Determining if the universe is infinite pushes the limits of our knowledge.
- The size and shape of the universe has yet to be resolved.
- The size of the universe is linked to understanding its shape and the limits of our observations.
- New studies and going deeper into space will help us answer the question: "Is the universe infinite?"
Does the universe keep extending endlessly into the abyss of space, or does it have a defined end?
Of all the scientific questions you may ponder, "Is the universe infinite?" is one of the hardest. It is impossible to answer with certainty at this point. Scientists have proposed both possibilities, and each has its own supporters and detractors. Determining whether the universe has some kind of boundary ultimately depends on figuring out its shape, size, and how much of it we can actually observe.
Is the universe infinite? And what shape is it?
The shape of the universe would have a lot to do with its size. Cosmologists have theorized that a universe would likely come in one of three possible shapes, which are dependent on the curvature of space. As described in Discover Magazine, the universe could be flat, having no curvature, but spatially infinite. Or it could be open, shaped like a saddle (with negative curvature) and also infinite. Or it could be closed, look like a sphere, and be spatially finite.
So which shape really is it? Nobel Prize-winning cosmologist John Mather of NASA's Goddard Space Flight Center, also the chief scientist for the James Webb Space Telescope, maintains that recent observations of cosmic microwave background radiation (CMB) remaining from the time of the Big Bang support the idea of the universe being flat, without any curvature (at least to the limit of what is observable).
"The universe is flat like an [endless] sheet of paper," shared Mather. "According to this, you could continue infinitely far in any direction and the universe would be just the same, more or less."
The geometry of the universe is determined by the density parameter Ω within cosmological Friedmann Equations.Credit: NASA / WMAP Science Team
Measuring the size of the universe
Current calculations say that the observable universe extends 46.5 billion light-years in every direction, making its diameter 93 billion light-years across.
Consider this: The age of the universe is 13.8 billion years, which means it took 13.8 billion light-years for the light from the farthest edge of the observable universe to reach us. But in that time, the universe has continued to expand at a rate that appears to be speeding up. Now, the edge of the observable universe has moved and is 46.5 billion light-years away.
These gargantuan numbers are almost impossible to grasp. How did scientists come up with them?
As shared in an interview with BBC by Caitlin Casey, an astronomer at the University of Texas at Austin, scientists use a variety of tools and methods called "the cosmic distance ladder" to estimate distances between objects in the vastness of space. They start out with distances they can actually measure directly, like through bouncing radio waves off nearby bodies in the solar system, noting the time required for the waves to come back to Earth.
For distances that are harder to gauge, like those for galaxies at the boundary of the universe, astronomers utilize inferences based on calculations and observational evidence.
For instance, they employ "parallax measurement" that relies on measuring a star's shift in relation to objects in its background, as well as "main sequence fitting," which takes advantage of our knowledge of stellar evolution. (Stars evolve over time, changing size and brightness.) Knowledge of how brightness is connected to distance is paramount in determining the location of distant objects. So is analysis of redshift, which involves measuring changes in the wavelengths of light coming from faraway galaxies.
What about the unobservable universe?
If you notice, the numbers above pertain to the observable universe, the ball-like part of the universe that can be somehow seen from Earth or detected using our space telescopes and probes. But what about parts of the universe we cannot see? Some portions of the universe may be just too far away for the light emitted after the Big Bang to have had sufficient time to reach us here on Earth.
One study from a group of UK scientists estimated that if you take that into account, the actual size of the universe could be at least 250 times larger. They found that if you refer to space in terms of a so-called Hubble volume, which is similar to the volume of space in the visible universe, a closed and finite universe would contain roughly 250 to 400 Hubble volumes.
Another possibility entertained by scientists like Nobel Prize-winning Roger Penrose is that the Big Bang was just one of the periods of cosmic regeneration that our universe has experienced. There could have been multiple Big Bangs, followed by Big Crunches, periods in which a universe would stop expanding and collapse upon itself.
If all we know about the universe is derived from how it expands after the latest Big Bang, the questions if the universe is infinite or what size it may be are almost moot. As is often the case, more study and confirmation of our theories is needed.
Is there an edge to the universe?
