Why There’s Less Gravity in Hudson Bay, Canada ?

The Hudson Bay region of Canada has less gravity than it’s supposed to. The reasons for the shortage have puzzled scientists for decades.

Gravity isn’t uniform all over the Earth’s surface. It’s a result of mass, which means the varying density of the Earth at different locations can affect how much you weigh there. Canadians aren’t all free-floating like Sandra Bullock, but the effect is definitely measurable. In the Hudson Bay region, the average resident weighs about a tenth of an ounce less than they would weigh elsewhere.

Researchers have puzzled for years over whether this was due to the crust there rebounding slowly after the end of the last ice age or a deeper issue involving convection in the Earth’s mantle or some combination of the two.

Now, ultra-precise measurements taken over four years by a pair of satellites known as GRACE (Gravity Recovery and Climate Experiment) reveal that each effect is equally responsible for Canada’s low gravity. The work could shed light on how continents form and evolve over time.

The two spacecraft fly 500 kilometres above the Earth, 220 kilometres apart. Using a microwave ranging system, the two spacecraft can measure distance differences between them as tiny as a micron. That allows them to measure tiny changes in the distribution of mass and hence gravity on the Earth. For example, if the leading spacecraft were to encounter an area with more gravity, it would be pulled ever-so-slightly closer to Earth than the trailing spacecraft, and that distance can be measured.

At first, researchers suspected it was due to an ice sheet called Laurentide that blanketed a sizeable chunk of North America during the last ice age. In places, the sheet was more than 3 kilometres thick, and it depressed the Earth’s crust beneath it.

When the ice age ended about 20,000 years ago, the ice rapidly melted. But the crust has been springing back much more slowly, and it is rebounding today by about 12 millimetres per year. But in the last decade or so, scientists have begun to suspect that convection in the Earth’s mantle, a layer of hot, flowing rock beneath the crust, also plays a role.

The sludge-like mantle rises and falls in plumes as it is heated from below and cooled from above. The mantle can drag the overlying tectonic plates with it as it moves. GRACE cannot directly detect that movement since it is so slow. But scientists inferred the gravitational contribution of convection by subtracting the post-glacier effect from the region’s overall gravity signal.

Even after the Earth’s crust rebounds completely from the glacier melting, there may still be a gravitational low over the area due to mantle convection. That would suggest that even parts of a continent away from the tectonic plate boundaries are affected by mantle convection.

In simple word during the last ice age, Canada was covered by a vast glacier called the Laurentide Ice Sheet. This sheet was two miles thick over northern Quebec and stretched as far south as modern-day New York and Chicago.

Ice is heavy, so five million square miles of it pushed down on the rock underneath, squishing it like a Nerf ball. When the ice began to melt, about 21,000 years ago, the Earth began to spring back, but, like a Nerf ball, it takes a while. To this day, the Earth in the Hudson Bay region is still deformed, with lots of rock-mass having been pushed outward by all the ice. Less mass means less gravity.

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Building A Base On The Moon

The cold war between the US and Russia ended half a century ago. But it paved the way for Space exploration for the year to come. On 12 April 1961 Yuri Alekseyevich Gagarin made history by becoming the first human to journey into outer space, achieving a major milestone in the Space Race. Then the Space Race ended when Neil Alden Armstrong became the first to walk on the moon.

Since then no human had set foot on any heavenly body. But now after Elon Musk's BFR announcement and China's successful landing on the far side of the moon another race to make a base on the moon is all set to start. And this time private companies and national space agencies are in it all together to put humans back on the lunar surface. But what we will need before we start building a Base On Moon.

Building a living space out of the Moon’s available resources makes sense. There’s the potential of using lava tubes, tunnels formed during the Moon’s volcanic past, as shelters with access to frozen water ice beneath the surface. But a more immediate plan is to build a habitat using lunar regolith, the fine dark basaltic grey sand that is similar to volcanic sand on Earth.

Building a moon base and actually living on the moon will require careful planning. First, we need to identify and map available lunar resources, including hydrogen and water ice. Such compounds are crucial if we are to create breathable air and rocket fuel, whether for an observatory or a launchpad to go to the outer planets in our solar system.

There are many desirable resources on the moon, from the water ice that can give us fuel and air and other volatile elements to titanium. These may have accumulated in permanently shadowed polar regions, where it is too cold for them to vaporise.

Professor Matthias Sperl from the University of Cologne works with the German Space Agency, DLR, using volcanic powder to make bricks. The regolith simulant is held together using a process called sintering, where concentrated sunlight or lasers bond the material together. He used 3D printers to construct different shaped bricks to see which worked best. “What we can build with current techniques and shapes is interlocking building elements,” said Sperl. “We’re not building Lego but we have interlocking bricks.”

