Mattberkshire
Super Member
Where is the safest place to stand outside in a thunderstorm?
Tall, pointy objects standing alone in an open space are more likely to get struck by lightning but it’s by no means a certainty. Sometimes the flat ground next to a tall tree can be hit. A car or other enclosed metal structure is the safest place to be in a thunderstorm. Failing that, a ditch, trench or group of shrubs of uniform height is better than nothing. Keep away from boundary areas between dissimilar terrain (water and land; rock and earth; trees and fields). Also keep at least five metres away from metal objects or other people as lightning will often jump from one object to another.
Why do identical twins have different fingerprints?
Although identical twins share the same DNA, they don’t look identical cell-for-cell, because not every aspect of your physical appearance is rigidly determined by your genes. Fingerprints are formed semi-randomly as the foetus develops in the womb andare affected by such things as chance fluctuations of hormone levels. Similarly, the pattern of freckles and moles on the skin is caused by random mutations and will vary between identical twins.
Is the human race still getting taller?
The average height, at least in Western society, is increasing because of better childhood nutrition and sexual selection. But the tendency of women to find men taller than six feet (183cm) more attractive can’t be extrapolated upward, and people above 6ft 2in (188cm) are much more likely to suffer back problems. Above 6ft 8in (203cm), and the heart strains to pump blood round the body.
Why do I feel cold and shiver when I have a fever?
A fever is when your body increases its internal thermostat, found in the hypothalamus. If you exercise hard or it’s a hot day, your body temperature might increase, but the thermostat remains at around 36.8°C. When you feel hot the hypothalamus tries to correct this with sweating and increased blood flow to the skin. But with a fever, it is the thermostat that has risen. This means your body temperature is now below 36.8°C, so you feel cold and shiver, to try and raise your temperature. The higher body temperature may help fight infection by speeding white blood cell production and slowing bacteria reproduction.
What is OK short for?
The most popular theory is that OK comes from ‘oll korrect’, a deliberately misspelled writing of ‘all correct’. It was popularised in Boston newspapers around the 1840s when it was fashionable to go around spelling things incorrectly for humorous effect. Legend also has it that New York Democrats later adopted the abbreviation to promote their candidate Martin Van Buren – the initials ‘OK’ were derived from his nickname, Old Kinderhook.
Why can’t we just fill in the ozone hole with man-made ozone?
The sheer scale of the notorious hole – or, more accurately, depleted region – in the Earth’s ozone layer over the Antarctic beggars belief. At its peak each September, it spans an area bigger than the continental United States, and tens of millions of tonnes of ozone would be needed to fill it up again. Simply creating that amount of ozone, let alone getting it where it’s needed, would be astronomically expensive.
Why do fingers and toes wrinkle when left in water?
The waterproof coating on our skin gets rubbed away from areas of our bodies like our hands and feet that are frequently in contact with objects. If you immerse yourself in water with a lower concentration of dissolved salts than that of your cell contents, water will be absorbed by osmosis and cause your skin cells to swell. Since they are anchored to the tissues below, they are forced to corrugate to accommodate this.
What is a hiccup?
A hiccup comes from an involuntary contraction of the diaphragm, producing asudden intake of air. The glottis (the vocal apparatus of the larynx) slams shut at the same time, so that the column of air strikes the closed glottis to produce the characteristic, onomatopoeic noise.
Is there an easy way to prove the Earth is round?
Yes, travel. Because the Earth’s surface is curved, you’ll notice that different constellations of stars are revealed.
Can you have a fish out of water?
Yes. Several species of fish can breathe air and crawl on land. There are about 50 species of flying fish, too.
Why is sea air good for you?
It isn't, particularly. In Victorian England, seaside resorts got a reputation for having healthy air – maybe in comparison to the era's city smogs. The seaside's "bracing" smell is caused by a chemical produced by coastal bacteria, present in very low concentrations. But a study last year found that sea salt can react with chemicals in marine exhaust fumes to worsen the atmospheric pollution in a busy port.
