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Vocapedia > Space > Space, Universe, Cosmos

 

 

 

 

Out There - Playlist        Video        The New York Times

 

YouTube

http://www.youtube.com/
playlist?list=PL4CGYNsoW2iClIx0Sr2cZRLyqLAHz5uA2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

life        UK

 

http://www.guardian.co.uk/books/2012/nov/04/
secrets-universe-where-why-how-book

 

http://www.guardian.co.uk/science/2010/nov/14/
exoplanets-astronomy-robin-mckie

 

 

 

 

 

 

life        USA

https://www.npr.org/sections/13.7/2017/12/15/
571122951/what-if-life-on-earth-didn-t-start-on-earth

 

http://www.npr.org/sections/13.7/2016/08/25/
491307739/are-we-the-earliest-intelligent-life-in-the-universe

 

 

 

 

human life        USA

http://www.npr.org/sections/13.7/2015/09/09/
438630784/moving-from-creation-of-the-cosmos-to-human-life

 

 

 

 

support life        USA

http://www.nytimes.com/2013/04/19/
science/space/2-new-planets-are-most-earth-like-yet-scientists-say.html

 

 

 

 

harbor life        USA

http://www.nytimes.com/2013/02/07/
science/living-bacteria-found-deep-under-antarctic-ice-scientists-say.html

 

 

 

 

bacteria        USA

http://www.nytimes.com/2013/02/07/
science/living-bacteria-found-deep-under-antarctic-ice-scientists-say.html

 

 

 

 

 

 

 

 

 

 

 

 

 

 

time

 

 

 

 

light

 

 

 

 

light-year        UK / USA

http://www.npr.org/sections/thetwo-way/2016/08/24/
490947403/this-planet-just-outside-our-solar-system-is-potentially-habitable

https://www.theguardian.com/science/2016/jul/07/
planet-with-three-suns-spotted-by-astronomers

 

http://www.nytimes.com/2013/04/19/
science/space/2-new-planets-are-most-earth-like-yet-scientists-say.html

 

 

 

 

1 light year

is the distance

light can travel in vacuum

in one year’s time.

 

This distance

is equivalent to roughly

9,461,000,000,000 km

or 5,878,000,000,000 miles.

 

This is such a large distance.

 

For comparison,

consider the circumference of the Earth

when measured at the equator: 40,075 km.

 

You can even throw in the center

to center distance

between the Earth and the Moon,

384,403 km,

and that value would still pale

in comparison to 1 light year.

 

Pluto,

at its farthest orbit distance from the Sun,

is only about 7,400,000,000 km

from the center of our Solar System.

 

Because of its great scale,

the light year is one of the units of distance

used for astronomical objects.

 

For example,

Andromeda Galaxy,

which is the nearest spiral galaxy

from the Milky Way,

is approximately

2.5 million light years away.

 

Alpha Centauri,

the nearest star system

from our own Solar System

is only 4.37 light years away.

http://www.universetoday.com/39725/1-light-year/

 

http://www.universetoday.com/39725/1-light-year/

http://www.universetoday.com/39725/1-light-year/#ixzz34hoGhKCY
 

 

 

 

 

at 240 million light years away

 

 

 

 

give off

 

 

 

 

energy

 

 

 

 

matter        USA

https://www.nytimes.com/2018/03/01/
obituaries/richard-e-taylor-nobel-winner-who-plumbed-matter-dies-at-88.html

 

 

 

 

quarks        USA

 one of the fundamental particles in the universe

https://www.nytimes.com/2018/03/01/
obituaries/richard-e-taylor-nobel-winner-who-plumbed-matter-dies-at-88.html

 

https://www.nytimes.com/2018/03/01/
obituaries/richard-e-taylor-nobel-winner-who-plumbed-matter-dies-at-88.html

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Do we live in a multiverse?        E        14 August 2015

 

 

 

 

Do we live in a multiverse?        The Economist        14 August 2015

 

It has long been thought that our universe is all there is,

but it is possible we may live in just one of many.

 

This is the second

in our six-part series on unsolved mysteries in science.