Whether we have a finite universe or an infinite universe like an ever-expanding bubble, does it still have an "edge"? Is there some place you can go and say, "Yep, this is the end of the universe"? The simple answer is likely no.
As explained to LiveScience by Robert McNees, an associate professor of physics at Loyola University Chicago, the universe is isotropic. That means it follows the so-called "cosmological principle" and has the same properties and follows the same laws of physics in all directions.
If that is so, then the universe is much like the surface of a balloon. Imagine being an ant walking along a balloon. You wouldn't know there's an edge to it if you kept walking forward. You'd likely come back to where you started eventually, but the journey around and around could keep going without end.
If someone were to blow more air into the balloon as you keep walking along it, you'd experience some parts of the balloon moving farther away from you. Still, you'd be no closer to finding the balloon's edge.
Much like the ants, we're unlikely to get to the end of the universe. But we may still be able to answer one day "is the universe infinite" or does it have an actual boundary?
How Nobel Prize winner physicist Lev Landau ranked the best physics minds of his generation.
- Nobel-Prize-winning Soviet physicist Lev Landau used a scale to rank the best physicists of the 20th century.
- The physicist based it on their level of contribution to science.
- The scale was logarithmic, with each level being 10 times more valuable.
Lev Landau (1908-1968) was one of Soviet Union's best physicists. He made contributions to nuclear theory, quantum field theory, and astrophysics, among others. In 1962, he won a Nobel Prize in Physics for developing the mathematical theory of superfluidity. Landau also wrote an immensely influential textbook on physics, teaching generations of scientists.
A brilliant mind, Landau liked to classify everything in his life. He ranked people by their intelligence, beauty (he had a penchant for blondes), contributions to science, how they dressed, and even how they talked – often with a healthy dose of sarcasm.
One of the most famous of Landau's classifications that has been passed down is his ranking of the greatest physicists of the 20th century. Of course, it wouldn't have later physicists, as he died in 1968, but these are arguably the most significant names.
This scale is logarithmic, meaning people ranked as rank 1 contributed ten times more (according to Landau) than people ranked as class 2, and so forth. In other words, the higher the number, the less valuable the physicist.
Here's how this scale broke down:
Rank 0.5 – Albert Einstein (1879 - 1955)
Einstein, the creator of the Theory of General Relativity, is in a class of his own. Landau thought he was by far the greatest mind among a very impressive group that redefined modern physics.
Landau added, however, that if the list was to be expanded to scientists of the previous centuries, Isaac Newton (1643 - 1727), the titan of classical physics, would also join Einstein at first place with 0.5.
Rank 0.5 – Albert Einstein
Albert Einstein With Displaced Children From Concentration Camps. 1949.
Photo by Keystone-France/Gamma-Keystone via Getty Images
The group in this class of the smartest physicists included the top minds that developed the theories of quantum mechanics.
Werner Heisenberg (1901 - 1976) - a German theoretical physicist, who's achieved pop-culture fame by being the name of Walter White's alter ego in Breaking Bad. He is known for the Heiseinberg Uncertainty Principle and his 1932 Nobel Prize award flatly states it was for nothing less than "the creation of quantum mechanics".
Erwin Schrödinger (1887 - 1961) - an Austrian-Irish physicist who gave us the infamous "Schroedinger's Cat" thought experiment and other mind-benders from quantum mechanics. The Nobel-prize-winner's Schrödinger equation calculates the wave function of a system and how it changes over time.
Erwin Schrödinger. 1933.
Paul Dirac (1902 - 1984) - another quantum mechanics giant, this English theoretical physicist shared the 1933 Nobel Prize with Erwin Schrödinger "for the discovery of new productive forms of atomic theory."
Niels Bohr (1885 - 1962) - a Danish physicist who made founder-level additions to what we know of atomic structure and quantum theory, which led to his 1922 Nobel Prize in Physics.
Satyendra Nath Bose (1894 - 1974) - an Indian mathematician and physicist, known for his quantum mechanics work. He collaborated with Einstein to develop the Bose-Einstein statistics and the theory of the Bose–Einstein condensate. Boson particles are named after him.
Satyendra Nath Bose. 1930s.