Do plants die of old age?
Given good conditions, some plants can live for ever. It takes a change in external conditions to finish them off. But annuals die soon after seeding.
Does chewing gum really stay inside you for years?
No. Chewing gum is indigestible but it doesn't have any magic property that allows it to escape the normal digestive transit. Three days is the usual limit.
Where do phobias come from?
Around 10 per cent of the population suffer from phobias. Some may be triggered by a traumatic event while others are linked to physical problems. Studies suggest that simple phobias are partly genetic while others may be due to cultural history. For example, a fear of spiders may be passed down from the Middle Ages when spiders were associated with the plague, as victims' deserted homes became shrouded in cobwebs.
Do men have cellulite?
Yes. It's not just women who are cursed with orange peel skin, although in men cellulite tends to be in different places, usually around the neck and abdomen.
Can germs catch germs?
Yes. The germ would be an even smaller organism that attacks its host germ from within.
Why do I get more car sick in the back?
It's probably because you don't have such a good view of the horizon. Motion sickness occurs when the balance mechanism in your ear registers movement while your eyes are telling you that you are stationary.
Could we live on water and supplements?
No. As well as vitamins and minerals we need carbohydrates, fats and proteins for energy and cell repair.
Do hot drinks cool you down?
Yes. They make your body think you are hotter than you really are so you sweat more and that leads to heat loss.
What would happen if there were no Moon?
The most immediate effect (other than the lack of moonlight, of course) would be on the Earth’s tides. With only the Sun’s gravitational influence, the difference between high and low tides would be reduced dramatically - as would tidal drag, which slows the Earth down at a rate adding about 0.002 seconds to the length of a day each century. Long term, the effects would be far more serious. The climate of the Earth is sensitively dependent on the 23.5° tilt of the Earth’s axis, and without the stabilising presence of our relatively huge Moon, the gravity of the other planets would produce big changes in this angle - as it does with Mars, whose tilt changes by 60° over a few million years.
Could I be allergic to water?
No. Allergies to a substance result when immune system antibodies attack it. But no antibodies exist that bind to water.
How is bullet-proof glass made?
It might be better to call it ‘bullet-resistant’ glass, because it resists penetration, although a series of bullets fired at the same place will eventually break through. It is usually made by sandwiching a layer of deformable polycarbonate plastic between glass layers. The bullet’s impact shatters the outer layer of glass, spreading the energy over a wide area so the plastic layer ‘gives’, but does not rupture.
How do seeds know which way to grow?
All plants can sense the direction of the gravitational field and orientate themselves accordingly. This is called geotaxis. In mature plants, phototaxis (growing towards the light source) overrides the gravitational impulse for the stalk and leaves, but the roots – and the seed while it is underground – rely on gravity for orientation.
Why are sumo-wrestlers so fat?
It’s to do with Newton’s second law of motion, which can be written as acceleration = force/mass. The heavier you are, the more force an opponent has to exert to get you moving and push you out of the ring, or to lift and throw you. The heaviest wrestler weighed 267kg, which no weightlifter has ever lifted.
Why do old men go bald, but get hairy nostrils?
Male pattern baldness is caused by the hormone DHT or dihydro-testosterone. This has many other effects on the body and it is thought to inhibit hair loss in the nostrils so that each shaft has a longer growing phase. But the exact mechanism is still not well understood.
What is the Universe made of?
This is one of the biggest mysteries facing 21st-century science. Recent studies of the heat left over from the Big Bang have revealed that conventional matter made from atoms accounts for just a few per cent of the matter in the Universe. Most of it is in the form of so-called cold dark matter (CDM), whose enigmatic name reflects the awkward fact that astronomers don’t know what it is.
Why does breathing pure oxygen kill you?
Our blood has evolved to capture the oxygen we breathe in and bind it safely to the transport molecule called haemoglobin. If you breathe air with a much higher than normal O2 concentration, the oxygen in the lungs overwhelms the blood’s ability to carry it away. The result is that free oxygen binds to the surface proteins of the lungs, interferes with the operation of the central nervous system and also attacks the retina.
