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Mysteries Unfolded

Black Hole : Strangest thing Explained!

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Black Hole

Black Holes

The black hole is one of the strangest things in existence. They don’t seem to make any sense at all. Where do they come from… …and what happens if you fall into one?

How Black Holes Form?

Stars are incredibly massive collections of mostly hydrogen atoms that collapsed from enormous gas cloud under their own gravity. In their core, nuclear fusion crushes hydrogen atoms into helium releasing a tremendous amount of energy. This energy, in the form of radiation, pushes against gravity, maintaining a delicate balance between the two forces. As long as there is fusion in the core, a star remains stable enough. But for stars, with way more mass than our own sun, the heat and pressure at the core allow them to fuse heavier elements until they reach iron.

Balanced Gravity and Radiation

Loss of balance between gravity and radiation

Loss of balance between gravity and radiation

Unlike all the elements that went before, the fusion process that creates iron doesn’t generate any energy. Iron builds up at the center of the star until it reaches a critical amount and the balance between radiation and gravity is suddenly broken. The core collapses. Within a fraction of a second, the star implodes. Moving at about the quarter of the speed of light, feeding even more mass into the core. It’s at this very moment that all the heavier elements in the universe are created, as the star dies, in a supernova explosion. This produces either a neutron star or if the star is massive enough, the entire mass of the core collapses into a black hole.

What Does Blackhole Consist of?

If you looked at a black hole, what you’d really be seeing is the event horizon. Anything that crosses the event horizon needs to be traveling faster than the speed of light to escape. In other words, it is impossible. So we just see a black sphere reflecting nothing. But if the event horizon is the black part, what is the “hole” part of the black hole?
Singularity and Event Horizon
The singularity. We’re not sure what it is exactly. A singularity may be indefinitely dense, meaning, all its mass is concentrated into a single point in space, with no surface or volume, or something completely different. Right now, we just don’t know, it’s like “dividing by zero”.
By the way, black holes do not suck things up like a vacuum cleaner, If we were to swap the sun for an equally massive black hole, nothing much would change for the earth, except that we would freeze to death, of course.

What would happen to you if you fell into a black hole?

The experience of time is different around black holes, from the outside, you seem to slow down as you approach the event horizon, as time passes slower for you. At some point, you would appear to freeze in time, slowly turn red, and disappear. While from your perspective, you can watch the rest of the universe in fast forward, kind of like seeing into the future.

Right now, we don’t know what happens next, but we think it could be one of two things:

One, you die a quick death. A black hole curves space so much, that once you cross the event horizon, there is only one possible direction. you can take this – literally – inside the event horizon, you can only go in one direction. The mass of a black hole is so concentrated, at some point, even tiny distances of a few centimeters would mean that gravity acts with millions of times more force on different parts of your body. Your cells get torn apart, as your body stretches more and more until you are a hot stream of plasma, one atom wide.

Two, you die a very quick death. Very soon after you cross the event horizon, you would hit a firewall and be terminated in an instant.

Either of these options is particularly pleasant. How soon you would die depends on the mass of the black hole. A smaller black hole would kill you before you even enter its event horizon, while you probably could travel inside a supersize massive black hole for quite a while. As a rule of thumb, the further away from the singularity, you are, the longer you live.

Size of Blackhole

Black holes come in different sizes. There are stellar mass black holes, with a few times the mass of the sun, and the diameter of an asteroid. And then there are the supermassive black holes, which are found at the heart of every galaxy, and have been feeding for billions of years. Currently, the largest supermassive black hole known is S5 0014+81. 40 billion times the mass of our sun. It is 236.7 billion kilometers in diameter, which is 47 times the distance from the sun to Pluto.

Hawking Radiation

As powerful as black holes are, they will eventually evaporate through a process called Hawking radiation. To understand how this works, we have to look at empty space. Empty space is not really empty but filled with virtual particles popping into existence and annihilating each other again. When this happens right on the edge of a black hole, one of the virtual particles will be drawn into the black hole, and the other will escape and become a real particle. So the black hole is losing energy.

