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## Dros Gymru’n Gwlad – Dafydd Iwan (song)

Today I thought I would blog about this beautiful song (hymn), “Dros Gymru’n Gwlad” (For Wales, our country), written by the Reverend Lewis Valentine, and here performed by Dafydd Iwan. It is sometimes referred to as Wales’ second national anthem. This version of the song is, in fact, entitled “Gweddi Dros Gymru” (A Prayer for Wales) by Dafydd Iwan; but it is the same song, just with a different (and maybe more apt) title.

“Gweddi dros Gymru” (Prayer for Wales) appeared on Dafydd Iwan’s 1986 album “Gwinllan a Roddwyd” (A vineyard was given).

I will blog next week about who Lewis Valentine was, because he holds a particular place in Welsh history for an act of defiance he committed in 1936 along with DJ Williams and Saunders Lewis. But, today I will just concentrate on this song/hymn.
“Dros Gymru’n Gwlad” is usually set to the tune of Sibelius’ Finlandia, as it is in the video I include below.

Here are the words (in Welsh)

Y winllan wen a roed i’n gofal ni;
D’amddiffyn cryf a’i cadwo’n ffyddlon byth,
A boed i’r gwir a’r glân gae1 ynddi nyth;
Er mwyn dy Fab a’i prynodd iddo’i hun,
O! crea hi yn Gymru ar dy lun.

O! deued dydd pan fo awelon Duw
Yn chwythu eto dros ein herwau gwyw,
A’r crindir cras dan ras cawodydd nef
Yn erddi Crist, yn ffrwythlon iddo Ef;
A’n heniaith fwyn â gorfoleddus hoen
Yn seinio fry haeddiannau’r Addfwyn Oen.

And now for my translation. As always, I am not going to attempt to retain any rhyme or meter, just translate the words as best I can; so that you get the meaning of what Lewis Valentine was trying to say in his song/hymn.

For Wales our country, O Father I raise a wail,
This pure vineyard which was given to us to care for;
May You protect it vigorously and keep it forever faithful,
And let the true and the pure find in her a nest;
For your Son who bought it for himself,
Oh! create a Wales in Your image.

Oh! Let there come a day when the breezes of God
Are once again blowing over our wilted acres,
And the awful wasteland under the grace of showers from heaven
Gardens of Christ, fruitful to Him;
And her old sweet language with a cheerful vigour
Ringing out on high, the deserves of the Gentle Lamb.

Here is an alternative translation which I found. It is far more poetic and less clumsy than mine, but less true to what Lewis Valentine was actually saying in his lyrics.

For Wales our land O Father hear our prayer,
This blessed vineyard granted to our care;
May you protect her always faithfully,
And prosper here all truth and purity;
For your Son’s sake who bought us with His blood,
O make our Wales in your own image Lord.

O come the day when o’er our barren land
Reviving winds blow sent from God’s own hand,
As grace pours down on parched and arid sand
We will bear fruit for Christ by his command,
Come with one voice and gentle vigour sing
The virtues of our gentle Lamb and King

Here is a video I have created on YouTube of Dafydd Iwan’s version of this song/hymn.

Had you heard of this song before?

## What is the redshift of the Cosmic Microwave Background (CMB)?

Last week, as I mentioned in this blog here, I had an article on the Cosmic Microwave Background’s accidental discovery in 1965 published in The Conversation. Here is a link to the article. As of writing this, there have been two questions/comments. One was from what I, quite frankly, refer to as a religious nutter, although that may be a bit harsh! But, the second comment/question by a Mark Robson was very interesting, so I thought I would blog the answer here.

This article on the Cosmic Microwave Background was published in The Conversation last Thursday (23rd July 2015)

Mark asked how we know the redshift of the CMB if it has no emission or absorption lines, which is the usual way to determine redshifts of e.g. stars and galaxies. I decided that the answer deserves its own blogpost – so here it is.

## How does the CMB come about

As I explain in more detail in my book on the CMB, the origin of the CMB is from the time that the Universe had cooled enough so that hydrogen atoms could form from the sea of protons and electrons that existed in the early Universe. Prior to when the CMB was “created”, the temperature was too high for hydrogen atoms to exist; electrons were prevented from combining with protons to form atoms because the energy of the photons in the Universe’s radiation (given by $E=h \nu$ where $\nu$ is the frequency) and of the thermal energy of the electrons was high enough to ionise any hydrogen atoms that did form. But, as the Universe expanded it cooled.

