What is the name of the biggest star. The smallest and largest star in our galaxy
When you look at the night sky, you can see a huge number of points of light. They are stars. From the ground, without special equipment, they seem exactly the same. There are so many stars in the sky that it is very difficult to answer the question of what is the largest star in the universe. The point is that on this moment about 50 billion stars are known. But every day scientists find more and more new luminaries.
Astronomers' modern equipment is capable of seeing at a distance of 9 billion light years. However, we will start with you by studying the most big stars from our galaxy. At a distance of 7,500 light years from us is a star with the strange name Eta Carinae. Scientists have found that the largest star in the Milky Way weighs 120 solar masses.
The largest star in our Galaxy is Eta Carinae.
This star is a million times brighter than the Sun. Like all stars, Eta Carinae gradually loses its mass due to gusts of stellar wind. However, Eta Carinae is so large that it loses up to 500 Earth masses every year. For this reason, scientists cannot name its exact radius. Approximately, Eta Carinae is 250 times larger than the Sun.
What is the largest star in the universe
Further space exploration allowed earth scientists to see the largest star in the universe. The discovery was made by Paul Crowter's group at the end of 2010. British scientists were researching the Large Magellanic Cloud when they found an even larger star. They gave her the name R136a1. The Hubble Telescope took part in this incredible discovery. This discovery has become very important for the study of space. The fact is that the mass of R136a1 exceeds the mass of the Sun by 256 times. Prior to the discovery of this supergiant, scientists believed that stars cannot have a mass that exceeds the mass of the Sun by more than 150 times. Continuing their study of the Large Magillanic Cloud, Crowther's team discovered several more luminaries that also exceed the Sun by 150 times in mass. At the same time, the brightness of R136a1 exceeds the brightness of the Sun by 10 million times. Remember when we said that all stars lose some of their mass? Scientists have calculated that at the beginning of its journey, the largest star in the universe weighed 320 solar masses. If R136a1 were in our galaxy, then the Sun would be similar in brightness to the Moon, in comparison with the Sun itself.
The biggest star in the universe photo
The largest star in the universe - R136a1 (clickable 1600 × 960 pixels) 
The largest star in the universe is R136a1. Comparison with the Earth and the Sun 
The largest star in the universe is R136a1. Comparison with other stars. The biggest star in the universe video
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10th place - AH Scorpio
The tenth line of the largest stars in our Universe is occupied by a red supergiant located in the constellation of Scorpio. The equatorial radius of this star is 1287 - 1535 the radii of our sun. Located about 12,000 light years from Earth.
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9th place - KY Swan
The ninth place is occupied by a star located in the constellation Cygnus at a distance of about 5 thousand light years from Earth. The equatorial radius of this star is 1420 solar radii. However, its mass is only 25 times the mass of the Sun. KY Swan shines about a million times brighter than the Sun.
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8th place - VV Cephei A
VV Cepheus is an Algol-type eclipsing binary star in the constellation Cepheus, about 5,000 light-years from Earth. It is the second largest star in the Milky Way Galaxy (after VY Canis Major). The equatorial radius of this star is 1050 - 1900 solar radii.
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7th place - VY Big Dog
The largest star in our Galaxy. The radius of the star lies in the range 1300 - 1540 radii of the sun. It would take 8 hours for the light to fly around the star in a circle. Studies have shown that the star is unstable. Astronomers predict that VY Big Dog explode like a hypernova in the next 100 thousand years. In theory, a hypernova explosion would cause gamma-ray bursts that could damage the contents of a local part of the universe, destroying any cell life within a radius of several light years, however, the hypergiant is not close enough to Earth to pose a threat (approximately 4 thousand light years).
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6th place - VX Sagittarius
A giant pulsating variable star. Its volume, as well as its temperature, change periodically. According to astronomers, the equatorial radius of this star is 1520 radii of the sun. The star got its name from the name of the constellation in which it is located. The manifestations of the star due to its pulsation resemble the biorhythms of the human heart.
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5th place - Westerland 1-26
The fifth line is occupied by a red supergiant, the radius of this star lies in the range 1520 - 1540 solar radii. It is located 11,500 light years from Earth. If Westerland 1-26 were in the center of the solar system, its photosphere would encompass Jupiter's orbit. For example, the typical depth of the photosphere for the Sun is 300 km.