Any moonbase is likely to be situated at the Moon’s poles as evidence of water ice was detected there. Oxygen within the lunar regolith itself could also be extracted for breathing. The most likely source is ilmenite (FeTiO3) which, when combined with hydrogen at temperatures of around 1,000C (1,832F), produces water vapour, which then needs to be separated to produce hydrogen and oxygen. 

So all there is left to do is to go there and build one right? The answer is not so black and white. The Moon has temperatures ranging from 127 to -173 C (260 to -343F). Then there’s radiation and the low gravity, one-sixth that of the Earth’s. A lunar day is also around 29 Earth days, which means two weeks of daylight followed by two weeks of darkness – an issue for solar power. Any new technologies for a lunar outpost must, therefore, work under these conditions.

As well as logistics is a huge challenge as we can't load everything on one single rocket yet. So yes it is within our reach to completely build a base on the Moon, but it will at least take a decade to do so. 

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What is Mars Solar Conjunction ?

Solar conjunction is the period when Earth and Mars, in their eternal march around the Sun, are obscured from each other by the fiery orb of the Sun itself. Like dancers on either side of a huge bonfire, the two planets are temporarily invisible to each other.

During this period the daily communication between antennas here on Earth and those on spacecraft at Mars stops for a few weeks. Sun emits hot, ionized gas from its corona, which stretches out far into space. During solar conjunction, this gas can meddle with radio signals when engineers attempt to speak with spacecraft at Mars, undermining directions and bringing about unforeseen conduct from our deep space explorers.

To be safe, engineers hold off on sending commands when Mars disappears far enough behind the Sun's corona that there's increased risk of radio interference.

Solar conjunction occurs every two years. This year, the solar conjunction moratorium on commanding all Mars spacecraft is between Aug. 28 and Sept. 7, 2019, when Mars is within 2 degrees of the Sun. 

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Turn Daily Plastic Waste Products Into Jet Fuel

For too long, the public conversation around plastic has been narrowly focused on plastic waste in the ocean. While marine debris is indeed a serious part of the problem, this limited focus leaves too much of the story untold. Plastic isn’t just a problem when it enters the environment as waste. Rather, plastic pollutes at every step of its life.

But now all those Plastic trash may help people fly as researchers have found a way to turn daily plastic waste products into jet fuel. Researchers at Washington State University melted plastic waste at high temperature with activated carbon to produce jet fuel.

For the study, the research team tested low-density polyethylene and mixed a variety of waste plastic products like water bottles, milk bottles, plastic bags and ground them down to around three millimetres, or about the size of a grain of rice.

During the research, the plastic granules were then placed on top of activated carbon in a tube reactor at a high temperature, ranging from 430 degree Celsius to 571 degrees Celsius. The carbon is a catalyst or a substance that speeds up a chemical reaction without being consumed by the reaction.

After testing several different catalysts at different temperatures, the best result they had produced a mixture of 85% jet fuel and 15%  diesel fuel, said the study published in the journal Applied Energy.

This new process shows promise in reducing that waste. At least 4.8 million tonnes of plastic enter the ocean each year worldwide, according to conservative estimates by scientists. But now we can almost recover 100% energy of the plastic and convert it into very high-quality fuel. 

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What Is 5G?

The world’s connectivity needs are changing. Global mobile data traffic is expected to multiply by 5 before the end of 2024. Particularly in dense urban areas, the current 4G networks simply won’t be able to keep up.

That’s where a new G comes into play. With 5G commercial networks being switched on, the first use cases are enhanced mobile broadband, which will bring better experiences for smartphone users, and fixed wireless access, providing fibre speeds without fibre to homes. 5G smartphones are already in the market from the beginning of 2019.

Being able to download a full-length HD movie in seconds and share your wow-moments with friends that’s just the beginning. The true value of 5G is the opportunity it presents for people, business and the world at large: industries, regions, towns and cities that are more connected, smarter and more sustainable.

With 5G, data transmitted over wireless broadband connections could travel at rates as high as 20 Gbps as well as offer latency of 1 ms or lower for uses that require real-time feedback. 5G will also enable a sharp increase in the amount of data transmitted over wireless systems due to more available bandwidth and advanced antenna technology.

5G offers network management features, among them network slicing, which allows mobile operators to create multiple virtual networks within a single physical 5G network. This capability will enable wireless network connections to support specific uses or business cases and could be sold on an as a service basis.

A self-driving car, for example, would require a network slice that offers extremely fast, low-latency connections so a vehicle could navigate in real-time. A home appliance, however, could be connected via a lower-power, slower connection because high performance is not crucial. The internet of things (IoT) could use secure, data-only connections.

So, how does 5G technology achieve all these cool features? How 5G works?

Well, Wireless networks are composed of cell sites divided into sectors that send data through radio waves. Fourth-generation (4G) Long-Term Evolution (LTE) wireless technology provides the foundation for 5G. Unlike 4G, which requires large, high-power cell towers to radiate signals over longer distances, 5G wireless signals will be transmitted via large numbers of small cell stations located in places like light poles or building roofs.