In fact, the relationship between the Universe’s size and its temperature is very simple; if $a(t)$ represents the size of the Universe at time $t$, then the temperature $T$ at time $t$ is just given by

$T(t) \propto \frac{ 1 }{ a(t) }$

This means that, as the Universe expands, the temperature just decreases in inverse proportion to its size. Double the size of the Universe, and the temperature will halve.

When the Universe had cooled to about 3,000K it was cool enough for the electrons to finally combine with the protons and form neutral hydrogen. At this temperature the photons were not energetic enough to ionise any hydrogen atoms, and the electrons had lost enough thermal energy that they too could not ionise electrons bound to protons. Finally, for the first time in the Universe’s history, neutral hydrogen atoms could form.

For reasons that I have never properly understood, astronomers and cosmologists tend to call this event recombination, although really it was combination, without the ‘re’ as it was happening for the first time. A term I prefer more is decoupling, it is when matter and radiation in the Universe decoupled, and the radiation was free to travel through the Universe. Before decoupling, the photons could not travel very far before they scattered off free electrons; after decoupling they were free to travel and this is the radiation we see as the CMB.

## The current temperature of the CMB

It was shown by Richard Tolman in 1934 in a book entitled Relativity, Thermodynamics, and Cosmology that a blackbody will retain its blackbody spectrum as the Universe expands; so the blackbody produced at the time of decoupling will have retained its blackbody spectrum through to the current epoch. But, because the Universe has expanded, the peak of the spectrum will have been stretched by the expansion of space (so it is not correct to think of the CMB spectrum as having cooled down, rather than space has expanded and stretched its peak emission to a lower temperature). The peak of a blackbody spectrum is related to its temperature in a very precise way, it is given by Wien’s displacement law, which I blogged about here.

In 1990 the FIRAS instrument on the NASA satellite COBE (COsmic Background Explorer) measured the spectrum of the CMB to high precision, and found it to be currently at a temperature of $2.725 \text{ Kelvin}$ (as an aside, the spectrum measured by FIRAS was the most perfect blackbody spectrum ever observed in nature).

The spectrum of the CMB as measured by the FIRAS instrument on COBE in 1990. It is the most perfect blackbody spectrum in nature ever observed. The error bars are four hundred times larger than normal, just so one can see them!

It is thus easy to calculate the current redshift of the CMB, it is given by

$z \text{ (redshift)} = \frac{3000}{2.725} = 1100$

and “voilà”, that is the redshift of the CMB.  Simples 😉

## The 100 best Beatles songs – number 49 – The Night Before

At number 49 in Rolling Stone Magazine’s 100 greatest Beatles songs is “The Night Before”, from their 1965 album and movie Help. It is very much a Paul McCartney song, with Lennon’s only contribution being the harmonies, and playing electric piano on the song. In the movie, the song is performed on Salisbury Plain, surrounded by tanks.

At number 49 in Rolling Stone Magazine’s list of the 100 greatest Beatles songs is “The Night Before”

“The Night Before” is the second track on the first side of the album Help, sandwiched between two Lennon songs, “Help” and “You’ve Got To Hide Your Love Away”.

We said our goodbyes, ah, the night before
Love was in your eyes, ah, the night before
Now today I find you have changed your mind
Treat me like you did the night before

Were you telling lies, ah, the night before?
Was I so unwise, ah, the night before?
When I held you near you were so sincere
Treat me like you did the night before

Last night is a night I will remember you by
When I think of things we did it makes me wanna cry

We said our goodbye, ah, the night before
Love was in your eyes, ah, the night before
Now today I find you have changed your mind
Treat me like you did the night before

Yes

When I held you near you were so sincere
Treat me like you did the night before

Last night is a night I will remember you by
When I think of things we did it makes me wanna cry

Were you telling lies, ah, the night before?
Was I so unwise, ah, the night before?
When I held you near you were so sincere
Treat me like you did the night before
Like the night before

Here is a video of this great song. Enjoy!

## The CMB: how an accidental discovery became the key to understanding the universe

Over the last couple of weeks I have been writing about the Cosmic Microwave Background, as this month of July marks the 50th anniversary since the paper announcing its discovery was published. In this blog here I showed the original 1948 paper in which Ralph Alpher and Robert Hermann predicted its existence, and in this blog here, I re-posted something that I had written back in April 2013, before I had started research for the book I have published on the CMB.

Today I had been planning to write about its accidental discovery by Bell Labs astronomers Arno Penzias and Robert Wilson, but on Thursday of last week I had the following article published in The Conversation, if you follow this link you can read the original article. This article obviates the need for me to blog about the history of the discovery, you may as well just read it in The Conversation.

