Why does time only go in one direction? And why is the future so different from the past? They seem obvious questions, but they have troubled scientists for over a century. A new theory has proposed an answer — that time doesn’t run just one way, and that there is another universe, a mirror of ours, where time runs backwards.
An experiment to recreate the beginning of our universe suggests that as the Big Bang happened, it sent off another one, the mirror image of ours, with the ‘arrow of time’ running the other way.
The experiment solves a key problem in theoretical physics: that all of it fundamental laws, such as relativity and gravity, work just as well if time is going the other way. And usually, when scientists model the beginning of our universe, it is happy to flow backwards as forwards.
The current theory suggests that entropy — the force of the universe that means that it tends to get more disordered over time — also drives time forwards. Since the universe began as an ordered thing, as it gets more disorganised, so does time.
But that depends on an assuming that the universe was exceptionally ordered at its beginning, according to Steven Carlip, of the University of California at Davis. And while that is many scientists’ working theory, it is impossible to prove.
Astronomy Photographer of the Year 2014: Shortlisted images revealed
Astronomy Photographer of the Year 2014: Shortlisted images revealed
1/19 NGC 6888 by Mark Hanson (USA)
This colourful starscape taken from Rancho Hidalgo, New Mexico, USA reveals the searing heat of the Crescent Nebula glowing in a whirl of red and blue. The emission nebula is a colossal shell of material ejected from a powerful but short-lived Wolf-Rayet star (WR 136), seen close to the image centre. Ultraviolet radiation and stellar wind now heats the swelling cloud, causing it to glow
2/19 The Turbulent Heart of the Scorpion by Rolf Wahl Olsen (New Zealand)
A spectacular display of light and shade with contrasting hues of the rarely imaged, colourful, action-packed core of the multiple star system, Rho Ophiuchi. A deep exposure showcases the full finery of the delicate whirling clouds, of an area in which the human eye would struggle to see much detail, even with the use of a telescope
3/19 Creature by Ole Christian Salomonsen (Norway)
On 30 October a CME (Coronal Mass Ejection) hit Earth, displaying multi-coloured auroras across the sky for most of the night in Kattfjordeidet, Tromsø, Norway. The old birch trees resemble arms reaching for the auroral corona appearing like a strange creature in the sky
4/19 Eta Aquarid Meteor Shower over Mount Bromo by Justin Ng (Singapore)
A bright meteor streaks across the magnificent night sky over the smoke-spewing Mount Bromo just one day before the peak of the Eta Aquarid meteor shower, which is caused by Halley’s Comet. Mount Bromo is one of the most well-known active volcanoes in East Java, Indonesia. Also seen in the photograph are the highest active volcano, Mount Semeru (3676m), and the extinct volcano, Mount Batok, which is located to the right of Mount Bromo
5/19 Occultation of Jupiter by Sebastián Guillermaz (Argentina)
An unusual daytime view of an astronomical alignment, captured from the photographer’s backyard in Los Polvorines, Buenos Aires, Argentina. The image shows the moments just before the planet Jupiter is blocked from view by the Moon. The planet can be seen as a pale dot to the right of the Moon’s body
6/19 Three Planets in Conjunction by Lóránd Fényes (Hungary)
The staggering colours of the sunset and flora of the African savannah afford a unique background for the planetary alignment of Jupiter, Venus and Mercury in June 2013. The golden hues of the sunrise, the three planets appeared as if they were strung on an invisible thread, and the bare tree and the human figure interwoven both point to one direction: Jupiter
7/19 Celestial Dance by Claus Possberg (Germany)
The spectacular Northern Lights pictured unfolding over a fjord, in Skjervøy, Troms, Norway. The vibrant colours are produced at various altitudes by different atmospheric gases, with blue light emitted by nitrogen and green by oxygen. Red light can be produced by both gases, while purples, pinks and yellows occur where the various colours mix and intersect
8/19 Centre of the Heart Nebula by Ivan Eder (Hungary)
Situated 7500 light years away in the ‘W’-shaped constellation of Cassiopeia, the Heart Nebula is a vast region of glowing gas, energized by a cluster of young stars at its centre. The image depicts the central region, where dust clouds are being eroded and moulded into rugged shapes by the searing cosmic radiation