The use of multiple small cells is necessary because the millimetre wave spectrum -- the band of spectrum between 30 GHz and 300 GHz that 5G relies on to generate high speeds -- can only travel over short distances and is subject to interference from weather and physical obstacles, like buildings.

The introduction of 5G will make it possible for communications service providers to improve their business in various ways. Just as 4G shook up the landscape, whereby data packages became more important than voice and SMS packages, 5G brings opportunities for communications service providers to offer new services. 5G will also improve cost-efficiency. A study suggests that 5G will enable 10 times lower cost per gigabyte than current 4G networks.

5G fixed wireless broadband services could deliver internet access to homes and businesses without a wired connection to the premises. To do that, network operators deploy NRs(5G New Radio is a new radio access technology (RAT) developed by 3GPP for the 5G (fifth generation) mobile network.) in small cell sites near buildings to beam a signal to a receiver on a rooftop or a windowsill that is amplified within the premises. 

Fixed broadband services are expected to make it less expensive for operators to deliver broadband services to homes and businesses because this approach eliminates the need to roll out fibre-optic lines to every residence. Instead, operators need only install fibre optics to cell sites, and customers receive broadband services through wireless modems located in their residences or businesses.

5G also presents an opportunity for operators to tap into revenue streams emerging from the digitalization of industries. Enabling new use cases, new services new business models and new eco-system which can add up to 36% growth in revenues. 

5G is enabling a new wave of innovation. It has the potential for changing the world, further powering the hottest trends in tech today: IoT (Internet of Things), AI (Artificial Intelligence) and AR (Augmented Reality) – among many more.

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Why do Fevers get Worse at Night?

The illness goes bump in the night may not be just a patient's imagination. Doctors have sensed for centuries that many diseases actually do get worse at night and science has begun to confirm this impression.

Fevers are often worse at night. The same is often said about asthma, arthritis and the flu. And although heart attacks commonly occur in the morning, researchers believe they are frequently triggered by night-time happenings in the body. There is a field of study in biology devoted to understanding how the time of day affects our health called chronobiology.

The symptoms of fever are abnormally high body temperature, shivering and sweating, headache, muscle ache, loss of appetite, and general fatigue. In some cases, children under 5 may suffer seizures during high fever spikes alarming for parents, but not usually life-threatening. 

It’s important to remember that fever itself is not a disease. In fact, it’s the exact opposite a sign that the body’s immune system is fighting off a bacterial or viral infection although it can be a cause for serious concern. Like if an infant less than two months of age is running a fever greater than 100.4 degrees Fahrenheit, or if anyone with a compromised immune system spikes a fever.

There are some fairly obvious explanations for fever symptoms to be magnified during the evening hours.  Just like our sleep schedules, our immune system also has a rest pattern of its own when it is more active and when it is not. Our immunity defends the body differs from day to night. Hence, doctors generally don’t rule out fever before 24-48 hours even if you are feeling completely fine during the day.

During the day, our immune cells protect us but as night approaches, immune cells get less active and do some inflammatory action, by deliberately increasing the body temperature in hopes of killing the bacteria. This phenomenon is called ‘temporary fever’, which fight infections.

It's the body’s defence mechanism ensuring that the entire immune defence force is prepared to put up a fight during the morning since it is the time when most productive things happen. 

There’ is one other element that we don’t quite fully understand, but it seems to be important. We know that two key hormones cortisol and adrenaline are suppressed when we sleep. From extensive studies on asthma management, we have learned that when the level of these hormones is reduced at night, it’s harder for asthmatics to breathe. Researchers believe this restriction also exacerbates fever symptoms at night. 

When you or your family members have a troubling fever, trust your instincts if you think something is wrong, then call your paediatrician or family doctor for advice.

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Two Supermassive Black Holes On A Collision Course

Supermassive black holes are thought to be at the centre of most galaxies, and they are huge. The Milky Way’s own supermassive black hole, Sagittarius A*, is about 4 million times the mass of our sun. But scientists have just spotted two absolute behemoths, that dwarf Sagittarius A*, and they are on a collision course. It’s the first time such massive black holes have been spotted this close together, and it could help us detect a hum of gravitational background noise. 

Of course “close” is a relative term and in this particular instance when scientists say close, they mean about 1,400 light-years apart. The black holes are located about 2.5 billion light-years from us, so since the light from them took 2.5 billion years to reach us, we are observing them as they were 2.5 billion years ago.

Coincidentally, the scientists who discovered them estimate that that’s about how long it will take before they collide. They could be merging with each other right now, unleashing huge gravitational waves millions of times more powerful than those previously detected by LIGO and Virgo. Of course, because of how far away they are, the waves won’t reach us for 2.5 billion years.

That is if they happen at all. We have observed stellar-mass black holes merging, but we are not sure if their supermassive counterparts can join forces by merging too. It seems odd, these things each have an incredible gravitational pull, why wouldn’t they run head-on into each other?

