Category The Universe

What is analemma?

This is what the sun looks like when you take a picture a week, for a year, always at the same time of the day, and in the same place.

Due to the 23.5° inclination of earth’s axis and the ellipticity of its orbit, the height of the sun is not the same every day, and the combined effects is what the image shows.

The height of the points corresponds to the declination of the sun on that date, while the horizontal coordinate indicates the deviation of the solar position with respect to the average time (shown by clocks).

The inclination of the figure depends on the latitude in which it is observed and on the time.

If earth’s orbit were a perfect circle and its axis were perpendicular to the orbit, the sun would be in the same spot every day and the analemma would be a point. With a circular orbit but an inclined axis, the two parts of the analemma would be symmetrical. If the axis were not inclined but the orbit were elliptical, the analemma would instead be a segment.

On other planets the analemma has a different shape, on Mars for example, it looks like a drop.


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What are some cool facts about the Universe?

Here are 17 coolest facts about the Universe.

1. Time concept is within the Universe. Time doesn’t exist, clock does. Time is just an illusion. If you think time is constant throughout the Universe then you’re probably wrong. It varies according to gravity and speed.

2. Universe wasn’t forever. It originated from a singularity.

3. According to NO BOUNDARY THEORY, no one has created the universe and no one directs are fate. Why? Since, everything needs time to be exited in, but time is within the Universe. Where and when would the creator live in?

4. The biggest black hole in the observable universe is TON 618.

5. The biggest star in the observable universe is UY SCUTY.

6. Black holes are actually not holes, they are collapsed and dead stars which leave a residue in the form of black holes whose gravity and mass is much more than the star itself and infinite density.

7. Spacetime tells matter how to move, matter tells spacetime how to curve.

8. There are more stars in a galaxy than the grains of sand on earth but there are more atoms in a grain of sand than the number of stars in a galaxy.

9. The sun has enough heat to enlighten the atmosphere for about 4 billion years from today.

10. If you leave earth at the age of 15 with the speed of light and return after 5 years, you’ll find all your friends are 65 y/o now. This is due to time dilation. Remember point 1? Time is an illusion.

11. In a way, we represent energy. And also energy can neither be created nor be destroyed. The energy we have within us is as old as the universe is i.e. 13.4 billion years old. Sounds like holy shit!

12. Whenever you look up in the sky, you see into the past in an encrypted way.

13. As the universe keeps expanding, in the beginning of the universe, it is said to have a size smaller than a proton.

14. If universe was forever, there would have been no life. Because all the stars in the universe are continuously heating up the universe. In this way, even sun would do the same work and the planets like earth would have no life due to extreme heat.

15. The light of sun you observe is the light sun radiated 8.20 minutes ago.

16. If there is an intelligent life other than us then they must be very very far away from us otherwise they would have visited us by now.

17. The most dangerous thing we can find on any other planet would be humans.

Adding some more:

18. There is no sound in space. Space is unbelievably silent. Sound has no medium to travel in space. Space travelers use technology to communicate in the space.

19. 700 million light years away from Earth, there is böotes void, one of the largest known voids of the observable universe with a diameter of 300 million light years and has approximately 50–60 galaxies only!

20. A year on Venus is 224 Earth days i.e. time of revolution and a day on Venus i.e. time of rotation is 243 Earth days. A year on Venus is longer than its day.

21. Don’t cry in space, your years won’t fall.

22. Imagine if alien females go through menstrual cycle, where would their blood flow on zero gravity?

25. When you look at the person in front of you, you look 0.0003 nanoseconds in the past.

26. If Andromeda galaxy was visible to us with naked eyes, it’d seem to be 6 times bigger than the moon.

27. A spacesuit costs US$ 12 million.

28. The observable universe, 93 billion light years, it just made of 103 folds of a paper. Seems unbelievable because it is impossible to fold a paper more than 8 times but this is proven by scientists. If you had a paper large enough that you can fold it as many times you want then the entire observable universe would fit in 103 folds!

29. Carl Sagan’s Cosmic Calendar. The 13.7 billion year lifetime of the universe mapped onto a single year. At this scale the Big Bang takes place on January 1 at midnight, the current time is December 31 at midnight, with Beyoncé in it. Each second is 434 years.

30. If you look outside from a black hole, you could look at the entire universe just as the size of your T.V.


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If humans suddenly disappeared, what would happen to our planet?

After just one day, the entire planet would be plunged into darkness.

Most fossil fuel power stations would shut down, causing cascading blackouts worldwide, once they ran out of fuel. Solar panels and wind turbines would still be able to generate electricity in some areas of the planet, but eventually, they would stop working after a few months or a couple of years.

