• Blades of Grass

    TBlades of Grass (3.5.)


    Tomato sprout (3.5.)

    As a small project on the side I planted some seeds in test tubes.

    The grass seed was planted on the 18th of April and sprouted about three days later. In the following ten days, the blade of grass grew to a length of about 10cm. Then, a second blade emerged that grew even faster. Now, the second blade is 20cm tall. The soil in the tube is interstratified with small white roots.

    A  seed from a fresh tomato was planted in another tube on the 24th of April. The seed germinated about a week later. A small white-violetish sprout emerged through the surface of the soil. A day later it unfolded and opened two small leaves. The leaves are closed at night and open when the daylight shines on the plant.

    An apple seed was planted on the 23th of April, but has not yet sprouted.

    Update (18.05.2011):
    The tomato sprout has grown a considerable amout in the last week, as you can see in the photos.

    Tomato sprout (18.5.)

    Tomato sprout (18.5.)

    Tomato sprout (18.5.)

    Tomato sprout (11.5.)

  • Eddy Current Video

    Eddy Current Video

    Take some strong neodymium magnets and place them onto a nonmagnetic but conducting material (for example aluminium). Then tilt the material and let the magnets slide down.

    You will notice that the magnets slide down slower than expected. This is due to the eddy currents which are induced in the conductor by the moving magnetic field of the magnets. The currents themselves generate a magnetic field with opposite polarity. The two fields attract each other therefore slowing the magnets down.

    This a nice demonstration of Lenz’s Law where the generated field counteracts its generation.

    Another cool demonstration of the effect can be found here.

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  • Welcome to my Blog.

    Just the obligatory ‘Hello World’.

    More to come soon … i hope.