DeepEarthScience

This week I spend quite some time reading, correcting and grading assignments for a course called planetary sciences (As a PhD student you also have to do numb making work, it builds character...they say ;)). The assignment was about dynamics in space and in particularly the first question made me go back in time. The story starts a long, long time ago (well a few years but that doesn't sound exciting) in a city far far close by. I was a student learning the marvelous secrets of astrodynamics. Especially the three-body dynamics  (no not that situation you are think of) caught my attention. In a three body system (like the Sun-Earth-satellite, asteroid or an English teapot, but now we are sliding in a different discussion), all sort of fancy motions occur due to the interaction of both the attraction of the Sun and the attraction of the Earth. With a few simple assumptions, equilibrium locations can be found where asteroids will be drawn to. A so...

A few years ago, I was surfing the web to learn anything about Schrodinger's cat. The one in the box, nor dead nor alive. After clicking on several wikipedia pages (as a pre-graduate student is accustomed to do), I came across the following page . This was not Schrodinger's cat, but another scientist's cat. Vladimir Arnold (1960) used a picture of a cat to show a particular and cool mathematical feature. Why scientists use cats, I don't know, maybe because these creatures have an intrinsic appearance of being wise and distinguished (except when you put them under the shower, then they transform in complete and utter self pity). The feature he described was a chaotic mapping procedure. He could transform a picture of a cat into  noise (wow, that is useful), and after some time the cat suddenly arose out of the noise in all its glory (it was as if seeing a magician at work). I wanted to see if I could do the same, hide a cat in chaotic noise and get him back. So I obt...

Satellite? But that is just a flying (we say orbiting) robot in outer space. Why am I so enthusiastic about a bit of metal rubble that is flying 7 km/s at an altitude of a few hundreds of kilometers above the roofs of our houses? Just because I can... A few days ago  Holland  was in a high energy state. We broke a record. *sigh* It was the hottest day in March since...well since we measured temperature. The Dutch media had nothing else to report, but this glorious moment in history. Luckily for you guys, there is the DeepEarthScience blog! So what did I do that day? I was standing on the roof of the tallest building in Delft looking at the city centre and thinking by myself: "This could be a good topic for the blog." The view was awesome: In the back, a beautiful view of city center Delft in all its glory. And even further away the city of our government Den Haag. In the front-right of the picture you can see our two antennas...

...was the verbal shout from across the room/desk. My colleague's vision on determinists. Are they hippies? Maybe its because there is an x in his last name, I don't know. But he has a point. Determinists are people that believe that the universe is governed by solid, deterministic laws. If you say you have free speech, they say it is only input-based output of the brain. Everything is a reaction to a cause. As the famous physicist Albert Einstein (No physics blog can do without him) said: "God doesn't play dice". He meant that there is no stochastic, chance-based effects in the world. The Universe is deterministic. However quantum mechanical observations disapprove this. In the quantum mechanics field, non-deterministic phenomenon are observed on a daily basis. Take for example the Heisenberg principle. If you know the location of the particle, you don't know its speed (exactly it is momentum, but that is the same as velocity times mass, so we d...

The sound of satellites can not be heard by our ears. However using complicated (or less complicated) electronics, we are capable of converting the signals into sound and pictures. How does the sound of a satellite looks like? I think it is beautiful. A perfect frequency shift, due to the motion of the satellite with respect to the receiving station. This figure is in the time-frequency domain, after I did a Fourier transformation on the .wav signal. Time runs from bottom to top and the frequency scale is inverted, just to make life easy. We did not know if the satellite would still be alive when we set up the equipment. But when it crossed the horizon, we heard the signal emerge from the noise. There it was, a piece of space junk that was launched a few years ago, still transmitting its daily data. A coded beeping sound, sending data about the status of its tiny solar cells and other components. We tried to tune another radio such that we could actually listen to the sign...