This happens incredibly slowly at first and gets faster as the black hole becomes smaller. When it arrives at the mass of a large asteroid, its radiating at room temperature. When it has the mass of a mountain, it radiates with about the heat of our sun. and in the last second of its life, the black hole radiates away with the energy of billions of nuclear bombs in a huge explosion. But this process is incredibly slow. The biggest black holes we know might take up a googol year to evaporate. This is so long that when the last black hole radiates away, nobody will be around to witness it. The universe will have become uninhabitable, long before then.
Hope you have got an idea of what is a black hole. Do share this post with your friends if you find it informative.
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Mysteries Unfolded

Do you Dream? Why? – Explained

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Why Do you Dream
While we sleep at night, most of us see dreams. Some which we like and somewhat we do not. But do you know why you see dreams? We will tell you today why you see dreams. Without wasting your time, let us start. Why do we dream? What’s going on inside our brains?
The scientific study of dreaming is called oneirology. And for most of history, it didn’t really exist, because you can’t hold a dream. It’s difficult to measure a dream, you can’t taste it. You can’t see other people’s dreams, and if you ask them to tell you what they dreamt, the results are almost always unreliable. In fact, it’s estimated that we forget 95 percent of the dreams we have, especially within the first ten minutes of having them.
But then, in 1952, something amazing happened. Researchers at the University of Chicago found something new. It’s a unique type of electrical activity that occurs during a certain stage of a person sleeping. When researchers awoke people during this stage, they almost always reported that they had been dreaming. Also, at the same time, during this stage, people’s eyeballs are going crazy, rapidly darting all over the place underneath their eyelids. You can actually see this happening if you watch people sleep. This Rapid Eye Moment is the reason why it is called REM Sleep.
Imaging of Electric Impulse

Imaging of Electric Impulse

During REM sleep, some pretty bizarre stuff happens. If you look at the electrical activity of a brain that is in REM sleep, it almost exactly mimics the way the brain acts when it’s awake. It is also call “paradox sleep” The biggest difference being that the production of chemicals inside the brain like norepinephrine, serotonin, and histamine is almost completely blocked, and that causes the muscles to stop moving, which is why you can dream about flying or running around or fighting ninjas, but your body doesn’t move.
People who have a disorder achieving complete REM atopia move around in their sleep and act out their dreams. They can even get out of bed and sleepwalk. Oh, before we move forward, I should say two things.
One is that it’s possible to wake up and not be able to move your body because you’re still in REM atopia. You’re completely conscious and you know that you’re awake, but your body is not ready to move. On the flip side, you can also be inside a dream and know that you’re dreaming. This phenomenon is known as lucid dreaming, and it’s particularly attractive because while in an elusive dream, I can make conscious decisions about what I do. I can go fly to wherever I want, or I can have a tea party with Abraham Lincoln. I’m in control, but achieving an elusive dream is quite elusive.
Researchers were able to deprive mice of REM sleep by using a small cup inverted inside a tub of water, way up to the tippy top, meaning that the mouse was only able to sit right on top of this little tiny surface. When that happens, the mouse can still fall into non-REM sleep, but as soon as they reach REM sleep and their muscles relax, they fall off the platform into the water waking up.
What they found was that when mice are not allowed to achieve REM sleep, they have an incredible amount of trouble remembering things. This happens in humans too. If you have people remember word pairs and then you don’t allow them to sleep, the next day, their memory for that stuff is incredibly terrible.
But memory and REM does not stop there. If a person learns a difficult new task during the day, say a new instrument or a new type of difficult puzzle, you can measure the electrical activity in their brain while they do that, and then while they sleep that night, whether they know it or not, their brain replays those electronic impulses.
Many popular theories about why we dream are variations on the idea that while we sleep, the unconscious part of our brain is busy organizing memories and strengthening connections from the day before that we need in the future while getting rid of the junk that would otherwise clog the brain.
Now, so the theory goes, these electrical impulses are detected by our conscious brain, and our cortex freaks out.
It doesn’t know what it means, and so it tries its best to create a cohesive story, creating a dream. This would explain why dreams are often so fantastic and seemingly random. They’re not supposed to make sense, they’re not an actual message from our brain. It’s just the results of our cortexes trying to synthesize the noise coming from all the work being done back in the unconsciousness. Under this way of thinking, dreams are an epiphenomenon. They’re not a primary process that has a purpose. Instead, they’re the accidental result of a more important process going on behind the conscious brain.
Fantasy Stories of Dream