Nuclear power plants around the world would shut down and enter an automatic safe mode so as to prevent a possible meltdown of the nuclear reactor, without people to use the energy that these power plants make.

Also, no power means that water pumps in subway systems would stop working. The tunnels in subway systems would fill with water.

Domestic animals, would either starve to death, or escape their houses, and start scavenging for food.

Pets still trapped inside their houses would be able to eat food in kitchens, but eventually their food supply would run out, and their only choice would be to escape and look for food elsewhere.

But the truth is that a lot of animals would not be able to survive. Many dog and cat breeds would be simply unfit for this new environment and they would be hunted down by animals like wolves.

Animals like rats and cockroaches would thrive off of the remaining food supply, but once their supply ran out, their populations would plummet.

Some animals would actually go extinct in the absence of humans. Such as head lice.

Head lice have evolved to feed exclusively on human blood. If we disappeared, head lice would join us.

Food everywhere would be rotting. Without power, there would be no refrigeration, and with no refrigeration, our food supply would start to decay.

Dairy products would begin to spoil within a few hours. The fruit would start to decay. As the fruit decays, it releases a gas called ethylene, which causes the other fruits to decay at a faster pace. Meat would also start rotting, and it would be eaten by flies, maggots and rats.

After more than a week, due to the heat coming from the fuel rods, spent fuel pools inside nuclear power plants would begin to boil away. The fuel rods themselves catch fire and burn.

The equivalent of 20 cores worth of radiation would be released into the environment, and nothing would be safe for miles in each direction. This would also cause some nuclear reactors to explode violently.

After several months, without people to keep them at bay, wild animals would start returning to the urban landscape.

Animals such as coyotes, bobcats, among others, would be the first new residents, followed by animals like bears, cougars, etc.

Animals trapped inside zoos would succumb to starvation. Other animals would be able to escape, then they would start roaming around, scavenging for food, trying to survive. You could see animals like apes, elephants, bears, wolves, all in the same place.

After one year, plant vegetation would start taking over. Weeds and grass would start growing in cracks in roads and highways.

Buildings would start getting overrun by plants and ivy. Plants would start to take root in stone and masonry work, and they would start to damage the foundations of buildings.

A lot of animal species would also flourish in our absence. Animals like the giant panda, the Asian elephant, among others, had to put up with humans destroying their habitats, and hunting them down for various reasons. If humans were to disappear, these animals would be extremely happy. Granted, they still would have things to worry about, but without humans, one of their biggest threats would be gone forever.

Certain species of birds would also be pretty happy. Without people, some species of birds would not have to worry about being shot by a hunter’s firearm, and they would also be able to fly without the fear of dying by flying into an airplane’s engine.

In the absence of humans, wildfires will go unchecked. A lightning strike has the possibility to start a fire in the countryside, or in a certain building in a city. Without firefighters to keep these fires at bay, they will spread quickly and raze entire cities to the ground.


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Is there anybody out there?

We don’t know. Life might be such a fluke that it only exists on Earth. But if scientists can find just one other place where there is life, we’ll know life’s no accident – and that there could be millions of aliens!

How will we find out?

People around the world have joined the Search for Extra-Terrestrial Intelligence (SETI). They spend their spare time on computers, studying waves from space, hoping to find alien messages.

Do aliens know about us?

It’s unlikely. Humans have only been making radio waves for about a century, so aliens would have to live very nearby to tune in.

Is it true? Aliens have visited the Earth.

Probably not. There’s no proof that aliens have visited us. Even if they could travel at the speed of light, they would take at least four years to reach us from the nearest stars.

Amazing! Some people think that the Universe is a living thing – and that the planets, stars and galaxies are just parts of its ‘body’!

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What is gravity?

Gravity is one of the basic forces in the Universe, like electromagnetism. It makes things with mass pull towards each other. More massive objects, such as the Earth, pull smaller objects, such as you, towards them until they stick together.

Is it true? An apple taught us about gravity.

Maybe. According to legend, super-scientist Isaac Newton first realized how gravity works over 330 years ago, after gravity pulled an apple from a tree he was sitting under, and it landed on his head!

Is the Universe expanding evenly?

No – the force of gravity stops everything from flying outwards. Lumpy bits of space become even lumpier, moving at different speeds. Gravity locks together little pockets of space and matter, such as galaxies.

Amazing! There are walls in space! Galaxies aren’t evenly spaced through the Universe. They are arranged more like walls around emptier regions of space. One wall has already been measured – it’s about a billion light years across!

What is the Great Attractor?

It’s a strange little knot in space that has the pulling power of 50 million billion Suns, but is not a black hole.

