How much does a shadow weight?

Awesome Universe

Ever wondered how big is the universe? what is the smallest thing we can observe? what small we are? Then click here and prepare to be amazed.

What can you do without a brain?

Why Do We Wear Clothes?

What If The Sun Disappeared?

How big can a person get?

100 GSDoAT - Jupiter’s Moons (6)

 Jupiter’s Moons

Year of Discovery: 1610
What is it? Other planets (besides Earth) have moons.
Who discovered it? Galileo Galilei

 Galileo discovered that other planets have moons and thus extended human understanding beyond our own planet. His careful work with the telescopes he built launched modern astronomy. His discoveries were the first astronomical discoveries using the telescope. Galileo proved that Earth is not unique among planets of the universe. He turned specks of light in the night sky into fascinating spherical objects -into places- rather than pinpricks of light. In so doing, he proved that Polish astronomer Nicholaus Copernicus had been right when he claimed that the sun was the center of the solar system. With his simple telescope Galileo single-handedly brought the solar system, galaxy, and greater universe within our grasp. His telescope provided vistas and understanding that did not exist before and could not exist without the telescope.

Fun Fact:

 Galileo would have been astonished to learn that Jupiter resembles a star in composition. In fact, if it had been about 80 times more massive, it would have been classified as a star rather than a planet.

100 GSDoAT - Planetary Motion (5)

Planetary Motion

Year of Discovery: 1609
What is it? The planets orbit the sun not in perfect circles, but in ellipses.
Who discovered it? Johannes Kepler


 Even after Copernicus simplified and corrected the structure of the solar system by discovering that the sun, not the earth, lay at the center of it, he (like all astronomers before him) assumed that the planets orbited the sun in perfect circles. As a result, errors continued to exist in the predicted position of the planets. Kepler discovered the concept of the ellipse and proved that planets actually follow slightly elliptical or bits. With this discovery, science was finally presented with an accurate pictures of the position and mechanics of the solar system. After 400 years of vastly improved technology, our image of how planets move is still the one Kepler created. We haven’t changed or corrected it one bit, and likely never will.

Fun Fact:

Pluto was called the ninth planet for 75 years, since its discovery in 1930. Pluto’s orbit is the least circular (most elliptical) of all planets. At its farthest, it is 7.4 billion km from the sun. At its nearest it is only 4.34 billion km away. When Pluto is at its closest, its or bit actually slips inside that of Neptune. For 20 years out of every 248, Pluto is actually closer to the sun than Neptune is. That occurred from 1979 to 1999. For those 20 years Pluto was actually the eighth planet in our solar system and Neptune was the ninth!

Infinity and Big Numbers

 What is Infinity?

  Infinity is the idea of something that has no end. In our world we don't have anything like it. So we imagine traveling on and on, trying hard to get there, but that is not actually infinity. So don't think like that (it just hurts your brain!). Just think "endless", or "boundless". If there is no reason something should stop, then it is infinite.
  Infinity is not "getting larger", it is already fully formed. Sometimes people (including me) say it "goes on and on" which sounds like it is growing somehow. But infinity does not do anything, it just is.
  Infinity is not a real number, it is an idea. An idea of something without an end. Infinity cannot be measured.
Even these faraway galaxies can't compete with infinity.

Big Numbers

  There are some really impressively big numbers.
  A Googol is 1 followed by one hundred zeros (10¹⁰⁰) :

10,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,
000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000

  A Googol is already bigger than the number of elementary particles in the known Universe, but then there is the Googolplex. It is 1 followed by Googol zeros. I can't even write down the number, because there is not enough matter in the universe to form all the zeros:

10,000,000,000,000,000,000,000,000,000,000,000,000, ... (Googol number of Zeros)

  And there are even larger numbers that need to use "Power Towers" to write them down.
For example, a Googolplex can be written as this power tower:
That is ten to the power of (10 to the power of 100),
  But imagine an even bigger number like
And you can easily create much larger numbers than those!

