Space-Time Concepts, Gravity, Models of the Universe

Concepts of Time:

The equations of time

Timelapse of the future

The days are getting longer

A defense of the reality of time

A look into the fourth dimension

Bell's theorm for temporal order

Timelapse of the entire universe

Carlo Rovelli on the physics of time

Physicists find signs of a time crystal

Einstein says: It's 309.7-meter o'clock 

Testing Einstein's E=mc2 in outer space

BoBar experiment confirms time asymmetry

FOAM: the importance of time synchronization

Inquiry into the nature of time with A. H. Almaas

Forget everything you think you know about time

A rock is a clock: physicist uses matter to tell time

Perfectly accurate clocks turn out to be impossible 

In a 'rainbow' universe time may have no beginning

Light from galaxy clusters confirm theory of relativity

Physics explains why time passes faster as you age

Cosmic triangles open a window to the origin of time

The most accurate optical single-ion clock worldwide

The simple idea behind Eistein's greatest discoveries

Eva Silvastein: Other observations on history of science

Paradigm shift offers a new look at the beginning of time

Leap second: French time lords add one second to 2015

An inexpensive crystal makes a fine quantum time machine

Researchers explain why the Greenwich prime meridian moved

Superradiant laser may boost atomic clocks, create 'rulers' for sp

Scientists create time crystals, a rule-bending new form of matter

The discrete-time physics hiding inside our continuous-time world

The history of time and frequency from antiquity to the present day

1400km of optical fibre connect optical clocks in France and Germany

Quantum paradox experiment may lead to more accurate clocks and sensors

Does time really flow? New clues come freom a century-old approach to math 

Gravity:

Testing theories of modified gravity 

Why gravity is not like the other forces

The long path to understanding gravity   

Emergent gravity and the dark universe

A molecular clock for testing fundamental forces

New math bridges holography and twistor theory

Gravity recovery and climate experiment (GRACE)

Attractive force arises from black-body radiation, says physicists

Development of a displacement sensor to measure gravity of smallest source mass ever

A simple view of gravity does not fully explain the distribution of stars in crowded clusters

High-resolution data demonstrate gravitational lensing of the cosmic microwave background

Quantum Gravity:

Quantum gravity limits from planet observations

How holography could help solve quantum gravity

Researchers find quantum gravity has no symmetry

Physicists find a way to see the 'grin' of quantum gravity

Understanding how quantum gravity affects low-energy physics

Understanding of complex networks could help unify gravity and quantum mechanics

Physical Units and Constants:

Our relative velocities

The future of the kilo: a weighty matter

Universal units reflect their Earthly origins

A more fundamental International System of Units

Galileo, krypton, and how the Metric Standard came to be

Largest overhaul of scientific units since 1875 wins approval

Important milestone reached on road to a redefined kilogram

An atomic physics perspective on the kilogram's new definition

New measurement of Universe's expansion rate is 'stuck in the middle'

Gravitational constant appears universally constant, pulsar study suggests

Kilogram to be based on physical absolute instead of single, physical object

Space-Time: 

Powers of Ten

Planck results 2013

A wrinkle in space-time

Space-time vortex around Earth

Simulating extreme space-times

Spacetime has no time dimension

Space-time crystals on the horizon

Space-time crystals of trapped ions

Cosmography of the local Universe 

The fall and rise of the Doppler Effect

What is the geometry of the Universe?

The century of the cosmological constant   

A new study suggests we've got it all wrong

Spacetime: a smoother brew than we knew 

New discovery about the fabric of space-time

Time crystals realize new order of space-time

How our Universe could emerge as a hologram  

How spacetime is built by quantum entanglement

Structure in the fabric of space - the African Arrow

New mathrmatical model links space-time theories

Superfluid turbulence through the lens of black holes

Astronomers discover new way to measure Universe

Bringing time, space together for universal symmetry

First signs of weird quantum property of empty space 

Shape from sound - new methods to probe the Universe 

Scientists discover a jewel at the heart of quantum physics

Quantum computer as detector shows space is not squeezed

How space and time could be a quantum error-correcting code

Is nature continuous or discrete? How the atomist error was born

Is it possible to travel the span of the Universe at the speed of light? 

