Monday 31 March 2014

PARALLEL WORLDS: THE SCIENCE OF ALTERNATIVE UNIVERSES AND OUR FUTURE IN THE COSMOS by MICHIO KAKU


A Book Review byANDY FLEMING


The remit of this book is staggering – it is no less than the coverage of the development of cosmology from its beginnings in antiquity right up to the theory of the multiverse, and the fact that our universe may be just one of an infinite number, each possessing physical forces and constants with different strengths to ours. The fact that the publication is targeted at the lay person (who may have little knowledge of cosmology and astronomy), makes the remit even more remarkable.

Kaku is one of the co-founders of a branch of String Theory and as such, one may start to read the book with the misconception that its contents will be biased towards the perspective of this particular theory. However, this is not the case, and the reader is firstly treated to a commendably objective history of astronomy, classical physics and the Copernican/Galilean Revolution, relativity, quantum mechanics, string theory, and the discovery of dark energy and dark matter, along with some extremely well written explanations and diagrams.

The overriding power of modern cosmology in explaining the universe – the marriage of the study of large scale objects such as galaxies groups, with that of very small scale subatomic particles is a growing theme throughout the book, and includes a superb explanation of the Cosmic Microwave Background radiation, and culminates in a discussion of the Standard Model, Inflation, and the five eras of the development of our universe.

Wednesday 26 March 2014

STRENGTH OF GRAVITY HAS REMAINED CONSTANT FOR BILLIONS OF YEARS

Remains of a Type Ia supernovae (G299.2-2.9). Image Credit: X-ray: NASA/CXC/U.Texas/S. Park et al, ROSAT; Infrared: 2MASS/UMass/IPAC-Caltech/NASA/NSF.
byANDY FLEMING

Australian astronomers have combined all observations of supernovae ever made to determine that the strength of gravity has remained unchanged over the last nine billion years.

Newton's gravitational constant, known as G, describes the attractive force between two objects, together with the separation between them and their masses. It has been previously suggested that G could have been slowly changing over the 13.8 billion years since the Big Bang.

If G has been decreasing over time, this would mean that Earth's distance to the Sun was slightly larger in the past, meaning that we would experience longer seasons now compared to much earlier points in Earth's history.

But researchers at Swinburne University of Technology in Melbourne have now analysed the light given off by 580 supernova explosions in the nearby and far Universe and have shown that the strength of gravity has not changed.

Tuesday 25 March 2014

FLIPPING MAGNETIC ATTRACTION: DMR NETWORK, 00:00hrs THURSDAY

Graphic depicting the Earth's magnetosphere and the profound effect it has on protecting the biosphere from the Sun's charged particles.
byANDY FLEMING

It's another one of our planet's amazing attributes that makes life possible here.

It's called the magnetosphere and it is generated by the Earth's spinning molten core.

It is a gigantic magnetic field extending tens of thousands of miles in to space and it diverts solar radiation and atomic particles such as protons towards the planet's poles, in the process creating stunning auroral displays. 

More importantly the magnetosphere is responsible for protecting all life on the Earth from deadly solar radiation. It also prevents our planet from ending up like Mars, a dry, dessicated world that once was oceanic and wet, but whose molten core froze leading to the loss of its magnetosphere that in turn allowed the solar wind to destroy the Red Planet's atmosphere.

Sunday 23 March 2014

ASTRONOMY 101: THE MOON


Our Moon is far more important to all life on Earth than most people realise.  Simply illuminating the night sky or being responsible for ocean tides is of relatively little significance when one realises its true effect on the Earth and us.  It has been intrinsic to the very evolution of life itself, and by definition the appearance of homo sapiens!  And it's not hard to see why it is so important. 

The Moon with labelled 'seas' and craters.
To start with it is the only Moon of a major planet in the solar system that is so large relative to its parent planet, indeed many astronomers consider the Earth/Moon system to be a double or binary planetary system.  At 385,000 kilometres distant it is the closest celestial body to the Earth.

The Moon was created from the Earth itself, confirmed by the geological experiments undertaken during the NASA Apollo program.  Unlike the Earth, there is very little iron on its surface and it consists of terrestrial mantle material.