Fantasy Stories of Dream

But some researchers don’t believe that. They believe the dreams serve a primary purpose, and that purpose is to prepare us for threats. They think this because the most prevalent emotions felt during dreams are negative. Abandonment, anger, and the most common of all, anxiety. The theory goes like this: back when we were early humans especially, we had no idea what kind of threats we might encounter during the day. And so, to prepare us, our brain would simulate anxieties while we slept to make us better prepared for that feeling in the real world. So people who had terrifying dreams were better at dealing with anxiety in the real world and had stronger genes. All right, so the theories we discussed today are quite popular, but they don’t really enjoy a consensus. Not everyone agrees with them, and they barely scratch the surface of scientific thought about dreams. But that’s kind of the cool thing about dreams.
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Mysteries Unfolded

What is a Dyson Sphere? Should we Build it?

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What is a Dyson Sphere

The idea of Dyson spheres has captured our imaginations. Vast megastructures, capable of harvesting the power the output of entire stars, the as yet inexplicable Kepler Space Telescope observation of swarms of somethings partially eclipsing a distant star has led to some rampant speculation.

Kepler Space Telescope

Kepler Space Telescope

Today we ask, are Dyson spheres plausible? And are they inevitable?

In 1960, astrophysicist Freeman Dyson proposed that a sufficiently advanced civilization would have such extreme real estate and energy requirements that they might build artificial habitats in the form of vast shells surrounding their parent star. Such Dyson spheres would be possible targets for our search for extraterrestrial intelligence, appearing only as strange points of infrared lights but otherwise black at visible wavelengths.

We don’t really know how the energy requirements of advanced civilizations evolve. It may be that their most natural progression does not require cosmic levels of consumption. On the other hand, securing access to an entire star’s energy output officially elevates a civilization to type 2 on the Kardashev scale. We’re currently type 0. So obviously it would be nice to unlock the achievement.

Let’s assume that access to 10 to the power of 26 watts is desirable. Are Dyson spheres the way to go? The plausibility of a solid sphere the size of a planetary orbit is not really in question. They are not plausible. The incredible stresses on a solar structure that size is vastly greater than could be sustained by any known or yet imagined material. Even if a super advanced material with enough strength was discovered, you’d need impossibly large quantities, much more than there is non-hydrogen or helium matter in all of the planets in the solar system. The sphere would not be habitable, having only a tiny gravitational pull at its surface, and that would be towards the sun. And finally, it would be hopelessly unstable. Any small bump would cause one side to fall into the sun. Some of these issues could be dealt with. But in the end, it’s just not an efficient way to start your galactic empire.

Kardashev scale

Kardashev scale

So do we ditch Dyson’s original idea in our quest to reach type 2? Not so fast. It’s not feasible to build a giant solar sphere. But collecting the entire output of our home star may still be the smart choice. In fact, we can get around all of the issues I just described with a simple adjustment. Instead of building a Dyson sphere, build a Dyson swarm, individual solar collectors that are only kilometers or less in diameter and each with its own independent stable orbit around the sun. Build enough of these, and you can read the entire sun in all directions, absorbing its entire energy output.

The crazy thing about the Dyson swarm is that we could probably start building one in the not too distant future. In fact, we could get started on the first collector pretty much right away. The thing that makes it seem a crazy prospect is a sheer scope. We’d have to disassemble entire planets for the raw materials alone. But believe it or not, there is a plan. It was proposed by Stuart Armstrong, AI expert and futurist. The idea is to cannibalize the planet Mercury. And that’s just to begin the swarm.

Dyson swarm

Dyson swarm

Mercury is ideal because it has a gigantic solid iron core, comprising over 40% of the planet’s mass. Combine that with the abundant oxygen in its crust, and we can make hematite, a naturally occurring, highly reflective iron oxide that has been used for millennia as primitive mirrors. So each of the swarms collectors would then be a giant polished hematite mirror, perhaps a kilometer across, but as thin as tinfoil. It would reflect light into a small solar power plant that would then beam energy somewhere useful, perhaps with a laser or a maser.

The other nice thing about Mercury is that its gravity is low enough that launching mined raw material into space for construction is pretty efficient. Building the first collector would be the slowest. We start with limited mining, space launch, and orbital construction facilities, all of it autonomous.


