Posts Tagged ‘Universe’
“The Universe is under no obligation to make sense to you”*…
Uppsala University researchers have devised a new model for the Universe – one that may solve the enigma of dark energy. Their new article, published in Physical Review Letters, proposes a new structural concept, including dark energy, for a universe that rides on an expanding bubble in an additional dimension.
We have known for the past 20 years that the Universe is expanding at an ever accelerating rate. The explanation is the “dark energy” that permeates it throughout, pushing it to expand. Understanding the nature of this dark energy is one of the paramount enigmas of fundamental physics.
It has long been hoped that string theory will provide the answer. According to string theory, all matter consists of tiny, vibrating “stringlike” entities. The theory also requires there to be more spatial dimensions than the three that are already part of everyday knowledge. For 15 years, there have been models in string theory that have been thought to give rise to dark energy. However, these have come in for increasingly harsh criticism, and several researchers are now asserting that none of the models proposed to date are workable.
In their article, the scientists propose a new model with dark energy and our Universe riding on an expanding bubble in an extra dimension. The whole Universe is accommodated on the edge of this expanding bubble. All existing matter in the Universe corresponds to the ends of strings that extend out into the extra dimension. The researchers also show that expanding bubbles of this kind can come into existence within the framework of string theory. It is conceivable that there are more bubbles than ours, corresponding to other universes.
The Uppsala scientists’ model provides a new, different picture of the creation and future fate of the Universe, while it may also pave the way for methods of testing string theory…
(For a different emerging new theory– that may or may not be contradictory– see “Our universe has antimatter partner on the other side of the Big Bang.”)
* Neil deGrasse Tyson
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As we fumble with the fundamentals, we might send carefully-deduced birthday greetings to Richard Bevan Braithwaite; he was born on this date in 1900. A Cambridge philosopher who specialized in the philosophy of science, he focused on the logical features common to all sciences. Braithwaite was concerned with the impact of science on our beliefs about the world and the appropriate responses to that impact. He was especially interested in probability (and its applications in decision theory and games theory) and in the statistical sciences. He was president of the Aristotelian Society from 1946 to 1947, and was a Fellow of the British Academy.
It was Braithwaite’s poker that Ludwig Wittgenstein reportedly brandished at Karl Popper during their confrontation at a Moral Sciences Club meeting in Braithwaite’s rooms in King’s. The implement subsequently disappeared. (See here.)
“And so the Universe ended”*…
Conceptual illustration of the Higgs Field that physicists believe permeates the Universe, and that could theoretically bring about its end.
Every once in a while, physicists come up with a new way to destroy the Universe. There’s the Big Rip (a rending of spacetime), the Heat Death (expansion to a cold and empty Universe), and the Big Crunch (the reversal of cosmic expansion). My favourite, though, has always been vacuum decay. It’s a quick, clean and efficient way of wiping out the Universe…
Learn more about a possibility that really sucks: “Vacuum decay: the ultimate catastrophe.”
The Restaurant at the End of the Universe
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As we we abhor a vacuum even more than nature does, we might send closely-observed birthday greetings to Jesse Leonard Greenstein; he was born on this date in 1909. An astronomer who ran Cal Tech’s storied program for decades, he co-discovered (with Maarten Schmidt) the quasar. While other astronomers had previously observed the bright bodies, Greenstein and Schmidt were the first to to interpret the red shift of quasars and correctly identify them as compact, very distant– and thus very old– objects. Later, working with Louis Henyey, Greenstein designed and built a new spectrograph and wide-view camera to improve astronomical observations,
“Equipped with his five senses, man explores the universe around him and calls the adventure Science”*…
Caleb Scharf wants to take you on an epic tour. His latest book, The Zoomable Universe, starts from the ends of the observable universe, exploring its biggest structures, like groups of galaxies, and goes all the way down to the Planck length—less than a billionth of a billionth of a billionth of a meter. It is a breathtaking synthesis of the large and small. Readers journeying through the book are treated to pictures, diagrams, and illustrations all accompanied by Scharf’s lucid, conversational prose. These visual aids give vital depth and perspective to the phenomena that he points out like a cosmic safari guide. Did you know, he offers, that all the Milky Way’s stars can fit inside the volume of our solar system?
