Francesca Ferlaino and other researchers from Austrian Academy of Sciences and the University of Innsbruck created a report on Physical Review X on what they observed of the behavior of a supersolid in dipolar quantum gases made of dysprosium and erbium. Atoms are arranged in a crystalline pattern as well as they behave like a superfluid in a supersolid where particles can move even when there is no friction.
Dr. Lauriane Chomaz from the Institute for Experimental Physics at the University of Innsbruck and colleagues said that their work was mainly focused on attaining the supersolidity in helium but now the researchers are emphasizing more on atomic gases with strong dipolar interactions. Many experiments have been conducted and it has been observed and disclosed in one of the recent experiments that atomic gases have some common properties of that of superfluid helium and these features are the basic features required for achieving a basic condition with both spontaneous density modulation and global phase coherence.
Density modulation and global phase coherence are the indicators of supersolidity. The team created the two supersolids with the help of erbium and dysprosium quantum gases. The scientists said that they created different states by performing different experiments which will show the features of supersolidity by adjusting the relational strength among the particles in erbium quantum gases as well as the erbium quantum gases.
Dr. Francesca Ferlaino who is the senior author from the University of Innsbruck and the Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences said that the way the erbium works is only for the short period of time and he also adds that their dysprosium realization shows an unmatched balance.
In this experiment, the state of supersolidity can not only live longer but the state of supersolidity can be straightforwardly attained through the process of evaporative cooling which can be started from a thermal sample. The simple principle here is like getting energized over a cup of tea. The principle here is removing the particles which are carrying most of the energies so that the gas slowly cools down and down and slowly achieves the quantum-degenerate stationary state along with the help of the characteristics of the supersolid at the thermal equilibrium.
Thus we can conclude here that the experiment offers a very thrilling hope for more experiments in the future and the theories as well since the state of the supersolid is a bit affected by dissipative dynamics or excitations which leads to the pavement so that it can probe its excitation spectrum and its superfluid behavior.
February 5, 2019(updated July 10, 2019) Published by Kshitij Kumar
We all travel in time, don’t we? From the last year, we’ve moved up one year. Another way to say this is that we all are travelling forward at the same speed. But our topic at hand is, can we travel faster or slower? Or can we travel backwards or forward in time? It is indeed kind of mind-boggling to wrap our whole head around that concept. And there are countless imaginative theories. What if time-travel was possible? Would we be able to prevent something bad from happening? But if so, then what’s the guarantee that something more ominous might not happen? Let us dive deep into the depth of it all. Is all of this science fiction or is it truly possible?
To understand the concepts of time travel you need to understand a few theories and about a few hypothetical things.
The first name we get to our mind while talking about Time Travel is Albert Einstein and his Theory of Relativity. Understanding these theories completely is very difficult and there are very less people in the world who understand it completely. But this theory proves two special things with which we can travel in time. They are
1. If we travel with speeds closer to the speed of light, time will move slower for us (by the Special Theory of Relativity). But achieving such speed is very difficult and the reason again comes from Einstein. Einstein gave a mass velocity relation which tells that our inertial mass increases with velocity. The equation is
Einstein’s Mass Velocity Equation
v is the magnitude of the velocity
c is the speed of light
m0 is the rest mass of the body
m is the relativistic mass
2. Gravity distorts space and time and time moves slower in places with high gravitation (by the General Theory of Relativity). Know more about Gravity time dilation.
The Theory of General Relativity predicts the existence of something called Wormholes. A wormhole is a special solution to Einstein’s Field Equation. Wormholes are like passages or shortcuts between two points in space. Physicists say that we can travel in time through Wormholes but there are serious problems. We will discuss the problems in the next section.
One more hypothetical thing one needs to know is Exotic Matter. Exotic Matter is such a matter which have negative mass and repels the mass we see. At first, scientists believed that exotic matter cannot exist as it contradicts Einstein’s theories but some of the researchers have claimed that they have found a solution to Einsteins General theory of relativity which allows the existence of negative mass.
The BBC’s long-running science-fiction series Doctor Who, celebrating its fiftieth day of remembrance on twenty-three Nov, centres on its name character’s adventures through time and house. However, he may extremely skip between totally different periods of history at will?
Travelling forwards in time is amazingly simple. Einstein’s special theory of relativity, developed in 1905, made it clear that if we can travel at speeds close to the speed of light, we can travel into the future. Thanks to Einstein
If one were to go away from Earth inside a spacecraft moving at a considerable fraction of light speed, and is available back, solely a number of years may need to be passed on board however many years may have gone along on Earth. This leads to the “twins paradox“. What is twins paradox? Suppose one of a twin goes on the above-mentioned spacecraft and comes back, he would find himself much younger than his twin.