Friday 21 March 2014

ENJOY THE PASSION, BEAUTY AND JOY OF THE SEVEN SISTERS

The beautiful Seven Sisters or Pleiades star cluster in the constellation of Taurus, complete with labels marking the main stars visible to the naked eye. Credit: Anglo-Australian Observatory/Royal Observatory, Edinburgh.

byANDY FLEMING

There are certain objects in the night sky that paradoxically and almost counter-intuitively appear much better with the naked eyes or with ordinary common or garden binoculars rather than expensive telescopes. One such object still visible in the early March evening sky after dusk that also defies even the most appalling city and urban light pollution is the Seven Sisters or Pleiades open star cluster. With a prominent place in ancient mythology, it's perhaps one of the most popular astronomical targets for the beginner... after all most youngsters are either taught about this beautiful cluster of stars at home or at school. Some may also be familiar with the constellation from its appearance on the badge on the bonnet of Japanese Subaru cars: the manufacturer was named after the constellation.

Infact, The Pleiades cluster, otherwise known as Messier 45 far from containing the six or seven stars seen with the unaided eye actually contains hundreds, with many more becoming visible through binoculars. For those in the northern hemisphere, the cluster is above and to the right of Orion the Hunter as one faces south in the constellation of Taurus the Bull.

Thursday 20 March 2014

A DISCOVERY WITH PROFOUND GRAVITY

The 10-meter South Pole Telescope and the BICEP (Background Imaging of Cosmic Extragalactic Polarisation) Telescope are shown against the Milky Way. BICEP2 recently detected gravitational waves in the cosmic microwave background, a discovery that supports the cosmic inflation theory of how the universe began. (Image credit: Keith Vanderlinde, National Science Foundation)
Approximately fourteen billion years ago, our universe burst into existence in an extraordinary event that initiated the Big Bang. In an infinitesimally small fraction of a second, the universe expanded exponentially to a truly gargantuan size, inflating far in excess of the views of our most powerful telescopes. All this, of course, was just a theory.

Astronomers from the Background Imaging of Cosmic Extragalactic Polarisation (BICEP2) radio telescope at the South Pole have announced the first direct evidence for this cosmic inflation. Their data also represent the first images of gravitational waves, or ripples in space-time, a major prediction of Einstein’s 1915 Theory of General Relativity, in effect his theory of gravity. They have been described as the "first tremors of the Big Bang." Finally, the data confirm a deep connection between the (until now) irreconcilable pillars of modern physics: quantum mechanics and general relativity itself.



"Detecting this signal is one of the most important goals in cosmology today. A lot of work by a lot of people has led up to this point," said John Kovac (Harvard-Smithsonian Centre for Astrophysics), leader of the BICEP2 collaboration.

These ground-breaking results came from observations by the BICEP2 telescope of the cosmic microwave background - a faint glow left over from the Big Bang. Tiny fluctuations in this afterglow provide clues to conditions in the early universe. For example, small differences in temperature across the sky show where parts of the universe were denser, eventually condensing into became polarized too.

Wednesday 19 March 2014

RELATIVELY SPEAKING, THE TIME FOR RELATIVITY IS 01:00hrs UTC THURSDAY!

Nobel Prize winner Albert Einstein displaying his relativistic tongue later in life!
E=mc2. It's the name of the world’s most famous equation.

Everyone’s heard of it, and yet virtually no one has the faintest clue what it's about, or of its paramount importance to our civilisation, and come to think of it our existence at all.

I’m either very foolish or brave, but at 01:00hrs UTC/GMT on Thursday March 20 (tomorrow)/ 8.00pm Eastern, I’m going to endeavour to give a 101 crash course on Einstein’s (1905) scientific paper entitled On the Electrodynamics of Moving Bodies, more popularly known as his Theory of Special Relativity. It was derived from the equations of electromagnetism developed by James Clerk Maxwell in the nineteenth century.

On a positive note, Special Relativity is magnitudes easier than Einstein’s theory of gravity, or General Relativity!

Add caption
In the forthcoming programme I try to condense the essence of relativistic speeds as required for interstellar space travel down to just five minutes! And all in plain English lay person’s terms too, without the need for time dilation or Lorentz length contractions!