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4th place - WOH G64
WOH G64 is a red supergiant located in the constellation Dorado. Located in the neighboring galaxy the Large Magellanic Cloud. The solar system is approximately 163,000 light years away. The radius of the star lies in the range 1540 - 1730 solar radii. The star will end its existence and become a supernova in a few thousand or tens of thousands of years.
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3rd place - RW Cephei
Bronze goes to the star RW Cephei. The red supergiant is 2,739 light-years away. The equatorial radius of this star is 1636 solar radii.
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2nd place - NML Swan
The second line of the largest stars in the Universe is occupied by the red hypergiant in the constellation Cygnus. The radius of the star is approximately equal to 1650 solar radii. The distance to it is estimated to be about 5300 light years. Astronomers have found substances such as water, carbon monoxide, hydrogen sulfide, and sulfur oxide in the star.
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1st place - UY Shield
The largest star in our universe at the moment is a hypergiant in the constellation of the Shield. It is located at a distance of 9,500 light years from the Sun. The equatorial radius of the star is 1708 the radii of our sun. The star's luminosity is approximately 120,000 times the luminosity of the Sun in the visible part of the spectrum, the brightness would be much higher if there were not a large accumulation of gas and dust around the star.
An illustration of R136a1, the most massive star known to date. Credit & Copyright: Sephirohq / Wikipedia.
Look at the night sky - it is filled with stars. However, only a microscopic part of them is visible to the naked eye. In fact, according to scientists, there are 10,000 billion galaxies in the visible universe, each with more than a hundred billion stars. And this is no less than 10 24 stars. These spectacular thermal power plants come in a variety of colors and sizes - and in comparison to many of them, our Sun looks just tiny. However, which star is the real space giant? First, we need to define the concept of a giant star: should it have the largest radius or the largest mass?
To date, the star with the largest radius is recognized as the star UY Shield (Scuti) - a variable red supergiant in the constellation of Shield. It is more than 9500 light-years distant from us, and consists mainly of hydrogen and helium, as well as a number of other heavier elements. The chemical composition of the UY Shield resembles our Sun, but it has a radius 1708 (± 192) times larger than that of our star. That is, almost 1,200,000,000 km, resulting in a circumference of over 7.5 billion kilometers. To make it easier to understand such dimensions, one can imagine an airplane that will take 950 years to fly around the UY Shield - and even if the plane can move at the speed of light, its journey will last 6 hours and 55 minutes.
If we place the UY of the Shield in the place of our Sun, then its surface will pass somewhere between the orbits of Jupiter and Saturn - it goes without saying that the Earth in this case will be absorbed. Given the enormous size and mass of 20 to 40 solar masses, it can be calculated that the density of the UY Shield is only 7 × 10 -6 kg / m 3. In other words, this is more than a billion times less than the density of water. Indeed, if we could place this star in the pool, then theoretically it would float. More than a million times less dense than earthly atmosphere UY Shield, like a balloon, would fly in the air.
But if these crazy facts didn't surprise you, then let's move on to the heaviest star. The heavyweight star R136a1 is located in the Large Magellanic Cloud, approximately 165,000 light-years away. This star is only 35 times larger than our Sun, but it is 265 times heavier than it - which is really surprising considering the fact that it has already lost 55 solar masses in 1.6 million years of its life.
R136a1 is a highly unstable Wolf-Rayet star. It looks like a blue ball with a fuzzy surface, which constantly forms extremely powerful stellar winds. These winds move at speeds up to 2600 km / s. Due to such high activity, R136a1 loses 3.21 × 10 18 kg / s of its mass - this is approximately one Earth every 22 days. Stars of this type shine brightly and die quickly. R136a1 emits nine million times more energy than our Sun. Its brightness is 94,000 times that of the Sun. In fact, it is the brightest star ever found. The temperature on its surface is more than 53,000 Kelvin, and it has only two million years left to live, after which it will explode like a supernova.
