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Archive for September, 2014

This story caught my attention recently, it pertains to the earliest stars in the Universe. These earliest stars have not yet been directly observed, this story is about observations of unusual stars in our own Galaxy which are believed to be formed from the first generation of stars.



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In the early Universe, the only elements created were hydrogen and helium. All the elements heavier than hydrogen and helium have been formed in the interior of stars, and more recent generations of stars contain these heavier elements along with hydrogen and helium formed in the early Universe. As the earliest stars would have been formed from only hydrogen and helium, and because of the absence of an effect called “line blanketing”, this earliest generation of stars could form with masses much greater than subsequent generations. Theoreticians believe that masses beyond 100 solar masses were possible in the first generation of stars.

Theoretical models also suggest that such super-massive stars would have ended their lives in something called a pair-instabiliuty supernova, which is different from the supernova which signals the end of the high mass stars we see around us today. In a pair-instabiliuty supernova, the models suggest that no neutron star or black hole is left at the centre, instead all of the material in the exploding star is sent back into the interstellar medium.

Researchers using the Japanese Subaru telescope in Hawaii have been taking spectra of stars in our Galaxy which show a particularly low level of iron, a level which is about 1,000 times less than in our Sun. Such a low iron level suggests that the stars belong to an earlier generation than our Sun, which is believed to be a third-generation star. The stars they have been observing are not first generation stars, but probably second generation. They have found one star, named SDSS J0018-0939 (it was found to be low in iron by the Sloan Digital Sky Survey) to have a very unusual spectrum. The ratio of the abundance of various elements in the star’s spectrum suggests that it could have been formed from a pair-instabiliuty supernova, and thus be the direct descendent of a first generation star.

The original paper, entitled “A chemical signature of first-generation very massive stars” can be found here.

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Jumièges abbey

In the Seine valley just to the west of Rouen is a beautiful abbey in a small town called Jumièges.



The abbey is Jumièges

The abbey in Jumièges




The abbey was founded in 654, but most of what one sees today was built in the late 10th and early 11th Century. The Abbey was consecrated in the presence of William the Conqueror in 1067, who was also Duke of Normandy.



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At number 21 in BBC Radio 2’s list of the 100 greatest guitar riffs is “All Right Now” by Free.



At number 21 in BBC Radio 2's list of the 100 greatest guitar riffs is "All Right Now" by Free.

At number 21 in BBC Radio 2’s list of the 100 greatest guitar riffs is “All Right Now” by Free.




The song was released in May 1970 and got to number 2 in the Disunited Kingdom singles charts, and to number 4 in the US singles charts.


Whoa-oh-oh-oh-woha
There she stood in the street
Smilin’ from her head to her feet;

I said, “Hey, what is this?
Now maybe, baby,
Maybe she’s in need of a kiss.”

I said, “Hey, what’s your name?
Maybe we can see things the same.

“Now don’t you wait, or hesitate.
Let’s move before they raise the parking rate.”

All right now, baby, it’s a-all right now.
All right now, baby, it’s a-all right now.

(Let me tell you now)
I took her home to my place,
Watchin’ every move on her face;

She said, “Look, what’s your game?
Are you tryin’ to put me to shame?”

I said “Slow, don’t go so fast, don’t you think that love can last?”

She said, “Love, Lord above,
Now you’re tryin’ to trick me in love.”

All right now, baby, it’s a-all right now.
All right now, baby, it’s a-all right now


Here is a video of this song. Enjoy!


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Bayeux is, of course, most famous for its wonderful tapestry, which is well worth a visit. But, it is also a beautiful town (city?), and has a wonderful cathedral. The present cathedral was consecrated in 1077, some 11 years after William the Conqueror had killed Harold at the Battle of Hastings.

The cathedral in Bayeux, consecrated in 1077

The cathedral in Bayeux, consecrated in 1077

Another claim to fame for Bayeux is that it was the first town to be liberated by the Allies after the D-Day landings. Only one day after the landings on the 6th of June 1944, Bayeux was liberated by the Allied forces.

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At number 2 in Rolling Stone Magazine’s 10 best Bob Dylan songs is “A Hard Rain’s A-Gonna Fall” which Dylan recorded in December 1962. It was released on his 1963 album “The Freewheelin’ Bob Dylan”, and is the 6th (and last) track on the first side.