Scharf, the director of Columbia University’s Astrobiology Center, is a suitably engaging guide. He’s the author of the 2012 book Gravity’s Engines: How Bubble-Blowing Black Holes Rule Galaxies, Stars, and Life in the Universe, and last year he speculated in Nautilus about whether alien life could be so advanced as to be indistinguishable from physics.
In The Zoomable Universe, Scharf puts the notion of scale—in biology and physics—center-stage. “The start of your journey through this book and through all known scales of reality is at that edge between known and unknown,” he writes…
Another entry in a collection that long-time readers know your correspondent cultivates, visualizations of relative scale (inspired by Charles and Ray Eames’ Powers of Ten—see, e.g., here, here, here, and here): “This Will Help You Grasp the Sizes of Things in the Universe.”
* Edwin Powell Hubble
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As we keep things in perspective, we might spare a thought for Paolo Frisi; he died on this date in 1784. A mathematician, astronomer, and physicist who worked in hydraulics (he designed a canal between Milan and Pavia) and introduced the lightning conductor into Italy, he is probably best remembered for his compilation, interpretation, and dissemination of the work of other scientists, especially Galileo Galilei and Sir Isaac Newton.
Your correspondent is headed into the Thanksgiving Holiday– and so into a brief hiatus in posting. Regular service will resume on Sunday the 26th… or when the tryptophan haze clears, whichever comes first.
“The map is not the territory”*…
With the advent of GPS systems and cell-phone-based mapping guidance…
…many of us have stopped paying attention to the world around us because we are too intent on following directions. Some observers worry that this represents a new and dangerous shift in our style of navigation. Scientists since the 1940s have argued we normally possess an internal compass, “a map-like representation within the ‘black box’ of the nervous system,” as geographer Rob Kitchin puts it. It’s how we know where we are in our neighborhoods, our cities, the world.
Is it possible that today’s global positioning systems and smartphones are affecting our basic ability to navigate? Will technology alter forever how we get around?
Most certainly—because it already has. Three thousand years ago, our ancestors began a long experiment in figuring out how they fit into the world, by inventing a bold new tool: the map…
Get your bearings at: “From Ptolemy to GPS, the Brief History of Maps”
* Alfred Korzybski
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As we follow the directions, we might recall that it was on this date in 1595 that Johann Kepler (and here) published Mysterium cosmographicum (Mystery of the Cosmos), in which he described an invisible underlying structure determining the six known planets in their orbits. Kepler thought as a mathematician, devising a structure based on only five convex regular solids; the path of each planet lay on a sphere separated from its neighbors by touching an inscribed polyhedron.
It was an elegant model– and one that fit the orbital data available at the time. It was, nonetheless, wrong.
Detailed view of Kepler’s inner sphere
“When the going gets weird, the weird turn pro”*…
An international study claims to have found first observed evidence that our universe is a hologram.
What is the holographic universe idea? It’s not exactly that we are living in some kind of Star Trekky computer simulation. Rather the idea, first proposed in the 1990s by Leonard Susskind and Gerard ‘t Hooft, says that all the information in our 3-dimensional reality may actually be included in the 2-dimensional surface of its boundaries. It’s like watching a 3D show on a 2D television…
Just when one thought that things couldn’t get any stranger: “Scientists Find First Observed Evidence That Our Universe May Be a Hologram.”
Pair with this piece on recent experimental confirmation of what Albert Einstein called “spooky action at a distance.”
* Hunter S. Thompson
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As we batten down the hatches, we might send shady birthday greetings to Fritz Zwicky; he was born on this date in 1898. A distinguished astronomer who worked at Cal Tech most of his life, Zwicky is best remembered for being the first to infer the existence of “dark matter“: while examining the Coma galaxy cluster in 1933, he used the virial theorem to deduce the existence of what he then called dunkle Materie. Colleagues knew him as both both a genius and a curmudgeon. One of his favorite insults was to refer to people of whom he didn’t approve as “spherical bastards”– because, he explained, they were bastards no matter which way you looked at them.
