29th July 2005 – Eris’ discovery announced

Eris is the largest known dwarf planet in the solar system. In other words Eris is larger than Pluto. This was one of the factors that influenced the decision of the International Astronomical Union (IAU) to reclassify Pluto as a Dwarf Planet.

Her is Wikipedia’s entry on Eris

So what is a dwarf planet?

The official definition of a dwarf planet is as follows:

A “dwarf planet” is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.

And which solar system objects are larger than Eris?

Check out this graphical depiction of all known bodies in the solar system larger than 320 kilometers all shown to scale.

And of course the definition of a dwarf planet begs the question:

What is a planet?

The official definition of a planet is as follows:

A “planet” is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.

So in simple terms:

• Planets and dwarf planets orbit the Sun and are big/heavy enough to become almost spherical.
• Dwarf planets fail to be defined as planets because they have not cleared their orbits of other objects.
• Satellites do no qualify to be dwarf planets (even if they are larger than some planets and dwarf planets)

Word for the day – theory

The Bad Astronomer posted an article just over a week ago on his irritation with the argument that “evolution is just a theory”. He says:

It’s like saying the Eiffel Tower is just a tower.

His article links to this site which explains what scientists mean when they use the word theory.

In everyday use, theory means a guess or a hunch, something that maybe needs proof. In science, a theory is not a guess, not a hunch. It’s a well-substantiated, well-supported, well-documented explanation for our observations. It ties together all the facts about something, providing an explanation that fits all the observations and can be used to make predictions. In science, theory is the ultimate goal, the explanation. It’s as close to proven as anything in science can be.

So by saying “evolution is just a theory” what you are saying scientifically speaking is that evolution is as close to being proved as it can be. Which is what mainstream scientist have been confirming for the last 150 years.

Hole in the wall

On my visit to Vitensenteret Innlandet with my daughter and grandson on the 4th July I took this photograph.

Saturn is my grandson’s favorite planet so we all thought this was a neat idea. All the other planets (and the acknowledged dwarf planet Pluto) were displayed to scale with the Sun painted on the opposite wall (also to scale).

Related post: Radiometer

22nd July – Happy Pi Approximation Day!

Today is the 22nd of July otherwise known as 22/7 – which is the approximation to pi learned by countless agonizing pupils in math classes all over the world. In the US Pi day is celebrated on March 14 (3.14) but that doesn’t compute in many European date formats. So:

Happy pi approximation day

Books read this year #15

Book: 15
Title: Harry Potter and the Deathly Hallows

Author: J. K. Rowling
Why did you get this book? Bought it yesterday to complete this journey. Book 7 in the Harry Potter series.
Do you like the cover? OK
Did you enjoy the book? Yes; and so will you if you’ve liked the previous books enough to read them.
Was the author new to you and would you read something by this author again? Not new at all.
Are you keeping it or passing it on? Are you mad? I am keeping it.
Anything else? If your hoping for spoiler – forget it. I have been avoiding the internet pages about Harry Potter this last week in order to avoid those gits out there who would spoil the sense of wonder from reading this book with no previous knowledge.
Number of pages: 607
Total pages for the year: 5394

20th July 1969 – The Eagle has landed

Houston, Tranquility base here. The Eagle has landed

Niel Armstrong’s immortal words as the first human on another celestial body.

Now I have been interested in Astronomy and Space for almost as long as I can remember. Therefore I am biased. I think this event is one of the most significant in human history.

I have always found it hard to give compelling reasons to explain why I think space exploration and in the long run colonization are important.

One day in the not too distant future; space will be as natural a place for us humans to live, work, play, raise families and die as Earth is now. This may seem frivolous and a waste of money to some. I disagree for several reasons:

• The “space the final frontier” argument: as a species we have a strong sense of curiosity. We have a need explore new places and to meet the unknown. The next logical step is to explore and eventually colonize space.
• The “a meteor caused the extinction of the dinosaurs” argument: insurance against mass extinction events – having space faring technology will some day save our species – it will not save me mind you because I will never get out there
• The “because it’s there” argument: should we have refused to colonize America or Australia? Would you live in your parent’s home the rest of your life because it saves money?
• The “because I say so” argument: I want to live to see it happen – selfish I know
• The “because it’s hard” argument: we have to push limits in order to advance. Yes space exploration is hard to do. Tying your shoes was once hard. You mastered that because learning hard things is how we grow up. Mastering space is one of the things our species needs to do in order to grow up.
• The “man does not live by bread alone” argument: we need space more than space needs us – humans need long term goals that inspire us and give us a sense of wonder – the day we say “why bother” is the day we stop evolving as a species. If we use all our resources struggling to solve immediate problems we will drown in those problems. We have to use some resources on things that are not focused on the “here and now” but on the “there and then”
• The “and of what use is a new born baby?” argument: we will not know what amazing things we can accomplish out there until we go and try. This is the same reason I think basic research is at least, if not more important than, applied research.