There’s just one drawback, once after you travel into future, coming back to the time where you started is difficult. There is a possibility of travelling back in time if traversable wormholes exist in reality. Wormholes are known to exist at microscopic levels and even if traversable wormholes exist they would collapse in seconds because of gravity. To keep Wormholes open we would need Exotic matter which is still hypothetical.
Assuming exotic matter exists and wormholes also do, even then we can’t go to any point in past. First of all, we need to have a machine to travel through a wormhole and with that machine we can travel back only to the time when the machine was created. Even if we create machines which have no effect with time and if could travel back to any point in time, we still have problems like the Grandfather paradox.
More restrictively still, theoretical work by Kip Thorne of Caltech employing a partial unification of general theory of relativity with natural philosophy recommended that any hole that enables time travel would collapse as before long because it fashioned. Thorne did, however, resolve a noticeable issue that might arise because of my time travel (within the orbit of general relativity). The “grandfather paradox” involves going back in time and accidentally killing one’s grandfather before one’s father is planned – preventing one’s own birth.
Not only that, if time travel becomes possible anyone could go into the past and change the future randomly which is very dangerous.
Some paradoxes and facts about Time-Travel
Time Travel (Credi: Pixabay)
Infinite Loop Paradox
A man travels back into the past and marries a woman. After that, he returns to the present. The woman whom he married gets pregnant and has a son. After a few years, that son becomes the time traveller who goes to the past and marries the woman.
So who is the son and who is the father?
Stephen Hawking once believed that time travel is impossible
Stephen Hawking used to think that time travel is impossible. He claimed there would be some physical law which would prevent time travel and he even named it as “chronology protection conjecture”. But in the following years, unable to find any such physical law, he changed his statement and he stated as below
Many researches have proved that time flows quickly on higher altitudes on earth. Scientists have compared time from two atomic clocks, one was on a mountain and one was at sea level. The clock on the mountain was faster by 90 Billionths of a second.
So if you want to add a few billionths of a second to your life, stay in basements.
4. End of Humans Paradox
If someone travels back in time and kills the first human, there should be no life and the human who went there should disappear. What? These paradoxes really sound terrific.
There are many other paradoxes and theories, people say that
All great scientists could probably be time travels and didn’t know how to go back
All the amazing structures like the Pyramids, Kailashnath Temple etc might be built by the time travellers and the list goes on
Space and time are two sides of the same coin
Space And Time are simultaneous phenomena (like mass and energy), and together form the fabric of the universe known as space-time. A demonstration of four-dimensional space-time’s inseparability is the fact that, as astronomers often remind us, we cannot look into space without looking back into time. We see the Moon as it was 1.2 seconds ago and the Sun as it was 8 minutes ago.
Also, in accordance with Einstein’s general theory of relativity, a massive object in space stretches the fabric of both the space and time around it. For example, our Sun’s mass bends its surrounding space so that the Earth moves in a straight line but also circles within the Sun’s curvature in space. The Sun’s effect on time is to slow it down, so time runs slower for those objects close to the massive object. Interestingly, gravity is the result of mass stretching the fabric of the space-time around it. Gravity also has an infinite range such that no matter how far apart two masses are in space they will always experience some gravitational pull towards each other. Theoretical physicists have tried to explain this phenomenon in terms of gravitons, S-Theory, and M-Theory, but even today a successful quantum theory of gravity is yet to be found.
While time travel does not appear possible — at least, possible in the sense that the humans would survive it — with the physics that we use today, the field is constantly changing. Advances in quantum theories could perhaps provide some understanding of how to overcome time travel paradoxes.
One possibility, although it would not necessarily lead to time travel, is solving the mystery of how certain particles can communicate instantaneously with each other faster than the speed of light.
In the meantime, however, interested time travellers can at least experience it vicariously through movies, television and books.
February 5, 2019(updated May 27, 2019) Published by Kshitij Kumar
Dark Matter & the Ultimate Fate of the Universe
So what is dark energy?
Well, the easy answer is that we do not recognize.
It looks to contradict several of our understandings regarding the manner the universe works. We all recognize that light-weight waves, conjointly known as radiation, carry energy. You feel that energy the instant you step outside on a hot summer day.
