Why don’t more people appreciate science? Personally, I believe it has something to do with science communication and the way we teach science in our schools.
With this in mind, here are ten amazing scientific facts. I hope these facts inspire you to learn something new every day — they’ve certainly inspired me. However, this list is much too short; keep it growing by adding your own science facts in the comments section.
- 1 1. There is enough DNA in the average person’s body to stretch from the sun to Pluto and back — 17 times
- 2 2. The average human body carries ten times more bacterial cells than human cells
- 3 3. It takes a photon up to 40,000 years to travel from the core of the sun to its surface, but only 8 minutes to travel the rest of the way to Earth
- 4 4. At over 2,000 kilometers long, The Great Barrier Reef is the largest living structure on Earth
- 5 5. There are 8 times as many atoms in a teaspoonful of water as there are teaspoonfuls of water in the Atlantic ocean
- 6 6. The average person walks the equivalent of five times around the world in a lifetime
- 7 7. When Helium is cooled to almost absolute zero (-460°F or -273°C, the lowest temperature possible), it becomes a liquid with surprising properties: it flows against gravity and will start running up and over the lip of a glass container!
- 8 8. If Betelgeuse exploded, transitioning from the red supergiant stage to supernova, it would light our sky continuously for two months. It could happen anytime — within a couple of thousand years, tomorrow or even now
- 9 9. An individual blood cell takes about 60 seconds to make a complete circuit of the body
- 10 10. The known universe is made up of 50,000,000,000 galaxies.
1. There is enough DNA in the average person’s body to stretch from the sun to Pluto and back — 17 times
The human genome (the genetic code in each human cell) contains 23 DNA molecules (called chromosomes), each containing from 500,000 to 2.5 million nucleotide pairs. DNA molecules of this size are 1.7 to 8.5 cm long when uncoiled — about 5 cm on average. There are about 37 trillion cells in the human body, so if you were to uncoil all of the DNA encased in each cell and place the molecules end to end, it would sum to a total length of 2×1014 meters — enough for 17 Pluto round-trips (the distance from the sun to Pluto and then back again is 1.2×1013 meters).
2. The average human body carries ten times more bacterial cells than human cells
It’s funny how we compulsively wash our hands, spray our countertops and grimace when someone sneezes near us, when, in fact, each and every one of us is a walking petri dish! All the bacteria living inside you could fill a half-gallon jug — there are 10 times more bacterial cells in your body than human cells, according to Carolyn Bohach, a microbiologist at the University of Idaho. Don’t worry, though: most of these bacteria are helpful. In fact, we couldn’t survive without them.
For example, bacteria produce chemicals that help us harness energy and nutrients from our food. Germ-free rodents have to consume nearly a third more calories than normal rodents to maintain their body weight, and when the same animals were later given a dose of bacteria, their body fat levels spiked despite the fact that they didn’t eat any more than they had before. Gut bacteria is also very important for maintaining immunity. (image source)
3. It takes a photon up to 40,000 years to travel from the core of the sun to its surface, but only 8 minutes to travel the rest of the way to Earth
A photon travels, on average, a particular distance before being briefly absorbed and released by an atom, which scatters it in a new random direction. To travel from the sun’s core to the sun’s surface (696,000 kilometers) so it can escape into space, a photon needs to make a huge number of drunken jumps.
The calculation is a little tricky, but the conclusion is that a photon takes many thousands and many millions of years to drunkenly wander to the surface of the Sun. In a way, some of the light that reaches us today is energy produced millions of years ago. Amazing!
4. At over 2,000 kilometers long, The Great Barrier Reef is the largest living structure on Earth
Coral reefs consist of huge numbers of individual coral polyps (soft-bodied, invertebrate animals) that are linked together by tissue. The Great Barrier Reef is an interlinked system of about 3,000 reefs and 900 coral islands divided by narrow passages, located just beneath the surface of the Coral Sea. Spanning more than 2,000 km and covering an area of some 350,000 sq km, it is the largest living structure on Earth and the only one visible from space. However, this fragile coral colony is beginning to crumble, battered by the effects of climate change, pollution, and manmade disasters.
5. There are 8 times as many atoms in a teaspoonful of water as there are teaspoonfuls of water in the Atlantic ocean
A teaspoon of water (about 5 mL) contains 2×1023 water molecules, but each water molecule is comprised of 3 atoms: two hydrogen atoms and one of oxygen. Moreover, if you’d laid down end to end each water molecule from a teaspoon down end to end, you’d end up with a length of 50 billion km — 10 times the width of our solar system.
6. The average person walks the equivalent of five times around the world in a lifetime
The average moderately active person takes around 7,500 step/day. If you maintain that daily average and live until 80 years of age, you’ll have walked about 216,262,500 steps in your lifetime. Doing the math; the average person with the average stride living until 80 will walk a distance of around 110,000 miles — which is the equivalent of walking about 5 times around the Earth, right on the equator.
7. When Helium is cooled to almost absolute zero (-460°F or -273°C, the lowest temperature possible), it becomes a liquid with surprising properties: it flows against gravity and will start running up and over the lip of a glass container!
We all know helium as a gas for blowing up balloons and making people talk like chipmunks, but what most people don’t know is that it comes in two distinct liquid states — one of which is borderline creepy. When helium is just a few degrees below its boiling point of –452°F (–269°C), it can suddenly do things that other fluids can’t, like dribble through molecule-thin cracks, climb up and over the sides of a dish, and remain motionless when its container is spun. No longer a mere liquid, the helium has become a superfluid — a liquid that flows without friction.
“If you set [down] a cup with a liquid circulating around and you come back 10 minutes later, of course, it’s stopped moving,” says John Beamish, an experimental physicist at the University of Alberta in Edmonton.
This happens because atoms in the liquid will collide with one another and slow down.
“But if you did that with helium at low temperature and came back a million years later,” he says, “it would still be moving”.
8. If Betelgeuse exploded, transitioning from the red supergiant stage to supernova, it would light our sky continuously for two months. It could happen anytime — within a couple of thousand years, tomorrow or even now
Betelgeuse lies some 430 light-years from Earth, yet it’s already one of the brightest stars in Earth’s sky. The reason is that Betelgeuse is a supergiant star — the largest type of star in the Universe. Betelgeuse has a luminosity about 10,000 times greater than that of the Sun and its radius is calculated to be about 370 times that of the sun. If it were positioned at the center of our sun, its radius would extend out past the orbit of Mars. Because it’s near the end of its lifetime, Betelgeuse is likely to explode into a supernova. (image source)
9. An individual blood cell takes about 60 seconds to make a complete circuit of the body
You have about 5 litres of blood in your body (at least, most people do) and the average heart pumps about 70 mL of blood out with each beat. A healthy heart also beats around 70 times a minute. So, if you multiply the amount of blood that the heart can pump by the number of beats in a minute, you actually get about 4.9 litres of blood pumped per minute, which is almost your whole body’s worth of blood. In just a minute, the hearts pumps the entire blood volume around your body.
10. The known universe is made up of 50,000,000,000 galaxies.
There are between 100,000,000,000 and 1,000,000,000,000 stars in a normal galaxy. In the Milky Way alone there might be as many 100 billion Earth-like planets. Still think we’re alone?
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