Biggest star we ever discovered: VY Canis Majoris

 

Of all known stars, the VY Canis Majoris is the largest. This red Hypergiant star, found in the constellation Canis Major, is estimated to have a radius at least 1,800 that of the Sun’s. In astronomy-speak we use the term 1,800 solar radii to refer to this particular size. Although not the most luminous among all known stars, it still ranks among the top 50.
  Hypergiants are the most massive and luminous of stars. As such, they emit energy at a very fast rate. Thus, hypergiants only last for a few million years. Compare that to the Sun and similar stars that can keep on burning up to 10 billion years. VY Canis Majoris a.k.a. VY CMa is about 4,900 light years from the Earth. This value, however, is just a rough estimate because it is too far for parallax to be used. Parallax is the most common method for measuring star distances. It is actually a special kind of triangulation method, i.e., similar to the one employed by engineers that make use of angles and a fixed baseline.

                    If you still can't image how big VY Canis Majoris is, please watch this:

How big is the Universe?

                   You probably asked yourself too, so here is an awesome short video with your answer:

Did you know? Animal Edition Part 1

• Did you know a bear has 42 teeth
• Did you know an ostrich's eye is bigger than it's brain
• Did you know most lipsticks contain fish scales
• Did you know rabbits like licorice
• Did you know a lobsters blood is colorless but when exposed to oxygen it turns blue
• Did you know armadillos have 4 babies at a time and are all the same sex
• Did you know reindeer like bananas
• Did you know the longest recorded flight of a chicken was 13 seconds
• Did you know birds need gravity to swallow
• Did you know a cat has 32 muscles in each ear
• Did you know goldfish can see both infrared and ultraviolet light
• Did you know cats spend 66% of their life asleep
• Did you know macadamia nuts are toxic to dogs
• Did you know spiders are arachnids and not insects
• Did you know Koalas sleep around 18 hours a day
• Did you know all insects have 6 legs
• Did you know African Grey Parrots have vocabularies of over 200 words
• Did you know a giraffe can clean its ears with its 21 inch tongue
• Did you know cats have over 100 vocal chords
• Did you know camel's milk doesn't curdle
• Did you know elephants sleep between 4 - 5 hours in 24 period
• Did you know it's possible to lead a cow up stairs but not down
• Did you know frogs can't swallow with their eyes open
• Did you know elephants are the only mammal that can't jump
• Did you know frogs don’t drink (they absorb water through their skin)
• Did you know at birth dalmations are always white
• Did you know hummingbirds are the only bird that can fly backwards
• Did you know a duck can't walk without bobbing its head
• Did you know a hummingbird's heart beats at over a 1,000 times a minute
• Did you know dragonflies have 6 legs but can't walk
• Did you know a crocodile can't move its tongue
• Did you know hippopotamuses have killed more people in Africa than any other animal
• Did you know an elephants ears are used to regulate body temperature
• Did you know bats always turn left when exiting a cave
• Did you know crocodiles never outgrow their enclosure
• Did you know reindeer hair is hollow inside like a tube
• Did you know cows don't have upper front teeth
• Did you know an octopus pupil is rectangular
• Did you know cats can't move their jaw sideways
• Did you know its physically impossible for pigs to look up at the sky 
  

Did you know? Invention Edition

• Did you know M&M's chocolate stands for the initials for its inventors Mars and Murrie?
• Did you know the fortune cookie was invented in San Francisco?
• Did you know the croissant was invented in Austria?
• Did you know pop corn was invented by the Aztec Indians?
• Did you know Venetian blinds were invented in Japan?
• Did you know the wheelbarrow is invented in China?
• Did you know instant coffee was invented in 1901?
• Did you know the electric chair was invented by a dentist?
• Did you know the electric toothbrush was invented in 1939?
• Did you know Isaac Newton invented the cat door?
• Did you know the doorbell was invented in 1831?
• Did you know the tea bag was invented in 1908?
• Did you know volleyball was invented in 1895?
• Did you know the revolving door was invented in 1888?
• Did you know the lie detector was invented in 1921?
• Did you know the drinking straw was invented in 1886?
• Did you know Leonardo Da Vinci invented scissors?
• Did you know Shakespeare invented the words 'assassination' and 'bump'?
• Did you know bulletproof vests, fire escapes, windshield wipers, and laser printers were all all invented by women?
• Did you know John Kellogg invented corn flakes?
• Did you know Pez was invented in 1927?
• Did you know the elevator was invented in 1850?
• Did you know the first toothbrush was invented in 1498?
• Did you know Franklin Mars invented the Snickers Bar in 1930?
• Did you know the hottest chile in the world is the habanero?
• Did you know instant mashed potatoes (dehydrated potato flakes) were invented in Canadian in 1962?
• Did you know the corkscrew was invented in 1890?
• Did you know the typewriter was invented in 1829?
• Did you know the dishwasher was invented in 1889?
• Did you know the wristwatch was invented in 1904 ?