9/19 Star Trails on the Beach by Sebastián Guillermaz (Argentina)
Multiple shots have been used to produce a time-lapse effect, as the Earth’s rotation draws the light from the stars into long trails arcing over the beach in Mar de Ajo, Buenos Aires Province, Argentina
10/19 Orion Nebula by Anna Morris (USA)
In this view of M42, more commonly known as the Orion Nebula, the photographer has emphasized the delicate veils of dust surrounding the more familiar gleaming heart of the nebula. The image highlights the structure of the object, giving a sense of vast cavities filled with pink hydrogen gas and the blue haze of reflected starlight
11/19 Geminid Fireball by Patrick Cullis (USA)
The Geminid meteor shower races over the Flatirons of Boulder, Colorado, in December 2012. Here, a larger than usual fragment burns bright enough to outshine all of the planets, producing what is commonly called a Fireball. Orion can also be seen in the photograph trailing across the sky toward the Pleiades and the glow of Jupiter inside the constellation of Taurus
12/19 Father and Son Observe Comet PanSTARRS by Chris Cook (USA)
A father and his young son watch the evening display of Comet PanSTARRS on First Encounter Beach, Eastham, Massachusetts, USA. The photographer had spent weeks preparing the shoot to capture the comet, which will not be seen again for over 100,000 years, in order to foster his son’s interest in astronomy
13/19 In-flight Entertainment by Paul Williams (UK)
Resplendent aurora seen from the window of a transatlantic flight between London and New York in February 2014. The photographer balanced his camera on his backpack to capture this image of the greatest natural light show on earth from a rare perspective
14/19 The Great Orion Nebula by Gray Olson (USA)
The sprawling stellar nursery of the Orion Nebula situated 1350 light years away and home to stars at diverse stages of their lives, captured by 15 year old Gray Olson. It is one of the brightest nebulae, and is even visible to the naked eye in the night sky making it a popular target for amateur astronomers
15/19 A Giant's Star Trail by Rob Oliver (UK)
A composition of several images taken at the famed Giant’s Causeway in Northern Ireland. Our planet’s rotation draws the stars out into circles – considered to be the most perfect shape by ancient philosophers. Separated from the sky by the stark line of the horizon, the atomic symmetries of crystallized rock display themselves in the hexagonal columns of the Giant’s Causeway
16/19 Eclipse and Old Faithful by Robert Howell (USA)
Visitors witness the Old Faithful geyser in Yellowstone National Park erupt as the Moon partially eclipses the Sun. The scene captures a sense of awe set against blue sky and white geyser steam, as the onlookers strain to see the joining of these two phenomena – one geological and one astronomical
17/19 Cave With Aurora Skylight by Ingólfur Bjargmundsson (Iceland)
This image was taken while exploring a 1300m lava cave in Iceland. In some areas the roof has caved in, so snow piles up in the winter time and creates these snow peaks. The aurora at its peak gleams through the roof of the cave and despite only taking up a small portion of the photo, it remains the focal point
18/19 What the...! by Tommy Richardsen (Norway)
A flamboyant flare up of the aurora over Steinsvik beach, in Nordreisa, Troms, Norway. It lasted no more than ten minutes from start to finish but it lit up the entire sky and took the photographer by surprise, just as he was about to leave the shoot. The figure on the right is his brother, furiously searching for his lens cap to capture the same phenomena. It was hard for the photographer not to laugh at his brother while moving the camera left to right capturing the panorama, but luckily he stood still long enough to make the final capture
19/19 Oxbow Bend Reflections by David Kingham (USA)
The Milky Way reflected in the Snake River at the famous Oxbow Bend in Grand Teton National Park. The galaxy is poised just above the horizon mimicking a glowing cloud
But the new theory suggests that time doesn’t have to flow in just one direction, which would settle the problem entirely. When the universe began, it could have created another one, flowing in the other direction, write Julian Barbour, Tim Koslowski, and Flavio Mercati in the Physical Review Letters.
“Any internal observer must be in one half of the solution and will only be aware of the records of one branch and deduce a unique past and future direction from inspection of the available records,” they write. People think that time moves in one direction because they can only see one half of the universe, in other words.Reuse content