Here We Discuss Different Science Related Stuffs... Chapters & Contains. Innovations in Science world And Some Knowledge Stuff ... Come And See & Let Us Know How You Feel

What is Time?

Time is something that everyone is familiar with 60 seconds is one minute, 60 minutes is one hour, 24 hours is one day and so on. This is known as Linear Time and is something that everyone is familiar with and agrees upon. But consider this, if someone came up to you on the street and asked you to draw time, what would you draw?

You might draw a clock, or a watch ticking every second, Or you might draw a calendar with X's over each day to represent the passing of time. But that's all those drawings would be, just physical representations of the passing of time. Those drawings would just scrape the surface of the Enigma that is time. Something that seemingly runs our lives and is unavoidable can't be explained by even the smartest people on Earth. So what is time and can we prove that time even exists?



Aristotle once said, "Time is the most unknown of all unknown things." That was nearly 2,500 years ago, and it still stands true today. If you were to go to Google and type in, "What is time?", you would find that it says time is a dimension and in many ways it is. When you text a friend and ask them to meet for coffee, you wouldn't give them a place without a specific time.

However, there is a flaw in that definition of time; It leaves too many doors unopened - because time is also a measurement. For example, I was born in the 1990s. That was over 20 years ago If I were to say I was born 18 billion kilometres in the past, that wouldn't make much sense and people would probably look at me like I'm crazy.



With spatial dimensions - the 3D world that we live in - it's very easy to go back and forth between places because these things are essentially fixed in space. If I went to the store to buy groceries and I forgot the milk, I could easily go back and buy some milk. However, the time that it took to do that is unable to be retrieved. It is lost forever into the past.

An object placed in 3D space will stay there almost indefinitely. If I place a bottle on the table, it will just stay there, but that bottle still falls victim to time. See, time is like an arrow - it moves in one direction; forward. Scientists fittingly called this the arrow of time.



If you one day woke up and found yourself floating in the middle of empty space, would you be able to tell which way is up, down, left or right? Probably not. However, time is a much simpler ordeal. See, the time comes from the past, originating at the Big Bang, where our history lies and is fixed.

Through the present, where we are essentially prisoners of, towards the unknown and turbulent future. We can remember things from the past like how I can tell you that this morning I went to the store, bought groceries and then forgot to buy milk. But at the same time, I can't tell you what I ate for breakfast next Thursday.



The arrow of time originated at the Big Bang and has been moving forward ever since. We used the second law of thermodynamics to represent this. It is known as entropy. Think of entropy as a measure of disorder in the universe. 

At The Big Bang, all the matter in the universe was compacted into an infinitely small point. This is considered a very low entropy situation; a very orderly situation. It would be similar to stuffing every sock that was ever made into one drawer. In that situation, you know with 100% certainty where your socks would be. Ever since the Big Bang, all the matter in the universe has been expanding away from each other making the universe a higher entropy system. 



Because of entropy and because of the arrow of time, we have galaxies, stars, planets, and even life. Entropy is the reason that you can tell the difference between the past and the future. It explains why every human is born and then they live and then dies - always in that order. If there were no entropy -- if there were no change in the universe, you wouldn't be able to tell the difference between the year 2017 and the year 1 billion. No matter what you do, time moves forward and doesn't stop for anyone or anything.

At least on the macro scale. See, the arrow of time works and is extremely noticeable on large scales the skills that you and I operate on every day. But at a quantum level time operates differently. Take the situation where you woke up in the middle of space. There, you have no idea which way is up, down, left or right. It's a very unique situation that only applies in the vastness of empty space, but if you come back to Earth, it's very easy for you to orient yourself. The arrow of time works in a similar way. On a macro level -- the big level, it's very easy for you to tell that the year 1900 is different from the year 2018. It's very easy to view the flow of time.



However, on a micro scale, if we look at deep down into the physics that make up the universe, entropy and - subsequently - the time isn't so obvious. If I were to record myself cracking an egg and pouring its guts into a bowl and then I reversed the footage, you would easily be able to tell that the footage had been reversed. However, if I record a pendulum swinging back and forth for five minutes and then reversed the footage and show it to a random person on the street, will they be able to tell that that footage has been reversed? The answer is probably not.

See the arrow of time seems to flow in one direction on the macro scale, but as you take parts of it away and skim it down to the bare bones of particles that make up the universe, time seems to work and flow in every direction; both forward and backward. There are no laws of physics that state the past is any different from the future.



The only reason why you can think about what you want to have for dinner tomorrow as opposed to what you want to have for dinner yesterday is because of the arrow of time; because of entropy, because the universe had a beginning. Or at least it seems like it.

You might be starting to see why the arrow of time and entropy are so important. They quite literally govern our lives and the universe. See the fact that entropy is increasing is well known. It's the reason why life today is the way that it is.