Did you know? Color Edition

• Did you know a lobsters blood is colorless but when exposed to oxygen it turns blue?
• Did you know the flag for Libya is unlike any other being a solid green color?
• Did you know goldfish can see both infrared and ultraviolet light?
• Did you know there is no such thing as a naturally blue food?
• Did you know at birth dalmations are always white?
• Did you know black on yellow are the 2 colors with the strongest impact?
• Did you know the safest car color is white?
• Did you know a cats urine glows under a blacklight?
• Did you know white cats with blue eyes are usually deaf?
• Did you know Scotland has the most redheads?
• Did you know scorpions glow under ultra violet light?
• Did you know Mars appears red because it's covered in rust?
• Did you know the coloured part of your eye is called the iris?
• Did you know the rarest type of diamond is green?
• Did you know the meaning of 'Blue Chip' comes from blue casino chips which have a high value?
• Did you know crocodiles are colour blind?
• Did you know grasshoppers have white blood?
• Did you know blonde beards grow faster than darker beards?
• Did you know red light has the highest wavelength?
• Did you know turnips turn green when sunburnt?
• Did you know blue and white are the most common school colors?
• Did you know spiders have transparent blood?

• Did you know mosquitoes prefer children to adults and blondes to brunettes?
• Did you know the color of a chile pepper is no indication of its heat (usually the smaller the the hotter)?
• Did you know Orange Fanta is the 3rd largest selling soft drink in the world?
• Did you know the most popular toothbrush color is blue?
• Did you know the 'black box' that houses an airplanes voice recorder is actually orange so it can be more easily detected amid the debris of a plane crash?
• Did you know the human eye can detect more shades of green that any other colour?
• Did you know a garfish has green bones?
• Did you know dark green lettuce leaves are more nutritious than lighter ones?
• Did you know green tea has 50% more vitamin C than black tea?
• Did you know lettuce is the worlds most popular green vegitable?
• Did you know bees can see ultraviolet light?
• Did you know most spiders have transparent blood?
• Did you know humans are the only primates that don't have pigment in the palms of their hands?
• Did you know moths have white blood?
• Did you know coffee is generally roasted between 204 - 218°C (400 - 425°F) (the longer the beans are roasted the darker the roast)?
• Did you know dark roasted coffee beans contain less caffeine than medium roasted ones (the longer a coffee is roasted the more caffeine is burns off)?
• Did you know all owls lay white eggs?

DId you know? Human Body Edition

• Did you know 11% of people are left handed?
• Did you know unless food is mixed with saliva you can't taste it?
• Did you know the average person falls asleep in 7 minutes?
• Did you know 8% of people have an extra rib?
• Did you know the smallest bones in the human body are found in your ear?
• Did you know stewardesses is the longest word that is typed with only the left hand?
• Did you know that you burn more calories eating celery than it contains (the more you eat the thinner you become)?
• Did you know all the blinking in one day equates to having your eyes closed for 30 minutes?
• Did you know your foot has 26 bones in it?
• Did you know the average human brain contains around 78% water?
• Did you know your brain uses between 20 - 25% of the oxygen your breathe?
• Did you know a 1/4 of your bones are in your feet?
• Did you know your tongue is the fastest healing part of your body?
• Did you know a 1 minute kiss burns 26 calories?
• Did you know you burn more calories sleeping than watching TV?
• Did you know an average person will spend 25 years asleep?
• Did you know the most common mental illnesses are anxiety and depression?
• Did you know your skin is the largest organ making up the human body?
• Did you know enamel is the hardest substance in your body?
• Did you know the hyoid bone in your throat is the only bone in your body not attached to any other?