At number 2 in Rolling Stone Magazine's 10 greatest Bob Dylan songs is "A Hard Rain's A-Gonna Fall"

At number 2 in Rolling Stone Magazine’s 10 greatest Bob Dylan songs is “A Hard Rain’s A-Gonna Fall”



The lyrics to this song are available here on Bob Dylan’s official website, as well as short audio clips of the original album version and other, alternative, versions on other albums. I find it hard to believe that Dylan was only 21 when he wrote this song, it has such dark and foreboding lyrics it seems to me like the work of a much older person.


Oh, where have you been, my blue-eyed son?
Oh, where have you been, my darling young one?
I’ve stumbled on the side of twelve misty mountains
I’ve walked and I’ve crawled on six crooked highways
I’ve stepped in the middle of seven sad forests
I’ve been out in front of a dozen dead oceans
I’ve been ten thousand miles in the mouth of a graveyard
And it’s a hard, and it’s a hard, it’s a hard, and it’s a hard
And it’s a hard rain’s a-gonna fall

Oh, what did you see, my blue-eyed son?
Oh, what did you see, my darling young one?
I saw a newborn baby with wild wolves all around it
I saw a highway of diamonds with nobody on it
I saw a black branch with blood that kept drippin’
I saw a room full of men with their hammers a-bleedin’
I saw a white ladder all covered with water
I saw ten thousand talkers whose tongues were all broken
I saw guns and sharp swords in the hands of young children
And it’s a hard, and it’s a hard, it’s a hard, it’s a hard
And it’s a hard rain’s a-gonna fall

And what did you hear, my blue-eyed son?
And what did you hear, my darling young one?
I heard the sound of a thunder, it roared out a warnin’
Heard the roar of a wave that could drown the whole world
Heard one hundred drummers whose hands were a-blazin’
Heard ten thousand whisperin’ and nobody listenin’
Heard one person starve, I heard many people laughin’
Heard the song of a poet who died in the gutter
Heard the sound of a clown who cried in the alley
And it’s a hard, and it’s a hard, it’s a hard, it’s a hard
And it’s a hard rain’s a-gonna fall

Oh, who did you meet, my blue-eyed son?
Who did you meet, my darling young one?
I met a young child beside a dead pony
I met a white man who walked a black dog
I met a young woman whose body was burning
I met a young girl, she gave me a rainbow
I met one man who was wounded in love
I met another man who was wounded with hatred
And it’s a hard, it’s a hard, it’s a hard, it’s a hard
It’s a hard rain’s a-gonna fall

Oh, what’ll you do now, my blue-eyed son?
Oh, what’ll you do now, my darling young one?
I’m a-goin’ back out ’fore the rain starts a-fallin’
I’ll walk to the depths of the deepest black forest
Where the people are many and their hands are all empty
Where the pellets of poison are flooding their waters
Where the home in the valley meets the damp dirty prison
Where the executioner’s face is always well hidden
Where hunger is ugly, where souls are forgotten
Where black is the color, where none is the number
And I’ll tell it and think it and speak it and breathe it
And reflect it from the mountain so all souls can see it
Then I’ll stand on the ocean until I start sinkin’
But I’ll know my song well before I start singin’
And it’s a hard, it’s a hard, it’s a hard, it’s a hard
It’s a hard rain’s a-gonna fall


Here is a live version of this amazing song from 1963. Enjoy!


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One of the outstanding problems in astrophysics in the 1940s was how were the elements created. In the 1920s it was realised by Cecilia Payne-Gaposchkin in her PhD work that the Sun was mainly composed of hydrogen. Then, spectral analysis of others stars and the gases of the interstellar medium led astrophycisits to realise that the Universe was composed mainly of hydrogen (about 75\%), with the remainder being helium (about 24\%), and only 1\% or so being all the other elements (oxygen, nitrogen, carbon etc.)

In the mid 1940s Russian-American physicist George Gamow started thinking about how the elements originated, and he developed a theory with his student Ralph Alpher that they were all created in the early Universe when, he argued, it would have been hotter and denser than it currently is. He published his famous paper “The Origin of Chemical Elements” in Physical Review in 1948, adding renowned physicist Hans Bethe’s name to the author list as a joke so that the paper would have the author list Alpher, Bethe, Gamow (alpha,beta, gamma, geddit? There is also a story that he tried to get his post-doctoral researcher Bob Herman to change his last name to “Delta” 😛 )



The famous Alpher, Bethe, Gamow paper on the origin of the chemical elements

The famous Alpher, Bethe, Gamow paper, “The Origin of Chemical Elements”, which appeared in Physical Review in 1948.