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Is time the same everywhere?

No, time slows down when you’re travelling very quickly. Brainy boffin Albert Einstein predicted this odd effect in 1905 but we only proved it a few years ago by sending a super-precise atomic clock into orbit around the Earth.

Could time stand still?

Only if you travelled as fast as the speed of light – which most scientists agree is impossible! Some scientists think that time must stand still inside a black hole, but who’d want to find out?

Is it true? Einstein was the world’s best mathematician.

No. Although he was very clever, Albert Einstein often asked his wife to check over the trickier sums for him.  

Amazing! There might be ‘tunnels’ through space and time, which connect distant parts of the Universe. Scientists call these shortcuts wormholes. If light or even an object entered a wormhole, perhaps it would pass through incredibly quickly. It would be possible to travel billions of kilometres in an instant!

Is time travel possible?

Not as far as we know. If you could invent a machine which seemed to take you back or forwards in time, it would probably be taking you to different universes.

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What shape is our galaxy?

Our galaxy, the Milky Way, is a spiral galaxy. Viewed from above, it looks like a giant Danish pastry with swirls of white icing. From the side, it looks more like two fried eggs stuck back-to-back!

Amazing! Our galaxy has a twin. Andromeda is the biggest galaxy near the Milky Way. It’s the same age and a similar shape, but has many more stars.

What’s at the middle of the Milky Way?

The centre (the two ‘egg yolks’) is called the nuclear bulge. There’s probably a monster black hole there, more than a million times bigger than our Sun. Scientists call the black hole Sagittarius A*.

How big is the Milky Way?

The Milky Way is almost too big to imagine. It would take the world’s fastest jet, the Blackbird, about 30 billion years to cross the galaxy.

Is it true? We’re near the centre of the Milky Way.

No. Our Solar System is closer to the edge, on one of the spiralling arms. Our Sun takes 225 million years to go around the centre once!

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What is a galaxy?

A galaxy is a group of stars, dust and gases that are held together by gravity. Our galaxy is the Milky Way and contains about 100 billion stars, one of which is our Sun.

Is it true? All galaxies have names.

No. Each one that we detect is given numbers and letters, but only some, such as our Milky Way, are given a name as well. ‘Galaxy’ comes from the Ancient Greek word for ‘milk’.

How many galaxies are there?

No one knows for sure. There might be hundreds of billions of galaxies – and new ones are forming right now at the edges of the Universe.

Are there different kinds of galaxies?

Yes – each galaxy is unlike any other. Some are bright and some are dim. There are three basic galaxy shapes, though – spiral, elliptical (oval) and irregular. Of course, irregular just means no particular shape!

Amazing! There’s a galaxy named after a wide-brimmed Mexican hat. ‘Sombrero’ is the nickname of galaxy M104. Can you guess the galaxy’s shape?

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What is a black hole?

A black hole is a place in space that forms when a really huge star collapses. Everything around a black hole is sucked into it, like water down a plug hole. The force of gravity in a black hole is so strong that nothing can escape from it – not even light.

Amazing! No one has ever seen a black hole. Because beams of light cannot escape black holes, astronomers cannot see them – even with the most powerful telescopes.

What is dark matter?

Dark matter is what scientists call all the stuff in the Universe that they know is there but can’t find! They think it might be made of ghostly little particles called neutrinos.

Is it true? Black holes turn you into spaghetti.

Yes. Scientists think that, in the last moments before you disappeared forever into a black hole, the force of gravity would stretch you until it pulled you apart. They call this being ‘spaghettified’!

How do we know that dark matter is there?

Scientists can guess how much matter is in the Universe by measuring how galaxies move. This shows them that stars and planets only make up a small part of the Universe. The rest is invisible!

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When did the Universe begin?

Scientists have argued about this for centuries. At the moment, most people agree that the Universe began between 12 and 15 billion years ago. It all started with a mind-boggling explosion called the Big Bang.

Amazing! The Big Bang was super-hot! Scientists don’t even bother writing out all the zeros in its temperature. They write 1027 C meaning 10 with 27 zeros after it!

What was the Big Bang?

It was a huge explosion that created all the mass and energy in our Universe in less than a second! The effects of the blast are so strong that the Universe is still expanding.

What if the Big Bang happened again?

It couldn’t happen again in our Universe, but some people think it may be happening millions of times, making millions of different universes. Only a few would last as long as ours — most would pop like soap bubbles.

Is it true? You could see the Big Bang through a telescope.

Nearly. Our telescopes aren’t powerful enough yet – but we can already see light from the other side of the Universe that began its journey just after the Big Bang!

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