Saturn’s new ring

Take a look at this, fellow science geeks!

Advertisements

How Did We Get Here? – by Julian

How did us carbon based life forms get here? Let’s start with a checklist of things we might need. Carbon, oxygen, hydrogen, nitrogen, a handful of other useful elements. What we actually need is:

Oxygen (65%) – mostly in the form of water

Carbon (18%) – in lots of things, proteins, food, CO2

Hydrogen (10%) – again in water and proteins and, well everywhere.

Nitrogen (3%) – A vital part of amino acids, which make up proteins

Calcium (1.5%) – Bones and signalling in cells

Phosphorus (1.0%) – Nucleic acids, ATP and some other things

Potassium (0.35%) – used in nerves and inside cells for keeping
electrical potential

Sulfur (0.25%) – a popular bonding element in proteins

Sodium (0.15%) – good for nerves and osmotic control

Magnesium (0.05%) – used in various guises to help form nucleic acids,
proteins and ATP.

Tiny bits of Copper, Zinc, Selenium, Molybdenum, Fluorine, Chlorine, Iodine,
Manganese, Cobalt, Iron (0.70%)
Traces of Lithium, Strontium, Aluminum, Silicon, Lead, Vanadium,
Arsenic, Bromine

So – one fine non-day, a minute particle of something exploded. But this was no ordinary explosion. It wasn’t like putting a firecracker in a pot of M&Ms, lighting the touch paper and retiring with your mouth open hoping to catch one. Oh no, this explosion did not happen in space–it was the actual space that exploded. Let’s just consider that again: it wasn’t something exploding out into space, because there was no space to explode into. Come to that, there wasn’t any time for it to happen either at that point. This explosion was so special it created space and time together.

universe_expansion

Now, when all this set off it was incredibly hot, and very weird things happened in the first few nanoseconds.  I’m going to skate over the complicated bits that happened up to the first second–but basically that’s where *stuff* gets made. For some reason *stuff* isn’t made in exactly equal quantities like you might expect, and what’s left over is the building blocks of what we’ll be calling matter a few hundred years down the line. All this is happening at somewhere around 10,000,000,000 degrees (C, K or F – it really doesn’t matter). Now at this point there is nothing we would recognize around, except perhaps light in the form of photons. It is far too hot for anything else but elementary particles to hang together. The light is very energetic though, and you would need more than factor-50 to survive it. The universe is also opaque. All those photons which we use everyday to see things are continually running into electrons and protons and getting absorbed, and then reradiated. They can barely leave one particle before running into another. This radiation is what will give us the cosmic background radiation by the time space has stretched out far enough that its lengthened to microwave wavelengths.

Now–at about 3 minutes, the universe has grown big enough that things start to cool down, and finally when protons happen to bang together they are moving slowly enough that they can sometimes stick – this is called fusion, and still happens today in the Sun, stars and H-bombs. This continues for a full 17 minutes, and then the universe has cooled down to such an extent (because of its continual expansion) that now it is not hot enough for those protons to bang into another fast enough to overcome their electrical repulsion, and fusion ends.

What is the result of this? Well, the vast majority of all protons, 75%, have not managed to bang into anything hard enough, and they just hang around on their own. They will become hydrogen one day. Most of the other nuclei that have formed are helium, nearly 25%, and a tiny bit of element 3, lithium. So–not much carbon or oxygen then …

After this, it all gets a bit boring. Not much happens of significance for the next 300,000 years. There is still plenty of light around, but its still getting absorbed by all the free electrons hanging around, which are still too hot to get themselves attached to nuclei and form atoms. Then, it finally happens. The universe has cooled down enough that electrons are moving slowly enough to stick to nuclei and stay there, and we get hydrogen and helium – and suddenly there is the sort of light we might recognize. Light can now make it long distances and the universe has cleared and we can see what’s going on! If there was a first day, this is probably a good candidate, except for the fact it’s also the first night you can see the night sky (although it will probably be pretty empty). We also have our first required building block, hydrogen. Helium isn’t much use for anything chemically, and isn’t part of your body, except for the times you inhale it from party balloons to make your voice go squeaky.

