(Roughly) Daily

Posts Tagged ‘time

“There will be time, there will be time”*…

 

Infinity-Time1

Poets often think of time as a river, a free-flowing stream that carries us from the radiant morning of birth to the golden twilight of old age. It is the span that separates the delicate bud of spring from the lush flower of summer.

Physicists think of time in somewhat more practical terms. For them, time is a means of measuring change—an endless series of instants that, strung together like beads, turn an uncertain future into the present and the present into a definite past. The very concept of time allows researchers to calculate when a comet will round the sun or how a signal traverses a silicon chip. Each step in time provides a peek at the evolution of nature’s myriad phenomena.

In other words, time is a tool. In fact, it was the first scientific tool. Time can now be sliced into slivers as thin as one ten-trillionth of a second. But what is being sliced? Unlike mass and distance, time cannot be perceived by our physical senses. We don’t see, hear, smell, touch, or taste time. And yet we somehow measure it. As a cadre of theorists attempt to extend and refine the general theory of relativity, Einstein’s momentous law of gravitation, they have a problem with time. A big problem…

The crisis inside the physics of time: “Is It Time to Get Rid of Time?

See also: “Forget everything you know about time.”

[image above: source]

* T. S. Eliot

###

As we check our watches, we might say a grateful Happy Birthday to Winsor McCay, the cartoonist and animator, who was born on this date in 1867.  His two best-known creations are the pioneering comic strip Little Nemo in Slumberland, which ran from 1905 to 1914, and the animated cartoon Gertie the Dinosaur (1914),which set the standard for animators for decades to come.

Little Nemo… for a more legible image, click here

 

Written by LW

September 26, 2018 at 1:01 am

“Aside from velcro, time is the most mysterious substance in the universe”*…

 

Time

Detail from Salvador Dali’s Persistence of Memory

 

In normal life, you open the car door before getting into the car. Operation A happens before operation B. That’s the causal order of things. But a new quantum switch weirdly enables two operations to happen simultaneously. From Science News:

The device, known as a quantum switch, works by putting particles of light through a series of two operations — labeled A and B — that alter the shape of the light. These photons can travel along two separate paths to A and B. Along one path, A happens before B, and on the other, B happens before A.

Which path the photon takes is determined by its polarization, the direction in which its electromagnetic waves wiggle — up and down or side to side. Photons that have horizontal polarization experience operation A first, and those with vertical polarization experience B first.

But, thanks to the counterintuitive quantum property of superposition, the photon can be both horizontally and vertically polarized at once. In that case, the light experiences both A before B, and B before A, Romero and colleagues report.

While this is deeply weird and amazing, it unfortunately doesn’t occur at the human scale but rather in the quantum realm where measurements are in the nanometers. Still, quantum switches do have clear applications in future communications and computation systems.

Indefinite Causal Order in a Quantum Switch” (Physical Review Letters)

From the ever-illuminating David Pescovitz at Boing Boing: “Weird time-jumbling quantum device defies ‘before’ and ‘after’.”

* Dave Barry

###

As we check our watches, we might send timely birthday greetings to Louis Essen; he was born on this date in 1908.  A physicist, he drew on his World War II work on radar to develop the first generally-accepted scientific measurement of the speed of light (one that has held up well as measurement techniques have advanced.).

But Essen is probably better remembered as the father of the atomic clock: in 1955, in collaboration with Jack Parry, he developed the first practical atomic clock by integrating the caesium atomic standard with conventional quartz crystal oscillators to allow calibration of existing time-keeping.

Atomic_Clock-Louis_Essen

Louis Essen (right) and Jack Parry (left) standing next to the world’s first caesium-133 atomic clock

 

Written by LW

September 6, 2018 at 1:01 am

“Above all else show the data”*…

 

With the hope that your celebrations will be warm and peaceful, and with thanks for your kind attention over the last twelve months, (Roughly) Daily is going on it’s annual Holiday hiatus…  So here, to tide us over, The Economist Graphics Unit’s wonderful “2017 Daily chart advent calendar” (the first installment of which, above)– a collection of 25 of the years best infographics, each with a short accompanying essay.

See you in the New Year!