Of course, against such giants, our Sun seems to be a dwarf, but over time it will also increase in size. In about seven and a half billion years, it will reach its largest size and will turn into a red giant.
My 6-year-old daughter is a question-asking machine. A couple of days ago, we were driving from school and she was asking me about nature. One of her questions was, " What is the largest star in the universe? "I gave a simple answer." The universe is a big place, "I said," and there is no way we can know which star is the biggest"But that's not the real answer.
Radius and mass of the Sun:
When it comes to the size of stars, it's important to first look at ours for a sense of scale. Our star has a diameter of 1.4 million kilometers. This is such a huge number that it is difficult to get an idea of \u200b\u200bthe scale. By the way, the Sun accounts for 99.9% of all matter in ours. In fact, you could fit a million within the volume of the sun.
Using these values, astronomers have created the concepts of "solar radius" and "solar mass", which they use to compare larger or smaller stars and masses with our Sun. The solar radius is 690,000 km, and the solar mass is 2 x 10 30 kg. This is 2 nonillion kilograms, or 2,000,000,000,000,000,000,000,000,000,000 kg.
An illustration of a Morgan-Keenan spectral diagram showing the difference between main sequence stars. Credit: Wikipedia Commons.
It is also worth considering the fact that our Sun is quite small, it is a G-class main sequence star (in particular, a G2V star), which is widely known as and is located on the smaller side of the size chart (see above). Although the Sun is definitely larger than the most common M-class stars, or red dwarfs, it is itself dwarf (no pun intended!) Compared to blue giants and other spectral types of stars.
Classification:
Stars are grouped based on their characteristics, such as spectral class (i.e. color), temperature, size, and brightness. The most common classification method is called the Morgan-Keenan (MK) system, which classifies stars based on temperature using the letters O, B, A, F, G, K, and M, where O are the hottest stars and M are coldest. Each alphabetic class is subdivided into numerical subclasses from 0 (hottest) to 9 (coldest). That is, the hottest stars are O1, and the coldest stars are M9.
In the Morgan-Keenan system, the luminosity class is added using Roman numerals. This is done on the basis of a certain width of the absorption lines in the spectrum of the star, which change with the density of the atmosphere, which distinguishes giant stars from dwarfs. The luminosity has classes 0 and I for hyper- and supergiants; classes II, III and IV for bright, normal giants and subgiants, respectively; class V for main sequence stars; and classes VI and VII apply to subdwarfs and dwarfs.
Hertzsprung-Russell diagram showing the relationship between star color, luminosity and temperature. Credit: astronomy.starrynight.com.
There is also a Hertzsprung-Russell diagram concerning the stellar classification by absolute stellar magnitude (i.e., true brightness), luminosity and surface temperature. The same classification is used for spectral types, ranging from blue and white at one end to red at the other, which then combines the stars in absolute magnitude, placing them on a two-dimensional plot (see above).
On average, Class O stars are hotter than stars of other classes, reaching effective temperatures up to 30,000 Kelvin. At the same time, they are larger and more massive, reaching sizes over 6.5 solar radii and up to 16 solar masses. At the lower end of the diagram, K- and M-class stars (orange and red dwarfs) are usually colder with temperatures ranging from 2400 to 5700 Kelvin, which is 0.7 - 0.96 from and somewhere 0.08 - 0. 8 from solar mass.
Based on the complete classification of our Sun (G2V), we can say that it is a main sequence star with a temperature of about 5800 Kelvin. Now consider another famous star system in our galaxy - Eta Carinae - a system containing at least two stars located at a distance of 7500 light-years from us in the direction of the constellation Carina. The main star of this system is estimated to be 250 times larger than the Sun, has a mass of at least 120 solar masses and a million times brighter than the Sun, making it one of the largest and brightest starsever observed.
Eta Carinae, one of the most massive stars known, is located in the constellation Carinae. Credit: NASA
There is currently debate over the size of this star. Most stars emit stellar wind (the same as), losing mass over time. But This Kiel so large that it dumps 500 times more mass annually. With such a loss of mass, astronomers find it difficult to accurately measure where the star ends and the stellar wind begins. In addition, scientists believe that This Kiel will explode in the not so distant future, and it will be the most spectacular that people have ever seen.
