Tuesday, January 31, 2012

The Physics of Nothing

Energy of nothingness

The birthplace of stars, molecular cloud, is cold and empty: what a contrast between Barnard 68 and the Sun!

Speaking of contrasts in the Universe - nothing has plenty of meaning!

The Physics of Nothing; The Philosophy of Everything

Take a look at this August 16, 2012 posting by astrophysicist  Dr Ethan Siegel to get an idea how much!

Plenty of Empty

Barnard 68 molecular cloud is the exact opposite of the fiercely hot radiation Sun.

It is very cold and very empty.

The idea that such clouds are the wombs giving birth to stars is, as far as I know, quite novel in astronomy and truly surprising. The theory is also difficult to study because these clouds are hard to see.

Astronomers suggest that the "temperature" - or rather lack of it - is about 16 Kelvin.
That is way below freezing cold at -257o Celsius and uncomfortably near absolute zero.

lollipop asked three years ago from Yahoo answers:
Find the density in atoms per cubic entimeter of a Bok globule having a radius of 1 light year and a mass of 100 M. how does your result compare with the desnity of a typical H II region, between 80 and 600 atoms per cm3? (Assume that the globule is made purely of hydrogen atoms). please help with astronomy hw!?! 

And got this answer from ronwizfr:
100 Sun masses = 100 x 2 × 1033 gram = 2x1035 gram x 6 x1023 atoms/gram = 1.2x1058 atoms.
The volume of the sphere is 4/3*pi*1 lyr3 = 4.19 x (9.46 × 1017)3 cm3 = 3.55 x 10^54 cm3
So the density is 1.2x1058 atoms/3.55 x 1054cm3 = 3400 atoms/cm3


Really empty
Let us think the average density of Barnard 68 and other Bok globules given there: between 80 and 600 atoms per cubic centimetre.

Well, what does that mean in human language?

6.023 x 1023
Amadeo Avogadro (1776-1856) was the author of Avogadro's Hypothesis in 1811, which, together with Gay-Lussac's Law of Combining Volumes, was used by Stanislao Cannizzaro to elegantly remove all doubt about the establishment of the atomic weight scale at the Karlsruhe Conference of 1860.

The name "Avogadro's Number" is surely just an honorary name attached to the calculated value of the number of atoms, molecules, etc. in a gram molecular weight of any chemical substance. Of course if we used some other mass unit for the mole such as "pound mole", the "number" would be different.

The first person to have calculated the number of molecules in any mass of substance seems to have been Josef Loschmidt, (1821-1895), an Austrian high school teacher, who in 1865, using the new Kinetic Molecular Theory (KMT) calculated the number of molecules in one cubic centimeter of gaseous substance under oridnary conditions of temperature of pressure, to be somewhere around 2.6 x 1019 molecules. This has always been known as the "Loschmidt Number."
Avogadro's number

So upon earth there are about 1.0 x 1017.

Not so in the Barnard 68 cloud.

What does that mean in our normal world down hear upon the earth?
How can we grasp the meaning of such a numerical fact given to us by scientist and students of astronomy?

I have no words to compare the situation to grains of mustard in football stadium or stuff like that.

Instead, I give up and just say "plenty of empty".

Barnard 68 Bok globule

Barnard 68. Dark absorption nebula 
Molecular cloud in the constellation of Ophiuchus
APOD 29.1. 2012

Barnard 68 molecular cloud is only 500 light-years away and therefore the hydrogen in it is dense enough to block all visible spectrum starlight coming from behind it. It looks like a black hole. The name is from the catalogue of 350 dark clouds created by the American astronomer Edward Emerson Barnard (1857–1923). The cloud has the estimated mass of two suns and is about half light-year across.

Bok globule
Barnard 68 is a small molecular cloud and thus a very small Bok globule.

Bok globules are dark clouds of dense cosmic dust and gas in which star formation sometimes takes place. Bok globules are found within H II regions, and typically have a mass of about 2 to 50 solar masses contained within a region about a light year or so across (about 4.5 × 1047 m³, see Orders of magnitude (volume)). They contain molecular hydrogen (H2), carbon oxides and helium, and around 1% (by mass) of silicate dust. Bok globules most commonly result in the formation of double or multiple star systems.

 See APOD 12.6.2012 for a fascinating color image of Thackeray's globules IC 2944 taken by the 4-m Victor Blanco telescope at Cerro Tololo Inter-American ObservatoryChile.