Will my eyes pop out if I don’t close them when I sneeze?
No, for a whole variety of reasons, including the fact that the air spaces in the nose and throat involved in sneezing aren’t directly connected to anything behind the eye. That means they can’t create the pressure to push your eyeballs forward.
If humans died out, would we evolve again from apes?
Maybe, if we were wiped out by a species-specific plague, it’s possible that another ape species might go on to evolve greater intelligence and develop a fully bipedal gait.
Do any wasps make honey?
No. Adult wasps drink nectar from flowers but don’t turn it into honey. They feed their young by laying eggs inside prey.
What makes me feel hungry?
The vagus nerve sends information about the fullness of the stomach to the hypothalamus in the brain. Hunger is also controlled by hormones, including insulin, leptin, ghrelin and cholecystokinin. Levels of these change according to the levels of various nutrients in the blood and digestive tract.
How does Viagra work?
Viagra is the brand name for sildenafil citrate, a drug that was originally studied for use in patients with high blood pressure or heart disease. It works by blocking the action of an enzyme called PDE5. The role of this enzyme is to break down another enzyme called cGMP, which relaxes the smooth muscle of the corpus cavernosa (a mass of erectile tissue in the *****), which allows them to become filled with blood and therefore create an erection. When the sildenafil citrate blocks the PDE5, the cGMP levels continue to build so long as the man remains sexually aroused and thus the corpus cavernosa are inflated with blood to a much higher pressure than they would otherwise be. Smooth muscle relaxants have been used to create spontaneous erection as early as the 1980s. But what makes Viagra special is that it acts only when the man is aroused, and only on the *****. This is because the PDE5 enzyme is specific to the *****.
Why are flies attracted to bad smells?
The smells that are a warning of putrefaction to us are attractive to flies for just the same reason. When organic matter (animal or vegetable) starts to rot, it becomes soft and moist, and provides ideal breeding conditions for fly larvae. Female flies are attracted to rotting material, where they lay their eggs in batches (around 50 to 100 in the case of the house fly). The eggs can hatch within 12 hours, and the larvae burrow into the soft material and feed for several days before turning into pupae, which then produce adult flies. It can all take as little as 10 days from egg to adult. LF
After bumping my head, why do I ‘see stars’?
The stars you see are actually neurons in your visual cortex firing spontaneously. This occurs when their oxygenation level changes abruptly either because you have stood up too quickly or because your brain has been suddenly accelerated by a sharp blow, sloshing blood into or out of the capillaries. The neurons closest to capillaries are affected first and, if it happens fast enough, they fire well before the surrounding neurons. This results in isolated signals that your brain interprets as lights.
Why don’t birds get electrocuted while perching on power lines?
It’s not voltages per se that kill, but voltage differences, which are needed for electricity to flow. If a bird lands on a single power line at, say 35,000 volts, the lack of a voltage difference keeps it safe. If it extends its wings and touches another power line at a different voltage, though, it will be electrocuted. That’s why electricity companies put plenty of space between cables.
Why does sunshine make me happy?
There’s a fine balancing act in the brain and circulatory system that regulates our moods, boosting the feel-good factor or sometimes causing Seasonal Affective Disorder (SAD) in winter. The hormone melatonin, produced by the pineal gland in the brain, regulates our sleep/wake cycle, but excessive levels can cause depression. The action of light on our face suppresses melatonin synthesis, therefore boosting your overall mood. Evolutionary principles could apply too. There are plenty of nocturnal primates and presumably they aren’t always depressed. It seems likely that we have evolved to prefer light to darkness because humans are active during the day.
Is eating Red grapes as good for you as drinking red wine?
No. The benefits of red wine are largely down to ‘flavonoids’, which are twice as concentrated in wine as in grape juice.
Is iron in our blood influenced by strong magnetic fields?
Yes, but very weakly. Random thermal movements stop haemoglobin molecules from forming stable magnetic dipoles.
