The Moon

So after an extended break from blogging, and some pushing from my supervisor, I decided it was time for another post up in here. Earlier this year, Monique (whom I shall affectionately refer to as "the girlfriend") told me about a great deal one of her colleagues had for me. A whole SLR camera bundle, with 5 lenses, and a flash gun (external flash). The girlfriend, who is also an avid photographer (and who does a lot of it for the magazine she writes for) convinced me of the deal's worth, and that I would enjoy photography. Since then, I have learn't a thing or two about photography, and I decided it would make great subject matter for my blog. So today I bring you: The Moon.

A few nights before the last full moon, we got home late one night, and I saw this magnificent sight in the sky: A 3/4 full moon, in clear sky. I decided to try capture it, and this is the result.

It may be of interest to some exactly how I captured this level of detail. I was especially surprised to see the small craters near the day night line. To do this, all I did was hook my 300mm telephoto lens (which on my camera is equivalent to a 480mm), stuck the camera on to a tripod, and pointed it at the moon. I toyed with aperture and exposure settings until one worked. I settled on 1/15s and f/16. A smallish aperture exposed over some time gave me this. As a rule of thumb, a smaller aperture gives you a sharper image. Unfortunately, a bit of blur came in when I enlarged the image, due to a bit of camera shake which occurred when I pressed the button. Camera shake is emphasised at this level of zoom. I have some suggestions on how to make the next attempt better. However, the clouds rolled in a few second after I got this shot, and so I settled on this. I also cropped the photo, with the notable crater ~ midway along the day night line as a focus. Apparently, one's eye is drawn to one of 4 points on an image. I may try an experiment in future to see how true this is.

My idea for this blog is to post more photos in future, with maybe a small write up about how I took them. Photography is my new hobby and I am quite excited about it, and so I have been researching how to make mine better. So some of the details may be a bit technical, but I will also try to capture some kind of story in the posts too. I have a large backlog of cool images to put up here, and I will slowly work through them. Let me know in the comments if this sounds like a cool idea.

Black Hole Search Volume

Spent a few minutes toying with google trends. This nifty feature gives you a relative idea of how often a particular word or phrase is googled over time.

I used it to do some random research on how the Internet contributes to mass hysteria. Found three interesting results in a few minutes. First, do you remember when the Large Hadron Colider was commissioned in 2008 (10/9/2008 to be exact - http://en.wikipedia.org/wiki/Large_Hadron_Collider). There was all this talk about how it could create black holes and destroy the Earth. well, I did a google trends search for "black hole", and see what is showed.

black hole

Interesting, a huge spike just before the end of the 3rd quarter of 2008. Next, remember the movie 2012. Around the time that it came out (13 November 2009 - http://en.wikipedia.org/wiki/2012_(film)), there was a lot of hype about the world's end being tied to the end of the mayan calendar. People actually belived that the movie was an accurate prediction of things to come. Look at the google trend for "mayan calendar".

mayan calendar

I can guess what people were thinking. "Wow, the mayan calendar actually does end in 2012. Everything in that movie must be based on fact." Well, as a space physicist, I can say that is not true. The main plot (SPOILER ALERT!!!!!!!!!!!!!!)

involves neutrinos heating the core of the Earth. Now this is impossible (or if you have read my previous post: http://nerdyguy-fatman.blogspot.com/2011/09/schrodingers-cat.html, it is at best EXTREMELY unlikely). Hollywood Physics - gotta love it.

End of spoilers. Finally, remember earlier this year, we were all told that the world was going to end on May 21st. Well have a look at google trends for "end of the world"

end of the world

I see another big spike around the 21st March. I can see how that rumor spread. Mass hysteria set in. People blew all their savings, and racked up enormous bills not expecting to have to pay them on Monday morning. There was a lot of misinformation going about then. People don't seem to know what the Rapture actually is. But lets not get side tracked. 

In conclusion let me just say the obvious : Don't believe everything you read on the internet. It is an excellent tool for spreading misinformation, and creating mass hysteria.

Schrodinger's Cat

Our faculty is having a funwalk tomorrow, and as a school (School of Physics) we go as a group, and have T-shirts designed. I was asked to find some design for the tshirt. Well, I have kind of had this idea in my mind for the past few months that Schrodinger's Cat would make for a great physics themed t-shirt. I spent a bit of time trawling the internet for some ideas, and some really nice pictures popped up. Anyway, it got me to thinking, how many people actually know the story behind  the unfortunate feline companion of Erwin Schrodinger.