Monday, January 30, 2012

Heavenly weakling

Hydrogen molecules, again! (ref)

Our teacher patiently continues explaining the basics to us:

The electromagnetic interaction is also responsible for holding molecules together.

Although molecules are neutral, there is a residual of the electromagnetic interaction, called van der Waal's interaction, that holds them weakly together. 

Take hydrogen molecules, for example.
  • The electric charge around the atoms in the molecules is polarised - the electrons are pushed apart by electromagnetic repulsion towards the extremities leaving a positive field near the middle.
  • The molecules are held together by attraction between the negative extremity of one molecule's field and the positive middle of the other's. This is due to a polarization of the electric charge around the atoms in the molecule.
For example, in the hydrogen molecule, the electrons are pushed apart by electromagnetic repulsion towards the extremities, leaving a positive field near the middle.

The weak and strong interactions differ from the other two in one very important way: they only act over very short distances and are confined to the scale of atomic nuclei.

Heavenly weakling!

The weak interaction is responsible for radioactive beta decay, and it plays a vital role in the energy generating processes of stars, including our Sun.

Solar mass

Physic master classes puts it nicely and clearly:

There are four interactions known to science, they are called gravity, electromagnetism, weak and strong. These interactions often manifest themselves as forces between particles.
  • The gravitational interaction, for example, is responsible for the attractive force between masses.
  • The electromagnetic interaction is responsible for the attractive or repulsive forces between charges.
Gravity is the most familiar interaction to us, but it is by far the weakest of them all. Gravity acts on mass, and it is because we live next to a very big mass - the Earth - that gravity is so important to us. Gravity holds the planets in orbit around the Sun, it controls the behaviour of galaxies, and it is responsible for the large scale behaviour of the Universe.

The electromagnetic interaction is what brings light and energy to us from the Sun and holds electrons in orbit around nuclei to form atoms. Whereas gravity acts on mass, electromagnetism acts on electric charge - in fact we can think of mass as the charge of the gravitational interaction. Wherever there are electric charges, electromagnetism is at work - bringing electricity into our homes, painting the picture on our television screen, or causing dramatic bursts of lightning like this...

The quoted text helps us students to understand that the Sun has huge mass and so the weak force of gravity holds planets on their orbits around it. And kept those jumping American astronauts on the surface of the Moon.

Well then, how heavy is the Sun?

1,989,000,000,000,000,000,000,000,000,000 kg

Honestly, lots of zeros but I find it difficult to count how many and cannot grasp the meaning of them.

Again, Wikipedia comes to help:

The solar mass () is a standard unit of mass in astronomy, used to indicate the masses of other stars, as well as clusters, nebulae and galaxies. It is equal to the mass of the Sun, about two nonillion kilograms.

This is about 

332,950 times the mass of the Earth or 
1,048 times the mass of Jupiter.

Absolute zero

The rapid expansion of gases leaving the Boomerang Nebula 
causes the lowest observed temperature outside a laboratory.

As far as I know, nobody has reached 0 K, the Absolute Zero (no, not a Swedish drink).

I asked the scientists and they agreed - Pat Rowe saying that it is only a theoretical temperature that cannot be reached in real life.

Wikipedia explains:
Absolute zero is the theoretical temperature at which entropy reaches its minimum value. The laws of thermodynamics state that absolute zero cannot be reached using only thermodynamic means. A system at absolute zero still possesses quantum mechanical zero-point energy, the energy of its ground state. The kinetic energy of the ground state cannot be removed. However, in the classical interpretation it is zero and the thermal energy of matter vanishes.

The current world record was set in 1999 at 100 picokelvins (pK), or 0.000 000 000 1 of a Kelvin, by cooling the nuclear spins in a piece of rhodium metal.

How cold, how hot?

Let us put a pot of cold water H2O on a gas stove.

Let us then stand by it and tell to it as seriously as we can:  "Boil! I tell you, water, boil!"

But alas, nothing happens. The water stays cold no matter how long we stand there huffing and puffing and telling it to boil.

Until we lit the stove and the burning gas starts to move those molecules in the liquid, causing it to heat up and boil.

The crucial chemical reaction of heat on water molecules happens at boiling point. Swedish astronomer Anders Celsius (1701–1744) defines a scale where the boiling point of water is at 100 °C. Water freezes according to this scale below 0 at -4 °C.

This detail of water freezing a little below zero is of crucial importance to all life in water everywhere there are freezing conditions. God's great act of creation, this water thing (although the Bible does not tell explicitely that God created water. It is there after the Beginning.)