More is unknown than is thought. we all know what quantity dark energy there’s as a result of we all know however it affects the universe’s enlargement. apart from that, it’s an entire mystery. however, it’s a very important mystery. It seems that roughly sixty-eight of the universe is dark energy. matter makes up concerning twenty-seventh. the remainder – everything on Earth, everything ever determined with all of our instruments, all traditional matter – adds up to but five-hitter of the universe. come back to think about it, perhaps it should not be referred to as “normal” matter the least bit since it’s such a tiny low fraction of the universe.
One clarification for dark energy is that it’s a property of area. the physicist was the primary person to understand that a vacant area isn’t anything. the area has superb properties, several of that are simply starting to be understood. the primary property that Einstein discovered is that it’s potential for extra space to come back into existence.
Then one version of Einstein’s gravity theory, the version that contains a constant, makes a second prediction: “empty space” will possess its own energy. as a result of this energy may be a property of the area itself, it’d not be diluted as area expands. As extra space comes into existence, a lot of this energy-of-space would seem. As a result, this way of energy would cause the universe to expand quicker and quicker. sadly, nobody understands why the constant ought to even be there, abundant less why it’d have precisely the right worth to cause the discovered acceleration of the universe.
Another rationalization for the way house acquires energy comes from the scientific theory of matter. during this theory, “empty space” is really choked with temporary (“virtual”) particles that regularly type and so disappear. however once physicists tried to calculate what quantity energy this is able to offer empty house, the solution came out wrong – wrong by a great deal. the amount came out 10120 times too massive. that is a one with a hundred and twenty zeros once it. It’s laborious to urge a solution that unhealthy. that the mystery continues.
Another rationalization for dark energy is that it’s a brand new quite high-octane energy fluid or field, one thing that fills all of the areas however one thing whose result on the enlargement of the universe is that the opposite of that of matter and traditional energy. Some theorists have named this “quintessence,” when the fifth part of the Greek philosophers. But, if quintessence is that the answer, we have a tendency to still do not know what it’s like, what it interacts with, or why it exists. that the mystery continues.
The last chance is that Einstein’s theory of gravity isn’t correct. that will not solely have an effect on the enlargement of the universe, however, it might additionally have an effect on the method that ordinary matter in galaxies and clusters of galaxies behaved. This truth would supply the way to make your mind up if the answer to the dark energy downside may be a new gravity theory or not: we have a tendency to might observe however galaxies close in clusters. however, if it will prove that a brand new theory of gravity is required, what quite a theory would it not be? however, might it properly describe the motion of the bodies within the system, as Einstein’s theory is thought to try toto, and still provide the U.S.A. with the various prediction for the universe that we have a tendency to need? There area unit candidate theories, however none area uncompelling. that the mystery continues.
The issue that’s required to make your mind up between dark energy potentialities – a property of area, a brand new dynamic fluid, or a brand new theory of gravity – is additional knowledge, higher knowledge.
Dark energy or dark matter?
Dark energy makes up most of the universe, however, substance additionally covers a sizeable chunk. Comprising nearly twenty-seven p.c of the universe, and eighty p.c of the matter, substance additionally plays a dominant role.
Like dark energy, substance continues to confound scientists. whereas dark energy could be a force that accounts for the increasing universe, substance explains, however, teams of objects operate along.
In the Fifties, scientists learning different galaxies expected gravity to cause the centres to rotate quicker than the outer edges, supported the distribution of the objects within them. To their surprise, each region revolved at a similar rate, indicating that the spiral galaxies contained considerably a lot of mass than they perceived to. Studies of gas within elliptical galaxies and of clusters of galaxies disclosed that this hidden matter was unfolded throughout the universe. Scientists have a variety of potential candidates for substance, move to unbelievably dim objects to strange particles. however, regardless of the supply of each substance and dark energy, it’s clear that the universe is stricken by things that scientists cannotconventionally observe.
The fate of the Universe
The evolution of the universe is ruled by the number of matter and dark energy it contains, however, the densities of matter and dark energy—their concentrations inside given volume of space—are affected terribly otherwise by cosmic growth. we have a decent plan of what quantity matter the universe holds, and though we do not understand exactly what it’s, we have a tendency to do comprehend it is plagued by gravity. The key, then, to understanding the ultimate fate of the Universe lies in understanding the opposite half this dark equation: dark energy.
Currently, cosmologists perceive nearly nothing regarding dark energy albeit it seems to comprise regarding seventy % of the mass-energy content of the universe. they’re urgently seeking to uncover its elementary properties: its strength, its permanency, and any variation with direction. they need to learn the properties of matter before they will verify its influence on the increasing Universe.