Eugene Wigner (1902 - 1995) - a Hungarian-American theoretical physicist who received the 1963 Nobel Prize in Physics for work on the theory of the atomic nucleus and the elementary particles. Famously, he took part in the meeting with Leo Szilard and Albert Einstein that led to them writing a letter to President Franklin D. Roosevelt which resulted in the creation of the Manhattan Project.
Louis de Broglie (1892 - 1987) - a French theorist who made key contributions to quantum theory. He proposed the wave nature of electrons, suggesting that all matter has wave properties – an example of the concept of wave-particle duality, central to the theory of quantum mechanics.
Enrico Fermi (1901 - 1954) - an American physicist who's been called the "architect of the nuclear age" as well as the "architect of the Atomic bomb". He also created the world's first nuclear reactor and won the 1938 Nobel Prize in Physics for work on induced radioactivity and for discovering transuranium elements.
Enrico Fermi. 1950s.
Wolfgang Pauli (1900-1958) - an Austrian theoretical theorist, known as one of the pioneers of quantum physics. He won the 1945 Nobel Prize in Physics for discovering a new law of nature – the exclusion principle (aka the Pauli principle) and developing spin theory.
Max Planck (1858-1947) - a German theoretical physicist who won the 1918 Nobel Prize in Physics for energy quanta. He was the originator of quantum theory, the physics of atomic and subatomic processes.
Lev Landau. 1962.
Rank 2.5 is where Landau initially ranked himself, rather modestly, thinking he didn't produce any foundational accomplishments. He later moved his prominence, as his achievement mounted, to the higher 1.5.
Whether the data prove you right or wrong, it's crucial to ask: what else is it telling me?
- In 2018, Dr. Jim Allison was awarded the Nobel Prize in medicine for discovering an effective way to attack cancer through immunology.
- In his lab, Allison urges researchers to get rid of the idea that they can prove something with science. All they can do is fail to disprove.
- Jim Allison is the subject of Jim Allison: Breakthrough, a documentary narrated by Woody Harrelson that brings filmmakers and scientists together to tell the story of a Nobel Prize-winning cancer discovery that changed the world. In cinemas September 27th, 2019.
DocLands presents Jim Allison: Breakthrough (Official Trailer) www.youtube.com
How do you develop the next big idea? You pull together people who are both curious and passionate.
- In 2018, Dr. Jim Allison was awarded the Nobel Prize in medicine for discovering an effective way to attack cancer through immunology.
- In pursuing this discovery, he recruited other scientists who were curious, who cared about and were committed to science. "You have to put up with a lot of failure, 'cause if you're not, you're probably doing boring stuff," Allison says.
- When it comes to developing a theory that works, it's critical to ask as many people as possible on a project for their hypotheses on why a particular outcome may take place. By pulling together these ideas, and testing them, better data can be accumulated.
Jim Allison is the subject of Jim Allison: Breakthrough, a documentary narrated by Woody Harrelson that brings filmmakers and scientists together to tell the story of a Nobel Prize-winning cancer discovery that changed the world. In cinemas September 27th, 2019.
DocLands presents Jim Allison: Breakthrough (Official Trailer) www.youtube.com
From literature to physics, the annual Nobel Prizes aim to highlight the most groundbreaking achievements in every field.
- Each year, the Royal Swedish Academy of Sciences awards six Nobel Prizes.
- The categories are: literature, physics, chemistry, peace, economics, and physiology & medicine.
- The Nobel prizes will be announced each business-day until October 14.
Nobel Peace Prize
Ethiopian Prime Minister Abiy Ahmed Ali won the Nobel Peace on Friday for helping to resolve the border conflict with neighboring Eritrea.
Eritrea and Ethiopia, two of the world's poorest nations, fought a war against each other from 1998 to 2000. A peace treaty in 2000 stopped the large-scale fighting, but a stalemate ensued, and both sides have in recent years accused the other of sparking smaller border clashes.
I am humbled by the decision of the Norwegian Nobel Committee. My deepest gratitude to all committed and working fo… https://t.co/xdCOgyp49Q— Abiy Ahmed Ali (@Abiy Ahmed Ali)1570801685.0
But after taking office in 2018, Abiy pursued peace talks with Eritrea.