Right now the thinking is when galaxies merge, their supermassive black holes begin to orbit each other. As they do, dust and stars in between them sap some of their energy, causing their orbits to tighten. But as they get closer, that region of space between them shrinks, until theoretically there’s no way to lose more energy.

The two black holes find themselves stably orbiting each other but never getting closer. Some studies suggest that happens at about 1 parsec, or roughly 3.2 light-years distance, so it’s known as the final parsec problem. But all that is theoretical, and we’re lacking more observational data.

It’s possible our predictions are wrong and black holes of this size do merge instead of stalling out a parsec apart. Unfortunately, black hole pairs are very hard to spot. Remember how we mentioned earlier this is the closest we have seen two this big and they’re 1,400 light-years away from each other?

Because 1 parsec is way too close for us to distinguish two supermassive black holes apart. And now that we have found these two, it’s not like we can wait around 2.5 billion years to see if they merge. we will probably be dead by then. But since we have spotted these two, we can start to guess how common merging supermassive black holes would be. 

Based on their findings the scientists estimate that optimistically there are 112 black holes whose gravitational waves we can detect from Earth. This would make a kind of constant hum, the scientists likened this gravitational background noise to a chorus of chirping crickets. 

Normally it’d be impossible to distinguish one cricket from another. But if there’s no final parsec problem and they can merge, it should create a massive chirp at the moment they collide. When that happens, the waves will be at frequencies outside what LIGO and Virgo can detect. So instead, scientists will have to keep a close eye on pulsars, special stars that send out radio waves at regular intervals.

If a supermassive merger stretches or compresses the space between us and a pulsar, the rhythm will appear to be thrown off. These frequency changes are so small, just tens to hundreds of Nanohertz, it will require close to a decade of observation to spot the weak signal hiding in the noise. 

They are searching for more pairs of black holes to refine their prediction further, but it’s possible we never detect a merger and the final parsec problem is insurmountable after all. And while LIGO can’t detect supermassive mergers, it was recently upgraded, making it 40% more sensitive as it continues its hunt for merging stellar-mass black holes.

Source:-  The Astrophysical Journal Letters :- http://bit.ly/2z6YfJx

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Global Warming Explained By Quantum Mechanics

You have probably heard that carbon dioxide is warming the Earth, but how does it work? Is it like the glass of a greenhouse or like an insulating blanket? Well, not entirely. The answer involves a bit of quantum mechanics, but don't worry, we'll start with a rainbow.

If you look closely at sunlight separated through a prism, you will see dark gaps where bands of color went missing. Where did they go? Before reaching our eyes, different gases absorbed those specific parts of the spectrum. For example, oxygen gas snatched up some of the dark red light and sodium grabbed two bands of yellow.

But why do these gases absorb specific colors of light? This is where we enter the quantum realm. Every atom and molecule has a set number of possible energy levels for its electrons. To shift its electrons from the ground state to a higher level, a molecule needs to gain a certain amount of energy. No more, no less. It gets that energy from light, which comes in more energy levels than you could count.

Light consists of tiny particles called photons and the amount of energy in each photon corresponds to its color. Red light has lower energy and longer wavelengths. Purple light has higher energy and shorter wavelengths. Sunlight offers all the photons of the rainbow, so a gas molecule can choose the photons that carry the exact amount of energy needed to shift the molecule to its next energy level.

When this match is made, the photon disappears as the molecule gains its energy and we get a small gap in our rainbow. If a photon carries too much or too little energy, the molecule has no choice but to let it fly past. This is why glass is transparent. The atoms in glass do not pair well with any of the energy levels in visible light, so the photons pass through.

So, which photons does carbon dioxide prefer? Where is the black line in our rainbow that explains global warming? Well, it's not there. Carbon dioxide doesn't absorb light directly from the Sun. It absorbs light from a totally different celestial body. One that doesn't appear to be emitting light at all Earth.

If you are wondering why our planet doesn't seem to be glowing, it's because the Earth doesn't emit visible light. It emits infrared light. The light that our eyes can see, including all of the colors of the rainbow, is just a small part of the larger spectrum of electromagnetic radiation, which includes radio waves, microwaves, infrared, ultraviolet, x-rays and gamma rays.

It may seem strange to think of these things as light, but there is no fundamental difference between visible light and other electromagnetic radiation. It's the same energy, but at a higher or lower level. In fact, it's a bit presumptuous to define the term visible light by our own limitations. After all, infrared light is visible to snakes and ultraviolet light is visible to birds. If our eyes were adapted to see light of 1900 megahertz, then a mobile phone would be a flashlight, and a cell phone tower would look like a huge lantern.

Earth emits infrared radiation because every object with a temperature above absolute zero will emit light. This is called thermal radiation. The hotter an object gets, the higher frequency the light it emits. When you heat a piece of iron, it will emit more and more frequencies of infrared light, and then, at a temperature of around 450 degrees Celsius, its light will reach the visible spectrum.