In terms of net mass, first place goes to star R136a1located at a distance of 163,000 light years from us. It is believed that this star may contain 315 solar masses, which is a mystery to astronomers, since they believe that stars can contain a maximum of only 150 solar masses. The answer lies in the fact that star R136a1 formed, in all likelihood, when several massive stars merged together. Needless to say, R136a1 can explode any day like.
In terms of large stars, a good (and popular) example is Betelgeuse... Located in the shoulder of Orion, this famous supergiant has a radius of approximately 950-1200 solar radii, at which radius the Sun would have swallowed up in our solar system. In fact, whenever we want to put the size of our Sun in perspective, we often use Betelgeuse for this (see below).
However, even after we use this clumsy red giant to compare the Sun to large stars, there are still larger stars. Consider star WOH G64, a red supergiant located in the Large Magellanic Cloud, approximately 168,000 light-years from Earth. With a diameter of 1540 solar radii, this star is currently the largest star known to us in the universe.
But there is also RW Cephei, an orange hypergiant in the constellation Cepheus, located 3500 light years from Earth and measuring 1535 solar radii in diameter. Star Westerland 1-26 (Westerlund 1-26) unusually large, it is a red supergiant (or hypergiant) located in the Westerlund 1 supercluster at a distance of 11,500 light years from us and measuring 1,530 solar radii in diameter. Meanwhile, stars V354 Cepheus and VX Sagittarius also have a huge size of 1520 solar radii in diameter.
The biggest star of UY Shield (UY Scuti)
The title of the largest star in the universe (which we know of) comes down to two contenders. For example, UY Shield Currently at the top of the list, located 9,500 light-years away in the constellation Shield, this bright red supergiant and pulsating variable star has an average radius of 1,708 solar radii - or 2.4 billion kilometers (15.9 AU) , thereby giving it a volume of 5 million solar volumes.
However, this average estimate includes an error of ± 192 solar radii, which means that the radius of this star can be either 1900 or 1516 solar radii. The bottom border places it on par with V354 Cepheus and VX Sagittarius... Meanwhile, the second largest star on the list of possible the largest stars - this is NML Cygni (NML Cygni), a semi-regular variable star red hypergiant, located in the constellation Cygnus, 5300 light-years from Earth.
An enlarged view of the red giant UY Shield. Credit: Rutherford Observatory / Haktarfone.
Due to the location of this star in, it is heavily shaded by dust. As a result, according to astronomers' calculations, its size could be from 1642 to 2775 solar radii, which means that it could become the largest star known in the universe (with a reserve of about 1000 solar radii), or in fact the second largest, keeping up with UY Shield.
Just a few years ago the title the biggest star worn by VY Big Dog (VY Canis Majoris), a red hypergiant in the constellation Canis Majoris, located 5,000 light years from Earth. Back in 2006, Professor Robert Humphrey of the University of Minnesota calculated the upper limit of its size at 1540 larger than the Sun. Its average mass, however, was 1420 solar masses, which puts it in 8th place behind V354 Cepheus and VX Sagittarius.
The above were listed the biggest stars, which we know about, but there are probably dozens of bigger stars hidden by dust and gas, so we don't see them. But even if we cannot detect these stars, we can ponder their likely size and mass. So how big can stars be? Once again, Professor Robert Humphrey from Minnesota gave the answer.
Comparison of the sizes of the Sun and VY Canis Major, the star that once bore the title the largest known star in the universe... Credit: Wikipedia Commons / Oona Räisänen.
As she explained in her article, largest stars in the universe - the coldest. Therefore, although This Kiel is the brightest star we know of, it is extremely hot (25,000 Kelvin) and therefore only 250 solar radii in diameter. The largest starson the contrary, they will be cold supergiants. As in the case VY Big Dogwhich has a temperature of 3500 Kelvin, and a really large star will be even colder.
At 3000 Kelvin, Humphrey estimates that the cold supergiant would be 2,600 times the size of the Sun. This is below the upper bound of the estimates for NML Swan, but above average ratings as for NML Swanand for UY Shield... Hence, this is the upper limit of a star (at least in theory and based on all the information we have to date).