However, not many people are addressing the question that is: "Why was the entropy of the universe so low in the first place?" Well, the answer is simple. It was lower yesterday than it was today. You can take this logic all the way back to the Big Bang. You hear that a lot, "The universe came into being at the instance of the Big Bang." And for all we know as of now that may be true. However, it might not be true.

We have the physics of Einstein's general relativity that allows us to go back to mere seconds after the Big Bang. But after that, our equations break down. That is as far as we can go for now. There is no law of physics yet that states that there wasn't time before the Big Bang and perhaps a reversed arrow of time. We just don't have the science to look that far back yet.



Because the universe is expanding and because entropy is increasing with time, there will eventually be a time where everything in the universe is so far apart from one another that space will essentially be empty. Everything will be too far apart to interact with one another all the way down to the atoms that make up everything in the universe.

However, just as the temperature outside fluctuates day to day, so does the entropy of the universe. Albeit, very small fluctuations are small time scales such as a human life, over unreal time scale such as 10 to the 10 to the 10 to the 56 years. It is possible that quantum fluctuations could cause an extremely random extreme entropy decrease. This would create conditions similar to the Big Bang as we know it and could explain the arrow of time and the origin of our universe.



However, in order to answer these questions, we need to unite quantum mechanics with Einstein's general relativity. This would provide a scientific link between the quantum world of atoms with the macro world of stars, galaxies and black holes in the universe. This is dubbed "the theory of everything" and is something that many scientists are working on right now.

With this theory, we may be able to - for the first time - be able to explain how and why the universe we live in came into existence. And maybe, even prove that the multiverse exists.



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Problem Of The Nuclear Waste

Nuclear energy is one of the cleanest, most efficient, and most available sources of power on earth. To generate one kilowatt-hour of energy —the amount a modern household consumes in 48 minutes— nuclear power plants only emit 12 grams of carbon dioxide— enough to fill about three two-litre soda bottles. Meanwhile, to produce the same amount of energy, coal plants emit 820 grams of CO2—about a full bathtub’s worth. 

Factoring in the environmental cost of production, nuclear energy is cleaner than hydropower, than geothermal, than solar, than really any energy source except wind. But that doesn’t necessarily mean nuclear is the long-term solution for the world because nuclear material is perhaps the most poisonous substance on earth.



Two times in history have nuclear power plants leaked a significant amount of radiation—in 1986 in Chernobyl, Ukraine and in 2011 in Fukushima, Japan. 31 people died in Chernobyl with at least a further 4,000 expected to contract early lethal cancer due to the radiation.

Fukushima was better contained with only two deaths, both unrelated to radiation, and only 130 early cancer deaths expected, but additionally, each site still today has massive exclusion zones where humans cannot live due to ongoing radiation. Hundreds of thousands of people were displaced from their homes and will never be allowed to return.



The economic damage of Chernobyl is estimated at nearly $250 billion dollars—significantly more than the GDP of Ukraine. The Fukushima disaster, meanwhile, having taken place is a much more populated and developed area, is estimated to set Japan back over $500 billion dollars—a full 10% of their GDP.

In addition, uranium, the element most commonly used in nuclear reactors, is not in limitless supply. Using present-day extraction methods, there is only about a 230 year supply of uranium left. Many would say nuclear is only a short-term solution to reduce carbon emissions until truly sustainable energy can become commonplace, but the biggest problem with nuclear energy is not the risk of meltdown, it’s not the supply of uranium, it is the nuclear waste.



All current commercial nuclear power plants work through the process of nuclear fission. As a radioactive element decays, the individual atoms split into multiple, but when that happens the reaction also releases energy. There are plenty of different designs of nuclear reactors, but in general, they capture the released energy by using it to heat up water into steam which runs through turbines that spin generators.

The nuclear element used is typically uranium which, after about six to eight years of usage in a nuclear power plant will have released enough of its energy that it is no longer useful in nuclear reactors, but that doesn’t mean it’s done emitting energy. The fuel rods will remain radioactive enough to emit a lethal dose for tens or hundreds of thousands of years past their removal.



So the question is, what do you do with them? The answer is simple—put them somewhere where they can stay, undisturbed, isolated, forever, but that’s not all that easy. In fact, no nuclear waste worldwide is currently in what is considered long-term storage. Every bit of nuclear waste in existence is in temporary storage facilities to be used until a long-term solution is built.

Most of that nuclear waste is stored in pools of water. Water does a decently good job of shielding radiation so this is an inexpensive and easy way of storing the rods. Usually, these pools are physically inside nuclear power plants. So, when spent fuel is removed from the reactor, it’s put directly into the water and left there.



The radioactive material, since it’s still emitting energy, it continues to heat up the water, but cooling systems and pumps keep the water below boiling temperature, but to do that the plant needs power. If the power fails and the backup generators fail, the pumps and cooling systems stop working so the water heats up and can boil off. The water is what blocks the radiation so, without water, the radiation just goes right out into the environment.