What are Black Holes?

                                                                                        Black Holes 

  Don't let the name fool you: a black hole is anything but empty space. Rather, it is a great amount of matter packed into a very small area - think of a star ten times more massive than the Sun squeezed into a sphere approximately the diameter of New York City. The result is a gravitational field so strong that nothing, not even light, can escape. In recent years, NASA instruments have painted a new picture of these strange objects that are, to many, the most fascinating objects in space.

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  Although the term was not coined until 1967 by Princeton physicist John Wheeler, the idea of an object in space so massive and dense that light could not escape it has been around for centuries. Most famously, black holes were predicted by Einstein's theory of general relativity, which showed that when a massive star dies, it leaves behind a small, dense remnant core. If the core's mass is more than about three times the mass of the Sun, the equations showed, the force of gravity overwhelms all other forces and produces a black hole.

 Scientists can't directly observe black holes with telescopes that detect x-rays, light, or other forms of electromagnetic radiation. We can, however, infer the presence of black holes and study them by detecting their effect on other matter nearby. If a black hole passes through a cloud of interstellar matter, for example, it will draw matter inward in a process known as accretion. A similar process can occur if a normal star passes close to a black hole. In this case, the black hole can tear the star apart as it pulls it toward itself. As the attracted matter accelerates and heats up, it emits x-rays that radiate into space. Recent discoveries offer some tantalizing evidence that black holes have a dramatic influence on the neighborhoods around them - emitting powerful gamma ray bursts, devouring nearby stars, and spurring the growth of new stars in some areas while stalling it in others.

One Star's End is a Black Hole's Beginning

 Most black holes form from the remnants of a large star that dies in a supernova explosion. (Smaller stars become dense neutron stars, which are not massive enough to trap light.) If the total mass of the star is large enough (about three times the mass of the Sun), it can be proven theoretically that no force can keep the star from collapsing under the influence of gravity. However, as the star collapses, a strange thing occurs. As the surface of the star nears an imaginary surface called the "event horizon," time on the star slows relative to the time kept by observers far away. When the surface reaches the event horizon, time stands still, and the star can collapse no more - it is a frozen collapsing object.

  Even bigger black holes can result from stellar collisions. Soon after its launch in December 2004, NASA's Swift telescope observed the powerful, fleeting flashes of light known as gamma ray bursts. Chandra and NASA's Hubble Space Telescope later collected data from the event's "afterglow," and together the observations led astronomers to conclude that the powerful explosions can result when a black hole and a neutron star collide, producing another black hole.

Babies and Giants

 Although the basic formation process is understood, one perennial mystery in the science of black holes is that they appear to exist on two radically different size scales. On the one end, there are the countless black holes that are the remnants of massive stars. Peppered throughout the Universe, these "stellar mass" black holes are generally 10 to 24 times as massive as the Sun. Astronomers spot them when another star draws near enough for some of the matter surrounding it to be snared by the black hole's gravity, churning out x-rays in the process. Most stellar black holes, however, lead isolated lives and are impossible to detect. Judging from the number of stars large enough to produce such black holes, however, scientists estimate that there are as many as ten million to a billion such black holes in the Milky Way alone.

  On the other end of the size spectrum are the giants known as "supermassive" black holes, which are millions, if not billions, of times as massive as the Sun. Astronomers believe that supermassive black holes lie at the center of virtually all large galaxies, even our own Milky Way. Astronomers can detect them by watching for their effects on nearby stars and gas.

  Historically, astronomers have long believed that no mid-sized black holes exist.  However, recent evidence evidence from Chandra, XMM-Newton and Hubble strengthens the case that mid-size black holes do exist. One possible mechanism for the formation of supermassive black holes involves a chain reaction of collisions of stars in compact star clusters that results in the buildup of extremely massive stars, which then collapse to form intermediate-mass black holes. The star clusters then sink to the center of the galaxy, where the intermediate-mass black holes merge to form a supermassive black hole.