This article on the Cosmic Microwave Background was published in The Conversation last Thursday (23rd July 2015)

However, what is contained in this article is a summary of an even-more fascinating story, which you can read about in all its wonderful detail in my book, which can be bought directly from Springer, or from other booksellers such as Amazon.

My book “The Cosmic Microwave Background – how it changed our understanding of the Universe” is published by Springer and can be found by following this link.

To finish up this series on the CMB and its discovery, next week I will write about the Penzias and Wilson paper, and the accompanying paper by Robert Dicke and his Princeton team which attempted to explain the observation that Penzias and Wilson had made.

## Froome wins the Tour de France for the second time

Yesterday (Sunday the 26th July), Chris Froome won the Tour de France for the second time, having also won it in 2013. He won by one of the narrowest margins in recent history, with Colombia’s Nairo Quintana only 72 seconds behind him. Had Quintana not had a very poor ride on the second day of the 19-stage tour, when he lost over one and a half minutes to Froome, it may well have been Quintana winning the 2015 tour.

Chris Froome won the Tour de France for the second time, having also won in 2013.

Two things have struck me about this year’s tour. Let me first talk about the good – the penultimate stage up Alpe d’Huez, the most legendary climb in Tour de France history. With Quintana being a climbing specialist, Froome was in real danger of losing his overall lead to the Colombian. In an epic ride up the tortuous hairpins (“switch-backs” for my American reader(s) ) of this fearsome stage, Quintana attacked again and again, and Froome and his Sky teammates did all they could to make sure the gap that the Colombian opened up was not too great. It was mesmerising TV, with the sheer determination of Froome’s face evident as he dug in to make sure he did not lose too much time to the prolific mountain climber. Although Quintana halved Froome’s lead, it was not enough to surpass him in the General Classification, and Froome knew at the top of the mountain that he had won the Tour.

Now let me talk about the bad – the way that certain elements of the French press and public have treated Froome. It is appalling. He has had urine thrown at him, been spat at countless times, and why? Because the French don’t like him? I am a little unsure whether Britain should be claiming that Froome is British, given that he was born in Kenya and grew up in South Africa; but whatever his nationality he deserves some respect from the cycling press and fans. Surely we should be applauding cyclists like Froome and Bradley Wiggins, who ride drug-free and are trying to help cycling regain its reputation as a reformed sport after the debacle of Lance Armstrong and the institutionalised doping of which he was the most prominent example. Why some elements are so anti-Froome is beyond my comprehension, he comes across as humble and hardworking; not the kind of brash over-confidence that Armstrong exhibited.

Now we can move on to the most exciting three months of sport of 2015 – the Rugby World Cup! Wales have their first warm-up match against Ireland on the 8th of August in Cardiff, and I will be blogging about that on the 10th. I can’t wait!!!!

## Woman in Chains – Tears for Fears (song)

Today I thought I would share “Woman in Chains” by Tears for Fears. I blogged here about their album Seeds of Love when I shared its title track Sowing the Seeds of Love. For me, along with that song, “Woman in Chains”  is the  other great song on a pretty good album.

Woman in Chains” features Phil Collins (of Genesis) on drums, and was released in 1989 and got to number 26 in the Disunited Kingdom singles charts and to 36 in the U.S. It is particularly noteworthy for the singing of Oleta Adams, whom the band had discovered in 1985 singing in a hotel bar in Kansas City.

You better love loving and you better behave
You better love loving and you better behave
Woman in Chains
Woman in Chains

Calls her man the Great White Hope
Says she’s fine, she’ll always cope
Woman in Chains
Woman in Chains

Well I feel lying and waiting is a poor man’s deal
And I feel hopelessly weighed down by your eyes of steel
It’s a world gone crazy
Keeps Woman in Chains

Trades her soul as skin and bones
Sells the only thing she owns
Woman in Chains
Woman in Chains

Men of Stone
Men of Stone

Well I feel deep in your heart there are wounds Time can’t heals
And I feel somebody somewhere is trying to breathe
Well you know what I mean
It’s a world gone crazy
Keeps Woman in Chains
It’s under my skin but out of my hands
I’ll tear it apart but I won’t understand

I will not accept the Greatness of Man
It’s a world gone crazy
Keeps Woman in Chains
So Free Her
So Free Her

Here is a video of this great song. Enjoy!

Which is your favourite track on the Seeds of Love album?

## The 100 greatest Beatles songs – number 50 – Got To Get You Into My Life

Today I thought I would start a count down of Rolling Stone Magazine’s 100 greatest Beatles songs. I have decided not to count down the whole 100, as if I do one of the songs in the list once a week it is going to take two years! So, I will do the top 50, which is till going to take a year.