Some other things start to happen, too. As things continue to cool, these clouds of particles start to attract each other because of gravity–until now they’ve been too hot to get together. In actual fact the contribution of matter is probably pretty small in this, as the more exotic dark matter is far more influential. Normal matter we can see and hold accounts for about 4% of the universe. Dark matter comes in at about 23% and even more mysterious dark energy the remainder. Both matter and dark matter attract things gravitationally, so the result is sort of the same. Clumps of matter and dark matter start to form what we will later call galaxies. Occasional dense spots of matter start to form too, clumping together into proto-stars. While the rest of the universe is cooling down, these proto-stars are heating up as the particles all fall into a thick mass. As they get hotter and hotter, they eventually get hot enough so that fusion can occur again for the first time since 20 minutes after the start.

darkmatterpie

These first galaxies were probably pretty nasty places, if distant observations are anything to go by. They probably had very active centers throwing out extreme amounts of radiation in jets and generally throwing their weight around. Similarly, the stars at this stage were very boring. They would be composed of the original matter in the universe, so 3 parts hydrogen to 1 part helium. These stars (of which we’ve never seen any yet) are known as population III stars, and they would burn hydrogen deep in their core into helium.

182565main_1agn_hi

Now what happens next depends a lot on how big a star happens to be. Big stars live life in the fast lane, and they cling desperately to what they can get, but it’s all over in a few million years for them. After somewhere between 1 and 30 million years they will have shone their last. Small stars like our own live much longer, maybe 10 billion years, but they don’t do very much that’s exciting compared to these big boys, unless you count letting us live. In the early universe it is likely that massive stars were by far the most common. Anyway, big stars are where it’s at, and they can get to be 100 times more massive than our own sun. Above that size they tend to rip themselves apart before they get going.

After these big stars race through their supply of hydrogen, burning it like there is no tomorrow, things start to come unstuck. With all the easily fused hydrogen turned into helium in their cores, they resort to burning hydrogen in a thin shell around this core of helium. But at the same time, their cores start to shrink, and this causes them to heat up again. Now it gets hot enough for helium to fuse. However the obvious reaction of two heliums banging together to form beryllium doesn’t happen. Well actually it does, but beryllium is so unstable, it tends to decay back as fast as it forms. Just occasionally though, you get a helium banging into a beryllium just as it’s about to fall apart and you’ll get carbon, which does hang around. Hey – we have one of the ingredients for life at last! Known as the triple alpha process this let the star shine again, at least for a while, but the writing is on the wall.

Things get increasingly desperate, as the helium runs out larger stars can switch to burning the carbon into neon, magnesium, sodium and oxygen. Hello, we have another few ingredients we’re going to need later on! Burning carbon will keep a star going for maybe 10,000 years or so. Then they can try neon burning (good for a year), oxygen burning (6 months) and silicon burning. Things are by this point really, really desperate. Silicon is the last chance to get energy out, as this ends up as nickel and iron, and fusing anything from iron upwards requires you to put energy in. The entire silicon burning phase lasts about a day and then it’s curtains. Whilst these last few stages are going on, some heavy elements are being built up by the s-process. The s stands for slow, and it adds a neutron at a time to some of the elements in the star, and builds up small quantities of heavy elements. A typical s-process reaction takes about a 1000 years, so it’s not a great way to make stuff. There are also only certain elements that can be built this way, as many of the products are radioactive and decay in less than 1000 years.

When one of these big stars reaches the end of the fuel, it’s like they’ve been holding up an increasingly heavy load, and finally they buckle. The star collapses in on itself, and there is nothing half hearted about this phase. The outer portions race into the center at nearly a quarter the speed of light and there is an almighty explosion. This is a supernova, and suddenly there are vast amounts of neutrons around and every element under (well over actually) the sun can be built up in literally seconds. This is the r-process – r standing for rapid and in just one or two seconds vast amounts of heavy nuclei are made and blasted out into space.

keplers_supernova

This outflow of material percolates into interstellar space and mixes with the clouds of hydrogen hanging around there and causes them to stir around somewhat, and in places this causes them to get dense enough to contract, and we’re off again to form another star. These stars we do see around, and are called population II stars, because we can detect in them quantities of things heavier than helium. Our own star, the sun, is a population I star, and is therefore probably composed of bits of previous population II stars. So we’re on the third wave of cosmic recycling at least. Most of our atoms have probably been in the center of two burnings stars at least.

189284main_coronet_516

So when the Earth formed there was more than just hydrogen and helium for it to form from, and we get a rocky surface to walk on with all that iron and nickel so desperately created in the death throes of early stars at or center. A world for… well for what? What happened next?

planet_formation

Sarpedon’s Weird Science

Astronomy Lost

Greetings again for this month’s Science Links Article Thingy. This is February’s issue, but of course, it’s January’s news. This month’s theme: Astronomy Lost.

April might be the cruelest month, but for Astronomers who are also Catholic priests, it was this January. Why? Because Pope Benedict 16 evicted the Papal Observatory from its digs! The Castel Gadolfo, in addition to being the home of the Vatican Observatory for the last 75 years, is also the Pope’s vacation home, where he frequently hosts foreign diplomats and wandering wizards. He decided things were getting too cramped, so, out goes the Roman Catholic Church’s only official scientific endeavor. (Many great Catholic scientist-priests, such as Mendel and Le Maitre, had science as a hobby only.) The observatory will be moved to one of the Catholic Church’s many underused convents.

http://news.independent.co.uk/europe/article3307586.ece

Since this happened so early in the month, I decided to make Astronomy the theme of this month’s science column. Unfortunately, Astronomy is one of the more serious and well respected branches of the sciences, so there isn’t much nuttiness to be found. But, here goes:

Here’s another article that fits with the theme of Astronomy Lost: Scientists Fail to Observe Gravity Wave. Scientists observing Gamma Ray bursts failed to observe an accompanying gravity wave. This has led them to conclude that these bursts are not due to black holes and neutron stars crashing into each other.

http://www.sciencedaily.com/releases…0103132303.htm

Speaking of Black Holes Not Crashing in to Each Other; here is an article about how scientists observed a system of two black holes, with a small one orbiting a large one, to make an accurate measurement of the large one’s mass. Turns out to be 18 billion times as massive as our own sun.

http://news.bbc.co.uk/2/hi/science/nature/7181877.stm

Complex organic molecules have been found in a planetary accretion disk. These molecules can’t form on earth under current atmospheric conditions, but scientists have long hypothesized that they might have existed here when the earth was young, and that these may have been early precursors to life. This is evidence that these molecules could have been present in the early solar system.

http://www.sciencedaily.com/releases…0103132303.htm

And here is another amazing discovery: a natural particle accelerator. One of the great feats of modern science is the particle accelerator, where subatomic particles are smashed together to the delight of physicists everywhere. Now, astronomers have found that an immense cloud of dust and charged gases are producing a similar effect. Not only is this exciting news for astrophysicists, but also for ordinary people. If there is a place in the universe where the proudest and most technologically advanced thing we have managed to produce is found naturally, we should also hope to find stellar clusters composed of computer monitors, tennis-shoe asteroid fields and BMW moons. Shouldn’t we?

http://www.sciencedaily.com/releases…0125224810.htm

And lastly, for those who are astronomers themselves! Don’t miss today’s (February 1st) conjunction of Jupiter and Venus! The two brightest planets will be just a couple of degrees away from each other in the night sky. Click here for where to look.

http://www.astronomy.com/asy/default.aspx?c=a&id=6496

I hope you enjoyed this month’s science column, Astronomy Lost, and further hope you don’t freeze to death looking at Jupiter and Venus tonight.
If you have any requests for monthly themes, feel free to send them to me on RantsnRaves.

Burning Bruno: the Fire that Failed the Church – by Octavia

In 1591, Giordano Bruno, an Italian philosopher and priest, published a book on cosmology titled De Monade. This was not the book that originally outlined the astronomical ideas that saw Bruno burned at the stake nine years later, but it was the sentiments expressed therein which made that burning inevitable:

“I fought, and that’s a lot. I thought I could win… but nature and luck curbed my endeavour. But it’s already something that I took up the struggle, because I see that victory is in the hands of Fate. In me was what was possible and what no future century will be able to deny to me: what a winner could give from his own; that I did not fear death, that I did not submit, my face firm, to anyone of my breed; that I preferred courageous death to pavid life.”

Bruno had a lot of time to reconsider this piece of prescience. When he was imprisoned and brought to trial by the Inquisition, it was for eight years – a period that ended with his gruesome execution in 1600. The General Inquisitors who pronounced his guilt were damning in their denunciation of him: “…Giordano Bruno, the accused, examined, brought to trial and found guilty, impenitent, obstinate and pertinacious…”

On Saturday the 19th of February, in the Square of Flowers in Rome, Bruno was stripped naked, and bound to the stake. An iron spike had been hammered through his tongue, and another through his soft palate, and his jaw was further bound in iron. It is impossible not to assume that this was to prevent him from speaking further – Bruno had received his sentence from the judges with threatening words. “Perchance you who pronounce my sentence are in greater fear than I who receive it.” After eight years in prison, eight years of questioning from the Roman Inquisitors, Bruno could not have been without fear. Perhaps it was his own words in De Monade that gave him the courage to face his eventual death when recantation might have saved him. He did not recant, and was burnt alive. There is a disgustingly gloating letter surviving from a lackey named Gaspar Schopp, who was witness to the whole affair:

“[Bruno] was given eight days to recant, but in vain. So today he was led to the funeral pyre. When the image of our Saviour was shown to him before his death he angrily rejected it with averted face… Thus my dear Rittershausen is it our custom to proceed against such men or rather such monsters.”

For his bravery, Bruno has often been hailed as the first martyr to science and freethought. Despite his pantheism, he has been traditionally seen as an atheist (both by his contemporaries as a means of vilification, and by the modern atheist movement, which often co-opts him for his stance against organised religion). His execution has long been an embarrassment to the Church.

If De Monade emphasised the strength of Bruno’s convictions, it was De l’Infinito Universo et Mundi (published in 1584) that was the root of the problem. Arrested for many doctrinal errors, Bruno was particularly tasked with recanting his belief in the infinity of the universe, the plurality of worlds, and the possibility of extraterrestrial life. An extract from a dialogue in l’Infinito shows the explosive nature of his arguments:

“Proceed to make known to us what is in truth the heaven, what in truth are the planets and all the stars; how the infinity of worlds are distinguished one from the other, how an infinite Space is not impossible but necessary… Dissolve the notion that our earth is unique and central to the whole… Give to us the knowledge that the composition of our own star and world is even as that of many other stars and worlds as we can see…”

Not all of Bruno’s astronomical ideas were correct – for instance he also believed that matter was distributed evenly throughout the universe, when modern astrophysics tells us that it is not. Correctness aside, these beliefs were inimical to the Church. They defied scripture, and in the explosion of intellectualism that was the Renaissance, that defiance was another weapon in the increasing conflict between science and religion, rationalism and faith. This conflict was to result in the detention and trial of other scientists, including Galileo. Many scientific books were placed on the Index Librorum Prohibitorum.

Where did Bruno’s idea come from? It did not originate with him, but its history stretched back to ancient Greece. Interestingly, the concepts of the plurality of worlds, the infinite universe, and extraterrestrial life have consistently been at the forefront of the debate between freethought and religion.

Random moves versus the Prime Mover.

The conflict between Bruno and the Church is not dissimilar to that which took place in classical Athens, where the Atomists were pitted against the Geocentrists. Atomists were not necessarily atheists, but they were often accused of being so.

The argument for the plurality of worlds began with Leucippus, a Greek philosopher who lived in the fifth century BC. Leucippus was the first to postulate the existence of atoms, hence his position as founder of the Atomists. What little is known of his life and beliefs can be found in the work of his student, Democritus. The Atomists thought that the universe was made up of innumerable tiny and indivisible objects – the atoms – which were indestructible and therefore eternal. These atoms moved at random throughout the universe, and spent a great deal of time bumping into each other. Sometimes they would deflect after a collision and bounce away in another direction, but sometimes the collision would be so strong that the atoms would stick together. As these clusters of stuck atoms increased, they formed the substances found in the universe. These substances were not confined to physical matter only – Democritus posited that the soul was made out of atoms, as were the senses.

Given an infinite number of atoms, however, the Atomists postulated that their random motions and accretions could form an unlimited number of worlds throughout the universe, some of which could even be populated. As Democritus comments in one of his surviving fragments:

“The ordered worlds are boundless and differ in size; in some is neither sun nor moon; in others both are greater than with us, and in yet others more in number. The intervals between the ordered worlds are unequal, here more and there less; some worlds increase, others flourish, and others decay. They are destroyed by colliding one with another. Some ordered worlds are bare of animals and plants, and of all water.”

(The basis of the idea was correct, although the Atomists got the details wrong. Today we know that atoms are not indestructible, and they are not indivisible. Nor is there any evidence that atoms make up a human soul. The fact that the Atomists believed it did, however, is enough to show that they were not really atheists after all – merely labelled as such because their argument was inconvenient to the religious ideals of the time.)

The leader of the argument against the plurality of worlds was undoubtedly Aristotle. He ascribed the creation of the universe to a “perfect Prime Mover” who set in motion certain inalienable physical laws. One of these was the idea of the perfect circle. Another was the belief that Nature would not abide a void, or vacuum, and that because of this all matter within the universe collects in the centre of it. Aristotle believed that the Earth was the centre of the universe – a small universe with finite matter, shaped in a perfect circle, which revolved around the stationary Earth as water swirls around a plughole. The possibility of other worlds was horrifying to him, as that would have meant that there were two (or, Heaven forefend, even more!) centres, and two or more circumferences. With multiple central areas, the perfect circle and pattern of the universe would be disrupted, just as the circle of water swirling around a plughole is disrupted if several more plugholes appear near the first. No perfect Creator or Prime Mover would create something so aesthetically displeasing, and so contrary to order! (The problem with positing a Creator is that you are forced to posit his mental state as well.)

Aristotle found the perfect geocentricity of the solar system (as observed by the naked eye) to be proof of that Prime Mover. Denying that perfection meant denying the Prime Mover. Aristotle did not hold this position alone. As Democritus was supported by philosophers such as Thales, Epicurus, and Anaximander; Aristotle had the big guns of Plato and the Egyptian Ptolemy on his side. The influence of the Geocentrists was so pervasive that Ptolemy’s model of geocentrism as outlined in his Almagest was the prevailing idea for over 1500 years, until given the death blow by Copernicus in his 1543 book De Revolutionibus Orbium Coelestium.

This didn’t mean that the plurality position was left to dry on the vine, however. It was explored by several Roman philosophers, most especially Lucretius (99-55 BC), who supplemented the Atomist methodology of collision and accretion with his ideas on the “principle of plenitude”. In short form, this principle can be best described as the reflection of the imagination. If a person is capable of imagining something, then that thing exists in concrete form, and our imaginations reflect it like a great, unconscious mirror. We can imagine other worlds, therefore they exist. It has to be admitted that this argument can also be applied to God – the ontological proof of his existence. It’s probably equally reliable in both cases.

An example in point is the profusion of classical literature on the possibility of life (including intelligent life) on the Moon. Many classical philosophers wrote about the possibility, including Philolaus, Xenophanes, Plutarch, and Epicurus. By Lucretius’ reasoning, the Apollo spacecraft should have come across an entire menagerie of strange and amazing new life forms, and Neil Armstrong would have been the first to converse with intelligent life that was not of Earth. Wouldn’t it have been wonderful it he had? Alas, it was not to be. We are still alone – but it may not be forever. In his great poem De Rerum Naturae, Lucretius imagined life on other planets. Although his theory is defunct, perhaps one day his imagination will be proved correct.

The “noble and exalted” question.

Surprisingly, arguments about the possibility of other planets – including inhabited planets – carried on throughout the Middle Ages. On the cusp between the Classical and Middle Ages, St. Augustine of Hippo (354-430) disagreed with Epicurus on the plurality of worlds – his City of God pointed out the disconnection between the supposed random movement of the atoms and the Biblical concepts of creation and divine providence, and that was the end of that. However, in the latter half of the Middle Ages, discussion really began to start up again on the infinity of worlds and the possibility of extraterrestrial life. Not only did this occur despite the Church, which had an effective monopoly on the intellectual life of the time, but many of the debaters were churchmen. Although the plurality of worlds was a theologically iffy subject, it had gained a sort of intellectual cachet due to the rediscovery of Aristotle.

During the Middle Ages, Arabic science and technology were far more advanced than their Western counterparts, which had deteriorated from the high and heady times of the Classical era into not very much at all. In contrast, the Islamic Golden Age saw the invention of the decimal number system, algebra, optics, and Ptolemy’s Almagest. From the 11th century, Islamic scientists began to question Ptolemy’s model, but they mostly still worked within the traditional geocentric framework. A minority did posit possible heliocentric models – including Ibn al-Haytham (965-1039), who was particularly sceptical about the emphasis on the supposed “proof” of the perfect circle:

“Ptolemy assumed an arrangement that cannot exist, and the fact that this arrangement produces in his imagination the motions that belong to the planets does not free him from the error he committed in his assumed arrangement, for the existing motions of the planets cannot be the result of an arrangement that is impossible to exist…. for a man to imagine a circle in the heavens, and to imagine the planet moving in it does not bring about the planet’s motion.”

One of the first truly experimental scientists, al-Haytham’s scepticism extended to the idea of taking information on faith, especially when it came to scientific knowledge.

“Therefore, the seeker after the truth is not one who studies the writings of the ancients and, following his natural disposition, puts his trust in them, but rather the one who suspects his faith in them and questions what he gathers from them, the one who submits to argument and demonstration, and not to the sayings of a human being whose nature is fraught with all kinds of imperfection and deficiency. Thus the duty of the man who investigates the writings of scientists, if learning the truth is his goal, is to make himself an enemy of all that he reads, and, applying his mind to the core and margins of its content, attack it from every side. He should also suspect himself as he performs his critical examination of it, so that he may avoid falling into either prejudice or leniency.”

Unfortunately, al-Haytham was not to become the pattern of Islamic science. From the tenth century internecine conflicts between the rational and the orthodox branches of Islam occurred, and the latter gained ascendancy. Islamic science and technology stagnated – but not before the innovations they had created and the copies of Classical literature that had been saved were passed back to Europe.

This occurred mainly in Andalusia. The Moorish conquest of part of the Iberian peninsula saw the spread of Islamic science and al-Haytham’s experimental and research methods into the European continent. Latin translations were made of the great Islamic and Classical texts, and this kick-started the European effort, just as Islamic science was beginning its decline. The influence of the Classical texts – especially those of Aristotle – was potent. Aristotle’s conception of the Prime Mover gave him greater standing than other pre-Christian philosophers in the eyes of the Catholic Church. It was one thing to dismiss one of the greatest acknowledged thinkers of all time as a pagan doomed to hellfire for the crime of being born before the Church could redeem him. It was quite another to spin him as having a glimpse of the one true God – it made Aristotle not so doomed after all, and it was more acceptable for people to believe in his ideas than it was for them to believe in the “atheism” of Democritus and Epicurus.

One of Aristotle’s biggest champions was the priest Thomas Aquinas (1225-1274). Aquinas’ teacher, the Dominican monk Albertus Magnus, stated in his De Caelo et Mundo: “Do there exist many worlds, or is there but a single world? This is one of the most noble and exalted questions in the study of Nature.” The apple didn’t fall far from the tree, and Aquinas explored this question in his Summa Theologica. Basically, he agreed with Aristotle’s idea of order. The perfect circle, and the orderly nature of the observable cosmos, indicated to Aquinas that the Atomists were mistaken. Both Aquinas and Albertus rejected the idea of the plurality of worlds, but there is a wonderful irony in Aquinas’ reasoning.

Being a firm believer in the omnipotence of God, Aquinas reasoned that as God could do anything, it is possible that he could have created other worlds (but that he simply didn’t). This is in lovely contrast to the earlier views of Augustine, who had similarly set views as to the limit of God’s power. Augustine argued that there were certain things that God could not do – for instance, he could not commit suicide. Whether (or if) Augustine considered the possibility of God creating other worlds as within his power is unexplored.

It is a shame that we don’t have a working time machine. I would pay good money to see a squabble between Augustine and Aquinas over the mess of couldn’t, wouldn’t, and didn’t in their respective assumptions. Luckily, Aquinas’ argument spread to other philosophers, such as the French Bishop of Lisieux Nicholas of Oresme (1323-1382) who spent many happy hours postulating about the other worlds God could have created (but didn’t).

The clause was a necessary one. In 1277 the Bishop of Paris, Etienne Temper – under the authority of Pope John XXI – issued a Condemnation of a grab-bag of heretical “errors” (219 of them, plus assorted offensive books). Amongst these was the idea of the plurality of worlds. It was permissible to speculate on other worlds – but only with a prominent caveat that they did not, of course, exist. Given that the possibility of plural worlds and extraterrestrial life was so inimical to the Church, this can be seen as one of the early footprints on the road to the burning of Giordano Bruno. In deference to the compassion of the Church, however, I must grant that they could have been more successful in repressing this doctrine by beginning the burning earlier (but didn’t).

“No right to question…”

This repression intensified in the Renaissance, just as the debate on the theological state of any theoretical worlds was gathering momentum. William Vorilong (d.1463) was the one to get the ball rolling, with two inflammatory arguments: that if other worlds existed, they might be un-Fallen (thus making their rational inhabitants better than us!), and that even if they had Fallen like humans did, Christ only had to make the sacrifice on the Cross here and it applied to all other worlds automatically (thus raising images of this not being the case, and putting an infinity of bloody deaths into the starved and slavering imaginations of the great unwashed).

Naturally something had to be done, to stop mad scientists stirring up the masses – and not only regarding other worlds, but also concerning the state of this one. It had become a hot topic, with strong opinions on either side. The German cardinal Nicholas of Cusa (1401-1464) had come out against the perfect circle theory, and he was supported by such intellectual heavyweights such as the astronomers Nicolaus Copernicus(1473-1543), Johann Kepler (1571-1630), and Christiaan Huygens (1629-1695). It is important to note that, in many cases, the supporters of heliocentrism were also the supporters of the infinite universe.