But as we continue to peer into the Universe with all our telescopes and study it with robotic spacecraft and manned missions, you will surely find new amazing things that will amaze us further!
And be sure to check out this awesome animation below, which shows the sizes of various objects in space, from tiny to star UY Shield... Enjoy!
Title of the article you read "What is the largest star in the universe?".
People tend to gaze at the sky, observing millions and millions of stars. We dream of distant worlds and paint ourselves images of brothers in mind. Each world is illuminated by its own "sun". The research technology looks deep into space for 9 billion light years.
But this is not enough to say with precision how many stars are in space. At the current stage of the study, 50 billion are known. This number is steadily growing, as there is constant research, technology is being improved. People will learn about new giants and dwarfs in the world of space objects. What is the largest star in the universe?
Dimensions of the Sun
Thinking about the size of the stars, understand what to compare with, feel the scale. The dimensions of our Sun are impressive. Its diameter is 1.4 million km. This huge number is difficult to imagine. This will be helped by the fact that the mass of the Sun is 99.9% of the mass of all objects in the Solar System. Theoretically, a million planets could be located inside our star.
Using these numbers, astronomers have coined the terms "solar radius" and "solar mass", which are used to compare the size and mass of space objects. The sun has a radius of 690,000 km and weighs 2 billion kilograms. Compared to other stars, the Sun is a relatively small space object.
Former star champion
The stellar mass is constantly "losing weight" due to the "stellar wind". Thermonuclear processes, continuously shaking the universal stars, lead to the loss of hydrogen - "fuel" for reactions. Accordingly, the mass also decreases. Therefore, scientists find it difficult to give exact figures regarding the parameters of such large and incandescent objects. Luminaries age and after a supernova explosion turn into a neutron star or a black hole.
For decades, VY in the constellation Canis Major was recognized as the largest star. Not so long ago, the parameters were clarified, and scientists' calculations showed that its radius is 1300-1540 solar radii. The giant is 2 billion kilometers in diameter and is located 5,000 light years from Earth.
To imagine the size of this object, imagine that it will take 1200 years to fly around it, moving at a speed of 800 km / h. If you suddenly imagine that the Earth was compressed to 1 cm and VY was reduced in the same way, then the giant will be 2.2 km in size.
But the mass of the star is small and exceeds the mass of the Sun only 40 times. This is due to the low density of the substance. The brightness of the luminary is truly amazing. It emits light 500,000 times brighter than ours. VY was first mentioned in 1801. It was described by the scientist Joseph Jerome de Lalande. The entry says that the luminary belongs to the seventh class.
Since 1850, observations have indicated a gradual loss of brightness. The outer edge of VY began to increase because the forces of gravity no longer keep the mass at a constant level. Soon (by cosmic standards) the explosion of this supernova star is possible. Scientists say it could happen tomorrow or in a million years. Science has no exact figures.
Reigning Star Champion
Space exploration continues. In 2010, scientists led by Paul Crowter saw an impressive space object with the Hubble Telescope. While exploring the Large Magellanic Cloud, astronomers discovered a new star and named it R136a1. The distance from us to R136a1 is 163,000 light years.
The parameters shocked scientists. The giant's mass exceeds the mass of the Sun by 315 times, despite the fact that it was previously stated that there are no stars in space that exceed our Sun in mass by 150 times. Such a phenomenon occurred, according to the hypothesis of scientists, due to the combination of several objects. The brightness of the R136a1 glow exceeds the brightness of the radiation of our sun by 10 million times.
During the period from its discovery to our time, the star has lost one-fifth of its mass, but it is still considered the record holder even among its neighbors. Crowter's group also opened them. These objects also exceeded the limit of 150 solar masses.
Scientists have calculated that if R136a1 is placed in Solar system, then the brightness of the glow in comparison with our luminary will be the same as if the brightness of the Sun and the Moon were compared.
This is the largest star known to mankind so far. Surely in the Milky Way galaxy there are dozens, if not hundreds, of larger luminaries, closed from our eyes by gas and dust clouds.