At first, it will look red hot. And with even more heat, it will glow white with all of the frequencies of visible light. This is how traditional light bulbs were designed to work and that's why they are so wasteful. 95% of the light they emit is invisible to our eyes. It's wasted as heat. 

Earth's infrared radiation would escape to space if there weren't greenhouse gas molecules in our atmosphere. Just as oxygen gas prefers the dark red photons, carbon dioxide and other greenhouse gases match with infrared photons. They provide the right amount of energy to shift the gas molecules into their higher energy level.

Shortly after a carbon dioxide molecule absorbs an infrared photon, it will fall back to its previous energy level and spit a photon back out in a random direction. Some of that energy then returns to Earth's surface, causing warming.

The more carbon dioxide in the atmosphere, the more likely that infrared photons will land back on Earth and change our climate.

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Triton | The Largest Of Neptune's 13 Moons

Triton is an exceptionally unusual, although often forgotten, moon. It has so many unique characteristics, it makes it one of the most interesting objects in the Solar System. But because it is the largest moon of Neptune, the planet furthest away from us, it also means that we have only visited it once, very briefly, as Voyager 2 flew by all the way back in 1989, 30 years ago. But what did this visit reveal? And what have we found out about it since? 

First of all, let’s discuss where Triton fits into our solar system and its local system. Triton is one of 14 known moons of Neptune. 7 of these moons are regular moons or in other words, moons that orbit along Neptune’s ecliptic with very circular orbits or orbits with very low eccentricity. After these inner, regular moons, we get to the irregular moons, the first of which is Triton.

An irregular moon is a moon that follows an inclined, eccentric and often retrograde orbit. This by itself is already where Triton is set apart from any other spherical moon in the solar system, it has an irregular orbit. Triton orbits clockwise around Neptune as Neptune rotates counterclockwise, and Triton orbits at a 130° angle to the ecliptic of the planet, although it should be noted that its orbital eccentricity is close to zero, its orbit is almost perfectly circular.

All other large moons in the solar system are regular moons, orbiting the same direction as the rotation of their parent planet. What this heavily implies is that Triton did not form alongside Neptune, but it is, in fact, a captured object, specifically a captured dwarf planet.

No wonder then that it is by far the biggest of Neptune’s fourteen moons, comprising 99.5% of the mass found in Neptune’s orbit. But how big is that in scales we can relate to? 

Well, it is the second-largest moon in relation to its parent planet, second only to Earth and its moon. While it is smaller than our moon, it orbits closer to Neptune than our moon orbits Earth, which means it appears around the same size in the sky. It is the 7th largest moon in the entire solar system, and most interestingly, it is bigger than Pluto. 

Pluto is often considered the king of the Kuiper Belt, the biggest object that we know of that formed there, until we consider that Triton once ruled that area before Neptune captured it. So, although Triton is a moon of Neptune, it could also be said that it is the biggest and most massive Kuiper Belt object! 

Further evidence for this was found as New Horizons passed Pluto in 2015, suggesting Triton and Pluto share a near-identical composition, which supports the theory that they share a common origin. 

Beyond Triton are six other irregular moons, found much further out. They are almost certainly captured objects too, with unusually eccentric orbits that take years to complete. They were probably perturbed into these weird orbits by the gravity of Triton. 

So, if Triton was a captured object, how did that happen? Objects need to lose momentum to be captured, otherwise, they would have enough momentum to escape. Well, we can’t know for sure, but the leading theory right now is that Triton was once part of a binary system, perhaps like Pluto and Charon. As Neptune approached Triton and its moon, the gravity from the encounter would have caused the binary system to fall apart, with Triton’s moon being slingshot away and Triton losing enough momentum to be captured in orbit around Neptune. 

As mentioned before that Triton shares some similar characteristics with Pluto. So, what exactly does that entail? Well, they both have a predominantly nitrogen ice surface with other ices mixed in, like water and carbon dioxide. It has quite a flat terrain, its topography never varies by more than a kilometre, although Voyager 2 did see ridges and troughs, plateaus and ice plains. What you may find unusual though is that it has very little in the way of craters, this implies its surface is very young and is constantly being renewed.

Like Pluto, it also has some reddish patches, which is thought to be methane ice having reacted to UV light from the Sun, producing what is known as tholins, an organic compound that has a supposedly tar-like consistency. While organic compounds do not mean life is present there, organic compounds are the basic chemicals from which life forms. Life likely couldn’t exist on the surface of Triton anyway, as it is far too cold and the Sun far to dim to support any lifeform that we can imagine, but what’s interesting is what could be found under Triton’s crust.