International collaboration replicates amplification of cosmic magnetic fields

A robust constraint on cosmic textures from the cosmic microwave background

Maximum and minimum values, cosmology, a conjecture and Beckenstein bound 

NASA's gravity probe spacecraft confirms Einstein's 'Warping of spacetime & frame-dragging'         

Why our universe was born with 3 dimensions: a puzzle of superstring theory solved by supercomputer     

Expansion of the Universe:

What is the Universe expanding into?

Universe expanding faster than expected

Expansion of space measurement improved

Big bounce simulations challenge the Big Bang

Cosmologists debate how fast the Universe is expanding

Universe's expansion may not be the same in all directions

How (relatively) simple symmetries underlie our expanding universe

Could gravitational waves reveal how fast our universe is expanding? 

The universe's rate of expansion is in dispute - and we may need new physics to solve it

Worm-holes:

Inside the big wormhole

Travel through wormholes is possible, but slow 

Newfound wormhole allows information to escape black holes

How to tell the shape of a wormhole by its quasinormal modes

Wormholes reveal a way to manipulate black hole information in the lab

Energy:

Boosting of force from empty space  

Quantum vacuum: less than zero energy

String Theory:

Visualizing 11-dimensions

Making sense of string theory

Cosmic strings:

Some physicists see signs of cosmic strings from the Big Bang

Alternative Models of the Universe:

Recipe for a universe

How the Universe works

Caught in the cosmic web 

Reinterpreting dark matter

The scale of the Universe 2

How order arises in the cosmos

Is the Universe a bubble? Let's check

Misconceptions about the Universe

Beyond the horizon of the Universe

How we escaped from the Big Bang

Universe is older than previously thought

Getting the math of the Universe to cancel out

Collapse of the Universe is closer than ever before

Planck mission explores the history of our Universe

Estimating cosmological parametters from the dark matter distribution    

Paradoxes of cosmological physics in the beginning of the 21st Century

New findings bring physicists closer to understanding the formation of planets and stars

Multi-verse:

Many universes, many theories

Could a multiverse be hospitable to life?

Experimental limits on neutron disappearance into another braneworld

We are one of a vast Universe of new universes constantly being created

Scientists are searching for a mirror universe: it could besitting right in front of you

Hologramic Universe:

Are we Living in a hologram?

The Universe is really a hologram, according to new simulations

Light and Matter:

Light in a spin

A new Einstein Ring

Sounds from space emr

Dead star warps light of red star

Quest to test Einstein's speed limit 

Special relativity induced by granular space

Researchers shine a light on 150-year old mystery

Teaching general relativity to undergraduates 

Precise test confirms speed of light is constant 

Extending Einstein's theory beyond light speed

A journey of light through space and time (video)

5-dimensional black hole could 'break' general relativity

Bizarre binary star system pushes study of relativity to new limits

Scientists discover how to turn light into matter after 80-year quest 

Left-handed cosmic magnetic field could explain missing antimatter 

Researchers develop way to control speed of light, send it backwards

First successful test of Einstein's General Relativity near supermassive black hole 

Simulation shows that dark energy and matter can reproduce the Universe

 Flashes from faster-than-light spots may help illuminate astronomical secrets 

NIST pair of aluminum atomic clocks reveal Eistein's relativity at a personal scale

Transfer of atomic mass with a photon solves the momentum paradox of light

Newly discovered 3-star system to challenge Einstein's theory of General Relativity

Can strongly lensed Type 1a supernovae resolve one of cosmologies biggest controversies?

A heavy weight for Einstein: observations of the most massive neutron star confirms Eistein's theory

Detection of the cosmic gamma ray horizon measures all the light in the universe since the Big Bang

Wormholes:

Magnetic wormhole created for the first time

'Spooky action' builds a wormhole between 'entangled' particles