In fact, exactly that's what happened at Fukushima. Both the primary and backup power sources failed so the pumps and cooling systems for the spent fuel pools couldn’t run, leaving the water to heat up. The situation was brought under control before enough water had boiled off to release significant amounts of radiation into the environment, but had it not been, thousands could have been killed.



Once the nuclear waste has cooled down in storage pools for ten to twenty years, it typically is encased in casks. These concrete and steel containers block in radiation, but this solution is far from permanent. It does not consider earthquakes, it cannot withstand tsunamis, and it would not work without humans.

These casks require security and they require maintenance. Without humans, they could easily be damaged or breached over time and release radiation into the environment. Modern humans have only existed for about 200,000 years, so one can hardly be sure that the species will survive for the millions of years that the most toxic nuclear waste will continue to emit radiation.



What’s more, one can hardly expect that the dominant civilizations that have nuclear technology today will continue to exist for even thousands of years. The Roman Empire was once without a doubt the most powerful civilization on earth. Scholars even believe that it is the most powerful civilization to have ever existed on earth—more powerful than the US, than Europe, than any modern civilization, but it fell, and so too will the west.

Therefore, long-term nuclear waste storage needs to last longer than any political structure, it needs to work without the supervision of humans, it needs to be truly and unequivocally permanent.



Finland is building just that. This region is largely devoid of natural disasters. It doesn’t have earthquakes, it doesn’t see tsunamis, it really doesn’t encounter any natural phenomenon that could damage a nuclear waste storage site, especially if it’s 1,500 feet underground.

Beneath an island on the Finnish Baltic Sea coast, the country is digging. They are building the very first permanent nuclear waste storage facility in the world in the stable bedrock 1,500 feet below. Currently, they are just finishing their dig down then very soon, in 2020, they will start filling the facility with nuclear waste.



They will dig long tunnels with small holes in which they will place casks of nuclear waste then backfill the tunnels with clay to be left for an eternity. With this system, there is near zero risks of nuclear material leaking out into the groundwater and, once it’s filled in the year 2120, it can just be left, forever.

Because the material will be so far down and so difficult to get to, no human management will be necessary once completed. No security, no maintenance, nothing which means it should be truly secure, but before leaving it, they do need to fight against one thing—human nature.



As curious beings, it is hard to combat a person’s urge for discovery. If someone finds a mysterious structure from thousands of years ago, it would just be natural to want to open it up, and that’s a problem for nuclear waste sites. We essentially did just that with the pyramids in Egypt. These structures were built as the final, permanent resting places for the elites of Egypt and we opened them up because we were curious.

Opening the nuclear storage facilities would release radiation into a future civilization, so we have to tell them to leave the sites alone, but that’s easier said than done. The US Department of Energy commissioned a study on how to communicate the danger into the far future. The key is to create a message that conveys how uninteresting, how unimportant, and how dangerous nuclear waste is.



They settled on the following text: Sending this message was important to us. We considered ourselves to be a powerful culture. This place is not a place of honour… no highly esteemed deed is commemorated here… nothing valued is here. What is here was dangerous and repulsive to us. This message is a warning about danger. The danger is in a particular location… it increases toward a centre… the centre of danger is here... of a particular size and shape, and below us. The danger is still present, in your time, as it was in ours. The danger is to the body, and it can kill. The form of the danger is an emanation of energy. The danger is unleashed only if you substantially disturb this place physically. This place is best shunned and left uninhabited.

The idea would be to translate a message like this into every United Nations language— Arabic, Chinese, English, French, Russian, and Spanish. There is a reasonable hope that, at least in the next couple thousand years, one of those languages would be understood. But in the scope of hundreds of thousands of years, there is just little expectation that these languages would survive.



There is not even a reasonable expectation that humans would survive. So, you need to convey the same message without language. What the study suggests is to further push the message by building a landscape that conveys danger. It could be a scene of thorns, or spikes or forbidding blocks.

To satiate the discoverer’s curiosity, it’s also suggested to add monoliths explaining the history of the site through pictographs. Also included would be images like this, engraved in stone, conveying that the substance has danger that will be passed onto humans if touched, but the difficulty of this is that it very well might not be humans exploring earth 100,000 years from now. It could be a species that doesn’t recognize the likeness of what might be a long-extinct species.



What some have suggested is to just let the site be forgotten, to not mark it at all, to just seal it up and leave, but having something that significant disappear isn’t simple.

The site in Finland is designed to not need security or oversight, but its current location is very well documented in a potentially irreversible way. With books and brains and the internet, records of the site might exist until at least the end of human civilization. To truly be forgotten, to truly be left as part of nature, so too must humans be forgotten.



