A Candle in the Dark

A look on science, politics, religion and events

Archive for May 2007

Astronomy

with 5 comments

I had a really fun astronomy session yesterday, thanks to a monstorous 10 inch Newtonian reflector made by Celestron.

I had joined the assembly of curious astronomy enthusiasts sometime after sunset, when there was still some significant light pollution in the sky. Then, while trying to figure out the ecliptic by looking at Venus, Saturn and the Moon, I was able to see something unusual. It was a small, high speed light source which was visible as it passed the moon. After some initial confusion, we soon realised that it was an artifical communication satellite, and we had seen an Iridium flare.

Then, there was a lecture on the constellations, and some famous “landmarks” in the sky. Even now, I don’t understand how people claim Leo looks like a lion, by any strech of imagination. However much I try and imagine, it ends up looking suspiciously like a mouse. Anyway, after the lecturer pointed out some more constellations which I couldn’t visualize, it was finally time to play with the telescope.

The first object we looked at was Venus, which was in half phase. The planet was shimmering in greyish white and the surface was absolutely featureless, although I could make out the crescent shape. It was also scintilatting a lot, which must have been to the haze in the atmosphere.

After that, was the real treat of the night, when we pointed the telescope at Saturn. Wow! It was absolutely magnificent! It’s like a precious stone painted in a canvas of black. The rings are entirely visible and wonderful in color. You can even see the bands on the “surface” of the gas giant. And right next to Saturn is the dot that’s Cassini. Viewing Saturn through the telescope was the highlight of the night.

Next on the list was a very bright Jupiter. We had to wait a bit for the planet to rise from the horizon, but boy was it worth it! The view through the telescope was fantastic. Jupiter is visible as a giant squashed circular disc, and surrounding are 4 satellites (Io, Europa, Callisto, and Ganymede). Although the red spot was on the other side of the planet, the reddish cloud belts were clear to see.

Having completed this mini tour of the planets, we tried to see whatever deep sky objects that were visible over the city light. With the help of the more experienced enthusiasts in our group, we were able to focus on the M13 globular cluster. I found this a slight dissapointment, becuase I couldn’t make out much except an extremely fuzzy ball that was barely visible.

We also had a peek at the Beehive cluster (M44) and the optical binaries Mizar and Alcor in the Big Dipper (Ursa Major)

Finally, (on my insistence :p), we were able to point the telescope at the moon. I was dazzled by the brightness of the moon. We could see various craters near the terminator, and could even make out individual craters.

All in all, that was one of the most enjoyable evenings I’ve had.

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Written by parseval

May 27, 2007 at 2:00 pm

Posted in astronomy, personal

Hubble’s successor

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Nasa unveils Hubble’s successor

The US space agency Nasa has unveiled a model of a space telescope that scientists say will be able to see to the farthest reaches of the Universe.

The James Webb Space Telescope (JWST) is intended to replace the ageing Hubble telescope.

Officials said the JWST – named after a former Nasa administrator – was on course for launch in June 2013.

The full-scale model is being displayed outside the Smithsonian National Air and Space Museum in the US capital, Washington DC.

Yaay! I can’t wait for Nasa to launch this. It’s our window into the past, into the birth of our universe.

One of my friends pointed out that it costs as much as the age of the earth in years. Nice coincidence for something cosmic

Written by parseval

May 11, 2007 at 7:52 pm

Posted in astronomy, science

The Wikipedia debate

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By now, everyone would have used the free online encyclopedia that anyone can edit, Wikipedia. It’s is a portmanteau of wiki and encyclopedia. As you might have already known, “Wiki” comes from a Hawaiian word for quick, and an encyclopedia is where you get “reliable” information. By using Wikipedia, it is claimed that one can find information on practically anything. Also notice that a google search on any topic tends to throw up a Wikipedia page in it’s first three links.