                                    Here is an awesome video explaining the birth of a black hole:

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100 Greatest Science Discoveries of All Time - The Law of Falling Objects (4)

The Law of Falling Objects

Year of Discovery: 1598

What is it? Objects fall at the same speed regardless of their weight.
Who discovered it? Galileo Galilei

  It seems a simple and obvious discovery. Heavier objects don’t fall faster. Why does it qualify as one of the great discoveries? Because it ended the practice of science based on the ancient Greek theories of Aristotle and Ptolemy and launched modern science. Galileo’s discovery brought physics into the Renaissance and the modern age. It laid the foundation for Newton’s discoveries of universal gravitation and his laws of motion. Galileo’s work
was an essential building block of modern physics and engineering.

100 Greatest Science Discoveries of All Time - Human Anatomy (3)

Human Anatomy

Year of Discovery: 1543

What Is It? The first scientific, accurate guide to human anatomy.
Who Discovered It? Andreas Vesalius

The human anatomy references used by doctors through the year A.D. 1500 were actually based mostly on animal studies, more myth and error than truth. Andreas Vesalius was the first to insist on dissections, on exact physiological experiment and direct observation - scientific methods - to create his anatomy guides. His were the first reliable, accurate books on the structure and workings of the human body. Versalius’s work demolished the long-held reliance on the 1,500-year-old anatomical work by the early Greek, Galen, and marked a permanent turning point for medicine. For the first time, actual anatomical fact replaced conjecture as the basis for medical profession.

A potential cure for HIV: Bee Venom!

 

  A team at Washington University School of Medicine in St. Louis recently used nanoparticles carrying a toxin found in bee venom to destroy HIV without harming nearby cells. According to study results, which appear in the current issue of Antiviral Therapy, bee venom contains a potent toxin called melittin that can poke holes in the protective envelope that surrounds HIV, and other viruses. The paper’s senior author, Samuel A. Wickline, MD, the J. Russell Hornsby Professor of Biomedical Sciences, has even shown that melittin-loaded nanoparticles to be effective in killing tumor cells.
 
  What other naturally occurring substance do you know of that can tackle both HIV and cancer? Exactly.
The study’s authors believe that with further research, they could be able to create a vaginal gel, loaded with the bee venom particles, that could help prevent the spread of HIV.
 
  According to Joshua L. Hood, a research instructor in medicine involved in the study, most anti-HIV drugs inhibit the virus’s ability to replicate. But this anti-replication strategy does nothing to stop initial infection, and some strains of the virus have found ways around these drugs and reproduce anyway. The bee venom toxin is different because it attacks an essential part of the virus’ structure. The melittin forms little pore-like attack complexes and ruptures the envelope, stripping it off the virus.

  “We are attacking an inherent physical property of HIV,” Hood says. “Theoretically, there isn’t any way for the virus to adapt to that. The virus has to have a protective coat, a double-layered membrane that covers the virus.”

  Because the bee venom toxin has been engineered not to attack healthy cells, a vaginal gel could be ideal for couples where one partner has HIV and they want to have a baby. It’s also theoretically possible that intravenous injections of the nanoparticles would be able to clear HIV from the blood stream, a virtual miracle for those who have tested positive.

  Perfecting this treatment will take years. Let’s just hope the bees survive that long. Wouldn’t it be a shame to see a potential cure for HIV lost because we were too busy dumping bee-killing pesticides on everything in sight?

Top 20 Amazing Science Facts

                                                                Amazing Science Facts!
 
  1) There are 62,000 miles of blood vessels in the human body – laid end to end they would circle the earth 2.5 times;
  2) At over 2000 kilometers long, The Great Barrier Reef is the largest living structure on Earth;
  3) The risk of being struck by a falling meteorite for a human is one occurrence every 9,300 years;
  4) A thimbleful of a neutron star would weigh over 100 million tons;
  5) A typical hurricane produces the energy equivalent of 8,000 one megaton bombs;
  6) Blood sucking hookworms inhabit 700 million people worldwide;
  7) The highest speed ever achieved on a bicycle is 166.94 mph, by Fred Rompelberg;
  8) We can produce laser light a million times brighter than sunshine;
  9) 65% of those with autism are left handed;