* Edward Tufte

###

As we revel in new ways of seeing, we might send terrifyingly (and at the same time, amusingly) insightful birthday greetings to Edwin Abbott; he was born on this date in 1838.  A schoolmaster and theologian, Abbott is best remembered as the author of the remarkable novella Flatland: A Romance of Many Dimensions (1884). Writing pseudonymously as “A Square,” Abbott used the fictional two-dimensional world of Flatland to offer pointedly-satirical observations on the social hierarchy of Victorian culture. But the work has survived– and inspired legions of mathematicians and science fiction writers– by virtue of its fresh and accessible examination of dimensionality.  Indeed, Flatland was largely ignored on its original publication; but it was re-discovered after Einstein’s General Theory of Relativity– which posits a fourth dimension– was introduced; in a 1920 letter to Nature, Abbott is called a prophet for his intuition of the importance of time to explain certain phenomena.

 source

 

Written by LW

December 20, 2017 at 1:01 am

“Here we are, trapped in the amber of the moment”*…

 

We’ve all heard it before: There’s no time like the present. Broadly speaking, of course, it means to “seize the opportunity right now,” or maybe in my case, to avoid procrastinating. From a psychological perspective, this makes a lot of sense. As humans we experience time “passing,” and there is a special quality to the present moment. Hypnosis and dreams aside, there is no way to directly experience either the past or the future in the same way we experience the present. But is the aphorism true? Does modern physics actually tell us that there’s no time like the present?

Our best current physical theory of space and time is general relativity. Prior to Einstein’s revolution over a century ago, physics considered time to be an “external parameter”—an independent, fundamental feature of reality not influenced by any other factor in the universe. Whether or not the passage of time is real or illusory (this is an age-old philosophical debate that predates Einstein and is indeed not settled by his theory), we now know that time intervals are not external or universally determined. Time is an internal component of a physical system, a dimension intertwined with three spatial dimensions. Taken together, this is “spacetime,” and is influenced by varying factors and is influenced by varying factors, including speed (relative to other observers or systems) and gravitational forces. Because the theory of relativity posits the constancy of the speed of light for all observers (even if they are moving relative to each other), spacetime itself must dilate and the concept of a time interval becomes elastic.

As a result, there is no universal notion of the present that applies equally to all observers. What looks present to me could just as easily be in someone else’s future, and in a third person’s past. Simultaneity is relative…

Think there’s no time like the present? As Mark Shumelda suggests, modern physics begs to differ: “Actually, There Is a Time Like the Present.”

* Kurt Vonnegut Jr.

###

As we cogitate on carpe diem, we might send playful birthday greetings to Johan Huizinga; he was born on this date in 1872.  A Dutch historian and one of the founders of modern cultural history, he is probably best remembered for his 1938 book Homo Ludens, in which he argues for the importance of the play element of culture and society, suggesting that play is primary to and a necessary (though not sufficient) condition of the generation of culture.

 source

 

Written by LW

December 7, 2017 at 1:01 am

“You are not stuck in traffic. You ARE traffic.”*…

 

We’ve used 2016 information on population. There are now at least 3.8 billion people living inside the highlighted circle, and that’s not even including the tally from countries that are partially in the circle like Pakistan or Russia.

The circle holds 22 of the world’s 37 megacities – massive cities that hold at least 10 million inhabitants. It also includes the five most populous cities on the planet: Tokyo, Jakarta, Seoul, Karachi, and Shanghai, which alone combine to hold 144.5 million people.

This geographical region also holds many of the emerging markets of the future, countries that the World Economic Forum expects will lead global growth in years to come. Vietnam, Myanmar, Philippines, Indonesia, and Bangladesh are in the area highlighted, and Pakistan is partially there as well.

As a website called BrilliantMaps explains, there are some other subtleties to the circle that are worth detailing. The circle contains a lot of people, but it also has:

The highest mountain (Everest)

The deepest ocean trench (Mariana)

More Muslims than outside of it.

More Hindus than outside of it.

More Buddhists than outside of it.

More communists than outside of it.

The least sparsely populated country on earth (Mongolia)…

See the infographic in its entirety at “The Majority of the World’s Population Lives in This Circle.”