[For more on dunkle Materie: “Will We Ever Know What Dark Matter Is?“]
“Why should things be easy to understand?”*…
Dunning-Kruger Effect
The less competent an individual is at a specific task, the more likely they are to over-estimate their ability at that task.
Sure, ignorance is bliss. But being convinced you’re an expert at something, even though actually you’re ignorant — DAYUM — that’s the the best thing ever. People with poor abilities at some task can sometimes mistakenly believe that they are much more skilled at the task then they actually are. Examples of this are everywhere, from people who have never played a sport before, but just know they’ll be great at it, to people who’ve had one semester of french back in high school, but have no doubt that when the plane lands in Paris they’ll be able to talk like a native…
More on this all-too-timely phenomenon here— one the regular entries in Chris Spurgeon‘s marvelous newsletter, The Laws of the Universe, a regular series of postings…
Every once in a while — very rarely in the grand scheme of things — someone figures out how a tiny, tiny bit of the universe works. Through this newsletter I celebrate these discoveries, and the people they’re named after.
These tiny discoveries are known by many terms — laws, rules, constants, principles, theorems, effects. And they pop up in all areas of human endeavors — science of course, but also law and politics, arts and entertainment, popular culture and everyday life. Hubble’s Law, Dunbar’s Number, the Barbara Streisand Effect, Murphy’s Law — they’re all fair game. The only rules are:
1) the law must be named for someone, and
2) the law must shine a tiny bit of light onto one tiny bit of how the universe operates.
Browse the archive (and sign up) here.
* Thomas Pynchon
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As we revel in rules, we might spare a thought for Gregor Johann Mendel; he died on this date in 1884. After a profoundly-unpromising start, Mendel became a scientist, Augustinian friar, and abbot of St. Thomas’ Abbey in Brno, Moravia (today’s Czech Republic). A botanist and plant experimenter, he was the first to lay the mathematical foundation of the science of genetics (of which he is now consider the “Father”). Over the period 1856-63, Mendel grew and analyzed over 28,000 pea plants. He carefully studied for each their height, pod shape, pod color, flower position, seed color, seed shape and flower color– and from those observations derived two very important generalizations, known today as the Laws of Heredity.
“Outer space is so empty”*…
At the furthest-most reaches of the observable universe lies one of the most enigmatic mysteries of modern cosmology: the cosmic microwave background (CMB) Cold Spot.
Discovered in 2004, this strange feature etched into the primordial echo of the Big Bang has been the focus of many hypotheses — could it be the presence of another universe? Or is it just instrumental error? Now, astronomers may have acquired strong evidence as to the Cold Spot’s origin and, perhaps unsurprisingly, no multiverse hypothesis is required. But it’s not instrumental error either…
The Cold Spot area resides in the constellation Eridanus in the southern galactic hemisphere. The insets show the environment of this anomalous patch of the sky as mapped using PS1 and WISE data and as observed in the cosmic microwave background temperature data taken by the Planck satellite. The angular diameter of the vast supervoid aligned with the Cold Spot, which exceeds 30 degrees, is marked by the white circles.
More at “Mysterious ‘Cold Spot’: Fingerprint of Largest Structure in the Universe?”
* Theodore Sturgeon
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As we boldly go, we might recall that it was on this date in 1962 that NASA launched the Ranger 4, the first U.S. spacecraft to reach another celestial body. Ranger 4 was designed to transmit pictures to Earth and to test the radar-reflectivity of the lunar surface during a period of 10 minutes of flight prior to crashing upon the Moon, “rough-landing” a seismometer capsule as it did. In the event, an onboard computer glitch caused failure of the solar panels and navigation systems; as a result the spacecraft crashed on the far side of the Moon three days after it’s launch without returning any scientific data. Still, the “landing” was a first.
Happy Shakespeare’s Birthday!