10) The combined length of the roots of a Finnish pine tree is over 30 miles;
11) The oceans contain enough salt to cover all the continents to a depth of nearly 500 feet;
12) The interstellar gas cloud Sagittarius B contains a billion, billion, billion liters of alcohol;
13) Polar Bears can run at 25 miles an hour and jump over 6 feet in the air;
14) 60-65 million years ago dolphins and humans shared a common ancestor;
15) Polar Bears are nearly undetectable by infrared cameras, due to their transparent fur;
16) The average person accidentally eats 430 bugs each year of their life
17) A single rye plant can spread up to 400 miles of roots underground;
18) The temperature on the surface of Mercury exceeds 430 degrees Celsius during the day, and, at night, plummets to minus 180 degrees centigrade;
19) The evaporation from a large oak or beech tree is from ten to twenty-five gallons in twenty-four hours;
20) Butterflies taste with their hind feet, and their taste sensation works on touch – this allows them to determine whether a leaf is edible.

Tallest Mountain in the Solar System

  Olympus Mons is a large shield volcano on the planet Mars. By one measure, it has a height of nearly 22 km (14 mi). This makes it the tallest mountain on any planet in the Solar System (and, after the 2011 discovery of Rheasilvia Mons on 4 Vesta, the second largest mountain on any world known). It stands almost three times as tall as Mount Everest's height above sea level. Olympus Mons is the youngest of the large volcanoes on Mars, having formed during Mars's Amazonian Period. Olympus Mons had been known to astronomers since the late 19th century as the albedo feature Nix Olympica (Latin for "Olympic Snow"). Its mountainous nature was suspected well before space probes confirmed its identity as a mountain.

Mariana Trench Creatures

Human Body Facts #1

 Here are some awesome human body facts you probably didn't knew:

  1) 50,000 of the cells in your body will die and be replaced with new cells, all while you have been reading this sentence!
  2) Your body requires 1000-1500 calories per day just to simply survive (breathing, sleeping, eating).
  3) The brain itself cannot feel pain. While the brain might be the pain center when you cut your finger or burn yourself, the brain itself does not have pain receptors and cannot feel pain.
  4) The average human body contains enough: Sulfur to kill all fleas on an average dog, Carbon to make 900 pencils, Potassium to fire a toy cannon, Fat to make 7 bars of soap, Phosphorus to make 2,200 match heads, and enough Water to fill a ten gallon tank
  5) Your left lung is smaller than your right lung to make room for your heart. 
  6) The average human produces a quart of saliva a day or 10,000 gallons in a lifetime.
  7) Every day an adult body produces 300 billion new cells.
  8) In one hour, your heart works hard enough to produce the equivalent energy to raise almost 1 ton of weight 1 yard off the ground.
  9) Scientists say the higher your I.Q. the more you dream.
10) The largest cell in the human body is the female egg and the smallest it the male sperm.
11) You use 200 muscles to take one step

How does a star die?

Death of a star

   Stars burn hydrogen, and when that hydrogen runs out, they die. When they die and how they die, however, differ depending on the size and type of the star. Hot, bright stars die sooner than large, cooler stars. Massive stars violently explode, while smaller stars slowly swell, then shrink to a dim spark. When stars die, they either become black holes (rare), white or black dwarfs (our sun will become a white dwarf), or something called a neutron star.



Death of small stars

  Stars with the solar mass of about half our sun will either become something called a white dwarf or a red giant. These small stars do not collapse in upon themselves. Instead, they do one of two things: They either simply stop burning (in the case of very small stars) or the center of the star, which is usually still surrounded by some remnants of hydrogen, will fuse, causing the star to expand very slowly. These latter stars are actually called red giants, and they are more common than white dwarfs.
   Scientists speculate that white dwarfs will eventually cool down enough to become something called a black dwarf, but they have not been able to prove this, since black dwarfs would necessarily actually have to be older than the universe currently is. This means that the universe hasn't been around long enough to let any white dwarfs form into black dwarfs!