Also Read: The Most Mysterious Star in the Universe – KIC

Energy supply is the big limiting factor at the start, so it takes about 10 years to build the first collector. But once it’s complete, we have orders of magnitude more available power. We use it to power replicator robots, building new mining and manufacturing facilities, as well as replaceable replicators. It’s an exponential process. Every new collector increases the energy available to build more collectors. Within 70 years, we have a partial Dyson swarm, and Mercury is nothing more than a debris field. To fully encompass the sun, we’d probably need to devour VenusMars, and a good number of asteroids and outer solar system moons, too, assuming we want to leave Earth intact. Let’s assume that. Sound over the top? It’s totally nuts. But it’s likely doable.

Venus, Mars

Venus, Mars

Autonomy in manufacturing, mining, and transportation are all progressing exponentially. Engineers are in the serious planning phases for all sorts of space-based assembly projects, including 3D printing of giant telescope mirrors. Real companies are gearing up to do autonomous asteroid mining, perhaps within a couple of decades. And all of this is without considering nanorobotics, which could change the game entirely. Frankly, there’s no obvious deal breaker here. Once complete, the Dyson swarm would harvest a good fraction of the sun’s energy, so trillions of times the current energy output of the planet. What we then do with that energy is another matter.

But is the Dyson swarm really the best path to type 2 status? Would other civilizations have gone that route, casting very conspicuous shadows on their home stars for us to detect? The advantage of using sunlight is that the sun is already making it. However, in terms of power efficiency, it’s not all that great. Only 0.7% of the rest mass of the ongoing hydrogen fuel at the sun’s core is converted to energy. Also, we need a megastructure to harvest it, with a raw material requirement close to that of all the terrestrial planets in the solar system. Is there a better way? Maybe.

What if instead of converting 0.7% of fuel rest mass into energy we could achieve 100% efficiency? Anti-matter engines do this. But currently, it takes more energy to create the anti-matter fuel than we get back out. Perhaps we can do better there, but there are also other options, for example, black hole engines. Energy can be harvested from a black hole, either from the Hawking radiation, from heat generated from an infalling material, or by extracting angular momentum from the black hole’s spin. We talked about one example, the Kugelblitz. Tapping the Hawking radiation from an artificial black hole is appealing because once formed, we could perhaps sustain it from evaporation by feeding it with new matter. This is really 100% efficient conversion of mass into energy, assuming we can find a way to pump new matter into the proton-sized Kugelblitz against the tide of Hawking radiation. And we only need 1 billion Kugelblitzes to equal the sun’s output. That’s nothing, compared to the hundreds of quadrillion solar collectors in a full Dyson swarm.

Kugelblitz

Kugelblitz

Added benefits. We get to keep Venus and Mars. And also Kugelblitz and other 100% efficient mass converters are indefinitely scalable. The Dyson sphere/swarm can absorb at most the entire energy output of the sun. However, there’s enough mass in the solar system to run a type 3 civilization’s Kugelblitz swarm for many times the current age of the universe. Of course, the trick is making the black holes in the first place. To make an industry standard, 600 million kilogram Kugelblitz, it takes something like 10% of the sun’s energy output each second, focused into a single attometer at a single instant. But wait. That’s the power we get from even a partial Dyson swarm. So there’s something to do with the swarm’s energy.

Burn through Mercury. Then use that partial Dyson swarm’s energy to build Kugelblitzes, in orbit, say, around Jupiter. Type 3, here we come. Maybe this is why we don’t see Dyson swarms all through the galaxy. Aliens build partial swarms to provide the energy to build more efficient engines, which would be essentially undetectable. Or they try building their first Kugelblitz, and it goes very, very badly. Either way, Fermi paradox solved. Admittedly, the fading that the Kepler Space Telescope observed in Tabby’s star is sort of consistent with a partial swarm. I guess it couldn’t hurt to point some radio telescopes, to look for power leakage from the Kugelblitz swarm. But no. It’s never aliens unless every other explanation is exhausted.

