If you’ve ever been asked a question that tests your science know-how to the limit, you’ll be glad to discover you’re not the only one!
In a recent UK poll, four out of five adults hinted that they were baffled by the seemingly simple science questions asked by their kids!
The survey, conducted for the launch of ‘Science: So What, So Everything’ website http://sciencesowhat.direct.gov.uk/ , found that more than half the 1002 people interviewed felt their children knew more about science than they did!
So to remedy the situation, here are the top 3 science questions (and answers) asked by children, plus another 7 potentially puzzling queries to get to grips with so you’re properly armed with the facts!
1. Where do babies come from?
Answer: In most animals like us, babies are created when a cell from the mother and a cell from the father join together or ‘fuse’. In humans, to make a baby you need to have sperm from the father and an egg from the mother. Each of these cells contains exactly half the information needed to make a baby. After the two cells fuse they divide over and over again to create a ball of cells called an embryo that goes on to become a baby that grows inside the mother until it is born 9 months later.
2. Why is the sky blue?
Answer: The sky is blue because the Sun produces white light which is made up of all the colours of the rainbow.
But a clear, cloudless day-time sky is blue because gas molecules and particles in the air scatter blue light (which travels as short, small waves) from the Sun more easily than they do red light (which travels as longer, larger waves).
As the Sun sets low on the horizon though, the light has even more of the atmosphere to pass through before reaching our eyes, so more blue light is scattered, allowing more of the red and orange light to pass straight though to our eyes.
For more on why the sky is blue, visit http://spaceplace.nasa.gov/en/kids/misrsky/misr_sky.shtml
3. What is a rainbow?
Answer: A rainbow is made from light and water – with help from the Sun. Sunlight is refracted (bent), reflected (bounced off the inside) and then refracted again through droplets of rain, splitting it into the colours that we see (red, orange, yellow, green, blue, indigo and violet).
However, you have to be in the right place at the right time! To see one, you have to be between the Sun and the rain (with your back to the Sun) AND for all of these to be aligned so that the Sun, your eyes and the centre of the arc of the rainbow are in a straight line!
As this tends to mean we can only see a rainbow in the morning or late afternoon, you can work out where to look if conditions are right: a morning rainbow appears when the Sun shines in the East, and the rain falls in the West, and an afternoon rainbow appears when the Sun shines in the West, and the rain falls in the East.
For more on rainbows, visit http://en.wikipedia.org/wiki/Rainbow
4. What causes the tides?
Answer: Tides (the rising and falling of the oceans and seas) are caused by the gravitational pull of the Moon on the Earth. To a lesser extent, the Sun’s gravitational pull also impacts on the tides.
The Moon’s gravity ‘pulls’ at the Earth’s seas as it orbits the planet, causing buldges on both the side of the Earth the Moon is on and the opposite side (because the Moon is pulling the Earth away from the water on that side).
If you’re at the coast and the Moon is overhead, you’ll experience a high tide. This’ll also be true if you’re on the opposite side of the Earth.
Therefore, there are two high tides and two low tides at every coastal location each day.
For more on tides, visit http://www.bbc.co.uk/weather/features/coast_sea/tidesfaq.shtml
5. Why are bubbles round?
Answer: There is surface tension on the bubble’s skin that keeps it pulled in as tightly as it can. As air molecules trapped inside the bubble move around in all directions, its skin tends to form a sphere, being the shape with the least amount of surface area compared to the volume of air trapped inside.
For more on bubbles, visit http://www.bubbles.org
6. What are clouds made of?
Answer: Clouds are small droplets of water vapour (water gas) or ice crystals that are light enough to float on air. Water from the oceans and ground evaporates as it heats up and rises into the air, where it condenses on tiny dust particles. As they cool, the droplets grow bigger and become heavier they start to fall as rain, sleet or snow.
For more on clouds, visit http://cloudappreciationsociety.org
7. How do plants grow?
Answer: Plants need several things to grow. They make their own food (in the form of sugars) in a process called photosynthesis. Photosynthesis happens in the presence of sunlight, when water taken in through the plants roots is combined chemically with carbon dioxide gas taken in through small pores called stomata on the plants leaves.
But, they also need to be within a suitable temperature range and have access to the right minerals from the soil.
8. Why do bees buzz?
Answer: It has now been discovered that it is not the wing beat that actually causes the buzzing noise, but instead it is all part of the complex flight system found in bees and flies known as the ‘click mechanism’. This mechanism is what allows the bees to flap their wings fast enough to provide enough thrust and lift to fly their relatively heavy bodies.
The buzzing noise is created as the bees thorax clicks in and out of place at high speed, which enables them to not only flap their wings, but also to twist and turn them at an angle as they beat up and down, which reduces drag and allows the bee to beat their wings even faster. This means that they can get as many two beats or more for every tiny muscular contraction, which equates to as many as 200 beats per second. The click of the exoskeleton resonates in the thoracic cavity and creates that characteristic buzzing sound.
Scientist also think some bees, such as the larger bumble bees, also use this buzzing vibration to help shake pollen free from flowers, and this may explain why some bees still buzz loudly when they are on flowers, especially plants such as tomatoes and honey suckle as these have tubular anthers which are more difficult for larger bees to reach the pollen inside.
For more about bees, visit http://www.britishbee.org.uk
9. How many stars are in the sky?
Answer: Look-up at night at a clear, moonless sky from a city and you’ll be lucky to see a few hundred stars. Get away from the light-polluted sky though and you’ll see a couple of thousand.
Like our own local star, the Sun, each one of these twinkling points of light is a giant nuclear reaction. In our home galaxy, the Milky Way, it’s estimated there are somewhere in the region of 100 to 200 billion of these burning balls of gas.
However, the Universe appears to contain almost a similar number of galaxies as our galaxy contains stars. That means there could be 1,000,000,000,000,000,000,000,000 stars in total, if you assume all galaxies are the same size (they’re not – some are much bigger, some much smaller). But, even that number doesn’t take into account the fact that stars are constantly dying and new ones being born… so don’t expect to ever get an exact number!
For more about stars, visit http://www.esa.int/esaSC/SEM75BS1VED_index_0.html
10. Why does wood float, but stones sink?
Answer: The answer to why wood floats and stones sink lies in density. Density is a measure of how closely packed the particles in an object of a certain volume are.
Effectively, if you were to fill a space with water that was the same volume as one filled with wood, the space filled with wood would be lighter as it contains less mass.
Those things that are less dense than water will float, whilst those that are more dense sink.
For some great density experiments to try at home, visit http://www.stevespanglerscience.com/experiments/density-