Death of big stars

  Very large stars (categories by solar masses above 8) will look much like a red giant, but the core of the star will be busy triggering nuclear fusion reactions, with the eventual result of the formation of iron, which collides with other gasses and causes a huge explosion. This explosion is called a Supernova. Supernovas are incredibly bright and very rare.The last one happening in our galaxy took place in the seventeenth century and was so bright it could be seen during daylight hours.
   The gravity at the core of the star, and then supernova, will continue to pull the remains of the explosion towards itself, eventually forming something called a neutron star, which is incredibly dense (weighing trillions of tons).
   Stars that have an even larger solar mass (30 or above) will continue to collapse after the supernova to the point where they form black holes, an exceedingly rare event. The gravitational pull of a black hole is so strong that no energy can escape it, not even light.



                                    Here is an awesome short film showing the death of a star:

100 Greatest Science Discoveries of All Time - The Sun Is the Center of the Universe (2)

The Sun Is the Center of the Universe

Year of Discovery: A.D. 1520

 What is it? The sun is the center of the universe and the earth rotates around it.

Who Discovered It? Nicholaus Copernicus.


 Copernicus measured and ob served the planets and stars. He gathered, compiled, and compared the observations of dozens of other astronomers. In so doing Copernicus challenged a 2,000-year-old belief that the earth sat motionless at the center of the universe and that planets, sun, and stars rotated around it. His work represents the beginning point for our understanding of the universe around us and of modern astronomy. He was also the first to use scientific observation as the basis for the development of a scientific theory. (Before his time, logic and thought had been the basis for theory). In this way Copernicus launched both the field of modern astronomy and modern scientific methods.

100 Greatest Science Discoveries of All Time - Levers and Buoyancy

Levers and Buoyancy

Year of Discovery: 260 B.C.


 What is it? The two fundamental principles underlying all physics and engineering.
 Who Discovered It? Archimedes.

  The concepts of buoyancy (water pushes up on an object with a force equal to the weight of water that the object dis places) and of levers (a force pushing down on one side of
a lever creates a lifting force on the other side that is proportional to the lengths of the two sides of the lever) lie at the foundation of all quantitative science and engineering. They represent humanity’s earliest breakthroughs in understanding the relationships in the physical world around us and in devising mathematical ways to describe the physical phenomena of the world. Countless engineering and scientific advances have depended on those two discoveries. You can read all about it here!

Awesome Facts about Earth #1

  1) The word "planet" comes from the Greek word planetai for "wanderer".

  2) Earth began as sticky dust which clumped, like snowflakes, into a planetesimal, or a body that is about a half mile in diameter.

  3) Earth is made up of hydrogen gas, stardust, and gravity. The gas and dust floating in space were drawn together by gravity and they formed into a spinning disc. As this disc collided with and absorbed rock bodies, the Earth formed. Astronomers believe the formation of Earth was relatively quick.

  4) Orbiting debris smashed into the newly formed Earth, and gravity and radioactive processes heated its interior to nearly 2000 degrees Fahrenheit. A solid inner core formed as iron and nickel were absorbed into the center. This inner core was surrounded by a molten outer core, and then less dense silicates formed the mantle and crust.

  5) The name "Earth" comes from Old English and Old High Germanic words (eorthe and erda, respectively) for "ground" or "soil", and it is the only name for a planet of the solar system that does not come from Greco-Roman mythology.

  6) Earth is called a terrestrial planet because it is made almost entirely of rock and metal. Because Earth formed inside the snow line - meaning it was close enough to the sun that water, carbon, and nitrogen were all in a gaseous state - the elements so essential to supporting life had to be supplied in some other way. They were carried to the Earth by dirty snowballs - asteroids that retained water in hydrated minerals. Later those hydrated minerals were heated and the trapped water was released.

 7) The birth of Earth’s moon is singularly important because it stabilizes Earth’s tilt. Without the moon, Earth would still have wild changes in climate and be uninhabitable. The stabilizing tug of the moon tempers Earth, resulting in the minor tip that causes summer and winter seasons.

   And the most awesome fact!

 8) Earth was originally born as a twin to the planet Theia, which was about half as wide as Earth and roughly the size of Mars. The two planets shared an orbit for several million years until they collided. Earth absorbed Theia, and the remaining debris eventually coagulated into Earth’s moon. The mass donated by Theia gave Earth the gravity necessary to sustain a substantial atmosphere!