VV Cephei 2... VV Cepheus 2 is located at 2,400 light years, which is 1600-1900 times the size of the Sun. The radius is 1050 times the radius of our Sun. In terms of light emission, the star exceeds the landmark from 275 to 575 thousand times. It is a variable pulsar that pulsates with an interval of 150 days. Speed cosmic winddirected away from the star is 25 km / sec.
Dimensions of the Sun and Star VV Cephei 2 Research has proven that VV Cephei 2 is a double star. The second star B is eclipsed regularly every 20 years. VV Cephei B revolves around the main star VV Cepheus 2. It is blue, with a turnover period of 20 years. The eclipse lasts 3.6 years. The object is 10 times more massive than the Sun and 100,000 times more intense than the Sun.
Mu Cephei... In Cepheus, a red supergiant flaunts, 1650 times larger than the Sun. Mu Cephei is brightest star Of the Milky Way. The glow brightness is 38,000 times higher than the reference point. It is also known as Herschel's garnet star. Studying the star in the 1780s, the scientist called it "a delightfully beautiful garnet-colored object."
In the sky of the northern hemisphere, it is observed without a telescope from August to January, it resembles a drop of blood in the sky. After two to three million years, a giant supernova explosion is expected, which will turn the star into a black hole or a pulsar and a gas and dust cloud.
The red giant V838 shines in the constellation Unicorn 20,000 light-years from Earth. This cluster of stars, previously unknown to anyone, "became famous" in 2002. At this time, an explosion occurred there, which astronomers initially perceived as a supernova explosion. But due to its young age, the star did not approach the cosmic “demise”.
For a long time they could not even imagine what the cause of the cataclysm was. It has now been hypothesized that the object has swallowed up the "companion star" or objects orbiting around it.
The object is credited with dimensions from 1170 to 1970 solar radii. Due to the gigantic distance, scientists do not give exact figures for the mass of the red variable star.
Until recently, scientists believed that the parameters of WHO 64 are comparable to R136a1 from the constellation Canis Major.
But it was found that the size of this star is only 1540 times larger than the sun. It shines from the Great Magellanic Cloud.
V354 Cephei... The red supergiant V354 Cephei, 9,000 light years from Earth, is invisible without a telescope.
It is located in the Milky Way galaxy. The temperature on the shell is 3650 degrees Kelvin, the radius is 1520 times greater than the sun and is determined at 1.06 billion km.
KY Swan... It would take 5000 light years to fly to KY Cygnus. This time is difficult to imagine. Such numbers mean that a ray of light flies at a hyperluminal speed from the star to the Earth for 5000 years.
If we compare the radius of the object and the Sun, then it will be 1420 solar radii. The mass of the star is only 25 times the mass of the landmark. But KY will quite compete for the title of the brightest star in the part of the Universe open to us. Its luminosity surpasses that of the Sun by millions of times.
KW Sagittarius... 10,000 irresistible light years separate us from the KW star in Sagittarius.
It is a red supergiant with a size of 1,460 solar radii and a luminosity 360,000 times that of our Sun.
The constellation is visible in the sky of the southern hemisphere. It is easy to find it on the surface of the Milky Way. The star cluster was first described by Ptolemy in the second century.
RW Cephei... The dimensions of the RW Cephei are still being argued about. Some scientists argue that the dimensions are equal to 1260 radii of the landmark, others are inclined that they are 1650 solar radii. It is the largest variable star.
If we move it to the place of the Sun in our system, then the supergiant's photosphere will be between the trajectories of Saturn and Jupiter. The star is rapidly flying towards the solar system at a speed of 56 km / sec. The end of the star will turn it into a supernova, or the core will collapse into a black hole.
Betelgeuse. The red giant Betelgeuse is located in Orion 640 light years away. Betelgeuse is 1100 times the radius of the Sun. Astronomers are confident that in the near future there will be a period of transformation of a star into a black hole or supernova. Humanity will see this universal show from the "first row".
As we eagerly peer into the sky with all our instruments and explore it with robotic spacecraft and missions with human crews, we will certainly make new amazing discoveries that will take us even further into the vastness of space.
We are constantly exploring new objects among trillions of celestial bodies. We will open more than one new star, which will eclipse the already known in size. But alas, we will never know about the true scale of the universe.
