Category The Universe, Exploring the Universe, Solar System, The Moon, Space, Space Travel

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.

 

Credit : Quora

Picture Credit : Google

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.

 

Credit : Quora

Picture Credit : Google

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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An asteroid impact is believed to have contributed to the extinction of the dinosaurs. When did this happen?

The dinosaur-killing crash threw huge amounts of debris into the air and caused massive tidal waves to wash over parts of the American continents. There is also evidence of substantial fires from that point in history.

For a long time it was thought that the non-bird dinosaurs died out 65 million years ago.

But Paul explains, ‘The dating of those layers of clay around the world is very accurate – it’s estimated to within a couple of thousands of years.

As originally proposed in 1980 by a team of scientists led by Luis Alvarez and his son Walter, it is now generally thought that the K–Pg extinction was caused by the impact of a massive comet or asteroid 10 to 15 km (6 to 9 mi) wide, 66 million years ago, which devastated the global environment, mainly through a lingering impact winter which halted photosynthesis in plants and plankton.

The blame can’t solely rest on the asteroid. Prior to its crash landing, Earth was experiencing a period of climate change. This was making things harder for life on our planet.

In what is now central India, there was substantial volcanic activity that, although unrelated to the asteroid impact, was causing problems of its own. The resulting lava outcrop is now known as the Deccan Traps.

Paul says, ‘For two million years there was a huge amount of volcanic activity going on, spewing gases into the atmosphere and having a major impact on global climate.

 

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What is the purpose of Rudram-1 missile?

RudraM-1 is India’s first indigenous anti-radiation missile. It was successfully flight tested on October 9 by the Defence Research and Development Organisation (DRDO), which developed it. Once it is ready for induction. RudraM-1 will part of the tactical weaponry of the Indian Air Force. The new generation anti-radiation missile with a speed of Mach 2 (twice the speed of sound) is likely to be integrated into the IAFS Sukhoi fighter jets.

Purpose of an anti-radiation missile

An anti-radiation missile is a missile designed for use against enemy radars on the ground. Besides detecting these missiles can target radiation-emission sources, jammers (devices used to disrupt signals from reaching) and radios used for communication and Surveillance. Mainly used in the initial part of an air conflict to strike at the air defence systems of the enemy, they can play a crucial role in disrupting jamming platforms and destroying radars, thereby clearing the way for fighter jets to launch attacks. It is also said that the missiles can prevent own systems from getting jammed.

Bang on target

According to the DRDO, RudraM-1, launched from a Su-30 MKI fighter jet, hit the radiation target located on the Wheeler Island off the coast of Odisha with pinpoint accuracy. The target seeking air-to-surface missile has a strike range of 250 km and can be launched from heights of 500 metres to 15 km.

Its navigation mechanism comprises an Inertial Navigation System (a computerised mechanism) and a Global Positioning System, which is satellite-based. Armed with a guidance system called Passive Homing Head, which can detect, classify and engage targets, RudraM-1 can detect radio emissions 100 km away. Once the missile locks onto the radiation target it is capable of hitting it accurately even if the enemy switches off the radar midway.

 

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How heavy objects sent to space?

Every year the world sends satellites and spacecraft to space to improve communications on Earth or to explore planets and moons. But how are these heavy objects sent to space?

A rocket ride

We launch things into space by putting them onto rockets that carry tonnes of propellants (fuel). These propellants give the rocket enough energy to boost away from Earth’s surface. Because of Earth’s gravitational pull the heaviest and the largest satellites or spacecraft need the biggest of rockets with most propellant.

Action and reaction

We now know that we need a rocket to send objects to space, but how does a rocket lift off? The most important idea behind a rocket’s lift off is Issac Newton’s over 300-year-old law, which states that for every action there is an equal and opposite reaction.

If you have seen photos and videos of a rocket launch, you would not have missed seeing exhaust streaming from the bottom of the rocket. This exhaust is the flames, hot gases and smoke that come from burning the rockets propellants. This exhaust pushes out from a rocket’s engine down toward the ground. This is the action force. In response to this action, the rocket begins moving in the opposite direction, lifting off the ground. This is the reaction force.

Let’s keep moving

While the rocket will lift off due to the reactive force of the exhaust, Earth’s gravity will continue pulling it down. So how does the rocket continue moving upwards? When a rocket bums propellants and pushes out exhaust an upward force called thrust is created. To launch, the rocket needs enough propellants to create thrust that is greater than the force of the gravity pulling the rocket down. A rocket needs to speed up to at least 29,000 km/hr and fly above most of the atmosphere in a curved path around Earth. This will ensure that the gravity will not pull it back down.

 

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