Maurizio – Omnologos

Where no subject is left unturned

Archive for the ‘Astronomy’ Category

Do You Think You’re Important?

leave a comment »

(as my contribution to the Total Perspective Vortex, this is the transcript of my Apr 4th, 2011 10-min podcast for 365daysofastronomy.org, titled “A Copernican Gallop“)

Today we are going to have a Copernican Gallop. We are going to see how Astronomy has made us absolutely irrelevant. What have Astronomers done to us, in fact? Some say that Astronomy must be the important of all Sciences. Perhaps we wouldn’t even have Modern Science without Astronomy. But think also that…were it not for the extraordinary progress of 400 hundred years of astronomy, we would still believe to be the center of the cosmos…instead. we’re now sure we’re not. Not at all. Not by a long shot. And nothing we do is any special (physically speaking), and we actually are in a nondescript part of the Universe. Worse, the Universe itself might be just one of many.

Less than zilch, that’s what we are. And thanks to whom? Well, thanks to the..Astronomers!! None of the major philosophers and religious leaders in the history of humanity has remotely approached the ruthless efficiency with which the scholars of the cosmos have demonstrated again, and again and again what little piece of nothingness we actually are. Only to be replaced by another generation of astronomers, busying themselves in demonstrating that the previous notion of us being nothing, was actually a gross overstatement.

Who started this descent, or maybe you can call it ascent, an ascent to humility? Why, somebody called Niclas Koppernigk, known to us as Nicolaus Copernicus.

Imagine yourself then at his times. It’s around 1500, it’s the Renaissance, and Man is the center of everything. People are defining themselves as the middle point, like the Earth, the center between the perfection of Heaven and the imperfection of Hell. Everything is theirs for the taking, and now that the ancient philosophers of Greece are being rediscovered, it surely won’t take much before the whole world is understood. There comes Nicolaus, instead, no Santa Claus, him…he toppled Earth from the center, in his posthumous book “On the Revolutions of the Celestial Spheres”. And if the center is not here, we’re not the center either. Bye bye Renaissance men!

Worse, Copernicus played like the first ever giant Angry Birds game. He managed to start an incredible chain reaction that might (or might not) have just ended. First stop in the chain reaction, of course, Galileo Galilei with his observations of Venus in the year 1610 demonstrating that planets orbit the Sun, not the Earth. Then Newton, extraordinarily linking in 1687 the force that pushes us down with the force that keeps planets and satellites in their orbit.

Can you imagine? By this time, the revolutionary idea was taking hold, that Earth and the heavens obey the same laws. Let’s continue: Herschel’s map of the Galaxy in 1785, with the Sun located not exactly at the center. Kirchhoff and Bunsen developing spectroscopy in 1859, thereby helping us understand what the stars are made of, the same stuff as the Sun: in other words, determining that the Sun is just another ordinary star, made of more or less the same elements as any other and with billions of almost identical twins out there.

Move now to Harlow Shapley working on Globular Clusters, clusters of stars that is, showing in 1921 how they are distributed around a point some 15kpc from us, the center of the Galaxy therefore being quite away from our Solar System. Even our modern value of 8kpc between us and the galactic center still means we’re somewhere at the periphery.

The philosopher Immanuel Kant in 1755 and then the scientist Alexander von Humboldt in 1845 already made the point that as the Sun is in no special place in the Galaxy, our Galaxy is itself just one of many. And that’s exactly what a guy called Edwin Hubble demonstrated, in 1924.

But wait…isn’t that the same Hubble that came up with the idea of an expanding universe? Is that not supporting a birth for everything in what we call the “Big Bang”? Doesn’t that make us special, as we’re only 13 billion years away from it, that is next to nothing compared to quadrillions of quadrillions of years until the last photon is emitted?

Not so fast. One of the most popular ideas in contemporary cosmology is in fact the existence of a multiverse, a collection of universes just like ours, a concept that elucidates several issues including why our universe exists at all. Some say the number of universes is in the region of 10 to the 500, a number that is totally alien from all our levels of comprehension. Obviously, even if a minute fraction of that number is the true value for a count of all existing universes, our own universe is just, simply, merely one of several many. End of the story?

No. This humility extravaganza doesn’t only work at giant scales. Consider the consequence of finding as many extrasolar planets as we’ve actually discovered as yet…our own doesn’t appear to be either the strangest, or the most interesting (more or less the only thing keeping Earth apart is the existence of liquid water on its surface:
but I would expect a dramatic announcement about that too, sometimes in the near future).

Everywhere we look, at all times we look, we’re one of many.

Let me speak for the rest – we live on just another planet orbiting just another star in just another orbit around just another galaxy weakly attracted to just another supercluster that is anywhere and nowhere really in one universe out of quadrillions of pentillions of them.

And this is the end of the Copernican Gallop. Or is it? An atom in the whole Jupiter is relatively more important than us in the whole of the Cosmos. To what level of nothingness will next generation of astronomers elevate us?

One final word…please. Don’t feel depressed. It doesn’t count, anyway. And this is just another podcast by Omnologos. Thank you for listening.

Written by omnologos

2011/Apr/28 at 12:20:28

Posted in Astronomy, Astronomy & Space, Space

Tagged with

Our Past Is In The Sky

with one comment

Far-fetched as it might seem (and be!), we might be literally surrounded by information about the Earth’s, Sun’s, Galaxy’s past. By looking in the right direction with the right instruments, we could even be able to see how things were at different times, even billions of years ago.

By looking where? This idea is based on a little-known characteristics of black holes, namely the large amount of incoming light that is back-scattered, i.e. sent back more or less in the direction it came from. This phenomenon is visible as a halo around the black hole (see picture to the left).

Think then: by looking at a black hole 20 million light years away, we will be getting some light first emitted by our galaxy 40 million years ago, as the photons will have had to travel to the black hole and back. Correcting for the optical properties of the region around the black hole that we see as a halo, we would even be able to get a picture of our galactic surroundings.

Analogously for black holes nearer to us, eg 20,000 light years away, the halo will literally contain pictures of our neighborhood as of 40,000 years ago.

All of the above is unlikely to be easy, still any information in the back-scattered photons will be extremely valuable.

Written by omnologos

2010/Dec/08 at 15:32:23

Vote Your Favorite Planet

with one comment

Added bonus of this PBS/Nova interactive website is the clarifying that Pluto is not the only “dwarf” planet…

Written by omnologos

2010/Mar/01 at 10:32:18

Posted in Astronomy, Pluto

A Wonderful Place To Die

with one comment

It is called “Mars to Stay” and I hope it will involve a 85-year-yound Italian in 2052 going to Heaven but first stopping for around 30 years on the Red Planet. For the final resting place I select this:

Scalloped sand dunes in the southern hemisphere of Mars

Scalloped sand dunes in the southern hemisphere of Mars

Written by omnologos

2010/Feb/06 at 23:09:17

(Legally) Bombing The Moon

with one comment

Still not much out of the LCROSS team, victims of “HYPErspace” to say the least. Let’s entertain ourselves in the intervening time with a Forbes.com article “Bombing the Moon“. And for those in a hurry:

The LCROSS mission is an important and expensive scientific experiment. Nonetheless, comments on Web sites such as Scientific American and Nature indicate that quite a few people thought the whole venture to be some sort of outer-space vandalism. Some even wondered whether NASA might have acted illegally or violated an international law or treaty by setting out to “bomb the Moon.”

The answer is no. But while many might be surprised–dismayed, even–to hear that there is such a thing as “space law,” there are treaties governing activities in outer space, including the Moon.

Written by omnologos

2009/Oct/13 at 21:50:11

First Law of Planetary Building

with 3 comments

First Law of Planetary Building: no two planets will ever be alike.

Corollary #1: if two planets are almost identical, then at least one of them will have at least one outrageously peculiar feature.

Corollary #2: Universes made of perfectly identical planets are not allowed.

The First Law is manifest in the fact that each planet in the Solar System and elsewhere appears to be a unique, very specific experiment with peculiar conditions that are never repeated elsewhere. Even single satellites are all very different from one another. And if you want to top strangeness, how about Corot-7b with its clouds of minerals?

Mineral clouds

Mineral clouds

One objection could be raised about Venus and Earth, or Uranus and Neptune, as both couples look like made of identical twins. However, Venus’s hellish atmosphere and very slow, retrograde rotation are truly outrageously peculiar features; and Uranus basically lies to one side (hence corollary #1).

Corollary #2 is necessary otherwise the First Law is invalidated. It seems plausible, since the number of universes is large but not infinite.

Written by omnologos

2009/Oct/07 at 00:19:02

The Tragedy Of The Anti-Space Travel Space Scientist

with 4 comments

One can only feel sad upon reading Giovanni F Bignami’s op-ed piece about the race to the Moon and what choices to take for the future (“Once in a Blue Moon “, IHT, 18-19 July 2009). Prof Bignami’s argument appears to be about treating space-faring as a purely novelty product, like a fairly curious but ultimately useless item on a late-night TV shopping channel. Something you may be convinced to buy, but just the once.

And even if we have spent less than a week in total time exploring a few square miles of a place as big as the former Soviet Union, Prof Bignami tries to seriously argue that there is no “compelling reason” to go back to the Moon. And that we should embark on the enormous effort to reach Mars instead, presumably for a couple of trips before getting bored with travelling millions of kilometers too.

Here’s a “compelling reason” then: as it is well known, one needs a lot less fuel to travel to Mars from the Moon, than from Earth. Most of the launch cost lies in getting from our planet to low Earth orbit: beyond that, the whole planetary system is within relatively easy reach.

Prof Bignami remarks also that “the notion of mining on the moon would also [be] environmentally offensive“. I for one do not understand how will humans ever be able to “environmentally offend” a surface pummeled for billions of years by asteroids of all sizes, by a perfectly unhindered solar wind, and by cosmic radiations of all sorts. That is the Lunar surface, made of a type that likely covers several billion square kilometers on hundreds of natural satellites in our Solar System alone.

Paradoxically, the astronomical/astronautical community has been unable to support its own cause since the launch of the Sputnik. Nobody has gone anywhere because of effective lobbying by planetary geologists or solar scientists.

Bignami’s op-ed appears to be yet another example of how bizarrely brainy arguments about going to Mars vs returning to the Moon have succeeded so far only in keeping the human race in low Earth orbit, literally going around in circles instead of literally reaching for the stars.

Written by omnologos

2009/Jul/19 at 20:01:58