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Universe’s First Type of Molecule Is Found at Last

The first type of molecule that ever formed in the universe has been detected in space for the first time, after decades of searching. Scientists discovered its signature in our own galaxy using the world’s largest airborne observatory, NASA’s Stratospheric Observatory for Infrared Astronomy, or SOFIA, as the aircraft flew high above the Earth’s surface and pointed its sensitive instruments out into the cosmos.

When the universe was still very young, only a few kinds of atoms existed. Scientists believe that around 100,000 years after the big bang, helium and hydrogen combined to make a molecule called helium hydride for the first time. Helium hydride should be present in some parts of the modern universe, but it has never been detected in space — until now.



SOFIA found modern helium hydride in a planetary nebula, a remnant of what was once a Sun-like star. Located 3,000 light-years away near the constellation Cygnus, this planetary nebula, called NGC 7027, has conditions that allow this mystery molecule to form. The discovery serves as proof that helium hydride can, in fact, exist in space. This confirms a key part of our basic understanding of the chemistry of the early universe and how it evolved over billions of years into the complex chemistry of today.

“This molecule was lurking out there, but we needed the right instruments making observations in the right position — and SOFIA was able to do that perfectly,” said Harold Yorke, director of the SOFIA Science Center, in California’s Silicon Valley.



Today, the universe is filled with large, complex structures such as planets, stars and galaxies. But more than 13 billion years ago, following the big bang, the early universe was hot, and all that existed were a few types of atoms, mostly helium and hydrogen. As atoms combined to form the first molecules, the universe was finally able to cool and began to take shape. Scientists have inferred that helium hydride was this first, primordial molecule.

Once cooling began, hydrogen atoms could interact with helium hydride, leading to the creation of molecular hydrogen — the molecule primarily responsible for the formation of the first stars. Stars went on to forge all the elements that make up our rich, chemical cosmos of today. The problem, though, is that scientists could not find helium hydride in space. This first step in the birth of chemistry was unproven, until now. 



“The lack of evidence of the very existence of helium hydride in interstellar space was a dilemma for astronomy for decades,” said Rolf Guesten of the Max Planck Institute for Radio Astronomy, in Bonn, Germany, and lead author of the paper.

Helium hydride is a finicky molecule. Helium itself is a noble gas making it very unlikely to combine with any other kind of atom. But in 1925, scientists were able to create the molecule in a laboratory by coaxing the helium to share one of its electrons with a hydrogen ion.



Then, in the late 1970s, scientists studying the planetary nebula called NGC 7027 thought that this environment might be just right to form helium hydride. Ultraviolet radiation and heat from the ageing star create conditions suitable for helium hydride to form. But their observations were inconclusive. Subsequent efforts hinted it could be there, but the mystery molecule continued to elude detection. The space telescopes used did not have the specific technology to pick out the signal of helium hydride from the medley of other molecules in the nebula.

In 2016, scientists turned to SOFIA for help. Flying up to 45,000 feet, SOFIA makes observations above the interfering layers of Earth’s atmosphere. But it has a benefit space telescopes don't— it returns after every flight.



“We are able to change instruments and install the latest technology,” said Naseem Rangwala SOFIA deputy project scientist. “This flexibility allows us to improve observations and respond to the most pressing questions that scientists want to be answered.”

A recent upgrade to one of SOFIA’s instruments called the German Receiver at Terahertz Frequencies, or GREAT added the specific channel for helium hydride that previous telescopes did not have. The instrument works like a radio receiver. Scientists tune to the frequency of the molecule they’re searching for, similar to tuning an FM radio to the right station. When SOFIA took to the night skies, eager scientists were onboard reading the data from the instrument in real time. Helium hydride’s signal finally came through loud and clear.



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First 3-D Print Of Heart With Human Tissue

Scientists in Israel unveiled a 3D print of a heart with human tissue and vessels on 15.04.2019, calling it a first and a "major medical breakthrough" that advances possibilities for transplants.

While it remains a far way off, scientists hope one day to be able to produce hearts suitable for transplant into humans as well as patches to regenerate defective hearts. The heart produced by researchers at Tel Aviv University is about the size of a rabbit's.



It marked "the first time anyone anywhere has successfully engineered and printed an entire heart replete with cells, blood vessels, ventricles and chambers," said Tal Dvir, who led the project.

People have managed to 3D-print the structure of a heart in the past, but not with cells or with blood vessels. But the scientists said many challenges remain before fully working 3D printed hearts would be available for transplant into patients.



Journalists were shown a 3D print of a heart about the size of a cherry, immersed in liquid, at Tel Aviv University as the researchers announced their findings, published in the peer-reviewed journal Advanced Science.

Researchers must now teach the printed hearts "to behave" like real ones. The cells are currently able to contract but do not yet have the ability to pump. Then they plan to transplant them into animal models, hopefully in about a year.