Under Triton’s surface is thought to be a rocky and metallic interior, which gives Triton a reasonably high density for a moon, at 2 g/cm³. Because of this, and also due to the big step up in size from the next biggest moon in the solar system, Titan, it has more mass than all moons smaller than it in the whole solar system combined. The radioactive decay from the rocky core could be enough to heat and power convection in a subsurface ocean of water, much like what is thought to be under the surfaces of Europa, Enceladus and some other large moons in the solar system.

Just like Europa and Enceladus, cryovolcanism is an active process today on Triton. Liquid water in the mantle erupts onto the surface like lava on Earth. This is the main reason why the surface is so young, it is being actively renewed by liquid water erupting, and then freezing on Triton’s surface.

Some very young lava plains have been identified, sparse and flat regions, yet interestingly with a wall that surrounds the plain. We call this a planitia, or in other words, a solidified lava lake. We also can see caldera, which is the collapse found at the centre of a cryovolcano, where lava plains formed from.

It is thought that the water from these eruptions would have also brought minerals from the underground oceans onto the surface, perhaps even being the source of the tholins and organic matter mentioned earlier. If this is the case and organic compounds are found in the subsurface ocean, it means that there’s a possibility that conditions are right for life to have been able to form there.

We also see long lines permeating over the surface, these are likely faults caused either by tectonic activity or freeze-thaw weathering processes. If we look at the Voyager 2 images of Triton, we can see the results of some recent eruptions. You will notice what looks to be dark deposits on the surface, in cone or funnel-like shapes up to 150km long. However, these smaller eruptions may not originate from the mantle itself. Voyager 2 spotted some plumes reaching 8km high, but these are thought to because of a solid greenhouse effect within the moon’s icy crust.

Imagine the surface of Triton consisting of clear ice which has settled on dark deposits like tholins. The Sun shines through the ice, warming the darker, more absorbent tholins beneath, which sublimes a pocket of ice under the surface. As the ices sublime, the pressure builds in the air pocket until the surface above the pocket gives way, causing an eruption. This eruption also takes the darker deposits with it, spreading them out on the surface again.

If this is the case, a very similar process has been seen on Mars’ poles with carbon dioxide ices and darker deposits under the ice layer. This process can only exist because of one thing, Triton has an atmosphere, although not as thick as scientists were initially expecting. Triton’s atmosphere is thin, only 0.014 mbar, about the equivalent of 80km up on Earth, although like Pluto, this density varies through seasonal changes.

Since Voyager 2’s observations, Triton’s atmosphere has become denser, as the surface has warmed, evaporating a little of the nitrogen ices on the surface. However, when Voyager 2 passed, Triton’s atmosphere was still dense enough to support weather up to 8km above its surface. Like Pluto, Triton’s atmosphere is hazy, the cause of which is thought to be hydrocarbons in the atmosphere not yet broken down into tholins by UV light from the Sun.

The constant depositing of organic compounds through cryovolcanism, ices evaporating and freezing again through seasonal variations, and a weather rich, active atmosphere makes Triton a very dynamic world, unlike most other moons in the solar system. It is more a dwarf planet than a moon, likely a sibling of the more famous Pluto in the Kuiper belt. All these factors combined make it one exceptionally unusual moon.

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How Many Times A Falcon 9 Can Be Reused?

On the 21st of December 2015, SpaceX made history by landing their first Falcon 9 booster back on land. After years of development and testing, SpaceX was one step closer to dramatically reducing the cost of spaceflight.

Since then, over 45 boosters have been landed with over half of them being reused. But how many times can a Falcon 9 be reused And what does it take to refurbish each booster between flights?

In this article, we are going to look at how SpaceX upgraded the Falcon 9 to be more reusable. We are also going to look at what goes into refurbishing the Falcon 9 and how it will eventually be replaced by Starship.

In April 2018, SpaceX launched the new and improved ‘Block 5’ Falcon 9. This new version brought many upgrades to the engine heat shield, grid fins and landing legs, with an aim to reduce the amount of refurbishment and maximize the number of flights per booster.

Although this upgrade cut out the need for a lot of refurbishment, the average turnaround time for a booster has only dropped from 356 days to 107, with the quickest turnaround time being 72 days. The Space Shuttle, on the other hand, achieved a record of just 55 days between flights back in 1985, with regular refurbishment times of less than 100 days.

However, after the Challenger disaster, the safety standards increased and this put extra pressure on refurbishment. The process became an enormously expensive task, requiring over 9,000 employees to make the Shuttle ready for flight. With SpaceX aiming to achieve a refurbishment time of just 24 hours, they will need to match the turnaround process of airliners, with each rocket only needing a quick inspection between flights.

When the first stage booster returns to Earth either by land or by sea, it’s lifted onto a trailer and transported back to the SpaceX hangar. This can take multiple days to complete since each of the four landing legs need to be removed manually. Although they are designed to be quickly retracted, SpaceX has only been able to do this on two occasions.

Once the booster is back in the hangar, the refurbishment process begins with each engine going through a number of rigorous tests to make sure that every component is ready for flight. According to Musk, each Merlin engine could perform up to 1000 flights without major refurbishment.