Starting at number 50 is “Got To Get You Into My Life”. This Paul McCartney song is off the Beatles’ 1966 album <em"Revolver, which I blogged about here. The song is a bit of a homage to Motown, with a very colourful brass section and upbeat tempo typical of the Motown hits of the day.

At number 50 in Rolling Stone Magazine’s list of the 100 greatest Beatles songs is “Got To Get You Into My Life”.

I was alone, I took a ride
I didn’t know what I would find there
Another road where maybe I could see another kind of mind there

Ooh, then I suddenly see you
Ooh, did I tell you I need you
Every single day of my life

You didn’t run, you didn’t lie
You knew I wanted just to hold you
And had you gone you knew in time we’d meet again

Ooh, you were meant to be near me
Ooh, and I want you hear me
Say we’ll be together every day

Got to get you into my life

What can I do, what can I be
When I’m with you I want to stay there
If I’m true I’ll never leave
And if I do I know the way there

Ooh, then I suddenly see you
Ooh, did I tell you I need you
Every single day of my life

Got to get you into my life
Got to get you into my life

I was alone, I took a ride
I didn’t know what I would find there
Another road where maybe I could see another kind of mind there

Then suddenly I see you
Did I tell you I need you
Every single day?

Here is a video of this great song. Enjoy!

## Why do we have leap seconds?

At midnight on the night of Monday the 30th of June, an extra second was added to our clocks. A so-called leap second. Did you enjoy it? Me too 🙂 I got so much more done….. But, why do we have leap seconds?

In this blog here, I explained the difference between how long the Earth takes to rotate $360^{\circ}$ (the sidereal day) and how long it takes for the Sun to appear to go once around the Earth (the mean solar day). We set the length of our day, 24 hours, by the solar day. If there are 24 hours in a day, 60 minutes in an hour, and 60 seconds in a minute, then there should be $24 \times 60 \times 60 = 86,400 \text{ seconds}$ in a solar day. But, there aren’t! The Earth’s rotation is not consistent, that is if we measure the length of a mean solar day, it is not consistently 86,400 seconds. This difference is why we need leap seconds.

A leap second was added at midnight on the 30th of June. It was the first leap second to be added since 2012.

But, how do we accurately measure the mean solar day (the average time the Sun appears to take to go once around the sky) , and what is causing the length of the mean solar day to change?

## How do we define a second?

When the second was first defined, it was defined so that there were 86,400 seconds in a mean solar day. But, since the 1950s, we have a very accurate method qof measuring time, atomic clocks. Using these incredibly accurate time pieces (the most accurate atomic clocks will be correct to 1 second over some tens of thousands of years) we have been able to see that the mean solar day varies. It varies in two ways, there is a gradual lengthening, but there are also random changes which can be either the Earth speeding up or slowing down its rotation.

## How do we measure the Earth’s rotation so accurately

In order to measure the Earth’s rotation accurately we use the sidereal day, which is roughly four minutes shorter than the mean solar day. By definition, the sidereal day is the time it takes for a star to cross through a local meridian a second time. But, actually, stars in our Galaxy are not good for this as they are moving relative to our Sun. So, in fact, we use quasars, which are active galactic nuclei in the very distant Universe; and use radio telescopes to pinpoint their position.

## The gradual slowing down of the Earth’s rotation

There is a gradual and unrelenting slowing down of the Earth’s rotation, which may or may not be greater than the random changes I am going to discuss below. This gradual slowing down is due to the Moon, or more specifically to the Moon’s tidal effects on the Earth. As you know, the Moon produces two high tides a day, and this bulge rotates as the Earth rotates. But, the Moon moves around the Earth much more slowly (a month), so the Moon pulls back on the bulge of the Earth, slowing it down. To conserve angular momentum, the Earth slowing down means the Moon moves further away from the Earth, about 3cm further away each year.

## The random fluctuations in the Earth’s rotation

In addition to the unrelenting slowing down of the Earth’s rotation due to the Moon, there are also random changes in the Earth’s rotation. These can be due to all manner of things, including volcanoes and atmospheric pressure. These random fluctuations can either speed up or slow down the Earth’s rotation.

We have been having leap seconds since the 1970s when atomic clocks became accurate enough to measure the tiny changes in our planet’s rotation. Since them we have added a leap second when it is decided that we need it, typically but not quite once a year. However, having that extra second at the end of June can cause glitches with computers, and so there are discussions to remove the leap second and replace it with something larger on a less frequent basis.