"Maybe, in 10 years, there will be organ printers in the finest hospitals around the world, and these procedures will be conducted routinely," Dvir said.

But while the current 3D print was a primitive one and only the size of a rabbit's heart, larger human hearts require the same technology. 3D printing has opened up possibilities in numerous fields, provoking both promise and controversy. The technology has developed to include 3D prints of everything from homes to guns.



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Food Supply To The International Space Station

Since November 2, 2000, the International Space Station has been continuously crewed meaning humanity has had a permanent presence in space. This importance of this station cannot be overstated—NASA has literally filled a book with all the ways the ISS has benefited humans on earth. It’s helped develop new cancer treatments, enhanced robotic surgery technology, improved data processing techniques, its benefits stretch far and wide.It is quite possibly the most significant science experiment humanity has ever undertaken.



It is also quite possibly the most expensive single item humanity has ever built at an overall cost, so far, of about $160 billion. Breaking that down, each day that each astronaut spends on the ISS costs about $7.5 million. The ISS is a joint project between Russia’s Roscosmos agency, Japan’s JAXA, Europe’s ESA, Canada’s CSA, and the US’ NASA. Physically, though, it’s split up into the Russian segment and the US segment with these two countries more or less taking responsibility for managing and supplying their side.

At over 350 feet or 110 meters long, the station is longer than a 747 and has more interior space than the average six bedroom house. Space is still at a premium, though, as science experiments and equipment take up most of the room so normally there are only a maximum of six crew members onboard at any given time. Back on earth, though, there are thousands of people working to support the activities of those six.



Now that the international space station is built and operating, the whole mission is basically a big logistics problem—it involves getting people, food, water, supplies, and experiments up and down from the station in a consistent, cost-effective, and safe manner.

Food, as an example, is one of the only completely non-renewable resources onboard the ISS. Water can be recycled, oxygen can be generated, supplies can be reused, but food is one and done. That means there has to be consistent shipments from earth to the station. About half the food is supplied by the Russians and the other half by the Americans.



There are a few constraints to space food—it has to be shelf stable as there are no refrigerators onboard, it has to last about two years as resupplies only happen a few times a year, it has to be light as weight is precious on the resupply rockets, and it has to be easy to prepare as astronauts’ time is valuable.

Within those parameters, the Russians use a system of canned food while the Americans use a system of flexible pouches which have the advantage of being lighter weight than the cans. This NASA food is produced at the Johnson Space Center in Houston, Texas.



Long before they launch, the astronauts do a taste test to determine which foods they like most and they express these preferences. Based on those, NASA will produce and load more of the best-liked foods. The astronauts can choose from hundreds of items—spaghetti and meatballs, barbecue beef brisket, Caribbean chicken, vegetable quiche, beef enchiladas, the options go on and on.

Somewhat surprisingly, the ingredients for the food are just purchased at a grocery store like any other meal. There is no special sourcing or special ingredients, although they do inspect the ingredients carefully after buying to be extra sure that they are safe. As far as we know, no astronaut has yet gotten food poisoning in space and NASA wants to keep it that way.



The food is then prepared fairly conventionally until the last step. Food is made shelf stable and lightweight by one of two methods—thermostabilization or freeze-drying. With thermostabilization, heat is used to destroy microorganisms and enzymes that would cause food to spoil. With freeze-drying, the food is frozen and then almost all moisture is removed.

With this technique, there is nearly no water left in the food, which is normally the bulk of its weight, so a full serving of spaghetti, for example, weighs only one ounce or 28 grams. The space station has a water recycling system that recovers about 80% of the water onboard which means that, while they do occasionally have to resupply water from the earth, it’s more efficient to ship food up without water in it since the water onboard can be reused for multiple meals and that also helps keep it shelf stable.



Overall, freeze drying reduces the total food weight they have to take up. NASA currently pays about $29,000 per pound for shipment to the Space Station. Each gallon of water they bring therefore costs them about a quarter of a million dollars.mThat also means each of those one-ounce portions of spaghetti costs them about $1,800. They also typically include a few pieces of fresh fruit anytime a rocket goes up as a treat and, with these shipment costs, each apple is worth almost $10,000. This is why so much focus is put on minimizing weight.

In addition to the food they make, some foods are just shipped up as is. For example, if a crew member has a particular type of granola bar they like, the food preparation team will go out and buy some of those as a sample and perform some tests in their lab to figure out if it’s, as they call it, “flight compatible.” In that, they are basically looking to be sure that it’s not too crumbly as they don’t want crumbs floating around into all the nooks and crannies of the station, as well as being sure it’s not too liquidy, both for the purposes of weight and to be sure that it doesn’t cause free liquid to float around. Assuming it passes these tests, astronauts can pretty much bring what they want for snacks. It will be repackaged into NASA’s pouches, but there’s a surprising amount of simply store-bought food on the station.