Tall, pointy objects standing alone in an open space are more likely to get struck by lightning but it’s by no means a certainty. Sometimes the flat ground next to a tall tree can be hit. A car or other enclosed metal structure is the safest place to be in a thunderstorm. Failing that, a ditch, trench or group of shrubs of uniform height is better than nothing. Keep away from boundary areas between dissimilar terrain (water and land; rock and earth; trees and fields). Also keep at least five metres away from metal objects or other people as lightning will often jump from one object to another.
Why do identical twins have different fingerprints?
Although identical twins share the same DNA, they don’t look identical cell-for-cell, because not every aspect of your physical appearance is rigidly determined by your genes. Fingerprints are formed semi-randomly as the foetus develops in the womb andare affected by such things as chance fluctuations of hormone levels. Similarly, the pattern of freckles and moles on the skin is caused by random mutations and will vary between identical twins.
Is the human race still getting taller?
The average height, at least in Western society, is increasing because of better childhood nutrition and sexual selection. But the tendency of women to find men taller than six feet (183cm) more attractive can’t be extrapolated upward, and people above 6ft 2in (188cm) are much more likely to suffer back problems. Above 6ft 8in (203cm), and the heart strains to pump blood round the body.
Why do I feel cold and shiver when I have a fever?
A fever is when your body increases its internal thermostat, found in the hypothalamus. If you exercise hard or it’s a hot day, your body temperature might increase, but the thermostat remains at around 36.8°C. When you feel hot the hypothalamus tries to correct this with sweating and increased blood flow to the skin. But with a fever, it is the thermostat that has risen. This means your body temperature is now below 36.8°C, so you feel cold and shiver, to try and raise your temperature. The higher body temperature may help fight infection by speeding white blood cell production and slowing bacteria reproduction.
What is OK short for?
The most popular theory is that OK comes from ‘oll korrect’, a deliberately misspelled writing of ‘all correct’. It was popularised in Boston newspapers around the 1840s when it was fashionable to go around spelling things incorrectly for humorous effect. Legend also has it that New York Democrats later adopted the abbreviation to promote their candidate Martin Van Buren – the initials ‘OK’ were derived from his nickname, Old Kinderhook.
Why can’t we just fill in the ozone hole with man-made ozone?
The sheer scale of the notorious hole – or, more accurately, depleted region – in the Earth’s ozone layer over the Antarctic beggars belief. At its peak each September, it spans an area bigger than the continental United States, and tens of millions of tonnes of ozone would be needed to fill it up again. Simply creating that amount of ozone, let alone getting it where it’s needed, would be astronomically expensive.
Why do fingers and toes wrinkle when left in water?
The waterproof coating on our skin gets rubbed away from areas of our bodies like our hands and feet that are frequently in contact with objects. If you immerse yourself in water with a lower concentration of dissolved salts than that of your cell contents, water will be absorbed by osmosis and cause your skin cells to swell. Since they are anchored to the tissues below, they are forced to corrugate to accommodate this.
What is a hiccup?
A hiccup comes from an involuntary contraction of the diaphragm, producing asudden intake of air. The glottis (the vocal apparatus of the larynx) slams shut at the same time, so that the column of air strikes the closed glottis to produce the characteristic, onomatopoeic noise.
Is there an easy way to prove the Earth is round?
Yes, travel. Because the Earth’s surface is curved, you’ll notice that different constellations of stars are revealed.
Can you have a fish out of water?
Yes. Several species of fish can breathe air and crawl on land. There are about 50 species of flying fish, too.
Why is sea air good for you?
It isn't, particularly. In Victorian England, seaside resorts got a reputation for having healthy air – maybe in comparison to the era's city smogs. The seaside's "bracing" smell is caused by a chemical produced by coastal bacteria, present in very low concentrations. But a study last year found that sea salt can react with chemicals in marine exhaust fumes to worsen the atmospheric pollution in a busy port.
Do plants die of old age?
