Tag Archives: science projects
Some years ago, I was stunned to read that hydrogen protons can actually be heard with a (relatively) simple audio amplifier. At that time I was reading about magnetometers – devices that measure magnetic fields, and came across the “Proton Precession Magnetometer.” These things work by using a big electromagnet to magnetize a bottle of water (or other hydrogen-rich fluid). When the magnetizing current is switched off, the hydrogen protons inside will wobble about (“precess”) as they re-orient with the Earth’s magnetic field. This produces an electromagnetic signal which can be picked up by a coil of wire around the bottle, amplified and heard. The frequency of this signal tells us very accurately, how strong the Earth’s magnetic field is. Continue reading
Sodium Acetate: a chemical compound made by combining acetic acid and sodium bicarbonate, or simply just plain old vinegar and baking soda. It is used as a flavouring ingredient in snack foods and in hand warmers. Chemical formula: CH3COONa.
This is our second attempt at experimenting with sodium acetate (also known as “hot ice”). The aim was to create a tower using a solution of sodium acetate and water. It was a success!
Disclaimer: Kids’ Resource Center or the person who posted this video are not responsible for any harm or injury caused in using the information contained in this video. Use the information at your own risk.
Student Seismology Research Station – Seismometer and Magnetometer Recording Via Computer Sound Card
One cannot ordinarily record earthquakes via a computer sound card as they don’t respond much to the slow vibrations experienced in earthquakes. (Update: not strictly true. See my latest on this: Simplest Seismometer – Experiments with direct recording through PC sound card) However, with some cheap electronic trickery and clever software, it can be done, and very adequately for the purposes of study. The seismometer above, made by a high school student, in its first night of testing recorded this local 3.8 quake – a magnitude 1 in Taipei:
(click on the pictures for larger versions)
and as a surprise bonus, some filtering of background noise revealed this distant quake as well. It was a 5.9 from 1000 km away in the Philippines.
(Click on photos to see full size image.)
A magnetometer such as this can detect small changes in the Earth’s magnetic field. It can be useful to monitor these changes as they may indicate the occurrence of natural phenomena that can influence our lives. Certain kinds of solar activity for example, have the potential to disrupt communications and power systems. Large earthquakes are also known to produce magnetic changes prior to their arrival. (This project was originally intended to work in conjunction with the search coil magnetometer project for predicting earthquakes.) Continue reading
magnetometer: n. [Magneto- + -meter]
An instrument for measuring the intensity of magnetic forces [1913 Webster]
precursor: One who, or that which, precedes an event, and indicates its
approach; a forerunner [1913 Webster]
Scientists, particularly in Japan, have for many years been gathering evidence of electromagnetic signals that come from under the ground before earthquakes. The bigger the signal, the bigger the quake is likely to be. This can occur hours before, and in some cases, days or even weeks before the quake itself. Why it happens is not well understood but current theory is that it has to do with rocks creating large electric currents as a result of crushing or grinding under high pressure. Several methods have been used to detect these reportedly erratic, electromagnetic pulses. The method described here is one of the simplest. Technically, it’s called a “search coil magnetometer.” This does not respond to very slow magnetic changes, but it can sense short-term ones, making it suitable for detecting earthquake precursors. Continue reading
In my search for educational projects that can engage a kid’s interest, I recently began looking into seismology (from Ancient Greek, “seismos”, an earthquake and “logia”, study of.)
Being a rather high-tech subject, I was skeptical of my chances of reducing it to something kids could do, but I gave it a shot anyway, since it’s very applicable here in Taiwan, where earthquakes average a couple a day. (You can see them on this website: http://www.cwb.gov.tw/eng/index.htm )
The goal was to come up with some kind of a detector; the simplest and cheapest design possible that a student could plug into a computer and record real earthquakes. Although still in progress I wanted to share what I’ve done so far as it’s a fascinating field and full of good, observable data that will give anyone a deeper understanding of the planet we live on. Continue reading
This project is similar to the 4WD car, not only in that the student is working with wood and electrics, but also that the concept of drive ratios is involved. The crane takes this a little further: one can observe how the winch diameter affects lifting speed and power, and the very useful principle of mechanical advantage gained by the two pulleys. When this is taught in schools, it is normally not easy for kids to really get it as a concept; how the addition of pulleys increases the lifting power and reduces the speed. More often than not they only wind up memorizing formulas so they can pass the test and forget about it. But by making and playing with one themselves, they can see first-hand what actually happens when you add pulleys. They no longer need to memorize anything – they just know it.
This is also a lot of fun to play with. Continue reading
A galvanometer is a device for measuring the flow of an electric current. (From Galvani, a professor of physiology at Bologna, and meter, measure.)
In this day and age, electricity has found its way into our lives in the most unexpected areas. Nobody could have imagined how useful computers and cellphones would become, but how far can it go? I thought electric toothbrushes were pushing the limit once, but then I saw a computer controlled toilet seat….. Continue reading