There is a form of chemical communication that goes on. There was some research done recently where they looked at plants having their leaves pulled off, and they found that the plants scream chemicals to signal that this damage has occurred. There are a number of chemicals produced. One of them is called ethylene (H2C=CH2) and that is a signal that tells the plant that it is being damaged to grow some more. It also makes fruit ripen. Bananas produce lots of it and so can help other fruit to ripen much faster. There is also communication between plants and the fungi in the soil (a mycorrhizal relationship). Fungus is very good at extracting water and minerals from the soil, and it swaps these with a plant, which will provide it with sugars to give it energy, so both benefit. People used to think that there were two species of thistle, a dwarf and a tall thistle, but they were both the same species, just with different fungi, referred to as Hartig nets, growing around their roots.

 

It depends on the insect. The large ones like butterflies don't; they hide somewhere dry such as under a leaf as a raindrop would do them a lot of damage and make them much heavier. On the other hand tiny insects such as midges are so small that they will tend to get blown out of the way with the air rushing around the raindrop as it falls.

 

There must be a chemical in the asparagus that is absorbed into your blood through your gut, and then filtered out by your kidney into your urine. Scientists don't know what the chemical is, but it must move quickly as people can smell it in their urine after only half an hour. Interestingly some people claim not to be able to smell the difference.

 

Yes that is the normal process of cell division and they are made from stem cells in your thymus and bone marrow etc.

 

 

There is no reason why not. As Galileo noted, the important thing is your relative speed not the absolute one. So if the trailer is doing 60mph and the car 70mph, once the car is on the trailer it will only be doing 10mph relative to the trailer. So it would be like driving onto the trailer at 10mph. The one problem you could get is that if you don't make the transition with your foot on the clutch, the wheels will go from 70mph to 10mph while the engine is still trying to push them at 70. This will either cause a lot of burnt rubber or bits of your engine to fall out.

 

If you are close enough to breathe in a significant amount of the smoke from fireworks, you are too close. Most of the things in the smoke are the same as you would find in wood smoke. In Disneyland they have a large firework display every night over a lake, behind their castle. They commissioned a study to look at any pollution caused after 250 shows a year for 30 years. Even with modern techniques they couldn't actually detect any pollution, so it is probably ok.

 

There are some people who can memorise immense amounts and others who forget what they had for breakfast. The difference is down to your genes, we have a million million neurons in our brains and your memory works by making connections between these stronger by a process called long term potentiation. This happens in a part of the brain called the hippocampus and also the amygdala, but we don't know how memory actually works. What we do know for example, is that if you learn lots of languages, particularly from a young age, the part of the brain involved with language (the language cortex) gets bigger.

 

The microwave background radiation is left over from the big bang. Originally the whole universe was so hot it was a plasma and the electrons had so much energy they were wandering about separate from the nuclei. About 300 years after the big bang the universe cooled enough for the electrons to get trapped by nuclei-forming atoms. This released an immense amount of energy in the form of light.
Originally this would have been in the form of X-rays or ultra violet with a wavelength of less than a thousand trillionth of a metre. As the universe expanded, the light was stretched too, to the couple of millimetres it is on average now. Microwave background radiation is still around now because the universe is very empty and it hasn't all hit anything solid yet.

 

Smell molecules trigger nerve cells in your nose. These cells then connect to a structure called the olfactory tract and this links up to areas of the brain that are very close to where memories are laid down. This is in a primitive part of the brain, which controls animalistic behaviours such as emotions, sex drive and general arousal. So scientists think that smell can trigger all these other emotions. Also, memories don't seem to be laid down as a video clip, but are distributed all over your brain. So remembering something is like doing a jigsaw puzzle or a collage; the more pieces you have the easier it is to find more.

 

Unfortunately, blokes seem to get hairier as they get older. It's to do with testosterone - the hormone that makes us uniquely male. It makes hair grow on some parts of the body, makes your skin greasier, and makes hair fall out on the top of your head. The hairs in your nose and ears do have an important job, as they filter out large lumps of dust or fluff that would damage your lungs. Testosterone just makes them grow thicker and longer. It seems to be an exposure effect so over time we get hairier and hairier, and there is not a lot we can do about it apart from investing in a nose clipper.