 

Source: Space Time
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Mysteries Unfolded

The Most Mysterious Star in the Universe – KIC

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Most Mysterious Star in the Universe

Mysterious Star (KIC)

There are countless stars in the universe. There may be around one hundred billion stars just in our Milky Way galaxy alone. But the single strangest one that we’ve discovered so far is a pretty close one to home, known officially as KIC 8462852, it’s only a little larger than the Sun is, and is only located about 1280 light-years away from us. It’s been known to humanity for quite some time, but always remained relatively obscure until recent observations noticed something strange back in 2015.
KIC 8462852
It seemed like KIC 8462852 was getting dimmer, and nobody really understood why. Researchers became aware in 2015 that back in March of 2011, recordings made by the Kepler space telescope indicated that the star’s brightness was reduced by up to 15%, and by February 2013, it’s brightness had been reduced by up to 22%. The star continued to dim and brighten again, which suggested that something enormous was orbiting around it. For comparison, a planet the size of Jupiter would only obscure the star by just 1%.
This indicated that whatever was blocking the light from the star wasn’t a planet, but something way bigger, covering up to half of the entire width of the star. In addition to these day-long dimming and brightenings, a study of a century’s worth of photographic plates dating between 1890 and 1998 suggested that the star’s brightness had gradually faded by 20% in that time, an amount unprecedented by any other known star of this size and type.
Speculation began to run rampant about what was causing the star to fade, And one of the more interesting theories was that we were witnessing the construction of a giant alien mega-structure called a Dyson sphere. In a paper written back in 1960 by Freeman Dyson titled, “Search for Artificial Stellar Sources of Infrared Radiation” Dyson suggested that any other technological civilization in the universe would likely follow a similar power consumption pattern to that of humans.
Dyson sphere

Dyson sphere

Since humanity’s energy needs have been continuously growing year by year, It’s possible that eventually, we’ll need more energy than what we can produce on earth, so, the logical end step for maximum energy harvesting is to harvest it directly from the Sun from one of three different types of Dyson spheres.
  1. Type one is to build a ring of orbiting structures around the star that collect light and wirelessly transfer the energy back to the home planet.
  2. Type two is to build a bubble of satellites around the star that absorbs a good percentage of the light, but not all of it.
  3. Type three is to completely swallow the star with a solid shell of matter that absorbs 100% of the energy and light that the star produces. If a sphere like this was built around the Sun with a radius of one au, the spheres surface area would be 550 million times the surface area of Earth, and it would produce a ridiculous 384.6 Yottawatts of energy, about 33 trillion times the entire energy consumption of all of humanity in 1998

Also Read: What is a Dyson Sphere? Should we Build it?

Access to such an enormous amount of energy would essentially make any civilization that harnessed it appear to us to be as powerful as Gods. We don’t know what exactly would be possible; it would kind of be like showing paleolithic people what a nuclear reactor would be capable of doing.
Freeman Dyson

Freeman Dyson

Freeman Dyson speculated that any civilization in space that got advanced enough would eventually build one of these types of structures, which meant that in theory, we could detect their presence by observing a massive dip in light, sort of like what was happening with KIC 8462852.
However, Dyson also believes that most known substances that would make up a Dyson Sphere would be re-radiating energy in the infrared part of the electromagnetic spectrum, which was not being detected with our mysterious star. In 2016, the lead researcher into the light irregularities of the star said in a now-famous TED talk that extraordinary claims require extraordinary evidence, and it is my job, my responsibility, as an astronomer to remind people that alien hypotheses should always be a last resort.
To further add to the mystery though, the SETI Institute concluded that whatever material is blocking the light between us and the star is located inside the star’s habitable zone, where life like ours would be possible. The craziest theory is that we may be currently observing a gigantic interplanetary space battle that included the apocalyptic destruction of a planet that generated dust obscuring the light from the star.
Seriously, all natural explanations were turning up weak, until a recent study was concluded just last month in January 2018. More than 1,700 people donated over $100,000 to fund the study, which concluded that the most likely culprit blocking the star’s light was just dust. The data showed that different colors of light were being blocked at different intensities, which meant that whatever is passing between us and the star isn’t opaque, which is what would be expected from either a planet or an alien mega-structure. If it is dust though, it’s still not entirely clear why that much would be in the system though in the first place.
Considering that it doesn’t appear to be a young star system, dust should have coalesced into a series of planets by now, which is yet another part of the puzzle surrounding KIC 8462852. There is still work that needs to be done in finding answers out about this star. We still can’t say for certain what exactly is going on.
So that’s all about the mysterious Star. Do mention your views in the comment section below. And also allow the notification by pressing the bell icon you see in the lower corner to get notification of all our latest article. Also, subscribe to the newsletter if you liked our work.
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