Monthly Archives: July 2012

Idealism and realism


Idealism and Realism are terms that are used a lot to describe people, political ideas or groups, but a lot of people that use these words don’t really know what they mean. My last post is a good example of what idealism is, a notion that the world and reality are not as constant as they appear to be, that existing structures can be overthrown or changed by ideas or at least depend on how they are interpreted. On the other hand you have realism a notion that the reality or the world does not depend on how we interpret it, that our beliefs and ideas do not affect reality. These two opposites can of course be applied to different things, for example it is a lot easier to have an idealistic notion of society since it is clearly influenced by ideas and beliefs, while it requires a little bit more effort to construct an idealistic notion about the laws of physics. There are lots of other terms like these two that philosophers use to categorise ideas and beliefs, if you want to know more I would suggest starting with searching terms like Determinism and empiricism on either wikipedia or the Stanford Encyclopedia of Philosophy

Why are the laws of physics the way they are?


Today I’m going to talk about an idea I’ve had for a few years. Before Einstein discovered his theory of general relativity the math behind it, about curved space was already discovered for a while, the same is true with the slow discovery of Quantum mechanics, before that started a lot of the math used to describe it was already discovered. In a universe where the math or the idea is always discovered before it is linked to physical properties one could imagine that the idea itself is the cause of the physical properties. So if you would discover something totally new something noone has ever thought of before that idea would create new laws for our universe to follow. At first thought you would think this doesn’t make any sense aren’t the laws of physics eternal governing over both todays world as that of the past. But once you realise that essential things such as nuclear physics can be explained by simple addition, subtraction, multiplication and division it seems a little more plausible, but then you realise Mathematicians have made a lot more math than is used in physics or other sciences this must certainly be a problem? Well it doesn’t have to be, if you imagine that nature slowly tries to implant every idea into itself but tries to do it in a way that is still consistent with its previous state you would get something that slowly becomes more detailed and detailed, something that also happens to our understanding of the universe. In the end it is impossible to prove or disprove this idea at least it is for me, you could probably go a lot further in trying to if you had access to a lot of data and knew exactly when things where first thought of. Also to see that abstract math like the phibonacci series does find its way into nature check out Spirals Phibonacci and being a plant

Nerdy romance The Quantum poem


I decided to write another post about the nerdy romantic things I have done in the past. This one took place around valentine’s day about 2 years ago. That year a few days before valentine’s day me and the other physicist and astronomers of my year had our first quantum mechanics final, at the time I was also a little bit in love with one of the girls in my year, only from a far though I did have some conversations with her but we weren’t really close. Well for valentine’s day I wrote her a love poem with some quantum mechanical concepts mixed in, she didn’t really react the way I had hoped she would but I still like the poem:

The poem of the quantum love:

With the atoms my heart goes

For uncertainty is on the loose

I cannot know where it goes

While I still know where it is

But I hope it will be yours after time has done its work

The quantum mechanical concept I put into the poem is Heisenberg’s uncertainty principle which basically says that you cannot know the position and the momentum(classically mass times velocity) of a particle at the same time.

Colour Blindness


When you’re colour blind such as I am (for green and red) you know you can’t do certain jobs involving green and red lights, but I didn’t know until recently that experimental physics specialised in optics was one of those jobs. This year I had to do an experiment with an michelson morely interferometer, an device that initially gave one of the many hints that led to special relativity namely an indication that the speed of light was really a constant. What we (me and my lab partner) had to do however was use it to create a spectrum of various light sources (what wavelength/colour of light is present in the light source and with what intensity) one of the things we had to do to achieve this goal is make sure the interference gave a nice pattern that should look a little like a  rainbow, well what I saw was something grey that at the point where the interference was really perfect started to look a little like a rainbow, my lab partner not being colour blind on the other had had an much easier time detecting the rainbow like interference, so much easier that I really couldn’t see anything at all when he already began to see the rainbow. I don’t want to be an experimental physicist anyway theory is my way to go, but when I wasn’t so sure about that I thought that if I was going to be an experimental physicist I would like to specialise in optics. Well at least I like math a lot more than most other people do.

Flatland


If you watch the big bang theory (which you totally should) chances are you vaguely remember Sheldon Cooper talking about something called Flatland. Flatland is an satirical novel about Victorian culture with some nice mathematical concepts thrown in which are very well explained, it was written in 1884 by Edwin Abbott Abbott. In my post about Tachyons I talked a lot about string theory, 0 and 1 dimensional objects and more than 3 dimensions, this idea about different dimensional objects is one of the mathematical concepts that is very well explained in Flatland, but If you don’t want to read the novel I will explain it here. If the dot I just used to end the last sentence would have been infinitely small (truly in only one point) it would have been an 0 dimensional object also if _ the line I just used would have totally no width it would have been an 1 dimensional object, if you have a square that has totally no height it would be a 2 dimensional object, if the aforementioned square did have some height it would be a three dimensional object, at this point one would normally stop but mathematically there is no reason to stop at three dimensional objects, there could hypothetically be 4, 5 , 6 , etc dimensional objects sure it’s hard if not impossible for us to really understand what a higher dimensional object would look like, but mathematically we can calculate properties of such higher dimensional objects for example a line has an length L, a square has an Area L2 a cube has an volume L3, if you imagine a 4 dimensional “cube” you could imagine that it would have a property with value L4. If you want to read a little slower more story driven explanation of these concepts read flatland it’s so old that the copyright on it has elapsed but it is still good here are some links

Black holes


Black holes are something that is depicted a lot in Science fiction. Most of the time they are depicted as massive objects somewhere in space, but not all black holes are like that. A black hole is an object which has an Schwarzschild radius that is larger than its actual radius. The Schwarzschild radius of an object with mass is the distance from that object at which light cannot escape the gravitational pull of the object. Continue reading Black holes

Making offline backups


A lot of sites on the internet will stay online for a relatively long time such as Wikipedia, facebook etc. But not all webpage’s are as permanent as the before mentioned, especially webpage’s from college or universities courses aren’t always that permanent, therefore it is important for students to make offline backups if you want to use online recourses of a course you followed in the future. The easiest way (in my experience) to do so is to make a map for the website first save the course website itself in htm, and after that save the links you want to keep in the same directory if you don’t change any of the names while saving the files you should get an working offline backup of the website.

Encryption topic universal Hash function


If you want to encrypt an message you need encryption key, a list of numbers that tells you how the normal message is transformed into the encrypted message. Sometimes however it is the case that some part of you encryption key is known by someone you want to hide your message from, in that case there are several ways to still secure your message one of which is using a uneversal hash fuction to transform you encryption key into a shorter but more secure key. A universal hash function has the property that the probability that you get the same key out of two different encryption keys is smaller or equal that 1 over the length of the resulting key. One of the easiest examples of an universal hash function is that of a matrix with at random 1 or 0 in every entry.

Thesis time


It’s that time of year again where a most of the third years students are writing their thesis, making would be theoratical physicist whish they had studied math or somewhere they aren’t forced to do their research experimentaly, it’s not my turn yet but I already wish I had studied at a university where my thesis can be about something else than an experiment, espescialy after hearing stories about the research of the people that do their thesis this year