Given good conditions, some plants can live for ever. It takes a change in external conditions to finish them off. But annuals die soon after seeding.
Does chewing gum really stay inside you for years?
No. Chewing gum is indigestible but it doesn't have any magic property that allows it to escape the normal digestive transit. Three days is the usual limit.
Where do phobias come from?
Around 10 per cent of the population suffer from phobias. Some may be triggered by a traumatic event while others are linked to physical problems. Studies suggest that simple phobias are partly genetic while others may be due to cultural history. For example, a fear of spiders may be passed down from the Middle Ages when spiders were associated with the plague, as victims' deserted homes became shrouded in cobwebs.
Do men have cellulite?
Yes. It's not just women who are cursed with orange peel skin, although in men cellulite tends to be in different places, usually around the neck and abdomen.
Can germs catch germs?
Yes. The germ would be an even smaller organism that attacks its host germ from within.
Why do I get more car sick in the back?
It's probably because you don't have such a good view of the horizon. Motion sickness occurs when the balance mechanism in your ear registers movement while your eyes are telling you that you are stationary.
Could we live on water and supplements?
No. As well as vitamins and minerals we need carbohydrates, fats and proteins for energy and cell repair.
Do hot drinks cool you down?
Yes. They make your body think you are hotter than you really are so you sweat more and that leads to heat loss.
What would happen if there were no Moon?
The most immediate effect (other than the lack of moonlight, of course) would be on the Earth’s tides. With only the Sun’s gravitational influence, the difference between high and low tides would be reduced dramatically - as would tidal drag, which slows the Earth down at a rate adding about 0.002 seconds to the length of a day each century. Long term, the effects would be far more serious. The climate of the Earth is sensitively dependent on the 23.5° tilt of the Earth’s axis, and without the stabilising presence of our relatively huge Moon, the gravity of the other planets would produce big changes in this angle - as it does with Mars, whose tilt changes by 60° over a few million years.
Could I be allergic to water?
No. Allergies to a substance result when immune system antibodies attack it. But no antibodies exist that bind to water.
How is bullet-proof glass made?
It might be better to call it ‘bullet-resistant’ glass, because it resists penetration, although a series of bullets fired at the same place will eventually break through. It is usually made by sandwiching a layer of deformable polycarbonate plastic between glass layers. The bullet’s impact shatters the outer layer of glass, spreading the energy over a wide area so the plastic layer ‘gives’, but does not rupture.
How do seeds know which way to grow?
All plants can sense the direction of the gravitational field and orientate themselves accordingly. This is called geotaxis. In mature plants, phototaxis (growing towards the light source) overrides the gravitational impulse for the stalk and leaves, but the roots – and the seed while it is underground – rely on gravity for orientation.
Why are sumo-wrestlers so fat?
It’s to do with Newton’s second law of motion, which can be written as acceleration = force/mass. The heavier you are, the more force an opponent has to exert to get you moving and push you out of the ring, or to lift and throw you. The heaviest wrestler weighed 267kg, which no weightlifter has ever lifted.
Why do old men go bald, but get hairy nostrils?
Male pattern baldness is caused by the hormone DHT or dihydro-testosterone. This has many other effects on the body and it is thought to inhibit hair loss in the nostrils so that each shaft has a longer growing phase. But the exact mechanism is still not well understood.
What is the Universe made of?
This is one of the biggest mysteries facing 21st-century science. Recent studies of the heat left over from the Big Bang have revealed that conventional matter made from atoms accounts for just a few per cent of the matter in the Universe. Most of it is in the form of so-called cold dark matter (CDM), whose enigmatic name reflects the awkward fact that astronomers don’t know what it is.
Why does breathing pure oxygen kill you?
Our blood has evolved to capture the oxygen we breathe in and bind it safely to the transport molecule called haemoglobin. If you breathe air with a much higher than normal O2 concentration, the oxygen in the lungs overwhelms the blood’s ability to carry it away. The result is that free oxygen binds to the surface proteins of the lungs, interferes with the operation of the central nervous system and also attacks the retina.