The hydraulic grid fin system, which failed during a landing in the year 2018, must also be checked for any leaks. The fuel tanks and pressure vessels go through a series of ultrasonic tests to check for tiny cracks that could lead to a failure once the rocket is pressurized for flight. Once the booster has passed the inspection process, it performs a static fire test with all 9 engines, before being attached to the payload.

At the moment, all of these checks still need to be completed as they venture into the unknown territory of multiple reuses. Each mission will give them more knowledge on how many flights each booster can perform and over time, the refurbishment process should become more refined.

So far, there are three Falcon 9 boosters that have each completed triple launches. SpaceX currently has around eight Falcon 9 boosters in their fleet, but eventually, they aim to grow that number to 20. Although the Falcon 9 could theoretically fly up to 100 times with minimal refurbishment, each booster is only expected to perform a total of around 30 flights over the next decade.

However, with SpaceX working on a much more powerful and fully reusable rocket, the Falcon 9 could become obsolete much sooner than expected.

SpaceX is currently building the first prototypes of their ‘Starship’ rocket in Texas and Florida. And with customers already lined up, they aim to launch their first commercial payload in 2021. Not only will SpaceX use Starship for Mars and commercial satellite missions, but they also want to use Starship for travel here on Earth, providing flights to anywhere in the world in well under an hour.

Unlike the Falcon 9, Starship is designed to be fully reusable with an aim to complete thousands of flights before any major refurbishment is needed. If SpaceX can get Starship up and running, it could replace the Falcon 9 altogether since it would be capable of launching much heavier payloads for a fraction of the cost.

Over the next few years, SpaceX will be hiring thousands of new employees to work on Starship. When it comes to hiring, Elon Musk has admitted that he doesn’t care about college degrees. In fact, in the early days of SpaceX, Elon taught himself rocket science by reading books and talking to people in the industry.  So if you want to join SpaceX or anything you are interested in then starts gaining knowledge about it from today.  

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How To Produce More Brain Cells?

It was previously believed that we stopped creating new brain cells once we became adults. Science has proven this to be false and coined the term Brain Plasticity. The brain is flexible, everything we experience is constantly changing and shaping our brains to some degree.

The hippocampus an important part of the brain, responsible for learning and retaining new knowledge. Certain factors that you will learn from this article can have a big impact on the activity and brain mass of your hippocampus, and the size of it is directly related to the level of neurogenesis.

You can increase your rate of neurogenesis at any age, and in the reference studies, it was possible to increase it by up to 500%. So, how can we increase our production of new brain cells? Let's categorizes these things in five areas: diet, body, heart, mind, and spirit.

Let's take a closer look at each of these, starting with the diet. The four most powerful dietary neurogenesis factors are blueberries, omega-3 fatty acids (ALA, DHA and EPA) which are found in fish or krill oil. By the way, if you' are vegan you should look into supplementing with algae because flaxseed oil is not adequate.

Next up is Epigallocatechin gallate or EGCG for short, which is a powerful polyphenol found in green tea. However, chronic caffeine intake is detrimental to neurogenesis, so it is recommended to takin decaffeinated extract supplements. Lastly, curcumin, a compound found in turmeric.

Other food compounds and supplements that stimulate neurogenesis include Quercetin, Vitamin E, Grapeseed Extract, Ginseng root, Ginkgo Biloba, Goji Berries, Rhodiola Rosea root and Lotus root.

Let's move on to the body category. Exercise can massively increase your neurogenesis, specifically exercise that increases your heart rate, for example, high-intensity interval training. Other things include sex, proper sleep, music, silence, sounds of nature, and simply being in nature and lastly novelty and new sensory experiences.

The heart category is about emotions. Feeling good, experiencing joy, love, interest, excitement, essentially positive emotions. Of course, nobody feels these things all the time, but optimally you should be experiencing these things often.

Relationships are huge influencers. Positive relationships breed neurogenesis, while negative ones that cause stress, anger or anxiety, decrease neurogenesis. Feeling love increases neurogenesis by the means of oxytocin, the hormone associated with love and physical contact.

When it comes to the mind we have learning, reading, writing, problem-solving, complex work that involves using cognitive abilities, discussing ideas, musical training.  It has been observed that there seems to be a very strong link between how much you use your mind early during your life and the prevalence of Alzheimer's later in life. 

For example, nuns that were teachers had much lower chances of developing Alzheimer's than nuns that didn't teach. This is called cognitive reserve. 

In the spirit category, we find mindfulness meditation, where you pay attention to your breathing, and compassion meditation, which involves wishing wellness to others. Prayer can also have a similar effect to compassion meditation. 

A list of things that decrease your rate of neurogenesis and that you should avoid if you want a healthy brain. These are chronically elevated blood sugar levels, high amounts of carbohydrates, sugar, overeating, inflammatory foods such as fried foods, cooking oils, and factory-farmed meat, eggs, and dairy. Chronic caffeine intake, smoking, alcohol, obesity, stress, despair lack of engagement, depression. 

