An eclipse is an astronomical event when one celestial body partially or totally covers another celestial object. We can see two kinds of eclipses from Earth: eclipses of the Sun and eclipses of the Moon. Solar eclipses When the Moon passes between the Earth and the Sun. The Moon blocks the light of the Sun and a shadow of the Moon is cast on the Earth’s surface. There are three types of a solar eclipse: total, partial, and annular. A partial eclipse will also occur if the Sun, Moon, and Earth are not precisely lined up. The eclipse cannot be total unless the center of the Moon’s shadow is able to strike the Earth. An annular eclipse occurs when the Moon is at its farthest distance from the Earth and the Moon appears too small to completely block out the...
Cricket Calls are Nature’s Thermometer To convert cricket calls to degrees Celsius , count the number of chirps in 25 seconds, divide by 3, then add 4 to get the temperature. For example, you will hear 48 calls in 25 seconds when temperature is 20ºC because: 48/3 + 4 = 20° C Crickets chirp by rubbing their wings or legs over each other. Only the males of the species make this noise and they do so to attract mates. The notion that counting the chirps of crickets can serve as an informal way of getting the temperature is not new. In 1897, physicist Amos Dolbear proposed the reverse of that idea, stating that outdoor temperature determines the number of cricket calls heard. Over the years, his way of looking at this relationship was turned around, people now count the chirps to...
Both Alberto and I love the snow. I go skiing and he goes snowboarding and as we haven’t ever been together in a snow trip I’ve decided to share some of how this activity looks like to me. When you are a scientist you wake up in the morning in a nice village a few kilometers away from the ski resort, let’s say in the Pyrenees, you look up at the sky and then you wonder: How can there be clouds in winter when it is too cold for water to stay as a vapor? Although clouds look like they are made out of vapor that’s not true. You may notice when cooking that water vapor is invisible… so, why would that be visible on clouds? Water vapor is invisible because its molecules are too far apart to optically scatter light so there has to...
The Energy crisis The modern way of life depends on fossil fuels like oil, natural gas and coal. Although the majority of the people take them for granted it took nature about 5 million years to create the fossil fuels that the World consumes in one year. Oil powers 96% of all transportation. This demand will grow fast in the following years; considering the population grows at 3% per year, this means it doubles every 23 years. Since 1860 the World has used approximately half of the oil that has been discovered. At first oil was easy to find and cheap to extract, but once an oil well starts producing it’s only a matter of time before it starts to decline. Typically it takes 40 years after the peak of discovery for a country to reach its peak of production...
I have strange thoughts in the shower! I guess everybody does: – What if you could drill a tunnel through the whole planet and then jumped down this tunnel; would you be able to get out the other side? – If gravity suddenly increased would airplanes fall out of the sky, or would it compress the air in such a way that airplanes could keep flying? – Would humanity survive if the sun went out? Let’s talk about the last one… and I don’t mean what would happen if the sun explodes, but what would happen if someone, maybe a powerful Alien stole or switched it off. This is what scientists call a mental experiment. You don’t need fancy equipment to do science, just your imagination! If the sun suddenly disappeared we wouldn’t notice immediately. As you may know the light from...
I’ve been asked many times what do I speak about when I hang around with my scientist friends… well here is an example of what we talk about during Christmas: How fast does Santa travel? There are 2 (american) billion kids under 18 years old in the world but since Santa doesn’t appear to visit the Muslim, Hindu, Jewish and Buddhist children he must visit only 15% of the total. That’s around 400 million children, considering an average rate of 3.5 children per house that’s over 100 million places on one night. Santa has 32 hours of Christmas night to work with, thanks to the different time zones and the rotation of the earth. This means Santa has a thousandth of a second per home. In that thousandth of a second Santa parks, hops our of the sleigh, jumps down...
Light up bulbs by microwaving them. Grab a glass and fill it half full with water. Place the light bulb, socket-end first, into the glass of water and set the glass in the centre of the microwave. Close the door of the microwave and set the time to no more than 45 seconds. The bulb will light up!!!! Before removing both the glass and the light bulb from the microwave, allow them to cool and use a heavy glove to protect your hand. The light bulb doesn’t explode because the water acts as a shield against the metal of the bulb from the effect of the microwaves. The microwaves do, however, pass through the glass of the light bulb to excite the tungsten filament inside of it. The tungsten is thin enough that it glows when excited by the...
Keep Your Earphones From Tangling in your pocket. No matter how carefully you store a pair of earphones into your pocket, they emerge crazy tangled. Why does this happen? Is there anyway to avoid the tangling? Some scientist at UC San Diego unraveled the mystery of headphones tangling in a study titled “Spontaneous Knotting of an Agitated String” which won them an Ignobel Prize in 2008. The researchers put in a box strings of different length and rotated it. Then they opened the box to see if knots had formed. After over 3,000 trials, they identified a number of factors that lead to entanglement, the length of the cord being the first. A string shorter than 46 cm never tangled, but as the string gets longer, the probability of getting knots increases sharply. This is why a 3 meter long Christmas tree lights can melt your soul. So using earphones...
A fictional movie is very entertaining; however, movies can also make people pick up misconceptions. Here there are some of the more common movie plots that twist the truth. A cigarette end can’t set petrol on fire. Watched on: Zoolander, The Usual Suspects, Alfred Hitchcock’s The Birds. In dozens of films and TV programmes major explosions are started, either accidentally or deliberately, by a cigarette dropped into petrol. Researchers at America’s Bureau of Alcohol, Tobacco and Firearms, did some tests at their Maryland laboratories. This government department conducted 2,000 attempts to start a fire from exposed petrol using a cigarette. They dropped cigarettes of different brands into the petrol to see if this made any difference. But the petrol did not ignite. Actually, in the film industry they are pretty well aware of it. They don’t care. Despite what you see in action movies, dropping a lighted...
Chocolate is healthier than you think. Chocolate comes from cocoa, which comes from a tree, that makes it a plant. Therefore, chocolate counts as salad! Just joking, but despite its fame chocolate has some healthy properties not so well known: The smell of chocolate increases theta brain waves, which triggers relaxation. Eating a bar of chocolate may cheer you up, but smelling it calms you down, says a British psychologist. Neil Martin, a psychologist at Middlesex University, asked 60 volunteers to sit in a room wearing goggles and headphones while smelling different scents. He used electroencephalography to record their brain waves during the process. Half the volunteers were smelling real foods, while the others experienced synthetic smells. The real foods included chocolate, coffee, baked beans and rotting pork. But apart from chocolate, the smells had little effect on the subjects. Chocolate produced “theta” brain...