Some arguments do not hold for me:

• The “solve the population explosion” argument: we will never be able to move enough people off Earth fast enough to solve that problem. Space colonization can save us from future disaster – save us as a species – not individually
• The “spin-offs make life better” argument: if we need a new type of metal alloy; sending people into space is not a sensible way to get it

Do you see my problem? Most of my arguments are of the type “because it’s fun”. Not exactly compelling is it?

Books read this year #14

Book: 14
Title: Harry Potter and the Half-Blood Prince

Author: J. K. Rowling
Why did you get this book? Bought it ages ago. Read once before. Book 6 in the Harry Potter series.
Do you like the cover? OK
Did you enjoy the book? OK.
Was the author new to you and would you read something by this author again? Not new at all.
Are you keeping it or passing it on? Are you mad? I am keeping it.
Anything else? Darker again. Harry continues his journey.
Number of pages: 607
Total pages for the year: 4787

15th July 1799 – Rosetta Stone found

The stone contains the same text in two Egyptian languages (hieroglyphic and demotic) and in classic Greek. It was used as the key to deciphering hieroglyphics by Jean-François Champollion in 1822.

The Rosetta stone was found by the French at Rosetta in Egypt.

And here is the reason I am interested in the Rosetta stone…

The term Rosetta stone is used idiomatically to refer to the key to solving a decryption or translation process. Science fiction stories often consider mathematics and science to be the Rosetta stone that will enable humans to communicate with extra terrestrial intelligences. This is because mathematics and science are intimately connected to the cosmological principle. The same rules of mathematics and science apply all over the universe and consequently would be understood by sufficiently sentient beings anywhere.

Number of pages – Harry Potter

Here are the number of pages in the Harry Potter books listed.

Title	Pages (UK edition)
Harry Potter and the Philosopher’s Stone	223 pages
Harry Potter and the Chamber of Secrets	251 pages
Harry Potter and the Prisoner of Azkaban	317 pages
Harry Potter and the Goblet of Fire	636 pages
Harry Potter and the Order of the Phoenix	766 pages
Harry Potter and the Half-Blood Prince	607 pages
Harry Potter and the Deathly Hallows	607 pages

Enjoy!

I created this list because my wordpress statistics indicate that people do web searches for this information.

Note the US edition has more pages – here’s why according to one source..

A Psalm of Life

What the heart of the young man said to the psalmist

Tell me not, in mournful numbers,
Life is but an empty dream!–
For the soul is dead that slumbers,
And things are not what they seem.

Life is real! Life is earnest!
And the grave is not its goal;
Dust thou art, to dust returnest,
Was not spoken of the soul.

Not enjoyment, and not sorrow,
Is our destined end or way;
But to act, that each to-morrow
Find us farther than to-day.

Art is long, and Time is fleeting,
And our hearts, though stout and brave,
Still, like muffled drums, are beating
Funeral marches to the grave.

In the world’s broad field of battle,
In the bivouac of Life,
Be not like dumb, driven cattle!
Be a hero in the strife!

Trust no Future, howe’er pleasant!
Let the dead Past bury its dead!
Act,–act in the living Present!
Heart within, and God o’erhead!

Lives of great men all remind us
We can make our lives sublime,
And, departing, leave behind us
Footprints on the sands of time;–

Footprints, that perhaps another,
Sailing o’er life’s solemn main,
A forlorn and shipwrecked brother,
Seeing, shall take heart again.

Let us, then, be up and doing,
With a heart for any fate;
Still achieving, still pursuing,
Learn to labor and to wait.

Henry Wadsworth Longfellow (1807-1882)

This entry was inspired by watching CSI episode “Happy Ending” where another of Longfellow’s poems (The Arrow And The Song) is used.

I first became acquainted with “A Psalm of Life” as a young teenager reading “Fifty Celebrated Men Their Lives and Trials and the Deeds that Made Them Famous”. The book contained a couple of the verses from the poem (one in the preface and one to introduce a chapter).

I was given this book by a friend of my grandmother. The book has the following inscription on the first leaf:

Presented to John Hill for regular attendance by the Daisy Hill Sunday School Band of Hope Committe – Oct 13th 1888

The book was originally bought at “T. Brear & Co. Ltd. Booksellers & Stationers, Bradford”.