous structures, celestial bodies, and other things found in space, and it tells us a lot about our Universe now. Hubble Ultra Deep Field 2004
Hubble eXtreme Deep Field 2012
The Hubble Ultra Deep Field is an image released in 2004 and taken within the constellation Fornax. This image goes back 13,000 billion years. The Hubble eXtreme Deep Field released in 2012 goes back 13.2 billion years! 10
The OAS Word July 2013
It is safe for us to say that much of what is shown no longer exists as captured by these images, and yet, there they are, providing a wealth of information and a stunning sight. So, the next time you wish you could travel through time, just pick up a decent telescope and look out into the far reaches of our Universe.
Would you like to advertise here? Please email onlineastronomysociety@gmail.com for more details
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The OAS Word July 2013
OAS juniors – Light Pollution by Catherine Leith OAS Juniors aims to provide interesting articles targeted at our younger audience. Children are the future of astronomy and OAS hopes to not just educate but inspire the astronomers of the next generation. This month we look at ‌ Light pollution
This is how the United Kingdom looks from space. To many people this is beautiful, a real spectacle, but to astronomers it is a sorry sight indeed. The many streetlights and spotlights that we see every night on our streets and motorways cause this display of brightness. These days, a large amount of professional astronomy is done outside of our country, mainly due to weather but also the effects of light pollution. Your parents may well be members of a local amateur astronomy society, and it is groups like these that are trying to inform the local authorities as to the effect that these lights have on our skies. Light pollution has grown to such an extent that it threatens the remaining dark skies in the rural areas of the UK. So, what is light pollution all about? There are three main types of light pollution; the most common in astronomy is called Sky Glow and we will be concentrating on this in the article. This orange sky colour can be seen over the cities and towns near where you live. It is caused by light travelling through the atmosphere that then gets scattered by water droplets in the air or dust and pollution from factories. This glow can be seen from miles around and spreads to the darker rural areas. This bright orange colour hides distant stars, especially those low in the sky, and makes them invisible to our eyes. The orange colour of the glow is due to the streetlights on our roads and motorways. The problem is that all the light is aimed directly upwards from the light fitting as well as being 12
The OAS Word July 2013
reflected off whatever is being lit – the road, pavement or building. It is not just the streetlights, which are the problem, many buildings, and massive floodlights that shine directly up into our night sky needlessly light up structures throughout our cities. So, what is being done about this? The Campaign for Dark Skies is one of the main groups heading the fight against light pollution. It is a section of the British Astronomical Association (BAA) and was created by a group of astronomers in 1990. They became concerned about the amount of ill-directed light damaging the night sky and wish to see the right amount of light and only where it is needed. The Campaign to Protect Rural England (CPRE) also disagrees with the effects of lights on our stars and considers the dark sky to be one of the things that has defined the countryside. These organisations do not wish to see streetlights abolished, they understand the need for them, they just want to see streetlights redesigned to direct all the light downwards onto the ground where it is needed. So, how can you help? If your parents are a member of a local astronomy group ask them about light pollution and what their society is doing about it. Also be thoughtful about the lighting inside your own home, put lights off when not in use and if there are outdoor lights on outside then remind parents to turn them off. Thank you for reading about light pollution, join us next month when we look at the fascinating sight of a lunar eclipse!