"In close cooperation with Isaias Afwerki, the President of Eritrea, Abiy Ahmed quickly worked out the principles of a peace agreement to end the long "no peace, no war" stalemate between the two countries," the academy wrote.
"He spent his first 100 days as Prime Minister lifting the country's state of emergency, granting amnesty to thousands of political prisoners, discontinuing media censorship, legalising outlawed opposition groups, dismissing military and civilian leaders who were suspected of corruption, and significantly increasing the influence of women in Ethiopian political and community life. He has also pledged to strengthen democracy by holding free and fair elections."
Still, ethnic conflicts within Ethiopia have displaced more than 3 million people in recent years, and critics of Abiy – who's already survived one assassination attempt – argue that his policies will make matters worse.
"No doubt some people will think this year's prize is being awarded too early," the academy wrote. "The Norwegian Nobel Committee believes it is now that Abiy Ahmed's efforts deserve recognition and need encouragement."
Last year's Nobel Peace Prize was awarded to Dr. Denis Mukwege, a Congolese gynecologist, and Nadia Murad, a Yazidi woman and former captive of ISIS, for helping to combat wartime sexual assault.
Nobel Prize: Literature
The Swedish Academy awarded two writers the Nobel Prize in Literature: The Polish author and poet Olga Tokarczuk received the 2018 award, and the 2019 prize went to Austrian author and playwright Peter Handke.
Last year's Nobel Prize in Literature was postponed due to a sexual assault scandal involving the husband of an academy member. After the scandal, several board members departed and the academy changed the way it chooses winners.
Handke is a 76-year-old Austrian playwright, novelist, essayist, and poet who gained acclaim early in his career for his avant-garde play "Offending the Audience." He's also written many scripts for films, including Die linkshändige Frau (The Left–Handed Woman), which in 1978 was nominated for the Golden Palm Award at the Cannes Film Festival.
But Handke's win is proving controversial. The writer is a well-known apologist for former Serbian leader Slobodan Milosevic, who was accused by a United Nations tribunal of war crimes related to wars in Kosovo, Croatia, and Bosnia. In his writings, Handke controversially portrayed Serbia as a victim of the Yugoslav Wars. Although Handke declined Milosevic's request to appear as a witness at his U.N. trial., the writer did eulogize Milosevic after he died in prison awaiting trial.
"I think he was a rather tragic man," Handke said in a 2006 interview. "Not a hero, but a tragic human being. I am a writer and not a judge."
Surprisingly, in 2014 Handke said the Nobel Prize for literature "should be abolished" because it "promotes the false canonization of literature."
A handful of writers and literary organizations have already denounced the academy's decision to award the prize to Handke.
"We are dumbfounded by the selection of a writer who has used his public voice to undercut historical truth and offer public succor to perpetrators of genocide, like former Serbian President Slobodan Milosevic and Bosnian Serb leader Radovan Karadzic," the novelist Jennifer Egan, who is president of PEN America, said in a statement on behalf of the organization. "At a moment of rising nationalism, autocratic leadership, and widespread disinformation around the world, the literary community deserves better than this. We deeply regret the Nobel Committee on Literature's choice."
"Have we become so numb to racism, so emotionally desensitized to violence, so comfortable with appeasement that we can overlook one's subscription and service to the twisted agenda of a genocidal maniac?" tweeted Vlora Citaku, Kosovo's ambassador to the United States.
Tokarczuk, who also won last year's Man Booker International Prize for her novel "Flights," is the 15th woman to win the Nobel Prize for literature. The judges described her as "a writer preoccupied by local life ... but looking at earth from above ... her work is full of wit and cunning," and said she possesses "a narrative imagination that with encyclopedic passion represents the crossing of boundaries as a form of life."
Tokarczuk is a controversial figure in Poland, a nation dominated by right-wing populist politics, which she frequently criticizes. After she criticized Poland's history of colonialism in a 2014 interview, some right-wing nationalists called her a "targowiczanin," an archaic term for traitor.
Some of Tokarczuk's works to check out include: "The Journey of the Book-People," "Primeval and Other Times," and the screenplay for the crime film "Spoor", which was nominated for best foreign language film at the 2018 Oscars.