 

Although the gene could be turned on from birth and doing damage all the time, it may take a long time for the damage to cause a major problem. For example, if you have a gene for a blood disease that creates something to block up blood vessels, it could take fifty years before it has accumulated enough to actually block them. There is another disease called Huntingdon's disease, where the gene is active from birth, and produces a protein that builds up in a cell. Like a rubbish bin, you can keep adding rubbish until eventually it overflows and causes a problem, so the disease only hits when you get to 40 or 50 years old.

 

Gravity is nothing to do with rotation. If the earth were a perfect sphere, gravity would be the same in all directions. As the earth is actually slightly flattened, gravity will be slightly larger at the poles. What the rocks are below you also makes a difference. If you are on a very dense piece of rock, gravity will be slightly higher. Of course, if you are interested in how much you will appear to weigh, centrifugal force will also have an effect so you will appear to weigh less than you would do if the earth wasn't spinning.

 

 

It's True - According to published tables, the force required to withdraw a 5 cm nail from a piece of hardwood is the same as lifting 26 kilos. This is why it is so difficult to pull a nail out using a pair of pliers and why a claw hammer is so useful - because it turns the handle into a lever, meaning you only need apply a force equivalent to 1kg to get the nail started.

It's False - Famous Cambridge scientist Isaac Newton was the first to calculate the thickness of a soap bubble in his 1704 book Opticks. He realised that the rainbow colours on a bubble surface must be related to the thickness of the soap film. By comparing the bubble colours to the colours produced by two very closely-positioned pieces of glass he worked out that the soap film must be about 100nm or one ten-thousandth of a millimetre - that's a thousand times thinner than a human hair.

It's False - The earliest examples of waterproof clothing date from 1600BC; the meso-Americans used to mix latex from the rubber tree with the sap of the morning glory vine to make it workable and able to waterproof fabrics. But it was us Brits who took it a step further thanks to the efforts of Glaswegian inventor Charles MacIntosh. He patented his recipe for waterproof clothing in 1823. It consisted of the same rubber latex, called caoutchouc (pron. Kou-Chuk), dissolved in coal oil, a by-product of coal-gas production. The result was smeared onto cotton fabric. It was heavy, it leaked, but it worked!

It's False - The wheel first rolled onto the scene about 5000 years ago in Mesopotamia - what's now Iraq. It was based on the idea of using rollers - usually logs - to move things around. The first wheels were just slices of tree trunks, then came the idea of bolting planks of wood side by side. But the real masters were the ancient Greeks, who invented wheels with spokes.

It's False - Not even close. New York has a population of 8 million, on par with London (7.5 million). Both are miniscule compared with Tokyo, officially the world's largest city with 35 million.

It's True - And 96 million of them are made with the help of tea bags, which, legend has it, were invented in 1908 by New Yorker Thomas Sullivan.

It's False - According to a bit of kitchen science carried out by TV presenter Adam Hart-Davis, when filled with an identical volume of hot water, a stainless steel teapot loses heat much less quickly than a thicker ceramic equivalent. This is because the stainless steel teapot is shiny and therefore a poor conductor of heat because it is a poor radiator. Also, the specific heat capacity (how much energy it takes to warm up the material) of a thin steel teapot is much lower than the ceramic equivalent, so less heat is wasted.

It's True - When we go to bed at night and lie flat we become longer. But standing upright during the day causes our tissues, mainly in the spine, to become slightly squashed and so we lose about 1.25cm (half an inch) in height.

It's False - Actually the sperm whale has the record for largest mammal brain at 7.8kg. That's compared with 1.5 kg for the average human. So why aren't whales all geniuses? Because they have a huge body and hence need a large brain to control it.

It's True - This is true and it's an effect of gravity distorting "space-time" - the closer you are to a centre of mass, the more slowly time passes. So a clock at the top of a mountain (further from the Earth's centre) will run slightly faster than one at the bottom of the mountain.