Somewhat unfortunately, Dutch-German-Polish physicist Daniel Gabriel Fahrenheit (1686 – 1736) had already created a thermal scale before Celsius came up with his. This genius had invented two types of thermometers that are not based on the properties of water: one works with alcohol (1709) and the other with mercury in glass (1714), of all the things... Both types are still in use today from meteorology to measuring fever.

According to an article Fahrenheit wrote in 1724, he based his scale on three reference points of temperature. In his initial scale (which is not the final Fahrenheit scale), the zero point is determined by placing the thermometer in brine: he used a mixture of ice, water, and ammonium chloride, a salt, at a 1:1:1 ratio.

This is a frigorific mixture which stabilizes its temperature automatically: that stable temperature was defined as 0 °F (−17.78 °C). The second point, at 32 degrees, was a mixture of ice and water without the ammonium chloride at a 1:1 ratio. The third point, 96 degrees, was approximately the human body temperature, then called "blood-heat"

These two scales are both in use today, Celsius scale about everywhere, Fahrenheit in Calyman islands and Belize. So who cares? The conversion between Fahrenheit and Celsius readings is complicated as water freezes in 32 degrees °F and boils in 212 °F. So why bother?

Nobody would care - except that in addition to these two places Fahrenheit scale is used also in the United States of America.

Fahrenheit and Celsius scales are good for everyday life and give us means to get readings of crucial importance to us, like the heating temperature of the goose in the oven.

In the molecular clouds in deep space it is useful to have a temperature scale not needed in everyday life, where water, ethanol or mercury in glass will do. Not the boiling point of water but the point at which atoms stop moving around.

The Kelvin scale is named after the Belfast-born, Glasgow University engineer and physicist William Thomson, 1st Baron Kelvin (1824–1907), who wrote of the need for an "absolute thermometric scale". Unlike the degree Fahrenheit and degree Celsius, the kelvin is not referred to or typeset as a degree. The kelvin is the primary unit of measurement in the physical sciences, but is often used in conjunction with the degree Celsius, which has the same magnitude. Absolute zero at 0 K is −273.15 °C (−459.67 °F).

We see that it is easier for us humans to grasp "he temperature is near 0 K" than a sentence like "scientists have succeeded in reaching almost the point  −459.67 °F.

His sun

How did God create this fierce Ball of Fire from the darkest and coldest stuff in the universe - molecular clouds?

The Bible does not exactly tell how - it tells who did it: the God of Israel, the only real God there is.

In order to understand how, we are allowed and have to study the open Book of Nature. Admittedly it is not exactly an easy Book to read. Some people spend their entire life studying such matters as how stars are born.

Jesus Christ puts the Theology of the Sun nicely into perspective and spices it with a powerful ethical point to all humanity benefiting from this star of God:

But I say unto you, love your enemies, bless them that curse you, do good to them that hate you, and pray for them that despitefully use you and persecute you, that ye may be the children of your Father who is in Heaven. For He maketh His sun to rise on the evil and on the good, and sendeth rain on the just and on the unjust.
Matthew 5:44-45 KJ21

Double-note the expression "His sun".

Indeed, it is His!

Confession of a student
In these posts on Sun I write just some little notes on what I have learned about the subject as a layman. I confess that I am lacking the fundamental academic training in mathematics, astronomy, physics, chemistry, nuclear physics and other fields of research that would enable me to understand deeply and to evaluate critically various modern theories by myself.

The study of the Sun is a fascinating field of science and I am eager to learn more about His master work.
It is an international subject concerning the entire humanity and let me remind, that not all of the scientists come from the Biblical Judea-Christian background and that not all believe that the personal God of Israel exists. What unites all true scientists is the love for truth.

Sunday, January 29, 2012

Cold Mother Molecular

Spectacular photo of "star eggs" in a large molecular cloud

We humans have it so nice - nine months in the warm womb of mother and then immediate delivery of tasty nourishing food on our first demand for service in this world.

Creator has not made it so nice for the stars born in heavens.

Astronomy teaches us the surprising fact that those bright stars, fierce furnaces of nuclear reactions radiating light and warmth to the distances of millions of light years are actually born in the most desolate and cold regions of the universe - molecular clouds.

The wombs of the stars - often called interstellar nurseries - are surprisingly complicated clouds where hydrogen atoms are able to join together to create molecular hydrogen H2.

The name hydrogen comes from Greek and means "water producer".