Once all food is produced and packaged, it is shipped to one of four launch sites—either the Mid-Atlantic Regional Spaceport in Virginia where Northrop Grumman Cygnus resupply spacecraft are launched from. Cape Canaveral, Florida where SpaceX Dragon spacecraft are launched from. Baikonur Cosmodrome in Kazakstan where Russian Progress resupply and Soyuz crewed spacecraft are launched from; or Tanegashima Space Center in Japan where Japanese Kounotori spacecraft are launched from.

The food will be carefully packed alongside everything else making the trip ensuring proper spacecraft balance. Thanks to all these weight-saving techniques, supplies for crew, including food, only represent a small portion of the overall weight of each launch. For example, on one SpaceX launch, crew supplies only represented 530 pounds or 240 kilograms of the 6,000 pounds or 2,700 kilograms of cargo. The rest of the launch capacity is dedicated to equipment and experiments.



Now, part of the difficulty of this supply chain is that launch dates change a lot. For example, the SpaceX resupply, CRS-16, was initially scheduled for August 2018, then it was pushed back till the 29 of November, then till December 4th, then again to December 5th when it finally launched. 

These delays can come from quite mundane issues. The December 4th to December 5th delay, for example, came because it was found that the food loaded for lab mice who were making the trip was moldy and had to be replaced. 



Even just getting a launch or landing date in the first place is difficult enough. Each site has its own set of constraints potentially preventing use. For example, Tanegashima Space Center in Japan can only be used for launch at certain times of year since, during fishing season, there are large numbers of ships offshore from the launch site which could be hit and damaged if a rocket exploded. Elsewhere, a Soyuz landing in Kazakstan had to be rescheduled as there was a G8 summit nearby which, for security reasons, imposed airspace restrictions that prevented spacecraft search and rescue aircraft from flying.

Even the angle of the sun relative to the ISS constrains when a spacecraft can dock. The other factor that can affect the supply chain is that rockets are imperfect. 5 of the 117 resupply missions to date to the International Space Station did not make it for one reason or another meaning there’s a failure rate of 4.3%.



There was even a nine-month stretch from 2014 to 2015 when three resupply missions failed. In times like these, it’s quite important that the ISS has plenty of backup food, water and supplies. While the astronauts would never starve, running out of food or water could mean that they would have to return to earth early potentially leaving the ISS un-crewed and therefore wasting many millions or billions of dollars.

When that third mission failed on June 28th, 2015, the station had enough food to last them for about another fifty days. In this case, even with three failed missions, they had plenty of food to last them especially considering the next resupply mission, a Russian Progress spacecraft, was scheduled just a week after the failure and it was successful.



There have been close calls, though. After the Space Shuttle Columbia disaster in 2003, astronauts had to cut their daily caloric intake and supplies got as low as 7 to 14 days of food. They were one resupply failure away from having to evacuate.

Sometimes, in order to stretch the food supply, NASA will have to extend the certified shelf life of food onboard. For this purpose, they keep a sample of each batch of food they make on earth, packaged and stored in the exact same conditions as on the ISS, so they can test if food is still fit for consumption and safe.



Assuming a rocket doesn’t have any issues, it will typically make it to the ISS in about two to three days. Once the spacecraft is near the ISS, the crew will spend almost a whole working day dealing with the docking process. Once that’s completed, either the same day or the next morning, they’ll open the hatch. Typically right at the hatch is the crew care package. This will include those fresh fruits and vegetables as well as some items sent up by the crew’s families.

One time, the crew care package even included real ice cream. While there isn’t normally a freezer onboard, in this instance a portable freezer was sent up in order to transport samples from an experiment back to earth but, since it was empty on the trip up, the crew got this treat. Over the next few months, astronauts will go through their food one container at a time scanning a barcode each time they open one to let mission control know what their inventory level is like. That way, if the food is going quicker or more slowly than expected NASA can adjust future shipments.



Onboard, dehydrated food is heated up and hydrated using a food re-hydrator while other food can be heated up using another heater. The point of putting so much effort into food on the ISS is for the psychological well-being of the astronauts. With working long hours bottled up in a small space for up to a year, the mental stress of the job is enormous so any effort that can help reduce that is an effort worth doing. 

As part of this, NASA puts a good amount of work into movie night. They have a large projector screen and, in addition to their onboard digital library of about 500 movies, the crew can download new movies. The ISS does have an internet connection and they’ve been known to get some movies, such as Star Wars: The Last Jedi, while they’re still in theatres. That same internet connection lets astronauts browse the web quite freely, even if it’s not quick. While the station does have 300 megabits per second of downlink capacity, the vast majority of it is dedicated to experiment and other data, but astronauts are able to regularly video call their families using it.