Nobel Prize: Physics
How did the Big Bang produce the swirling galaxies that populate our universe, and how can scientists detect and study planets that orbit stars light-years away from Earth? The 2019 Nobel Prize in Physics goes to three scientists who helped shed light on these complex questions.
James Peebles, the Albert Einstein professor of science at Princeton, received half of the award, which includes half of the $918,000 prize money. Michel Mayor, an astrophysicist and professor emeritus of astronomy at the University of Geneva, and Didier Queloz, a professor of physics at the Cavendish Laboratory at Cambridge University and at the University of Geneva, together share the other half of the prize.
"While James Peebles' theoretical discoveries contributed to our understanding of how the universe evolved after the Big Bang, Michel Mayor and Didier Queloz explored our cosmic neighborhoods on the hunt for unknown planets. Their discoveries have forever changed our conceptions of the world," the secretary-general of the Royal Swedish Academy of Sciences, Goran Hansson, said.
BREAKING NEWS: The 2019 #NobelPrize in Physics has been awarded with one half to James Peebles “for theoretical dis… https://t.co/mDyUeJMuf7— The Nobel Prize (@The Nobel Prize)1570528353.0
How Dr. Peebles enriched cosmology
Since the 1960s, Dr. Peebles' work has helped to solidify and enrich cosmology, chiefly by finding ways to learn about the universe from the ancient radiation leftover from the Big Bang.
Some 400,000 years after the Big Bang, the universe cooled enough for light rays to travel through space. Today, billions of years later, this ancient radiation is still around us, though its temperature is near absolute zero. But Dr. Peebles discovered that the temperature of this background radiation provides clues about how much matter was created by the Big Bang.
The calculations made possible by this discovery also shed light on the matter and processes in the universe that we can't see: dark energy and dark matter.
"The results showed us a universe in which just five per cent of its content is known, the matter which constitutes stars, planets, trees – and us," the academy wrote. "The rest, 95 per cent, is unknown dark matter and dark energy. This is a mystery and a challenge to modern physics."
2019 #NobelPrize laureate James Peebles took on the cosmos, with its billions of galaxies and galaxy clusters. His… https://t.co/Fko2AUZt68— The Nobel Prize (@The Nobel Prize)1570528441.0
Mayor and Queloz: Finding exoplanets
Astronomers detect exoplanets by measuring extremely subtle changes in a star's activity. These changes occur as exoplanets orbit their host star, and the predictability of the changes allows scientists to learn quite a lot about the properties of exoplanets. In 1995, Mayor and Queloz used this approach to discover the first planet outside of our solar system. It might sound surprising to us today, but before their discovery astronomers considered that maybe it was extremely rare for stars to have planets orbiting them, meaning life outside of Earth would be even more unlikely, if not impossible."This discovery started a revolution in astronomy and over 4,000 exoplanets have since been found in the Milky Way," the academy wrote. "Strange new worlds are still being discovered, with an incredible wealth of sizes, forms and orbits. They challenge our preconceived ideas about planetary systems and are forcing scientists to revise their theories of the physical processes behind the origins of planets. With numerous projects planned to start searching for exoplanets, we may eventually find an answer to the eternal question of whether other life is out there."
Nobel Prize: Medicine
Photo by Xinhua/Zheng Huansong via Getty Images
The 2019 Nobel Prize in medicine was awarded to three scientists from the U.S. and U.K. working independently on the same problem: how cells sense and adapt to oxygen availability. Gregg Semenza of Johns Hopkins University, Sir Peter Ratcliffe of Oxford University, and William Kaelin, Jr., of Dana-Farber Cancer Institute/Harvard University received the 5 a.m. call from Stockholm. The three maintained an ongoing and informal conversation, sharing work and consequentially rocketing the entire field of study forward.
Their research unveiled a genuine textbook discovery. "They've unveiled the series of molecular events that allow cells to assess and respond to changing levels of available oxygen, with implications in the treatment of cancer, heart attacks, strokes, anemia, and other diseases," according to previous Big Think reporting. Read the full article dedicated to the findings here.