Blows to the head can be devastating to the brain. In fact, a single concussion doubles a person's chances of getting Alzheimer's later in life. Chemical and environmental pollution also play a role, for example, mercury which is found in many fish is the second most neurotoxic substance in the world.

Lastly, deprivation of sensory stimulation or emotional nourishment, basically living a boring life, not experiencing interesting things, never doing anything new and living every day exactly the same. And by the way, excessive TV is also linked to increased risk of Alzheimer's.

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Pneumonia | Why It Is So Deadly?

Our immune system has a whole arsenal, like macrophages, cytokines, t-cells and many more, to fight off an infection. But when it comes to some diseases, the way the body defends itself can have unintended consequences. In the case of Pneumonia, the immune system’s response can be very lethal hence earning it the nickname the ‘captain of the men of death.’

Pneumonia doesn’t just refer to a single virus or bacteria. It’s a condition that can actually be caused by a number of different bacteria, viruses or even fungi. The most common being the bacteria streptococcus pneumoniae, who will be our main bad guy today. So when we are talking about pneumonia, we are really referring to something that is happening to our lungs.

So pneumonia is an infection of the lungs and it is a very common infection. The problem is that the lungs are thought to be sterile, in fact, the lungs aren't sterile. But generally, there are very few bugs in your lungs. The problem is that our mouth and our nose are actually filled with bacteria and viruses and these can something get down into the lungs.

We are constantly being exposed to the bacteria and viruses that cause pneumonia-like Streptococcus pneumoniae. These pathogens can live in your upper respiratory tract without you even knowing it. That’s because, for most people, the immune system should be able to step in and stop them in their tracks, leading to immunity.

You become immune to the bugs that you encounter when you are very young and by about five years of age, you are pretty much immune. But, for children under 5, the immune system is weaker, leaving the body susceptible to infection. 

It’s not just children who are at risk. Unfortunately, pneumonia risk comes back again in the elderly. "Who is elderly?" you might say. Generally defined as people older than 65. So pneumonia is a disease of the extremes of life, the very young and the very old.

Now, it’s not only young children and older adults, anyone with a compromised immune system is at risk. With the immune system unable to mount a defence in the respiratory tract, the bacteria are able to pass into the lungs. Once there, the immune system will still try to defend the body.

But unfortunately, they have a lot of side effects when this response occurs. Macrophages first try to fight off the infection, but they can become overwhelmed, triggering the release of cytokines. These cytokines lead to inflammation of the lungs, causing air sacs called alveoli to fill with fluid.

So alveoli are air sacs in the lungs that are where the exchange of oxygen and carbon dioxide takes place. It is these alveoli that get filled with the fluid that's come from your bloodstream. Now, there's no particular reason for red cells to get out of the bloodstream but white cells that are included in the bloodstream are very potent cells able to kill bacteria and they move in from the bloodstream out into the tissues at the site of infection.

But, filling the alveoli with fluid does more than just fight off the infection. That’s because, basically, your lung sacs are filling with pus. The lungs are there and exquisitely designed for oxygen to pass from the air into your bloodstream. 

So, unfortunately, instead of having nice, clear air pockets where this exchange can take place, they are filled with fluid. Then the exchange of oxygen and the release of carbon dioxide, which you breathe out, is impaired.

This causes difficulty breathing as well as a whole host of symptoms that vary greatly in severity. The effects of walking or atypical pneumonia can be so mild, someone might not know even know they have it. In other cases, the infection can lead to death.

But, while pneumonia is still a disease that kills millions of people worldwide, there isn’t a good reason why it should still be so lethal. The main driver of mortality from pneumonia is access to treatment or lack thereof.

There are vaccines that work to protect from both bacterial and viral pneumonia. In fact, the most successful vaccine for prevention of pneumonia is a bacterial vaccine. So pneumonia deaths are really preventable by vaccines and can also be treatable by antibiotics.

Because of this, pneumonia deaths are much more common in poorer countries with fewer resources. Which is why Doctors are working on ways to develop more effective treatments in these areas of the world. 

But pneumonia deaths can still happen in places like USA, UK, Franch or any developed nation especially if something were to lead to people having compromised immune systems. That could happen from contracting other illnesses, some of which are entirely preventable. 

There have been outbreaks of measles recently in some developed country. And globally, measles has not been eradicated. One of the major problems with measles is that it diminishes your immune response. Kids who have measles can get bacterial and viral pneumonia after their measles. 

So, in fact, pneumonia is a major killer following measles exposure. And measles prevention is a very important way of preventing deaths from pneumonia. That's why you should take the vaccine and there's a very potent vaccine for measles avalable as well.

Also Read:- The Horseshoe Crab That May Have Saved Your Life Countless Times Is In Danger, But There Is A Hope

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