This evolution in cosmic scale is schematically shown within the higher than the figure for many cosmologies. during a universe with a high density of matter, the Edwin Bubble growth that began with the large Bang continues to decelerate thanks to the gravitation attraction of the matter filling the universe, ending during a massive crunch. during a universe with a lower vital density of matter, the growth coasts. during a universe with dark energy additionally as matter, the initial slowing is reversed at late times by the increasing dominance of dark energy.
If the hypothetic dark energy continues to dominate the universe’s energy balance, then the present growth of house can still accelerate, exponentially. Structures that don’t seem to be already gravitationally certain can ultimately fly apart. the planet and therefore the Milky Way Galaxy would stay undisturbed whereas the remainder of the universe seems to run far from the USA. The nature of dark energy is presently a matter of speculation. Some believe that dark energy could be “vacuum energy,” diagrammatic by the “cosmological constant” (Λ, the Greek capital letter lambda) normally relativity theory, a relentless uniform density of dark energy throughout all of the house that’s freelance of your time or the universe’s growth. This notion was introduced by Einstein and is according to our restricted observations so far. instead, dark energy would possibly vary with time. solely new sorts of observations will settle the difficulty.
We do understand this: Since the area is everyplace, this dark energy force is everyplace, and its effects increase as area expands. In distinction, gravity’s force is stronger once things area unit close and weaker after they area unit so much apart. as a result of gravity is weakening with the enlargement of area, dark energy currently makes up over 2/3 of all the energy within the universe. It sounds rather strange that we’ve got no firm plan regarding what makes up seventy-four of the universe. It’s as if we have a tendency to had explored all the land on the world Earth associate degreed ne’er all told our travels encountered an ocean. however currently that we’ve caught sight of the waves, we wish to grasp what this immense, strange, powerful entity extremely is.
The strangeness of dark energy is thrilling.
It shows scientists that there’s a spot in our information that must be crammed, beckoning the manner toward associate degree undiscovered realm of physics. we’ve got before the United States the proof that the cosmos could also be organized immensely otherwise than we have a tendency to imagine. Dark energy each signals that we have a tendency to still have a good deal to find out, and shows the United States that we have a tendency to stand poised for an additional nice leap in our understanding of the universe.
February 5, 2019(updated May 27, 2019) Published by Kshitij Kumar
How will the universe end, and could anything survive?
The universe serves up spectacle after spectacle with so much ease and effortlessness that you cannot help but wonder how it has so many complexities hidden within its ulterior cloak of beauty. On the surface, the universe is magnificent and splendid. The immortal souls that are credited for creating it are not yet finished with it. Perhaps, they get lost in its admiration and in its beauty and lose track of the job at hand. The fact that the universe can be so alluring despite its intricacies is in itself worth cherishing. But, like all good things, the universe will come to an end.
The end of the universe is not near, however, it is inevitable. There might not be any need to set alarm bells ringing anytime in the near future, but, the universe does have an expiration date.There have been several theories on how the universe could end. If the universe has been a cause for fascination and you want to learn more about how it could potentially all end, then, this article is just for you. Read on.
Let’s start from the beginning, the Origin of the Universe
To predict an ending, you would have to understand the beginning. Like all spectacular things, the universe too had a spectacular origin. This beginning was the Big Bang. The Big Bang theory explains the evolution that the universe had to undergo. This theory states that the universe was initially extremely hot and dense.As time passed, the universe began to cool and expand.
Image Source: Coldcreation
According to the Standard model, the four fundamental forces in the universe are gravity, strong and weak attractive forces and electromagnetic radiation. Of the four, gravity is considered to be the weakest. It is hypothesized that during the beginning of the universe that gravity was as strong as the other fundamental forces. All the matter in the universe was condensed into such small spaces that the gravity had to be extremely high. The universe did not stay in this condensed state for too long and began to expand. The expansion is considered to be perpetual and is taking place even while you are reading this.
What is really scary is the fact that the rate of this expansion keeps increasing every second. This expansion is credited to dark energy, but, nobody really knows for sure what it is. Here are the theories that try to explain how the universe could end.
The Big Rip
For as long as we have known, the universe has been expanding. During this process of expansion, lots and lots of space was created. Galaxies began to move apart since the space between them increased. Within the galaxy, the space also expanded. However, the gravity acted as the glue that kept it all together. The gravity provides the force that keeps the galaxies together. It is strong enough to negate the expansion. In the Big Rip scenario, the rate of expansion increases so drastically that it reaches a point where gravity cannot counter or negate the effect of the expansion of space. The acceleration of space expansion would be tremendously high.This causes the universe to, well, rip. This is what is referred to as the Big Rip.