Really, it sounds so simple, like one plus one - gas of molecular hydrogens.

Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of 1.00794 u (1.007825 u for hydrogen-1), hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass.
Stars in the main sequence are mainly composed of hydrogen in its plasma state. Naturally occurring elemental hydrogen is relatively rare on Earth.

One proton, one electron - the simplicity itself?

Put two together and you get a hydrogen molecules...

Hydrogen molecules H2

The electromagnetic interaction is also responsible for holding molecules together. Although molecules are neutral, there is a residual of the electromagnetic interaction, called van der Waal's interaction, that holds them weakly together. Take hydrogen molecules, for example. The electric charge around the atoms in the molecules is polarised - the electrons are pushed apart by electromagnetic repulsion towards the extremities leaving a positive field near the middle. The molecules are held together by attraction between the negative extremity of one molecule's field and the positive middle of the other's. This is due to a polarization of the electric charge around the atoms in the molecule. For example, in the hydrogen molecule, the electrons are pushed apart by electromagnetic repulsion towards the extremities, leaving a positive field near the middle.
Physics master classes

Understanding electromagnetic interaction in hydrogen molecules is quite a challenge to a layman like me with only basic understanding of Physics. It is hard even with the help of great websites.

God made this fundamentally important one plus one.

And I think He is the only One who can build flaming stars from a cloud of such "simple" molecules.

For a breath-taking infrared image of the famous molecular clouds and the Eagle Nebula see the APOD image February 3, 2012,

Thursday, January 19, 2012

Hawking radiation

Well, let us think!

If, assuming that, and taking into consideration, it might be logically that while this so in light of that we could perhaps with caution assume ...

And think we do.

For our God has given to the living creatures He so lovingly made an amazing ability to think. Ants clearly consider the path to be taken, birds think which worm to choose and a cat thinks hard how to get from her owner more good fish...

In a special spur of creativity God let the human brain grow with exceptional evolutionary speed from 400 cm3 to our average 1400 cm3.  He gave us the most amazing and complex organ, our brain. Human brain is not only capable of cold rational thinking but also consider mentally such matters as
to be or not to be
to believe or not to believe
to judge between good and bad
to write the melody in a minor or major key
and to ask from Him a blessing or gift in prayer.

And we think all the time all kinds of things, what to dress this morning so that we make a good impression in the coming meeting, what to have for breakfast today without too many calories and where is my driving license, after all...

We even create think tanks.

Stephen Hawking was also thinking (he still thinks, this is what he was pondering almost half a century ago)

Assuming that one takes quantum theory into account, it seems that black holes should glow slightly photons, neutrinos, and to a lesser extent all sorts of massive particles. If this is so black holes are not totally black.

Furthermore, it seems that if the mass of a black hole is M solar masses, it should glow like a blackbody of temperature
                     6 × 10-8/M kelvins,
so only for very small black holes would this radiation be significant.

Therefore it seems that if a black hole is left alone and unfed it should radiate away its mass, slowly at first but then faster and faster as it shrinks, finally dying in a blaze of glory like a hydrogen bomb.

How long would this take, that a black hole blows up?

Let us see, it appears that the total lifetime of a black hole of M solar masses works out to be
                     1071 M3 seconds

(not so loosely based on Physics FAQ Joan Baez 1994)
Yes, Stephen Hawking has been thinking.

He published those particular ideas in a seminal 21 pages long paper
Stephen W. Hawking, Particle creation by black holes, Commun. Math. Phys. 43 (1975), 199—220.

Other theoretical physicists have been thinking this challenging line of argumentation ever since. The problem is that Hawking radiation is so dim that bigger black holes busily eating nearby stellar materials are producing such noise, burps and all, that it is hard to detect.

As science goes, some have tried to disprove and others prove what the man wrote. For he was only thinking and could not experimentally prove the point.

Today's consensus among those who understand this (and I do not belong to that crowd) is that Stephen Hawking got it right.

By using his brain, he was able to suggest something about the cosmos.

Which our God has created with very deep mathematical thinking.

A brain reached the Brain and understood!

Tuesday, January 17, 2012

Pathological image of a dead sun

Cold body of a dead sun
APOD 14 January 2012

A little white dwarf in the middle of this NASA image is all that is left of a once bright and warm sun. It is surrounded by a glowing cloud of the explosion that destroyed it. The cloud will soon evaporate and the sun is no more. any planets that may once have rotated it were utterly destroyed at the death cramps of the sun that ran out of hydrogen fuel.