* TomTom SATNAV Advertisement

###

As we contemplate concentration, we might recall that it was on this date in 1880 that Greenwich Mean Time (GMT)– the mean solar time at the Royal Observatory in Greenwich, London–  was officially adopted by Parliament.  Originally set-up to aid naval navigation (in the calculation of longitude), Greenwich had been the national (and imperial) center for time since 1675.  In 1847, GMT became the standard for British Railroads, and quickly became the de facto standard for all other purposes.  The 1880 Act simply made de jure what had become de facto.

GMT became the international civil time standard, but was superseded in that function (in 1960) by Coordinated Universal Time (UTC).

 source

 

Written by LW

August 2, 2017 at 1:01 am

“Time is the longest distance between two places”*…

 

In quantum mechanics, time is universal and absolute; its steady ticks dictate the evolving entanglements between particles. But in general relativity (Albert Einstein’s theory of gravity), time is relative and dynamical, a dimension that’s inextricably interwoven with directions x, y and z into a four-dimensional “space-time” fabric. The fabric warps under the weight of matter, causing nearby stuff to fall toward it (this is gravity), and slowing the passage of time relative to clocks far away. Or hop in a rocket and use fuel rather than gravity to accelerate through space, and time dilates; you age less than someone who stayed at home.

Unifying quantum mechanics and general relativity requires reconciling their absolute and relative notions of time. Recently, a promising burst of research on quantum gravity has provided an outline of what the reconciliation might look like — as well as insights on the true nature of time…

The effort to unify quantum mechanics and general relativity means reconciling totally different notions of time; catch up on the state of play at “Quantum Gravity’s Time Problem.”

* Tennessee Williams, The Glass Menagerie

###

As we set our watches, we might send carefully-calculated birthday greetings to Gabrielle-Émilie Le Tonnelier de Breteuil, Marquise du Châtelet, the French mathematician and physicist who is probably (if unfairly) better known as Voltaire’s mistress; she was born on this date in 1706.  Fascinated by the work of Newton and Leibniz, she dressed as a man to frequent the cafes where the scientific discussions of the time were held.  Her major work was a translation of Newton’s Principia, for which Voltaire wrote the preface; it was published a decade after her death, and was for many years the only translation of the Principia into French.

Judge me for my own merits, or lack of them, but do not look upon me as a mere appendage to this great general or that great scholar, this star that shines at the court of France or that famed author. I am in my own right a whole person, responsible to myself alone for all that I am, all that I say, all that I do. it may be that there are metaphysicians and philosophers whose learning is greater than mine, although I have not met them. Yet, they are but frail humans, too, and have their faults; so, when I add the sum total of my graces, I confess I am inferior to no one.
– Mme du Châtelet to Frederick the Great of Prussia

source

Written by LW

December 17, 2016 at 1:01 am

“Nothing puzzles me more than time and space; and yet nothing troubles me less”…

 

Time crystals– crystals that break both spacial and temporal symmetry– were first predicted by Nobel laureate Frank Wilczek in 2012… and were widely deemed amusing, but impossible (e.g., here).  Now researchers have created time crystals for the first time and say they could one day be used as quantum memories… and might help reconcile Quantum Mechanics with the Theory of Relativity.

Bend your mind at “Physicists Create World’s First Time Crystal,” also here and here (source of the photo above).

* Charles Lamb

###

As we ponder Einstein’s insistence that time is an illusion, we might send well-structured birthday greetings to Pierre-Gilles de Gennes; he was born on this date in 1932.  A French physicist, he was awarded the 1991 Nobel Prize for Physics for “discovering that methods developed for studying order phenomena in simple systems can be generalized to more complex forms of matter, in particular to liquid crystals and polymers.”  He described mathematically how, for example, magnetic dipoles, long molecules or molecule chains can under certain conditions form ordered states, and what happens when they pass from an ordered to a disordered state.  Such changes of order occur when, for example, a heated magnet changes from a state in which all the small atomic magnets are lined up in parallel to a disordered state in which the magnets are randomly oriented.  Later, he was concerned with the physical chemistry of adhesion.

 source

 

Written by LW

October 24, 2016 at 1:01 am

%d bloggers like this: