20121129

Water ice on Mercury?

For a long time now scientists have pondered the idea that Mercury, the first planet of out solar system, harbors water ice on its polar regions. This was first strongly indicated by data from Arecibo radio-telescope, when it was noticed that the radar reflections from some places on the pole seemed much brighter than that from the rest of the surface. These brighter reflections suggested that there might be water ice on surface of Mercury, which is, as we thought, not really a planet on which we'd expect to find frozen water. However, due to its extremely small rotational tilt, which is less than 1° (which means that the rotational axis of Mercury is almost perpendicular to the plane of its orbit around the Sun), some craters near the pole, or rather floor of some craters, never gets hit by the light from the Sun. And, true enough, these bright radar reflections coincided with big craters pictured by the Mariner 10 in the 1970s.

Enter MESSENGER.
MESSENGER in orbit around Mercury (artist's impression).
MESSENGER is a robotic spacecraft which arrived at Mercury last year, becoming the first spacecraft ever to enter into the orbit around it. Since then, it had presented us with data such as we'd never see before. And now it seems to have confirmed the 'water ice on poles' hypothesis. Pictures taken by its Dual Imaging System show that the radar-bright patches are indeed within the shadowed regions around both poles. 
Red: permanently shadowed regions; yellow: polar deposits indicated by Earth-based radar
You'll notice how well yellow points correlate to craters. This really is the best place to expect water ice on Mercury, since, as said before, these are the parts of its surface that never get warm enough for water to evaporate. So there we have a strong indication of water ice on one of the hottest places in our solar system.

Next, using neutron spectroscopy, the average hydrogen concentrations in these radar-bright regions are measured. The data from this experiment shows a hydrogen-rich layer, 0.5 to 20 meters thick, a few dozen centimeters below the surface. The amount of hydrogen in this layer is consistent with the amounts found in almost pure water ice. So this data also strongly corroborates the hypothesis.

One other amazing thing was found, too. There are indications that some regions in the craters are dark, while others are bright. The best explanation for this phenomenon is the presence of organic molecules. Now, don't jump out of your chair just yet - this does not mean there is life on Mercury! It does show, however, that the basic building blocks of life can survive some pretty harsh conditions. This organic matter is carried around our solar system on comets and asteroids, and seems to be quite abundant (it might have seeded the Earth, too, a long time ago). And with one more place with (almost) confirmed water, we can now see that the ingredients for life as we know it are much more common in the vast expanse of our solar system, and, very likely, the entire universe, then we previously thought.


If you want to read more about MESSENGER mission and this most recent discovery, I recommend these two links:


20121127

When the absence of evidence becomes evidence of absence

There is a traditional axiom that states: “absence of evidence is not evidence of absence”. But this statement is simply false, which is quite easy to understand. Irving Copi, an American philosopher and logician, said: 
"In some circumstances it can be safely assumed that if a certain event had occurred, evidence of it could be discovered by qualified investigators. In such circumstances it is perfectly reasonable to take the absence of proof of its occurrence as positive proof of its non-occurrence."
So when does the absence of evidence become evidence of absence? As an example I'm going to use the awesomest creatures of all time - unicorns (if you don't like unicorns you are a terrible, terrible person and I hope a herd of space unicorns runs over you with their hoofs of fiery doom). We almost certainly know that unicorns do not exist. There is a minor possibility that they do, perhaps. There are still some places on Earth we haven't explored, or they may be really good at hiding. Perhaps they live on trees so we don't see them from all the leaves (also, who would even think of looking at trees while searching for unicorns?). But surely someone would have collected at least one piece of evidence for their existence by now if they really existed, right? Yet there is no evidence. None. Zero. We can't prove with complete certainty that there are no unicorns. We can't really create an experiment which shows that there are absolutely no unicorns somewhere on Earth, except for sending a billion search parties to simultaneously comb the entire planet. Yet the absence of evidence clearly speaks for itself, thus becoming the evidence of absence. Sorry to disappoint you, but there are no unicorns. (I myself am very saddened by this).
Well, shit.
Okay, now simply replace ‘unicorns’ with ‘god’ and the argument starts to take shape. God is supposed to be this all-powerful super-being who mingles with lives of ordinary people on a daily basis. This means the evidence should be more than abundant. Yet there has still been no scientific proof whatsoever for the existence of god or his ‘miracles’.

First off, what is a ‘miracle’, anyway? By definition, it should be an extraordinary event, something that’s statistically so unlikely to happen that, for all practical reasons, we can regard it as impossible. However, language is a tricky business so we oftenly use a word ‘miracle’ to describe ordinary, but beneficial or simply ‘very nice’ things, like a birth or a victory over a disease. To be clear, I do not consider this a miracle, nor does any sane person confuse this kind of ‘miracle’ with an ‘actual’, out-of-this-world-force induced miracle. So, what would we consider a real miracle? One situation I can think of is if someone who lost a leg grew one over the night, or over a month, or over a year. Yet, somehow, this has never happened, as far as we know, in the whole history of mankind (except if you are part human part starfish - then it might have happened, which is awesome, and I want to be your friend). There are probably a few stories and anecdotes, but recorded evidence from reliable sources is missing. So we can assume this kind of miracle doesn’t happen. Another miracle would be if the Sun suddenly disappeared from the sky. If we don’t count eclipses, since in the case of an eclipse the Sun remains where it always is, this kind of thing never happens. And thank goodness it doesn’t, because that would be one very stupid and counter-productive miracle. So we have no real evidence of miracles. Occasionally, the media reports a supposed miracle, which somehow always crumples to dust when confronted with a team of objective researchers. For example, weeping madonnas are surprisingly easy to fake. Then there is the case of Audrey Santo. There are also all kinds of reflections on windows which happen to be chemical instabilities in the glass, or supposed faces in tree-bark, bread, stones, whatever you want, which can be easily dismissed as cases of pareidolia. Lots of 'miracles', less than zero evidence.
Holy crap it's a rainbow vaguely resembling a veiled woman!
So what we do have is a bunch of old stories, anecdotes and hearsay of a supposed miracles that either cannot be proven, were scientifically debunked, or are simply misinterpreted events that are not likely to happen, but with a significant statistical chance to happen after all (a person waking up from coma, surviving cancer, or winning a game of Arkham Horror). Surely by now we should have at least one solid piece of evidence for one of these alleged miracles which 'prove that god exists'? Yet there is none! And no evidence in such a long time, with so many chances of being recorded, scrutinized and shown to be true, leads to only two possible solutions - either your god is terribly shy and at least as good as unicorns at hiding, or he does not exist. And Occam's razor states that the simpler hypothesis is true, so I think we can all guess which one of these two possibilities is an actual case.

Also, don't forget: if you can't explain something, that doesn't make it a miracle. Similarly, just because science doesn't have an explanation of a certain occurrence, it doesn't mean it never will, or that it's a miracle. Sorry.

20121124

Save the whales!

Today I just wanted to share a beautiful short video I found on Vimeo. I recommend watching it on full screen with HD option on. It's well worth it, believe me. 


Requiem 2019 from Sil van der Woerd on Vimeo.

Whales are the largest animals that ever lived on the Earth, with blue whales reaching up to 30 meters and 180 tonnes. They are one of the best examples of evolution at work, with vestigial hindlimbs sometimes present inside their bodies even today. This shows that whales are descendants of land-dwelling mammals which belonged to Artiodactyl order. Their closest relatives today are hippos. (This does not mean they evolved from hippos, of course, but that both of these species have a common ancestor). You can read more about the evolution of whales here
A humpback whale breaching.
Some people consider whales highly intelligent, what with such a long presence on the planet, and while I'm still very skeptical on this front, it is interesting to consider that they do have different dialects and accents, just like we humans do. Intelligent or not, whales are wonderful animals which should be cherished, instead of slowly killed out (whaling is still legal in some countries, which is both appalling and sad). Not only do humans pollute the oceans with different chemicals and garbage, we also create a terrible sound pollution with ship engines and sonars, which confuse and distress whales that rely on sound for navigation in the dark deep waters. To read more about the threats to whales and dolphins, visit this page

It's saddening to see how anthropocentric we as a species have become, and it will take us a long time to figure out how to live in harmony with all the different kinds of animals, whales included. I just hope it will happen soon, before we destroy the biodiversity of the planet, and, with that, ourselves.

P.S. This post may or may not have something to do with today being a 153rd anniversary of official publication of Charles Darwin's On the Origin of Species, one of the most important books in the history of mankind.

20121122

Scenes from the Garden: Leaves

Another beautiful autumn day here in Dubrovnik, warm and sunny as if it was spring. Today I decided to take photos of some of the different leaves you can find in my Garden (I follow Google+ trending topics, you know). Since it is autumn whether it seems like it or not, a lot of plants are in the process of loosing their leaves, so I bring you only five photos I deemed most worthy.

The first plant is Mimosa pudica, one of the prettiest trees we've ever had in our Garden. It used to be a huge tree, but when the roots started to do damage to the walls, we had to cut it down. I was pleasantly surprised to see a few young offshoots growing more than five years after we've cut the original tree down. It's a very interesting plant, with bipinnately compound leaves which can rapidly close under certain stimuli, like touching, warming etc.
Mimosa pudica
Mimosa pudica
Next comes a well known plant, Rosa rosa, or, if you don't speak Latin, a rose.
Rosa rosa
Rosa rosa
For the next one I chose a beautiful (when in bloom) Lilac vulgaris, or Common Lilac. This one has also grown in the Garden since the dawn of ages, and I remember looking for a five-petal flowers to drop down my shirt, which supposedly brings you good luck, if you believe in that sort of nonsense (as many kids do, I guess).
Lilac vulgaris
Lilac vulgaris
Last one is so abundant in the Garden that I decided to take two photos of it. It is also one of my favorite plants, an invasive and poisonous species which serves as a great background for numerous spooky, haunted old houses. It is, of course, Hedera helix, also known as Common Ivy. If you don't mind having such a nuisance of a plant in your garden, it is great for attracting all kinds of bugs and birds which you can watch for hours when you're bored.
Hedera helix
Hedera helix and Tricyclus antiquus
Hedera helix
So, anyway, these are only some of the plants in the Garden. Which plant is your favorite? :)

20121121

Scenes from the Forest: Mushrooms

Not many people are lucky to have a forest near their living place, especially now that we're all living in cities. I am, however, lucky enough to have a whole forest right out of my apartment. I spent my entire childhood running through it and playing with my friends, and today still I kept a habit of visiting it every now and then, although none of my friends accompany me any more. So today, since it was a surprisingly nice and warm day (my girlfriend even went for a swim), while returning from the hospital I decided to go through the Forest. It is not a huge forest, and it takes about 10-15 minutes to walk its entire length, but it's a relaxing 10 minutes nevertheless. Anyway, while checking what I surely hope is a fresh dog grave, I noticed a few mushrooms a few meters away, plucked out of the ground and thrown aside. Now, I hate it when people pick flowers and plants, but it's even worse with mushrooms since many of them live for less than a week, so I was somewhat sad when I noticed them. However, it did give me something to do this afternoon: I tried to classify two of them. Since I'm not a mycologist, nor have I ever before tried to classify fungi, it was a fun and a bit frustrating endeavor.
Many people don't really think much about mushrooms, except when choosing toppings for their pizza, but they are actually quite a peculiar sort of beings. Neither plants nor animals, mushrooms are actually fruit of a fungal organism hidden beneath the ground, just like an apple is a fruit of an apple tree. Hence it is also a reproductive organism of the fungi, carrying the spores with which it ensures the continuous survival of its species.
Russula aurea and Amanita virosa, side by side
As I said, I picked two of the mushrooms I found and carried them back home with me, hoping to be able to do the classification. Using the amazing powers of the almighty Internet, I now think I might have managed to do so.

The first mushroom is, I believe, Russula aurea, also known as gilded brittlegill. It is almost without a doubt of the Russula genus, and as for the species, it's hard to be completely certain since it has apparently been out of the ground for some time now, so it's already rotten a little. It could also be Russula vesca, but it's usually more brown than the one I found. If this is indeed Russula aurea, then I got really lucky, since it's an uncommon species which, as opposed to many others from its genus, is edible and also, according to Wikipedia, mild-tasting. I decided to skip the eating and tasting part, so I'm gonna trust Wikipedia with this one.
Russula aurea
The other one should be Amanita virosa, with a very foreboding common name, European destroying angel. It's apparently deadly poisonous, if you didn't catch that from the name. This one is quite big, with a 13 cm wide cap and 10 cm long and 2 cm thick stem. It's quite a nice specimen, which makes me even angrier at the person who destroyed it.
Amanita virosaAmanita virosa
Now, again, I'm not a mycologist and I have no idea if my classification is anywhere near correct. If you know the exact species of the mushrooms I found, please do tell in a comment. Whether correct or not, it was very fun and quite an educational afternoon, so I'm really happy and content, and a little angry and sad.

So, do you have any experience with fungi? :)

20121119

Florida senator Marco Rubio confused about the age of the Earth

Before I start this post, I want you to read this quote very carefully:
I'm not a scientist, man. I can tell you what recorded history says, I can tell you what the Bible says, but I think that's a dispute amongst theologians and I think it has nothing to do with the gross domestic product or economic growth of the United States. I think the age of the universe has zero to do with how our economy is going to grow. I'm not a scientist. I don't think I'm qualified to answer a question like that. At the end of the day, I think there are multiple theories out there on how the universe was created and I think this is a country where people should have the opportunity to teach them all. I think parents should be able to teach their kids what their faith says, what science says. Whether the Earth was created in 7 days, or 7 actual eras, I'm not sure we'll ever be able to answer that. It's one of the great mysteries.
You did? Great. Now read it again, then laugh and/or weep. Since you are reading this post, I'm gonna presume you know how to read. From that, I'm gonna extrapolate that you have some basic education. Assuming you're not deliberately ignoring a century of scientific work, by this point in your life you should very well know that the age of the Earth is somewhere around 4.5 billion years. If you want to be precise, it's 4.54 billion years ± 50 million years, with an accuracy of 99%. And we know this because a huge number of scientific areas converge and agree on this point. So when you read a quote that says something along the "I don't know" lines, what you should do is smirk and ignore it, or, if you're into that kind of stuff, react by trying to educate the person who originated the quote. And all stops there, you try, succeed or fail, and move on. But when a quote like this comes from a senator from Florida, Marco Rubio, you should probably start worrying about the state of this civilization. The quote comes from an interview published by GQ magazine, and it's the reason why I've been both laughing and crying since I read it a few hours ago. What's worse, Rubio  sits on the Senate Commerce, Science, and Transportation Committee. Oh the irony.
"The age of the Earth, you say? Hmm... Nope, I have no idea. You should go ask my priest."
So lets just analyze the quote for a moment. Rubio starts off fair by saying "I'm not a scientist, man," thus reaching the point where his answer should end. Instead, he continues to presenting the age of the Earth as a theological problem, completely (and I'd say deliberately) ignoring all the scientist and sciences that for years worked on this problem ("[...] I think that's a dispute amongst theologians [...]"). He then blatantly diminishes the significance of science by saying "I'm not sure we'll ever be able to answer that." Seriously, mister senator? Guess what: we've answered that a long time ago. So I would suggest some reading and studying, before making yourself look uneducated and ignorant in front of the whole world.

I'm not gonna preach about this any more. But I want you to think about this, and figure out in your head how much do you want people like this to lead your nation, country, city, village or whatever. Bear in mind that the people you vote for have an immensely important role in your life, and not just your own. And that it is you, the people, who vote for them. So I suggest being a little more careful the next time.

20121109

Carl Sagan Day

"Carl Edward Sagan (November 9, 1934 – December 20, 1996) was an American astronomer, astrophysicist, cosmologist, author, science popularizer, and science communicator in astronomy and natural sciences. He spent most of his career as a professor of astronomy at Cornell University where he directed the Laboratory for Planetary Studies. He published more than 600 scientific papers and articles and was author, co-author or editor of more than 20 books. He advocated scientifically skeptical inquiry and the scientific method, pioneered exobiology and promoted the Search for Extra-Terrestrial Intelligence (SETI)."
-
from wikipedia
Carl Sagan is one of my role-models, a figure which I will always remember by his playful smile, the way he admired the beauty of nature, and the way he talked about it. When I first watched 'Cosmos', I immediately knew 'what I wanted to be when I grew up'.

Carl, you will never be forgotten.

20121105

Scenes from the Garden: Swallowtail Caterpillar

Papilio machaon, also know as the Old World Swallowtail, with its yellows and blues and reds, is one of the most beautiful butterflies I have seen so far. But this species is special to me for one more reason other than its beauty: its caterpillar is also gorgeous! Not many caterpillars can be called pretty, but this one definitely can. If you don't believe me (to be honest, a lot of caterpillars are just damn ugly), check these images and judge for yourselves (as always, click to embiggen):

20121104

Model Building: Apollo Lunar and Command Modules

One of my favorite hobbies is model building. I prefer aircraft and spacecraft models, though I also have two ships: USS Dwight D. Eisenhower aircraft carrier and USS Bismarck Sea escort carrier. Today I finally built two models I brought with me from my visit to Space Expo: Apollo Lunar Module 'Eagle' and Apollo Command Module, both in 1:100 scale.

The command module was quite easy to build, with not many parts, something around 17.

The 'Eagle' module was not that easy to build. It consists of many really small parts (54 total, I think), like antennae and thrusters and stuff. This one was much more fun to build.

Anyhow, I have two new models! :)

Oh, and yeah, I don't color my models. I just like it more when you can see that these are actual hand-made models. When you color them, they look like factory-made toys, at least to me, and that's no fun.
Well, it is fun, and I like space toys, but these are MODELS. I like models. xD
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