We are always looking for new articles for the mag if anyone wishes to contribute
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The OAS Word July 2013
Your Images Images of Saturn Dave Kershaw from OAS Group
Ed Jon Holts first posting to OAS Group M42 Orion Nebula
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The OAS Word July 2013
Dave Evans Sunspots April and May 2013 Composite of daily images of each month by Dave Evans Data: Mauna Loa Observatory
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The OAS Word July 2013
This is my drawing of the Sun on the 23rd June 2013 at 19.22 pm BST.IT was made with a 40 mm PST H-Alpha scope with 15x. I had to set the scope up on a tripod due to where the Sun was but it was very windy and was blowing the scope about all the place. There was also about 6 very large complex plage areas visible but with my lack of artistic ability, I had no chance of drawing them correctly. I did another drawing to the weather not being very good for imaging. Can’t wait for the next day so I can image again. Michael Nichol
Mobile Planetarium Dome for hire, please see www.oasplanetariumcom for more details
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The OAS Word July 2013
SPACEFEST V Tucson, Arizona. – Sam Mundell Christmas 2012. Whilst most of the population was eagerly anticipating Christmas Day, myself and quite a few others around the world were excitedly awaiting the arrival of Dec 26th. For this was the day tickets for Spacefest V went on sale, and that was better than Christmas itself! Spacefest V, a gathering of astronauts, scientists, authors, artists and space fans from around the world, was a feast for the senses. Where else could you hear astronauts share their experiences of walking on the Moon, see amazing space artwork, and handle meteorites? This year, Spacefest V was held in Tucson, Arizona, at the beautiful Starr Pass Resort from 24-27 May. The surrounding hills, covered in tall cacti, made the perfect backdrop to what was to be the most exciting week of my life. Before I left the UK, I had formed many friendships on Facebook and Twitter with people who shared my passion for all things space and astronomy. We even had our own Facebook Group where we got to know each other and shared invaluable travel tips. Little did I realise that these online friendships would culminate in real friendships that will last a lifetime. After a long and exhausting trip across The Pond and US, I finally arrived in Tucson in the early hours of 23rd May. I met my roommates for the week, Jeanette Lamb, astrophotographer and amateur astronomer, and Kate Doolan, author of ‘Fallen Astronauts’. Both had travelled from Australia for the event. I didn’t attend the VIP mixer and art show that evening, but rumours were abound as the night wore on, that Professor Brian Cox had arrived, and my tiredness quickly evaporated….he was here!! Friday morning soon arrived the anticipation of the day’s events was almost electric. I started my morning with talks by a panel of authors, including Colin Burgess, Jay Gallentineand Kate Doolan. Each giving an insight into their own works, with the research needed to produce them. One of the highlights of Friday was meeting and talking to Fred Haise, LMP from Apollo 13 and Commander in the Space Shuttle approach and landing tests. As he signed my photo of him taken during the near-disaster of the Apollo 13 mission, he tried to remember who took it, saying he wasn’t sure if it was Jim Lovell or Jack Swigert, but he thought it was probably 17
The OAS Word July 2013
Jim. I was in awe of this remarkable man, and having my photo taken with him was just incredible!
Friday evening bought us the long-awaited lectures by two world-renowned scientists, Dr Carolyn Porco, Planetary Scientist and imaging team leader for the Cassini-Huygens spacecraft, and our very own Professor Brian Cox, who needs no introduction! Dr Porco enthralled the audience with some ‘hot off the press’and unpublished findings of Saturn and Enceledus. We were privileged to see some stunning images taken by Cassini, each one more beautiful than the last. This was science at its most magnificent, and each one of us there knew how lucky we were to be listening to Dr Porco. Professor Brian Cox took to the stage, and gave a fascinating talk on his work at the LHC, and covered the complex yet fascinating subject of proton physics. As well as talking about the links between theoretical physics and cosmology, he expressed the importance of the continued investment in space exploration and science, to furious nods of heads.