The unloading process of resupply vessels is quite a slow process, partially just because there isn’t much storage space onboard. Once a resupply vessel is unloaded, though, the crew will start loading it again with trash. The Northrop Grumman Cygnus, Russian Progress, and Japanese Kounotori spacecraft cannot return to earth so they just burn up in the atmosphere along with all the trash.

The SpaceX Dragon and crewed Russian Soyuz spacecrafts do return to earth so they can bring back samples and experiments. Once ready, the spacecraft will undock and slowly drift away from the ISS until it disappears from view and at that point, the ISS is ready for another delivery of humans or cargo—one of the most unique regular deliveries in our universe.



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Really, Sharks Will Cure Cancer?

It seems like every time scientists learn something about sharks like, a new genome is published everyone suddenly starts going on about whether this new bit of information will finally show us how sharks will cure cancer. There is no doubt about it that sharks are awesome. And they can do some pretty incredible things. But wiping human cancers off the face of the Earth is not ever going to be one of them.

Sharks are not invincible. They still get old. They get sick. And just like the rest of us, they can get cancer. There is no magic cure hidden in their genes— just like there wasn’t one in their cartilage. So let us kill this zombie of a myth once and for all.




The idea that sharks are swimming cancer cures all started in the 1970s. Back then, researchers observed that cartilage— a flexible but firm kind of connective tissue— inhibited blood vessels from developing into different kinds of tissues. Since tumours tend to need a lot of blood to survive and grow, blocking this kind of blood vessel formation could help treat cancers. And a shark’s skeleton is primarily made up of cartilage.

When researchers stuck shark cartilage near tumours, it restricted the growth of new blood vessels. Somehow, that led people to think that sharks never get cancer and ingesting shark cartilage in pill form could be used to treat cancer in humans.




This turned out to be flat-out wrong— multiple studies have proved that shark cartilage is not an effective treatment for cancer. And sharks definitely get cancer. Scientists have even found ones with tumours in their cartilage. So countless sharks around the world were slaughtered for nothing, and to make matters worse, this myth pulled desperate cancer patients away from actually helpful treatments.

Now, the myth is back once again, but this time, the secret cancer cure is supposedly hidden in their genes. This all came up in 2019 because scientists were finally able to figure out what the genome of great white shark looks like— and they found some interesting things. Like, the animals have unique adaptations in genes associated with fighting infections and aspects of wound healing like blood clotting, which could explain how they mend their tissues so quickly. And their whole genome is one-and-a-half times larger than the human genome!




A lot of that extra bulk is thanks to genetic features called LINEs. These small DNA segments are a kind of transposon, meaning they can move around on their own. And the proportion of LINEs in the white shark genome is among the highest found in vertebrates so far. That’s note because LINEs can cause genomes to become unstable, resulting in cancer.

You see, a cell only becomes cancerous after enough errors have accumulated in its DNA—errors that make it grow and divide when it shouldn’t, for example. So with all those jumping genes, you would think white sharks were super prone to developing cancer.




But they are probably not, and that’s likely thanks to remarkable DNA repair. The researchers working on the white shark genome discovered the animals also have a lot of tweaks to genes that help fix DNA damage. That suggests the sharks have evolved a very effective genome clean-up crew— though functional studies would have to be done to confirm that’s true.

Their repair mechanisms might even be good enough to make their risk of getting cancer lower than other animals’. But that doesn’t mean they can’t get cancer. Scientists don’t actually have any evidence that sharks develop tumours less often than other vertebrates. And they have caught wild great whites with cancerous tumours.




But let’s say for a moment these DNA repair mechanisms are so amazing that the animals get cancer less often than, say, humans. That still doesn’t really help us treat humans with cancer. DNA repair mechanisms aren’t things we can inject or swallow to improve our cells’ ability to fix genetic mistakes. If we wanted to take advantage of them, we would have to do something drastic like add them to our DNA. And I think we all have learned from King Shark’s supervillainous ways that engineering human-shark hybrids is a bad idea.

Also, that would only maybe prevent cancer. Great DNA repair can help keep a cell from developing cancer-causing mutations. But once a cell is passed that tipping point, it’s not able to undo them. In fact, making DNA repair better once you have a tumour actually makes matters worse. 




That’s because health professionals often use treatments like radiation therapy to damage the genetic material of cancerous cells, effectively killing them, and stopping their growth. But if repair mechanisms in those cancerous cells work too well, they might fix the damage, allowing the tumour to bounce back.

So oncologists are actively looking for ways to block DNA repair. There are molecules, called DNA repair inhibitors, that gum up these processes. And in theory, if you treat a patient with one of those, then traditional measures like chemotherapy or radiation therapy will inflict enough damage to kill the cancerous cells.




The hard part is finding something that can slow or stop DNA repair in tumour cells without causing too much harm to healthy cells, because, you know, you don’t want to make more cancers while you are treating one. Still, there are some potential candidates already being tested. For example, a compound called mibefradil dihydrochloride can hamper DNA repair in brain tumour cells, and clinical trials of the stuff to date have been promising.