Look into the future of our Sun?

Yes, this is according to current understanding of the life cycle of stars how our dear Sun will look in about five billion human years from now.

Astronomers call the object in the image Planetary nebula because the dust clouds left from the explosion surround it like planets surround a sun. The Little Ghost Nebula is officially registered as NGC 6369.

William Herschel (1732-1822)

Famed German-born British astronomer William Herschel discovered this beautiful nebula in the constellation of Ophiucus. The finding witnesses his extraordinarily accurate skills of observation concerning how dim the nebula is and the quality of telescopes he could use.

Ophiuchus is a large, obscure constellation hiding a number of gems. Typically depicted holding Serpens, the constellation represnts Esculapius [Asclepius], the Greek god of medicine. Son of Apollo and the nymph Coronis, Chiron, the centaur taught him. His skill at healing was legendary; he could even raise the dead. This last skill roused the anger of Zeus, who slew Esculapius with a thunderbolt. His sons carried on their father's medical tradition, serving the wounded of the Greek army before the walls of Troy.
Hawaiian Astronomical Society page

Sceptre of Asclepius is today
an internationally recognized symbol for
the medical profession and pharmacology

This little sun in the constellation of Ophiucus died a normal death and all that remains of it is a glowing ghost!

Sunday, January 15, 2012

Rashi and the counting of stars

Exterior of Rashi's Synagogue, Worms, Germany

In today's Haaretz Weekly Portion Lift up your eyes Yakov Meir writes a beautiful and rich explanation to the interpretation of the stars and Abraham by Rashi.

Rabbi Shlomo Yitzhaki (1040 – 1105), Rashi
was a medieval French rabbi famed as the author of a comprehensive commentary on the Talmud, as well as a comprehensive commentary on the Tanakh (Hebrew Bible). He is considered the "father" of all commentaries that followed on the Talmud (i.e., the Baalei Tosafot) and the Tanakh (i.e., Ramban, Ibn Ezra, Ohr HaChaim, et al.)

The article is well worth of reading and gives us an authentic glimpse of the meaning of stars and space in Judaism during the early Medieval period in France.

Friday, January 13, 2012

Horny Saturn and the Hooker

More and more I am convinced that history of observation tools and methods is one of the most important keys for modern man to understand what is going on today in natural sciences. Humanity on the road of learning depends on the instruments it has in its possession. Think, for example, the Large Hadrone Collider of CERN.

Going to moon requires instruments

The view of the importance of learning and exploration for humanity was strongly emphsized by one of the pioneers of modern rocket science, Hermann Oberth (1894-1989) who significantly helped humanity in the mission impossible - setting foot on the Moon.

Inspired by Jules Verne he dedicated his life to building better tools for such learning and exploration - rockets for interplanetary flights and better fuels for such long trips. He lost his dear scientist daughter in 1944 when she was working in a liquid oxygen plant that exploded.

His contribution was so valued that NASA invited him in 1969 to the Space Centre in Florida to witness the   launching of Saturn V rocket carrying the Apollo 11 mission.

Oberth in 1901
A boy whose dream came true

Horny Saturn

Instruments of observation are crucial to our ability to understand Space.

Late 16th century Dutchmen invented lens - a simple piece of glass that has been polished to certain shape.

When such pieces of glass are set on the line of sight in given order the eye can observe items through a magnifying glass, microscope or telescope, as we call them.

Galileo Galilei (1564-1642) got the news in Italy and decided to make his own telescope by setting polished pieces of glass into a long tube.

When he pointed that self-made instrument to the night sky he observed, that planet Saturn has horns.

Entire humanity living on planet Earth had never before seen those horns.

North Americans like big things, especially in Texas (starting from the cowboy hats)

So they decided to build the largest telescope ever made.

And they did it despite of all the difficulties of getting such a 2.5 meter mirror polished and transporting it to the Observatory on top of Mount Wilson where night skies are bright and rarely cloudy. At that time the light pollution from Los Angeles was not that bad.

Edwin Hubble (1889-1953) sat there many lonely cold nights and looked through Hooker far beyond Saturn and its thin beautiful rings.

The rest is history as far as the learning of humanity a la Oberth is considered. Red shift and all that. Even Albert Einstein was impressed enough to climb up to meet the man looking out there through the Hooker.

North Americans like big things.

Now they are building an even bigger space telescope to replace ageing Hubble.

Introduce the James Webb Space Telescope.

The entire world of Astronomy is waiting holding breath for the pictures to come.