Saturday gave us day, with many struggling to pick lecture to attend! morning 18
another full attendees which I spent the wandering
The OAS Word July 2013
around the main ballroom, enjoying the space artwork by artists such as Lucy West-Binnell, Kim Poor, Dr Dan Durda and Astronaut Alan Bean. I bought some meteorite fragments from one of the ‘Meteorite Men’ Geoff Notkin, and tried to take in the fact I was sharing breathing space with JimMcDivitt, Richard Gordon, Dave Scott, Ed Mitchell, Scott Carpenter, Walt Cunningham and Bruce McCandless to name but a few! I also attended the lecture by the ‘Bad Astronomer’ Phil Plait. To a packed room, he gave an outstanding talk on Mars, and the landing of the Curiosity Rover. Interspaced with stunning visuals and videos, his passion was evident as he captivated us with a guide to the work MSL is doing on the red planet. Saturday evening saw some guests attend the VIP Banquet. Those of us who didn’t attend, made the most of the clear Tucson night skies before the Moon rose, at the Star Party. Held on the lawn away from the main hotel, we were able to look through a number of telescopes, enjoying the sight of Saturn, with experts on hand to guide us through the night sky. Onto Sunday and the ultimate in panel talks, The Apollo Astronauts Panel hosted by Professor Cox. The line-up of Walt Cunningham (Apollo7), JimMcDivitt(Gemini 4,Apollo 7), Richard Gordon(Gemini 11,Apollo 12), Fred Haise(Apollo 13, Shuttle ALT), Ed Mitchell(Apollo 14) and Bruce McCandless (STS41B,STS31) was one of those moments that will be forever etched in the memories of those of us fortunate enough to be there. One by one, each of these great men shared their incredible experiences, captivating their audience who hung onto their every word. They reminisced about successful and unsuccessful missions, talked about the future of space exploration, encouraged children to aim for the moon and beyond, answered questions, laughed, joked and high fived each other, and we the audience, were lucky enough to be there for the ride.
Next up was Nick Howes, astronomer and comet hunter. He talked passionately about the two comets, which transformed his life. Comet C2007Q3, discovered by Donna Burton at the Siding Springs Observatory in 2007, fragmented whilst Nick was imaging it with the Faulkes telescope a few years ago. He described how this event, and the subsequent media attention, catapulted Nick into his role as pro-am programme manager for Faulkes. He then talked about his role on the EPOXI campaign, which led to him working on two research papers, and the very successful asteroid hunt with a high school student. He told us 19
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about ‘Project Snoopy’, the hunt for the Apollo 10 lunar module, informing us that the data for finding it is huge. Nick now works as a research associate with the Lowell Observatory’s LARI project, amongst the many other NASA/ESA and magazine writing jobs he’s engaged in. I also had the honour of meeting Gene Cernan that afternoon. The last man to step foot on the surface on the Moon! We chatted about my children, and he was thrilled to hear that my youngest son Zac, has Gene as one of his middle names, in his honour- Photograph dutifully signed to his namesake! Sitting next to him for a photograph, this great man turned to me and said “come on, let’s show Zac that us two oldies met one day”. That made my day!!
The talk by Geoff Notkin, one of the ‘Meteorite Men’ was fantastic. He explained about the best hunting grounds for meteorites, with places with little or no vegetation/water, such as deserts and dry lake beds being the best types. However, he has searched for them in areas of dense forest, and even water, with some success. He believes that there are meteorites on the ocean bed, and jokingly asked if anyone could get him a submarine….! But a word of warning…if you are ever lucky enough to meet him…don’t call him a Meteor hunter, that’s guaranteed to annoy him! Sunday night was the last night for some of the ‘Spacefesters’, and we enjoyed a ‘SpaceJam’ by band ‘Top Dead Center’, with special appearances from Geoff Notkin on drums, and author Andrew Chaikin on guitar and lead vocals. And that was it. Although Spacefest officially finished on Monday, people were leaving, going onto new adventures across the States. For all of us who attended, it was a life changing experience. We were overwhelmed by who we met, by who we heard speak. We came away knowing we had experienced the extraordinary, and we have all vowed to return to the US next year for SPACEFESTVI.
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The OAS Word July 2013
Cosmology – What’s That All About? Written by Mark Woodland FRAS So, Cosmology is my current field of study (along with Astrophysics) but I think that it is somewhat of a mysterious subject to most. What do Cosmologists do? What is involved in Cosmology? What is the point? Well hopefully I shall try to shed some of the mystery….. What IS Cosmology? So, the Oxford English Dictionary defines “Cosmology” as; “The science of the origin, and development of the universe." So, what we are studying in Cosmology, is the Universe as a whole. Where it came from, and where is it going? We are looking at trying to constrain the fundamental parameters that govern the universe (the Matter, Radiation and Dark Matter energy densities) and to try to figure out how the universe is moving. Space, its big, its dark, and its fast… So, as we all know, space is big. I mean REALLY big! Our current best estimates of just how big are in the order of 93 billion light years (1Ly is the distance travelled by light (at ) per year) This is known as the observable horizon. It is likely that in actual fact, space is far larger than this, but the observable horizon as the name suggests is the limit of where we can observe with current techniques.