## Handbags and Gladrags – Stereophonics (song)

The other day I was chatting to an American friend about famous Welsh people. After the usual list of “Tom Jones, Richard Burton, Catherine Zeta Jones, Gareth Bale” (except an American would not have heard of the most expensive footballer in the World), I asked her if she knew The Stereophonics. As she didn’t, I sent her a link to their one US hit, “Have a Nice Day”. I was living in the US when this was a hit there, and it was quite a thrill to hear a band from Cwmaman (about 50 miles from where I grew up) playing on US radio.

But, today I am not sharing that song, but rather their version of“Handbags and Gladrags”.

The Stereophonics’ version of “Handbags and Gladrags”

Here is The Stereophonics’ version, which is the first version I heard when it was used as the theme tune for the hit BBC comedy ‘The Office’.

Most people think that this song was originally done by Rod Stewart, but his is the most well-known version, not the original. The song, written by Mike d’Abo, was originally performed by Chris Farlowe in 1967, Stewart’s version was recorded in 1969.

This is Rod Stewart performing ‘his’ song with The Stereophonics.

## 500 Greatest Songs of All Time – no. 1 – “Like A Rolling Stone” – by Bob Dylan.

So we finally get to the number 1 in Rolling Stone Magazine’s list of the 500 greatest songs of all time. At number 1 is (drum roll…..) “Like a Rolling Stone’ by Bob Dylan.

I cannot argue with this choice; the song is groundbreaking in many aspects, and is just perfect as a song. Strangely, Dylan was not known for writing hit singles, but this song started as an attempt to do just that. The version released as a single from his sessions for the 1966 album “Highway 61 Revisited” ran to over 6 minutes, twice the length of most singles. Dylan was told that radio stations would not play such a long song, but they did and it got to number 2 in the US charts, and to number 4 in the Disunited Kingdom charts.

At number 1 in Rolling Stone Magazine’s ‘500 Greatest Songs of all Time’ is “Like A Rolling Stone” by Bob Dylan.

I have already blogged about this song in my countdown of Bob Dylan’s best songs (here), but unfortunately the video I inserted into that post no longer works.

Apparently the lyrics shown below, which are what Dylan sung in the version of the song which appeared as a single and which is on “Highway 61 Revisited” are just a small part of some 70 (seventy!) verses that Dylan had written.

Once upon a time you dressed so fine
Threw the bums a dime in your prime, didn’t you?
People call say ‘beware doll, you’re bound to fall’
You thought they were all kidding you
Everybody that was hanging out
Now you don’t talk so loud
Now you don’t seem so proud

How does it feel, how does it feel?
To be without a home
Like a complete unknown, like a rolling stone

Ahh you’ve gone to the finest schools, alright Miss Lonely
But you know you only used to get juiced in it
Nobody’s ever taught you how to live out on the street
And now you’re gonna have to get used to it
You say you never compromise
With the mystery tramp, but now you realize
He’s not selling any alibis
As you stare into the vacuum of his eyes
And say do you want to make a deal?

How does it feel, how does it feel?
To be on your own, with no direction home
A complete unknown, like a rolling stone

Ah you never turned around to see the frowns
On the jugglers and the clowns when they all did tricks for you
You never understood that it ain’t no good
You shouldn’t let other people get your kicks for you
You used to be so amused
At Napoleon in rags and the language that he used
Go to him now, he calls you, you can’t refuse
When you ain’t got nothing, you got nothing to lose
You’re invisible now, you’ve got no secrets to conceal

How does it feel, how does it feel?
To have on your own, with no direction home
Like a complete unknown, like a rolling stone

Ahh princess on a steeple and all the pretty people
They’re all drinking, thinking that they’ve got it made
But you better take your diamond ring, you better pawn it babe
You used to ride on a chrome horse with your diplomat
Who carried on his shoulder a Siamese cat
Ain’t it hard when you discovered that
He really wasn’t where it’s at
After he took from you everything he could steal

How does it feel, ah how does it feel?
To be on your own, with no direction home
Like a complete unknown, like a rolling stone

In this video (taken from Martin Scorcese’s film “No Direction Home”), Dylan explains his inspiration for “Like a Rolling Stone”.

The beginning of Dylan performing the song at a concert in Manchester (England) in 1966 has one of the seminal moments in rock ‘n’ roll history. Dylan had alienated many of his fans by “going electric” the previous year, and during this tour of Europe and the United States he spent a good fraction of each set being booed by fans who felt that he had betrayed them and “gone commercial”. As Dylan came on stage to end his set at Manchester with “Like a Rolling Stone”, this happened. The last thing he says before the song starts, as he turns to his band, is “Play it fucking loud”.

Which is your favourite song of all time?