To learn how it may be possible to travel to the stars in no time at all using mass converted to pure energy with perhaps warp drives thrown in too listen to the next Podcast-UFO to be broadcast on ArtBell’s Dark Matter Radio Network at 01:00hrs UTC/GMT on Thursday March 20. Click the links or logo to listen! Wish me luck!

FEEL THE PB&J (PASSION, BEAUTY, AND JOY) OF THE COSMOS? SHARE IT!


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ASTRONOMY 101: THE SUN


The Sun is an ordinary star and is the brightest object in our sky.  As such you should certainly never look at the Sun directly and certainly never through binoculars or a telescope.

It’s one of more than one hundred billion stars that populate our Milky Way galaxy.  It’s a gigantic ball of hydrogen 870,000 miles wide.  The Sun has a diameter 109 times that of the Earth and is one third of a million times its mass.



The Sun collapsed from a cloud of hydrogen gas approximately 4.5 billion years ago.  The pressure and temperature of the hydrogen in its centre became so great that nuclear fusion chain reactions started where 600,000,000 tons of hydrogen are converted into helium each second.  In the process, under Einstein’s famous equation E equals M C squared, a small amount of mass is lost as energy including light.

This energy is what we and all living things depend on for our existence.  The visible light we see from the Sun takes eight minutes to travel the 93 million miles before it reaches our eyes and is only a small part of the energy released from our star.  Its nuclear reactions also produce vast quantities of ultra violet light along with deadly x-rays and gamma ray radiation.  Indeed if it wasn’t for the Earth’s protective magnetic field this radiation would strip off our life-giving atmosphere and all life on Earth would be burnt to a crisp.

Temperatures at the core of our star Sun reach a staggering 10 million degrees Celsius, but it’s surface is less hot at about 5,000 degrees Celsius.

The Sun consists of approximately 75% hydrogen and 25% helium and is halfway through its life.  In 4.5 billion years it will run out of its hydrogen fuel and will start to fuse helium into even heavier elements.  In the process it will become a bloated Red Giant star that will engulf the orbit of the inner planets.  Finally it will puff off its outer layers as a planetary nebula before contracting to the size of the Earth.  It will have become a white dwarf star made of pure carbon diamond… a cosmic ember.  I don’t think however we’ll be around to see it!

FEEL THE PB&J (PASSION, BEAUTY, AND JOY) OF THE COSMOS? SHARE IT!


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Sunday 16 March 2014

THE MAGIC FURNACE: THE SEARCH FOR THE ORIGIN OF ATOMS by MARCUS CHOWN

Nuclear fusion has long been the holy grail of energy production. It is the process going on inside the sun, but importantly has created most of the heavier elements in the universe. Image credit:SOHO-EIT Consortium, ESA, NASA.
A Book Review byANDY FLEMING

'If the atoms that make up the world around us could tell their stories, each and every one of them would sing a tale to dwarf the greatest epics of literature', Chown proclaims in the prologue of this book. The work is his attempt to chronicle humankind’s efforts, commencing with Democritus in Ancient Greece over two millennia ago, to discover what the smallest constituents of matter are, and from where they came.

It’s an enthralling, comprehensive history lesson in the development of astronomy and atomic physics, encapsulating key moments and discoveries in the search to answer the question of why 98% of the mass of visible matter in the universe is composed of hydrogen and helium, and where the remaining two per cent of ‘metals’ came from.

Friday 14 March 2014

SPACE, SANITY, PREJUDICE AND UFOs

Graphical representation of one of the ubiquitous black triangle UFO sightings, this time near Amsterdam, Holland and during daylight hours, Black triangles feature in a large number of reported sightings.
ByANDY FLEMING


Immediately your friends, acquaintances and colleagues discover that your hobby is amateur astronomy, you can prepare for the two main predictable questions: what do you think about black holes, and have you ever witnessed a UFO? Well here’s what I think: I love black holes though I’ve never directly witnessed such a beast, and yes, I’ve seen a UFO that may or may not have originated on another world. Oh, and I believe in them both despite never observing the former with my own eyeballs. There you are, a sceptical amateur astronomer who is prepared to place his lack of professional reputation and total lack of funding on the line and lose nothing apart from any meagre credibility in the astronomical community.

My friends’ former question about black holes is, of course a perfectly commendable scientific query about an actual astronomical entity, although still the subject of much speculation rather than fact. On the other hand, the enquiry about UFOs raises another subject altogether. It’s commonly referred to, often in a derogatory fashion as ‘ufology’ and involves a whole battery of educational disciplines including, physics, astronomy, biology, sociology, psychology, history and religion, not to mention some aeronautical engineering, just thrown in for some good measure. Just like religion on its own, it may well be that astronomers, whether amateur or professional are not necessarily the best qualified individuals to comment and encroach on another field of research.

Granted, ufology generally conjures up a whole smorgasbord of fact, fiction, wild speculation, the paranormal, the super-natural, hearsay, conspiracy theories, vivid imaginings, plain old charlatanry and sheer profiteering by certain so-called ‘experts’, but these are not the exclusive domains of ‘ufology’. It may well turn out that what we think of as our current scientific grasp on reality (whatever that word means) may not be so firm after all. There is, of course the whole cosmos set out before us. But there is also a whole cosmos set out within. As Carl Sagan (1980) noted we are the Cosmos with consciousness. In defining reality, we really need to establish which reality we’re talking about as the cosmos has surprises and characteristics that look increasingly beyond our measure.

On the subject of black holes, astronomers are qualified to make valid professional comments as their field of study has gathered overwhelming (albeit indirect) observational proof of the existence of them, and Einstein’s General Theory of Relativity, one of the foundations of modern physics, has predicted their existence since 1915. Indeed, most astronomers now believe that there is a black hole of super-massive proportions at the centre of each galaxy, including our very own Milky Way. The enormous velocities of stars at its centre as they rotate around something with a gargantuan mass is indirect evidence from mathematical calculations that this object, known as Sagittarius A* (pronounced ‘A-star') must be something with the density of a black hole.

Leaving astronomy to one side for now, my thoughts, views and beliefs about UFOs, unlike my studies of black holes go one step further. I’ve actually seen one, in the flesh, perhaps not up close and personal, but a “Close Encounter of the First Kind” in the night sky nonetheless. So what did it look like, this object over my home area of Teesside in north east England? Well, I’ve made a graphical representation for illustration purposes using free Stellarium Planetarium software, a favourite tool for amateur astronomers. In the true spirit of astronomy and science one has to be sceptical before making extraordinary claims. Such claims do after all, require extraordinary evidence.

Before I go further, I’d better repeat the commonly held definition of the acronym 'UFO': a guided spacecraft of non-human origin, emanating from either beneath the Earth, its oceans or an alien world. The proper definition of 'natural or unnatural unidentified aerial phenomena' is somewhat more useful.  As I mentioned earlier, it is probable that what I saw may very much have been of terrestrial origin, but as an amateur astronomer I can certainly discount what I know it wasn't.

Wednesday 12 March 2014

KEPLER'S 715 EXOPLANET BONANZA

This image from NASA's Kepler mission shows the field of view possessed by the space telescope. In particular, an expansive star-rich patch of sky in the constellations Cygnus and Lyra stretching across 100 square degrees, or the equivalent of two side-by-side dips of Ursa Major, the Plough or Big Dipper. 

A cluster of stars, called NGC 6791, and a star with a known planet, called TrES-2, are outlined. The cluster is eight billion years old, and located 13,000 light-years from Earth. It is called an open cluster because its stars are loosely bound and have started to spread out. TrES-2 is a hot Jupiter-like planet known to cross in front of, or transit, its star every 2.5 days. Kepler has spent four years hunting for transiting planets that are as small as Earth. (Credit: NASA/Ames/JPL-Caltech).

The important news in the exoplanet hunting community at the moment is that NASA has recently announced that its Kepler space telescope mission has discovered no fewer than 715 new planets in multiple-planet systems much like our own solar system.

Most of them are smaller than Neptune, which is almost four times the size of Earth. This
discovery marks a significant increase in the number of known small-sized planets more akin to the Earth. John Grunsfeld, associate administrator for NASA's Science Mission Directorate said, "That these new planets and solar systems look somewhat like our own, and portend to a great future when we have the James Webb Space Telescope in space to characterize the new worlds.”

Since the discovery of the first planets outside our solar system roughly two decades ago, verification has been a laborious planet-by-planet process. Now, scientists have a statistical technique called multiplicity that can be applied to many planets at once, when they are found in systems that harbour more than one planet around the same star. It relies in part on the logic of probability, it is a process that ultimately verifies multiple planet candidates in bulk and is unveiling a veritable bonanza of new worlds." These multiple-planet systems are fertile grounds for studying individual planets and the configuration of planetary neighbourhoods. This provides clues to planet formation.

Sunday 9 March 2014

A BIRTH RIGHT RECLAIMED: THE P,B and J UNDER A VELVET DARK SKY

 
The Triangulum Galaxy (Messier Object 33, or M33). In a dark sky location under excellent seeing conditions you may just be able to see this galaxy which has very low surface luninousity with the naked eye. Image Credit: NASA, Robert Gendler, Subaru Telescope (NAOJ)
ByANDY and DAVID FLEMING

It is one of life’s subtle ironies that thanks to our industry and high technology that in some ways brings so many benefits to our everyday lives, one of the greatest of all natural wonders, has been lost to the majority of our planet’s human population. We’re talking, of course about a velvet-black night sky dotted with countless stars, nebulae, and galaxies. It's the key to sharing the P,B and J (the Passion, Beauty and Joy) that typifies the emotions felt when identifying our place in space and time (thanks to Bill Nye the Science and Planetary Guy for inventing this apt phrase).

Truth be told, it is not our technology that denies us this most beautiful of natural spectacles, but our shameful and profligate waste of our natural resources and energy. Namely, of course, it is light pollution, coupled with industrial pollutants, vehicle emissions and particulates.

It is a severe problem here in the River Tees Valley in north east England where I'm based. The industry at Teesmouth illuminates our horizons with the glare of a thousand artificial sodium vapour suns. If you’re lucky, and located in a dark, secluded corner of this conurbation of one million inhabitants, you can just about succeed with the “Ursa Minor test” and pick out all of the stars in that constellation down to Magnitude 5 with the naked eye (albeit with averted vision). We won’t be unduly negative about our abode however – there are still wonders aplenty to be seen from our back garden including double stars, the planets, galaxies and planetary nebulae and of course the stunning and lovely Great Nebula in the Sword of Orion.

But they are washed out, shadows of themselves even through a telescope, reminiscent of a television set with the contrast dramatically reduced. They are awe-inspiring, but we have doubtless been robbed of much of the awe. An initial tour of the gorgeous black skies of a location such as the North Yorkshire Moors National Park therefore creates a soaring sense of wonder and awe – an uplifting surge of sheer excitement that will never be forgotten. Of course, an enjoyable tour of anything requires a good and learned tour guide with a well-planned itinerary, and in this respect we were lucky enough to share this memorable late October evening with one of local astronomy group's most astronomically literate members, Rob.

Monday 3 March 2014

THE LOST WORLD OF BARNARD'S STAR

Fomalhaut b is a confirmed, directly-imaged extrasolar object and candidate planet orbiting the A-type main-sequence star Fomalhaut, approximately 25 light-years away in the constellation of Piscis Austrinus. The object was initially announced in 2008 and confirmed as real in 2012 from images taken with the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope. It has a 2,000-year highly elliptical orbit and as of May 25, 2013 it is approximately 110 Astronomical Units (AU – Sun-Earth distances) from its parent star.


byANDY FLEMING

These days, it is accepted as a scientific fact that we live in a universe teeming with planets orbiting other stars. Indeed, as of 24 September, there are 490 worlds that we know of orbiting stars other than our Sun. Detecting these planets has become a routine voyage of discovery engaging well-tested and accepted methods.

The primary methods include radial velocity (Doppler displacement of spectral lines in the star's light due to the star 'wobbling' as it orbits the common centre of mass of the star and its planetary companion), and the transit method (a dip in starlight as an exoplanet moves across the disc of the star, thus reducing the amount of starlight). Other successful methods include astrometry, where there are minuscule changes over time in a star's precise co-ordinates in the night sky because of its orbit around the stellar system's centre of mass, and microlensing (a bending of light from a distant star due to the gravity of the foreground star and its associated planet – see below).



Finally, of course, there's the most spectacular method, one that will become more important as detectors improve -- that of direct imaging, as in the cases of Fomalhaut b and Beta Pictoris b and associated stellar debris discs, as observed by NASA's Hubble Space Telescope (HST).