Will my eyes pop out if I don’t close them when I sneeze?
No, for a whole variety of reasons, including the fact that the air spaces in the nose and throat involved in sneezing aren’t directly connected to anything behind the eye. That means they can’t create the pressure to push your eyeballs forward.
If humans died out, would we evolve again from apes?
Maybe, if we were wiped out by a species-specific plague, it’s possible that another ape species might go on to evolve greater intelligence and develop a fully bipedal gait.
Do any wasps make honey?
No. Adult wasps drink nectar from flowers but don’t turn it into honey. They feed their young by laying eggs inside prey.
What makes me feel hungry?
The vagus nerve sends information about the fullness of the stomach to the hypothalamus in the brain. Hunger is also controlled by hormones, including insulin, leptin, ghrelin and cholecystokinin. Levels of these change according to the levels of various nutrients in the blood and digestive tract.
How does Viagra work?
Viagra is the brand name for sildenafil citrate, a drug that was originally studied for use in patients with high blood pressure or heart disease. It works by blocking the action of an enzyme called PDE5. The role of this enzyme is to break down another enzyme called cGMP, which relaxes the smooth muscle of the corpus cavernosa (a mass of erectile tissue in the *****), which allows them to become filled with blood and therefore create an erection. When the sildenafil citrate blocks the PDE5, the cGMP levels continue to build so long as the man remains sexually aroused and thus the corpus cavernosa are inflated with blood to a much higher pressure than they would otherwise be. Smooth muscle relaxants have been used to create spontaneous erection as early as the 1980s. But what makes Viagra special is that it acts only when the man is aroused, and only on the *****. This is because the PDE5 enzyme is specific to the *****.
Why are flies attracted to bad smells?
The smells that are a warning of putrefaction to us are attractive to flies for just the same reason. When organic matter (animal or vegetable) starts to rot, it becomes soft and moist, and provides ideal breeding conditions for fly larvae. Female flies are attracted to rotting material, where they lay their eggs in batches (around 50 to 100 in the case of the house fly). The eggs can hatch within 12 hours, and the larvae burrow into the soft material and feed for several days before turning into pupae, which then produce adult flies. It can all take as little as 10 days from egg to adult. LF
After bumping my head, why do I ‘see stars’?
The stars you see are actually neurons in your visual cortex firing spontaneously. This occurs when their oxygenation level changes abruptly either because you have stood up too quickly or because your brain has been suddenly accelerated by a sharp blow, sloshing blood into or out of the capillaries. The neurons closest to capillaries are affected first and, if it happens fast enough, they fire well before the surrounding neurons. This results in isolated signals that your brain interprets as lights.
Why don’t birds get electrocuted while perching on power lines?
It’s not voltages per se that kill, but voltage differences, which are needed for electricity to flow. If a bird lands on a single power line at, say 35,000 volts, the lack of a voltage difference keeps it safe. If it extends its wings and touches another power line at a different voltage, though, it will be electrocuted. That’s why electricity companies put plenty of space between cables.
Why does sunshine make me happy?
There’s a fine balancing act in the brain and circulatory system that regulates our moods, boosting the feel-good factor or sometimes causing Seasonal Affective Disorder (SAD) in winter. The hormone melatonin, produced by the pineal gland in the brain, regulates our sleep/wake cycle, but excessive levels can cause depression. The action of light on our face suppresses melatonin synthesis, therefore boosting your overall mood. Evolutionary principles could apply too. There are plenty of nocturnal primates and presumably they aren’t always depressed. It seems likely that we have evolved to prefer light to darkness because humans are active during the day.
Is eating Red grapes as good for you as drinking red wine?
No. The benefits of red wine are largely down to ‘flavonoids’, which are twice as concentrated in wine as in grape juice.
Is iron in our blood influenced by strong magnetic fields?
Yes, but very weakly. Random thermal movements stop haemoglobin molecules from forming stable magnetic dipoles.