So in short: sharks are awe-inspiring creatures. They are amazing and we should learn as much as we can about them. But the cure to cancer is not locked away in their cartilage or their DNA, since, their effective repair mechanisms can’t reverse cancerous mutations. 




Maybe we could learn a bit more about DNA repair by studying their unique mechanisms for it, and that, in a very tangential way, could eventually lead to new drugs that help shut it down when we need to. But that even is kind of a stretch. And all this focus on how they are going to cure cancer distracts from the important stuff we can learn by studying them.

Digging deeper into those novel infection-fighting mutations could lead to new kinds of antibiotics that help us stay one step ahead of resistant microbes, for example. Or, understanding how sharks repair their flesh so quickly could lead to topical treatments that help seal up surgical wounds faster or reduce scarring.




Ultimately, most of what we learn from sequencing shark genome isn’t directly related to human health. Comparing their genes to ours and other animals can provide new insights into how these animals evolved and how evolution works in general.

So sharks can help us answer bigger questions about life on this planet and how we all got here. And that makes them worth studying, even though they probably aren’t going to cure cancer.



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What is Graphene?

Graphene is a two-dimensional atomic-scale material, that is made of a single layer of carbon atoms that have a high level of cohesion through hybridisation bonds sp2 and arranged in a uniform surface, slightly undulating, with a similar appearance to a honeycomb lattice because of its hexagonal configuration. Graphene is an allotropic form of carbon, like graphite or diamond. Thus, one millimetre of graphite contains three million layers of graphene.

It is the strongest material known in nature, stronger than structural steel with the same density and even harder than diamond, and at the same time, it has a thickness that varies between 1 and 10 carbon atoms. Because of its thinness, this material is considered two-dimensional; it is the only material that can remain stable at just one atom thick.



It is elastic and flexible, graphene also has great electrical and thermal conductivity. This allows for heat dissipation and withstanding intense electrical currents without heating. It is virtually transparent, waterproof and so dense that not even helium can pass through it. It also exhibits many other qualities, such as high electron mobility, a property that will make it particularly interesting in the future for its potential use in fast nanodevices.

Graphene has incredible mechanical, electronic, chemical, magnetic and optical properties, and for this reason, it is one of the most investigated materials at the moment. Furthermore, graphene is pure carbon, abundantly available in nature and ecologically friendly. 



For all these reasons, graphene is very promising for thousands of applications in very different fields. It has the potential to replace fundamental materials such as silicon during the next decade. The array of possibilities for its applications is so wide and so varied that it has the potential to lead to a technological revolution.

It was discovered by Konstantin Novoselov and Andre Geim in 2004, both winners of the Nobel Prize in Physics in 2010.



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First Ever Image Of Black Hole

An utterly, wonderous achievement. Astronomers using the Event Horizon Telescope have taken the first ever photograph of a black hole.

Here's the story, about a hundred years ago, Albert Einstein gave us a new description of the force of gravity in which gravity exerts its influence through warps and curves in the fabric of space and time.



Just a couple of years later, Karl Schwarzschild, he was a German astronomer who was stationed on the Russian front during World War I in charge of calculating artillery trajectories, he somehow gets ahold of Einstein's manuscript and realizes something amazing. If you take a spherical object and squeeze it down to sufficiently small size, according to Einstein's math, the gravitational pull will be so enormous that nothing will be able to escape. Not even light, and that is what we mean by a black hole.

Now, when Einstein caught wind of these results, he didn't believe it. He didn't think these objects would actually be out there in the universe and yet in the ensuing decades, theoretical developments began to mount showing that black holes were the inevitable outcome of massive stars that had used up their nuclear fuel, undergone a supernova explosion and the resulting core would have no ability to withstand the pull of gravity when it collapsed down into a black hole.



The observational cases also began to mount studies of the centre of our Milky Way galaxy showed stars whipping around the centre at such an enormous speed that the only explanation for the object that could exert the powerful gravity responsible for that motion would be a very massive black hole, perhaps four million times the mass of the sun. And perhaps the most compelling convincing observational evidence to date actually comes from gravitational waves.

When we received the first ripples in the fabric of space back in 2015, the only explanation for the pattern of those waves were two black holes, very distant, that collided, setting off a tidal wave in space that we were able to detect. Now, even with the mounting theoretical and observational evidence, we never directly seen a black hole itself. And that is what now has changed.



Using eight radio telescopes from around the world, the Event Horizon Telescope, the name of this consortium, has now taken the first ever snapshot of a black hole itself.

The image provides the first direct test of Einstein's theory and the strong gravitational field of a black hole, and as far as we can tell Einstein was once again comes through with flying colours. 



In many ways, this image really is an emblem of the power of the human intellect to explore, to discover, and understand the cosmos.
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