Figure 1 CMB Map from PLANK
The CMB (Cosmic Microwave Background) actually is the current edge of the observable universe. This is what is known as the surface of last scattering and is a baby picture of the universe. Those of you who are familiar with astronomy are likely thinking “now hold on there one minute, the universe is only 13.8 billion years old, how it can be 93 billion light years across?” Well, that is an interesting question in itself. The answer is deceptively simple. Light travels at a fixed speed (as mentioned above, and as stipulated by Einstein’s Special
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Relativity) BUT space itself has no limit on how fast it can expand, that’s why we have 93 billion light-years worth of room, in only 13.8 billion years. 1 Cup Dark Energy, 1 Cup Matter, bake for 13 billion years… So, as I mentioned before, there are 4 main “parameters” which Cosmologists spend their time trying to constrain. The Energy Density Parameters of Matter, Radiation and Dark Energy. The fourth parameter is what is known as the “Hubble Parameter” named after the famous (and rather crotchety Edwin Hubble) which is a measure of the rate of expansion of the universe. This Hubble parameter is derived from the density parameters. What the Hubble parameter tells us, is that the universe is expanding. Not only is it expanding, but it is actually accelerating too! The current, most popular explanation for this is due to the mysterious dark energy (not to be confused with dark matter, as they share nothing in common, but the word dark in their name) So, where is this taking our universe? A Date with Fate… In an expanding, accelerating universe, it has been postulated that a possible outcome is, what is whimsically known as the “Big Tear” where the universe literally expands to a point where it rips apart. There is no need to worry about this impending fate however, this will happen long after the universe has cooled to freezing, and all the atoms have split apart due to the expanse of space. I’m an Astronomer, why do I care about Cosmology?... Cosmology has many far-reaching implications for the astronomer, too much in fact to go into in detail. However, the most well know is Redshift. This is the light equivalent of the speeding ambulance. As it approaches its pitch increases, and as it passes, the pitch decreases, (relative to you standing at the side of the road.) For light, there is no change in pitch, there is a change in frequency. An object moving away from us, will appear red, and an object moving toward us, blue. This is a key feature in astronomy, as it enables us to calculate the speed at which objects (like the Andromeda galaxy for instance) is moving away from us. It also gives us a way to give create a cosmological time scale. What’s the Date, Mr Hubble?... The furthest away galaxies we can observe with current technology, are at redshifts (z) of around 12. The surface of last scattering (the baby picture of the universe) is at z=1000. So when we are looking back, we are not only looking back in time, but we are also looking back at a time when the universe was very much smaller than it is now. As the galaxies move away from us, the light emitted by them is stretched (due to the stretching of space-time) which changes the frequency. Edwin Hubble was one of the first astronomers (not definitively the first however) to actually recognise that the universe WAS expanding. (It was widely accepted pre 1920 that the universe was static. To such a point that Albert Einstein when fiddling with his equations actually generated a fiddle factor to
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The OAS Word July 2013 cancel out the expansion he predicted. He was later quoted as saying “it was the greatest blunder of my life” but there isn’t actually any proof he did say this.) This fiddle factor that Einstein included in his equation he named “The Cosmological Constant” and as it happens we know it today, as the Dark Energy Density Parameter. So, we have come full circle. From the birth of the universe, some 13.8 billion years ago, through the expanding universe. We have been red shifted, blue shifted, gravitationally red shifted, and spotted by Hubble moving away from us, and ended up in a chance meeting with Einstein.
References: http://oxforddictionaries.com/definition/english/cosmology?q=Cosmology
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