What does this Google-Wikipedia synergy actually lead to? It means that, whenever you need to find information about something, and you Google for it1, there’s a high probably that you end up on a Wikipedia page. So, the next logical question is, how does it matter? If Wikipedia is an encyclopedia, then it should be a good place to find information, shouldn’t it?

This is where some people think there’s a problem. By letting anyone edit, there’s a fundamental flaw in Wikipedia, and it’s the problem of credibility. This flaw is especially true in science related articles. The fact that anyone can edit Wikipedia, means that someone who’s not an expert can easily edit and publish the article, without any peer review or scrutiny from experts. The proponents of Wikipedia argue, based on faith, that the good and accurate articles will end up surviving, and the erroneous information will be removed.

So, although Wikipedia has an impressive collection of fairly accurate articles, such Pink Floyd or Topsy, is it something you should use when you want to learn something for the first time? A number of critics, including myself, believe that Wikipedia is not the place to go if you need scientific information, because it cannot guarantee reliable, accurate or valid informaton.

From John Baez’s2 website on physics 3

At any given time, the Wikipedia unquestionably boasts some very impressive articles on scientific topics. Nonetheless, its utility as an encyclopedia is fatally compromised by the existence of a surprising number of articles which appear at first glance to be sober, factual, and supported by impressive citations, but which are nonetheless a farrago of misinformation. The problem here is that only an expert may be able to spot subtle misinformation in articles on highly technical scientific topics. The point is that an “encyclopedia” which can be safely consulted only by those who are already experts on the topic at hand is not a true encyclopedia at all!

A steadily growing number of Wikipedia articles uncritically promote fringe science “theories” or scientifically suspect investment schemes, including a surprising number of devices which, if they functioned as advertised, would constitute perpetual motion machines. It is an article of wikifaith that Wikipedia articles will improve monotonically as more people contribute edits, eventually approaching a stable state of near-perfection. In particular, adherents of the faith allege that “army of watchful volunteers” will quickly spot and correct any misinformation. However, I have been tracking problem articles for almost two years, and I know that this faith is misplaced. Many of the worst physics articles have very obviously never once been edited by a genuine physicist. Even worse, I have carefully examined the edit history of hundreds of bad science-related articles in the Wikipedia, and in dozens of cases, I believe that the evidence suggests that articles which were allegedly written by a disinterested volunteer, were in fact written by someone having a direct financial stake in the claims described in the article. (This kind of deception is known as “wikishilling”; it is simply the latest variation on a technique which has long been employed by scam artists.) These observations appear to be consistent with a general trend toward increasingly sophisticated and insidious attempts by pseudonymous editors to manipulate information presented in the Wikipedia in order to pursue some hidden personal agenda.

The trouble is that Wikipedia has erected almost no barricades to guard against such abuses. Indeed, many feel that, while traditional printed encyclopedias are biased toward mainstream knowledge — and justifiably so, since mainstream knowledge is the most stable and reliable — the Wikipedia is if anything biased against mainstream scholarship.

So, how does one best use Wikipedia? The best way to use it, would be with extreme caution. You could use it as a starting point of your quest for information, and verify whatever information you get with other independent websites. However, In the case of learning science, you’re probably better of sticking to your book. A textbook is a structured, credible, peer-reviewed and best source of information if you want to learn something new.

If you’re interested in the debate, there are some excellent articles written by various authors you can find in the External Links section.

Notes & External Links

[1] – And let’s face it, you’re hardly going to search in a different way.
[2] – Yes, the irony was intentional…
[3]Misinformation Concerning Cosmology and Relativity

Some external links
Why Wikipedia Must Jettison Its Anti-Elitism – Larry Sanger, co-founder, Wikipedia
The Faith-Based Encyclopedia
On “Digital Maoism: The Hazards of the New Online Collectivism” – Jaron Lanier.
Avoid Wikipedia, warns Wikipedia chief

Written by parseval

May 3, 2007 at 2:33 pm

Posted in internet, science