This effect would start with the larger bodies and slowly propagate to the smaller bodies. It would first start with the galaxies. These galaxies would get ripped apart. Then, black holes, stars, and planets would die. Since the gravity is not strong enough, they would simply just dissolve into their constituents. Then these smaller components would disintegrate. Everything we know would get ripped apart.
Space would then start expanding so fast that it would be faster than even light! Atoms and subatomic particles would also tear apart. Since space is moving so fast, there would be no interaction between particles. So, even the small particles that remain after this massive expansion cannot interact with anything in the universe to form bigger particles. This universe would be so strange that when you compare it with today’s universe, it would seem ridiculous.The possibility is unfathomable, but, not impossible.
The Big Freeze
Simply put, the difference between the Big Freeze and the Big Rip is that in the Big Freeze scenario, matter does not disintegrate, it gets converted into radiation in a process that could take forever. To understand this, you will need to understand entropy. The second law of thermodynamics states that the entropy of an isolated system can never decrease, therefore, every body moves to a state which increases its entropy. This means that every body cools down and it disintegrates until it reaches some form of equilibrium. This is true for the universe as well. The matter in the universe slowly disintegrates and spreads out. Every body, whether big or small, will have its matter disintegrating into radiation.
The gas clouds required to generate stars would disintegrate. The universe will become an extremely dark place as a result. The suns would also disintegrate. Black holes would be the only entities left in the universe. These black holes, however, will also lose energy in the form of Hawking radiation and also disintegrate. Slowly but almost surely, only a few light particles would remain. But, even these will eventually decay. The universe would be reduced to nothing. A place of nothingness. Entropy would have reached its maximum, and the highest form of equilibrium would have been reached. The universe would have finally ended.
However, all hope is not lost. The phenomenon of quantum tunneling could cause a change in the entropy leading to another Big Bang. In this case, the universe would just restart as if nothing really happened.
The Big Crunch and The Big Bounce
Gravity, which is the weakest of all fundamental forces could one day become the most powerful. This is possible if the amount of dark energy reduces substantially over time. This would mean that the universe would simply stop expanding. This would mean that the rate of expansion would slow down at some point and keep slowing down until the process of expansion ceases. Then, it slows down even more and reverses. The universe, instead of growing, would begin to contract and become smaller and smaller. Galaxies will merge, and the universe will get significantly hotter. The temperatures would reach such high levels that bodies that cannot bear such temperatures would disintegrate. Everything will get denser.
Big Crunch Illustration. Image Source : Wikipedia
Black holes that consume everything close to them, would begin consuming bodies. As things get closer and closer, more objects would get closer to black holes. These black holes would consume everything including other black holes. The amount of gravity will be immense. All black holes will eventually form a single supermassive blackhole at the center of the universe. At the last moment of the Big Crunch, the entire universe would be consumed by the gigantic black hole and finally, it would consume itself. The Big Bounce theory states that this entire process has been taking place for a long while. According to the Big Crunch, the universe is stuck in a loop of expansion and contraction leading to many deaths and rebirths of the universe.
The timeline for the end of the universe
Our planet will cease to exist in about 1 billion years from now. The Sun would burn 10% brighter and the heat from the sun would dry up all the water on earth. All life will be extinguished. In about 5 to 8 billion years, the sun would undergo expansion to reach a size that is so big that it would devour most planets. In about 1 trillion years from now, all galaxies would merge into one. In 100 trillion years, we would enter the degenerate era. This era is marked by the death of all stars in the galaxies, which, results in black holes. In 10 to 100 quintillion years, everything would be consumed by black holes. In a decillion years time, we might have the black hole era, where the universe is dominated by black holes. Eventually, these black holes will lose energy in the form of Hawking radiation and die too. In about a googol year, the universe would cease to exist.
Erich Fromm, a renowned psychologist, and sociologist once said, “The quest for certainty blocks the search for meaning. Uncertainty is the very condition to impel man to unfold his powers”. There is so much uncertainty around. Everything in the universe is uncertain, so much so that even the universe itself is uncertain! The universe always has a clever way to teach important lessons. Uncertainty should compel humanity to make the most of the time we have.
The universe can die but it can start all over again. The reality that we observe today may not be considered reality at all in the distant future. Whether the universe ends or not, one thing is certain, the universe should be cherished and celebrated while we can all still bask in its splendor.
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