The lot of scientists and freethinkers (the tiny minority) throughout the Renaissance was a mixed one. On the one hand, the great flowering of science and technology (including the progression of optics and the invention of the telescope just about the time Bruno was having the stars taken out of his own eyes) meant that whole new worlds were (literally) opening up to them. On the other, the existence of a rationalist philosophy was rightly seen by the Catholic Church as an increasing source of danger to them, and steps were taken to negate the possibility of the scientific method being turned against the viability of the scriptures as the inspired and literal word of God.

Thus the conservative backlash against this disruptive position was based upon the inerrancy of the Bible, and the absolute authority of the Catholic Church to interpret it. Luiz Nuñez Coronel (an early physicist, and author of Physicae Perscrutationes) asserted in 1511 that because the Church had pronounced the position for the plurality of worlds as heretical, then members of the Church had no right to regard any of it as open to question. In effect, Nuñez was advocating a gag order – denying freedom of thought and speech in order to shore up the position of the Church.

This is a truly conservative viewpoint, but it was not one that was likely to last in the intellectual environment of the Renaissance. The essence of both science and freethought is the ability to question received wisdom – whether religious or scientific – and to replace it with new information if that information better explains the world around us. There are some who see this as a weakness of science: “Why should I believe what the scientists say, when tomorrow they’ll be telling me something different?” The answer to this question is that science does not provide certain results. It provides certain methodology. This methodology gives answers, but they are self-correcting ones. Hypotheses are made and tested – just as Ibn al-Haytham tested his optical theories – and the old ones are thrown out if the new are found to be even a little bit better. The new answers do not have to give the whole truth, but science corrects itself to give a more complete one. As new discoveries flooded the Renaissance, and technology slowly became more and more advanced, the means of testing and the entrenchment of both the scientific method and William of Ockham’s principle of parsimony gave a new impetus to rational inquiry. This has been reflected in the centuries since Bruno’s murder, with science and freethought continuing to gain momentum at the expense of those who would crush it; that which would advocate that we should wallow in ignorance like the proverbial pig in its sty, piously telling ourselves all the while that doing so is indicative of a humble nature, and illustrates a noble and trusting test of faith.

Giordano Bruno would have known how to answer that.

Bruno was unlucky. Arrested before the invention of the telescope or the many other fascinating and marvellous devices humanity has invented since, he had no means of producing verifiable and replicable proof against an institution determined not to face the fact that their viewpoint had become obsolete.

The universe today.

Blackened around the edges or not, Bruno’s idea of the infinite universe was correct. This has been a difficult idea to grasp – and not only by the religious – because of the apparent paradox inherent in the formation of an infinite universe from the Big Bang, where primordial material of extreme density and temperature exploded to form the expanding universe as we know it today. This paradox can be more easily understood by analogy. Imagine that the primordial, pre-Bang state is that of an egg. (This follows in the footsteps of the Hindu creation mythology of the cosmic egg, which was later picked up by the scientists of the 1930s to explain the Bang itself.) Within this egg, all matter is compressed, just as a hen’s egg has yolk and egg white compressed within it. That matter is finite. To use the hen’s egg example: we can hold it in our hand. Now if, shuffling around the kitchen in an early morning stupor, I was to drop my breakfast egg before I was able to put it in the frying pan, the egg would fall to the ground and shatter. There would be a very sticky mess – but it would be a finite mess. I could easily clean it up, which I would not be able to do if the finite yolk and egg white suddenly began to expand into infinity, spilling out of the house and eventually taking up all space in the universe.

Hence the paradox. The universe is expanding – that has been determined experimentally through the phenomenon of red shift. This universe is filled with matter. How can it be, if the universe is infinite and the matter is not? The answer is quite simple. The momentum from the initial explosion – from the moment when the egg shattered – is still driving the matter outwards. Galaxies are flying apart from each other, and the universe is expanding, but the matter itself is not, although it may be transformed. The only thing that is increasing is the space between the clumps. Imagine ten soap bubbles in an enclosed room, and compare it to ten soap bubbles outside during a windy day. Although the same number of bubbles are present each time, the space between the outside bubbles increases because of the wind. There are not any more of them, but they are becoming more spread out than the bubbles in the room. This is what is happening with the galaxies. Space itself continues to expand, and the matter is propelled into it. We are propelled through the infinite universe on the surface of our own planetary bubble – although please note that the analogy of the bubbles does not extend to the necessity of a bubble-blower!