Erwin Schrodinger was a big player in the early development of quantum mechanics, and is responsible for providing the world with Schrodinger's Equation, which allows one to determine the time evolution of quantum states. I'll say no more about that. One of the underlying concepts in quatum mechanics is the one of probability, namely that nothing is certain. Our everyday understanding of how the world works, does not apply in the realm of quantum mechanics. For instance, if I drop a glass full of red wine onto the floor (shame on me), then we all expect that that glass would hit the floor, and spill. But, quantum mechanics predicts that there is a small chance of the glass passing right through the floor, and landing in the basement (either result is bad for me though).

Okay, so back to Schrodinger's Cat. Schrodinger proposed a thought experiment (meaning that he only conducted the experiment in his mind).  For this experiment, one would place a cat in a box, with a sealed vial of poison, and seal the box. The vial of poison is set to release its contents at an undetermined time. So, without opening the box, one has no way of knowing whether the cat is alive or dead. And so we can think of the cat as both alive and dead. Weird, but this is the kind of stuff that quantum mechanics deals with. It is a very complex field.

Anyway, this brings me to my tshirt design idea. I have attached the picture, which I think is from an episode of Big Bang Theory. Also, I should point out that the powers that be opted for a different design, but oh well. Now that you know where it comes from, you can see that it is a rather clever design.

NerdyGuy: Traffic Circles

NerdyGuy: Traffic Circles: I had an interesting, but not entirely unfamiliar experience this weekend. It surprises me that in Umhlanga, where traffic circles are so an...

Traffic Circles

I had an interesting, but not entirely unfamiliar experience this weekend. It surprises me that in Umhlanga, where traffic circles are so annoyingly prevelent, that so many of the local drivers don't understand how to use them. I was going around a traffic circle (I was going straight), much in the way that I have always accepted as correct, and some driver came around my outside, trying to go right. He slammed on breaks, missing the collision, but what made it worse, is that he had the nerve to hoot and use some unrated hand signals. Traffic circles are easy in principle, but there seems to me an inconsistent understanding on what do do if there are two lanes in the circle. My rule of thumb: If you are going let or straight, use the outside lane. If you are going straight or right, use the inside lane. If you are going all the way around (back the way you came) then use the lane you are most comfortable with, but you make very sure you don't obstruct any one when you exit, because no one expects this. Also, appropriate use of indicators is just polite.

But, as my girlfriend has revealed to me, there is an online source from a professional traffic adviser, which explains, with the aid of  a picture-video, exactly how to use them. Unfortunately this does not include any advice for the 360, which in my opinion, raises the most chance for a fender bender.

You can check it out at http://www.arrivealive.co.za/pages.aspx?i=2163. This is something which everyone needs to know how to do, even if you are from Gauteng where (based on what I have seen of their traffic circle etiquette) there are probably very few traffic circles.

Anyway, lets open this up for discussion. Post a comment of how you usually handle the 2-lane daemon (it should be automatic after all).

Cloning a disk using Linux's dd

As a scientist, it is pretty convenient to use linux for my work. It is a flexible, lightweight and not to mention free OS. Over the past 4.5 years of using this system, I have learn't a few handy things, but this OS never runs out of things to teach me. Today, I learn't about using dd to create a cloned hard disk. Now, you will of course need to know something about how linux manages disks and partitions, but hopefully the elegance of this will be evident even if you do not.

dd creates a byte by byte replica of a source to some destination (hard drive to hard drive, or hard drive/cdrom to an image file). The advantages of this are that it only sees 1's and 0's, not files. It will replicate partitions, and file distribution. There are some downsides, like it will preserve "fragmentation" of the drive, and empty space, will still take up space on the image, ie: creating an image from a 40GB drive will produce a 40GB image file, even if the original hard drive was half empty. But, when you want to be sure that your data is preserved, then these are a small price to pay.  

To use dd (which might need to be installed on your particular distro), you would use something like the following (from a terminal of course):

dd if=/dev/sda of=/dev/sdb

where if is the source, and of is the destination. The source can be anything like

/dev/sda; /dev/sda1; /dev/cdrom; /home/user/

and the destination can be anything like

/dev/sdb; /dev/sdb1; /home/user/image.img (hard drive image), or /home/user/image.iso (cd/dvd image).

You might already see how this could be used to create a hard drive image, or optical disk image, which can serve as a backup, or for replication onto several other devices.

Some tips on how to optomise this process are:

1: Change the blocksize to 1MB using "bs=1M"
2: Compress the image file using gzip (or pigz - a parallel version of gzip)

Go Linux!

Another Sunny Video

The Sun demonstrated another spectacular display recently. Here you can see a small limb extending from the sun, and just below it, you can see some "closed magnetic loops". See how the plasma races along these field lines. This is the net I spoke of in my previous post. If enough plasma gets trapped in there, it can burst as a CME.

Credit to www.spaceweather.com for the image.