Space-Time Concepts, Gravity, Models of the Universe

Concepts of Time:

Cosmic triangles open a window to the origin of time

The simple idea behind Eistein's greatest discoveries

Einstein says: It's 309.7-meter o'clock    The equations of time

Timelapse of the entire universe    Timelapse of the future

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

A defense of the reality of time    In a 'rainbow' universe time may have no beginning

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

Forget everything you think you know about time    Bell's theorm for temporal order

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

FOAM: the importance of time synchronization    Inquiry into the nature of time with A. H. Almaas

BoBar experiment confirms time asymmetry     Paradigm shift offers a new look at the beginning of time  

Perfectly accurate clocks turn out to be impossible    The most accurate optical single-ion clock worldwide

Quantum paradox experiment may lead to more accurate clocks and sensors

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

Leap second: French time lords add one second to 2015    The days are getting longer

Researchers explain why the Greenwich prime meridian moved

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

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

Physicists find signs of a time crystal    A rock is a clock: physicist uses matter to tell time   

An inexpensive crystal makes a fine quantum time machine   

Carlo Rovelli on the physics of time    Eva Silvastein: Other observations on history of science 

A look into the fourth dimension    Physics explains why time passes faster as you age


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:

A more fundamental International System of Units

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

Important milestone reached on road to a redefined kilogram

An atomic physics perspective on the kilogram's new definition

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

Universal units reflect their Earthly origins    The future of the kilo: a weighty matter

Gravitational constant appears universally constant, pulsar study suggests

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

Largest overhaul of scientific units since 1875 wins approval

Our relative velocities


What is the geometry of the Universe?    A new study suggests we've got it all wrong

Spacetime: a smoother brew than we knew    Spacetime has No Time Dimension   

New Discovery about the Fabric of Space-Time    Space-Time crystals of trapped ions

A wrinkle in space-time      Space-Time Vortex around Earth

Structure in the fabric of space - the African Arrow

How spacetime is built by quantum entanglement

Simulating extreme space-times

The century of the Cosmological Constant     

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

First signs of weird quantum property of empty space     

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

Scientists discover a jewel at the heart of quantum physics

Quantum computer as detector shows space is not squeezed    

Bringing time, space together for universal symmetry     

New mathrmatical model links space-time theories    

Space-Time crystals on the horizon    Time crystals realize new order of space-time

Shape from sound - new methods to probe the Universe     Cosmography of the Local Universe

A robust constraint on cosmic textures from the cosmic microwave background

International collaboration replicates amplification of cosmic magnetic fields     

Superfluid turbulence through the lens of black holes

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

The mechanism that explains why our universe was born with 3 dimensions: a 40-year-old puzzle of superstring theory solved by supercomputer

NASA's Gravity Probe Spacecraft Confirms Einstein's 'Warping of SpaceTime & Frame-Dragging'

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

How our Universe could emerge as a hologram

Powers of Ten    Planck results 2013

The fall and rise of the Doppler Effect

Expansion of the Universe:

What is the Universe expanding into?

Expansion of space measurement improved

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

Big bounce simulations challenge the Big Bang


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


Boosting of force from empty space  

Quantum vacuum: less than zero energy

String Theory:

Making sense of string theory

Visualizing 11-dimensions

Alternative Models of the Universe:

How the Universe works    Many universes, many theories    The Scale  of the Universe 2

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

Estimating cosmological parametters from the dark matter distribution

Caught in the cosmic web    How order arises in the cosmos

Could a Multiverse be hospitable to life?

Misconceptions about the universe    Reinterpreting dark matter

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

Astronomers discover new way to measure Universe    Universe expanding faster than expected

Recipe for a universe    Is the Universe a bubble? Let's check    Are We Living in a Hologram?

The universe is really a hologram, according to new simulations  

We are One of a Vast Universe of New Universes Constantly Being Created

Experimental limits on neutron disappearance into another braneworld

How we escaped from the Big Bang    Beyond the horizon of the Universe 

Getting the math of the universe to cancel out

Collapse of the universe is closer than ever before

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

Universe is older than previously thought    Planck mission explores the history of our universe

Light and Matter:

Researchers shine a light on 150-year old mystery

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

Light in a spin    A journey of light through space and time (video)    Sounds from space emr

Precise test confirms speed of light is constant    Quest to test Einstein's speed limit 

Teaching general relativity to undergraduates    Special relativity induced by granular space

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

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

Scientists discover how to turn light into matter after 80-year quest  Testing Einstein's E=mc2 in outer space

Simulation shows that dark energy and matter can reproduce the Universe     

A new Einstein Ring    5-dimensional black hole could 'break' general relativity

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

Extending Einstein's theory beyond light speed   Light from galaxy clusters confirm theory of relativity

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

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

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

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

Bizarre binary star system pushes study of relativity to new limits   Dead star warps light of red star

Left-handed cosmic magnetic field could explain missing antimatter

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


Magnetic wormhole created for the first time

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


Square Kilometre Array (SKA) 

New system produces high-res images at low cost