In fact, Bethe played no part in writing the paper, but he was happy for Gamow to include his name for Gamow’s little joke. In this paper, Gamow and Alpher argued that all the elements were created in the early Universe. However, when others went through the details it was realised that the numbers did not add up, the Universe expanded and cooled too quickly for all the elements to be created in this way. Although it was possible for hydrogen and helium to be created in the first few minutes of the Universe, by the time the Universe was a few minutes old it had become too cool and the density too low to form the heavier elements beyond helium. Part of the reason for heavier elements not being built up in these first few minutes was due to something called the deuterium bottleneck, which I will explain in a future blog.

In the 1950s an alternative theory for the origin of the elements was put forward by Fred Hoyle and his collaborators Willy Fowler and Geoffrey and Margaret Burbidge. In a series of papers they argued that the elements had been built up in the interior of stars, the most famous of this series of papers was a 1957 paper entitled “Synthesis of the Elements in Stars” which appeared in Reviews of Modern Physics. Hoyle was the main advocate of a theory called the Steady State Theory which he had first proposed in 1948. This was a competing theory to the hot big bang theory, and so of course Hoyle did not believe any elements had been formed in a hot, dense early Universe as he did not believe such a Universe ever existed.



The first page of Burbidge teal.'s famous paper Synthesis of the Elements in Stars published in Reviews of Modern Physics in 1957

The first page of Burbidge teal.’s famous paper “Synthesis of the Elements in Stars” published in Reviews of Modern Physics in 1957



Again, as with Alpher and Gamow’s theory, detailed calculations found flaws in the Burbidge etal. theory. Although it could explain the creation of elements beyond helium, it was not possible to create enough helium in stars to account for the approximately 25\% found to be present in the Universe today. In part 2 of this blog, I will explain what our current understanding is of the origin of the elements in the proportions we observe in the Universe, and what the deuterium bottleneck is and why it is important.

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Recently my wife and I went to Normandy. Whilst winding through the backroads of Normandy from Cherbourg to le Mont Saint Michel (we got off the motorway on purpose), we stumbled across this lovely windmill – moulin à vent du Cotentin, which has recently been restored.



The moulin à vent du Cotentin

The moulin à vent du Cotentin



Of course it helped that we had beautiful weather with cloudless skies, but if you get the chance to visit this lovely building it is well worth it.



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In this post I blogged about BBC Radio 2’s list of the 100 greatest guitar riffs. At number 23 in the list is “Sweet Home Alabama” by Lynyrd Skynyrd. The song was released in 1974 and got to number 8 in the US singles charts.



"Sweet Home Alabama" is Lynyrd Skynyrd's best known song

“Sweet Home Alabama” is Lynyrd Skynyrd’s best known song



It is a song I have known since I was a teenager, and in fact is the only song I know by Lynyrd Skynyrd. It certainly has a memorable guitar riff, and also some great lyrics.


Big wheels keep on turning
Carry me home to see my kin
Singing songs about the south-land
I miss ‘ole’ ‘bamy once again
And I think it’s a sin

Well I heard Mister Young sing about her
Well I heard ole Neil put her down
Well, I hope Neil Young will remember
A southern man don’t need him around any how

Sweet home Alabama
Where the skies are so blue
Sweet home Alabama
Lord, I’m coming home to you

In Birmingham they love the Gov’nor
Now we all did what we could do
Now Watergate does not bother me
Does your conscience bother you?
Tell the truth

Sweet home Alabama
Where the skies are so blue
Sweet home Alabama
Lord, I’m coming home to you

Now Muscle Shoals has got the Swampers
And they’ve been known to pick a song or two
Lord they get me off so much
They pick me up when I’m feeling blue
Now how bout you?

Sweet home Alabama
Where the skies are so blue
Sweet home Alabama
Lord, I’m coming home to you


Here is a video of this great song. Enjoy!


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I first visited le Mont Saint Michel the day after the total solar eclipse which passed through Normandy in August 1999. It would seem that most of the people who had flocked to Normandy to see the eclipse had had the same idea, I don’t think I have ever been in such a large crowd before, and sadly it made moving around the island at one’s own pace impossible.

Since that visit, I have been back to le Mont Saint Michel twice, but have not been back onto the island itself in either of these two more recent visits. When I was there in 1999, one could drive one’s car quite close to the island and just park somewhere on the side of the road, but things have changed. Now, there is a large car park with a visitor centre about 1.5km from the island, and no cars are allowed any closer than that. To get to the island you can either walk, or take one of the free shuttle buses which run every 10 minutes or so.

Between this car park and the island are some shops and galleries and eating places. There are also these “pop cows”, which certainly brighten up the place!



Pop cows at le Mont Saint Michel

Pop cows at le Mont Saint Michel




Here is a gallery of all the cows I managed to spot, but there may be some I missed 😉



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At number 3 in Rolling Stone Magazine’s 10 best Bob Dylan songs is his 1975 song “Tangled up in Blue”. The song appears on “Blood on the Tracks”, which is one of my favourite Dylan albums, I blogged about that fantastic album here. The album is listed at number 16 in Rolling Stone’s 500 greatest albums. “Tangled up in Blue” is the opening track on “Blood on the Tracks”, and it sets the tone for this album which is full of songs about heartbreak and loss.



At number 3 in Rolling Stone Magazine's 10 greatest Bob Dylan songs is "Tangled Up In Blue"

At number 3 in Rolling Stone Magazine’s 10 greatest Bob Dylan songs is “Tangled Up In Blue”



“Tangled up in Blue” is an epic journey through Dylan’s relationship with his then-estranged wife Sarah, from their meeting to their separation. However, Dylan is telling a story here, so not all the imagery he creates in this amazing song is factual. The lyrics below are from Bob Dylan’s official website, and the page also contains an audio clip of the original version of this song, as well as several alternative versions.


Early one mornin’ the sun was shinin’
I was layin’ in bed
Wond’rin’ if she’d changed at all
If her hair was still red
Her folks they said our lives together
Sure was gonna be rough
They never did like Mama’s homemade dress
Papa’s bankbook wasn’t big enough
And I was standin’ on the side of the road
Rain fallin’ on my shoes
Heading out for the East Coast
Lord knows I’ve paid some dues gettin’ through
Tangled up in blue

She was married when we first met
Soon to be divorced
I helped her out of a jam, I guess
But I used a little too much force
We drove that car as far as we could
Abandoned it out West
Split up on a dark sad night
Both agreeing it was best
She turned around to look at me
As I was walkin’ away
I heard her say over my shoulder
“We’ll meet again someday on the avenue”
Tangled up in blue

I had a job in the great north woods
Working as a cook for a spell
But I never did like it all that much
And one day the ax just fell
So I drifted down to New Orleans
Where I happened to be employed
Workin’ for a while on a fishin’ boat
Right outside of Delacroix
But all the while I was alone
The past was close behind
I seen a lot of women
But she never escaped my mind, and I just grew
Tangled up in blue

She was workin’ in a topless place
And I stopped in for a beer
I just kept lookin’ at the side of her face
In the spotlight so clear
And later on as the crowd thinned out
I’s just about to do the same
She was standing there in back of my chair
Said to me, “Don’t I know your name?”
I muttered somethin’ underneath my breath
She studied the lines on my face
I must admit I felt a little uneasy
When she bent down to tie the laces of my shoe
Tangled up in blue

She lit a burner on the stove
And offered me a pipe
“I thought you’d never say hello,” she said
“You look like the silent type”
Then she opened up a book of poems
And handed it to me
Written by an Italian poet
From the thirteenth century
And every one of them words rang true
And glowed like burnin’ coal
Pourin’ off of every page
Like it was written in my soul from me to you
Tangled up in blue

I lived with them on Montague Street
In a basement down the stairs
There was music in the cafés at night
And revolution in the air
Then he started into dealing with slaves
And something inside of him died
She had to sell everything she owned
And froze up inside
And when finally the bottom fell out
I became withdrawn
The only thing I knew how to do
Was to keep on keepin’ on like a bird that flew
Tangled up in blue

So now I’m goin’ back again
I got to get to her somehow
All the people we used to know
They’re an illusion to me now
Some are mathematicians
Some are carpenters’ wives
Don’t know how it all got started
I don’t know what they’re doin’ with their lives
But me, I’m still on the road
Headin’ for another joint
We always did feel the same
We just saw it from a different point of view
Tangled up in blue


I have found a live version of this song. Although I do not like this live version as much as the original studio version, the original studio version is not available on YouTube. Enjoy!





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