But if the universe is infinite, how can it expand? How can it become more infinite, or “infinity squared!” as children tiresomely shriek when getting into a “Bags one!” “Bags two!” “Bags infinity!” contest as to who gets to sit in the front seat. Wonderfully, the noisy brat who squares infinity is in the wrong. Infinity squared is still infinity, and is no more or less infinite than the square root – this can be proved by a relatively simple one-to-one correspondence in series mathematics, a subject available in any undergraduate university mathematics department.

There is also no longer any doubt as to the existence of other planets. To date, 254 extrasolar planets have been found, with the aid of radio arrays and orbiting telescopes such as Hubble. Many of these planets are very different from Earth – some are gas giants such as Jupiter, others are rocky ice giants. An example of one of the exoplanets found this year is the Neptune-sized ice giant GJ436b, which orbits the M-class star Gliese 436, located 30 light years from Earth. From density measurements, GJ436b is thought to be half rock, half compressed and frozen water.

Bruno’s assertions on the infinity of the universe and the plurality of worlds have been proven. Not so his speculations about the existence of extraterrestrial life. The search goes on, however. National space organisations such as NASA and the ESA, and non-governmental projects like SETI (the Search for Extra-Terrestrial Intelligence) continue to capture the funding and imagination necessary for their work to continue.

Rehabilitating Bruno.

In his 1881 book, Colonel Robert Ingersoll – an American state attorney, political orator, and strong supporter of humanism and freethought – had this to say about the death of Giordano Bruno.

“The murder of this man will never be completely and perfectly avenged until from Rome shall be swept every vestige of priest and pope, until over the shapeless ruin of St. Peter’s, the crumbled Vatican and the fallen cross, shall rise a monument to Bruno, — the thinker, philosopher, philanthropist, atheist, martyr.”

This harks back to Diderot’s even more bloody religious condemnation of the previous century: “Man will never be free until the last king is strangled with the entrails of the last priest”. Sympathetic as I am to these sentiments, one really has to ask if they are at bottom any different from the mindset that murdered Bruno.

Giordano Bruno was not killed by the priests of today – or even the priests of the nineteenth century, despite Ingersoll’s attempt to smear them all with the same bloody brush. Nor does demolishing every trace of that institution – including some of the great world treasures of art – provide any sort of useful revenge. The man is dead, after all. Satisfying as bellowing hyperbole may be, there is always someone stupid enough to take it seriously, and wanton destruction won’t bring Bruno back.

The most that can be done for Bruno is to vindicate his astronomical ideas. Not all of them had any lasting merit, but his beliefs on the expansion of the universe and the possibility of extraterrestrial life have attracted such a weight of proof that even the Catholic Church, the same institution that silenced him for holding these views in the first place, is slowly coming around. In 2000, Pope John Paul II formally apologised for his murder, although Bruno is never likely to be rehabilitated. According to Cardinal Paul Poupard, who is Chair of the Vatican Cultural Council, Bruno’s teachings are “incompatible” with those of the Church.

What good is an apology now? One might ask. It’s several hundred years too late, and Bruno’s not around to benefit from it.

We are.

Many religious institutions around the world hold various beliefs which are irreconcilable with scientific evidence. Worse, they put forward these beliefs under the umbrella of science in a misguided attempt at legitimacy. An example of this is the attempt to shoehorn Creationism into public school science classes by tarting it up as “Intelligent Design”. Worse still, those who dissent are still subject to religious sanction. For Catholics, this no longer means recanting or being burnt at the stake. Other religions are not so lenient. That does not mean that the atheists, the agnostics, the scientists, and other freethinkers should descend to that level, and Ingersoll and Diderot do their cause a disservice by suggesting otherwise.

Those of us who want the freedom to question entrenched dogma of any kind live in a fortunate time. In the centuries long collision between science and religion, the former is finally winning out. It may be slow, and there may be setbacks. We may even be wrong, and some of our theories proved impossible. No matter. Let us be slow, and thwarted, and wrong, but let us also remember the value of curiosity, and of questioning. Let us maintain that value to the end. Let us be Bruno – and let us hope that his statue, which now presides in Rome’s Campo di Fiori, outlasts the institution that burnt him alive at that same spot so many centuries ago.