 

YouTube > The Economist

https://www.youtube.com/watch?v=Rx7erWZ8TjA

 

 

 

 

 

 

 

 

 

 

 

 

 

 

universe / cosmos        UK

http://www.npr.org/2016/12/30/
506734040/as-a-rough-year-ends-we-turn-to-the-cosmos-for-some-perspective

 

http://www.theguardian.com/science/2015/apr/20/
astronomers-discover-largest-known-structure-in-the-universe-is-a-big-hole

 

http://www.theguardian.com/technology/gallery/2014/jan/13/
universe-space-sun-2013-pictures

 

http://www.guardian.co.uk/science/video/2013/feb/08/
how-big-universe-grain-sand-video

 

http://www.guardian.co.uk/books/2012/nov/04/
secrets-universe-where-why-how-book

https://www.npr.org/sections/13.7/2012/06/12/
154839526/maureen-dowd-fears-the-cosmos-should-you

 

http://www.guardian.co.uk/science/2008/sep/07/
particlephysics.darkmatter

http://www.guardian.co.uk/science/2008/apr/26/
universe.physics

 

 

 

 

universe / cosmos        USA

http://www.npr.org/sections/13.7/2017/05/24/
529675773/what-does-an-expanding-universe-really-mean

https://www.nytimes.com/2017/02/20/
science/hubble-constant-universe-expanding-speed.html

 

http://www.npr.org/2016/12/30/
506734040/as-a-rough-year-ends-we-turn-to-the-cosmos-for-some-perspective

http://www.npr.org/sections/thetwo-way/2016/10/14/
497965415/the-universe-has-almost-10-times-more-galaxies-than-we-thought

http://www.npr.org/sections/13.7/2016/08/25/
491307739/are-we-the-earliest-intelligent-life-in-the-universe

http://www.npr.org/sections/13.7/2016/02/03/
465401401/evaluating-our-importance-in-the-universe

 

http://www.nytimes.com/2014/10/14/
science/space/in-cosmigraphics-our-changing-pictures-of-space-through-time.html

http://www.nytimes.com/2014/03/18/
science/space/detection-of-waves-in-space-buttresses-landmark-theory-of-big-bang.html

http://www.nytimes.com/2014/02/11/
science/space/the-archaeology-of-the-stars.html

 

http://www.nytimes.com/2013/11/19/
opinion/are-we-alone-in-the-universe.html

http://www.nytimes.com/2013/07/02/
science/space/timeless-questions-about-the-universe.html

 

 

 

 

cosmology        USA

http://www.npr.org/sections/13.7/2017/05/24/
529675773/what-does-an-expanding-universe-really-mean

 

 

 

 

cosmologists

— physicists that work on the properties of the universe        USA

http://www.npr.org/sections/13.7/2017/05/24/
529675773/what-does-an-expanding-universe-really-mean

 

 

 

 

expand

https://www.nytimes.com/2017/02/20/
science/hubble-constant-universe-expanding-speed.html

 

http://www.nytimes.com/2014/03/18/
science/space/detection-of-waves-in-space-buttresses-landmark-theory-of-big-bang.html

 

 

 

 

expanding universe        USA

http://www.npr.org/sections/13.7/2017/05/24/
529675773/what-does-an-expanding-universe-really-mean

https://www.nytimes.com/2017/02/20/
science/hubble-constant-universe-expanding-speed.html

 

 

 

 

expansion of the universe        USA

http://www.nytimes.com/2011/10/05/
science/space/05nobel.html

 

 

 

 

multiverse        UK / USA

https://www.nytimes.com/2018/02/07
/obituaries/joseph-polchinski-63-leading-theorist-on-multiple-universes-dies.html

https://www.npr.org/sections/13.7/2018/01/22/
579666359/scientific-theory-and-the-multiverse-madness

 

https://www.youtube.com/
watch?v=Rx7erWZ8TjA - The Economist, Aug. 15, 2015

 

 

 

 

in the outer cosmos        USA

http://www.nytimes.com/2013/04/19/science/space/
2-new-planets-are-most-earth-like-yet-scientists-say.html

 

 

 

 

hole        UK

http://www.theguardian.com/science/2015/apr/20/
astronomers-discover-largest-known-structure-in-the-universe-is-a-big-hole

 

 

 

 

Stephen Hawking        UK

https://www.theguardian.com/science/hawking

 

http://www.guardian.co.uk/science/2012/dec/10/
stephen-hawking-physics-prize

http://www.guardian.co.uk/science/2012/jan/08/
stephen-hawking-70-cambridge-speech

 

 

 

 

Stephen Hawking > universe        UK

http://www.guardian.co.uk/science/2010/sep/02/
stephen-hawking-big-bang-creator

 

 

 

 

timeline of the universe        UK

http://www.guardian.co.uk/science/2008/apr/26/
universe.physics

 

 

 

 

big bang / big-bang theory

http://www.npr.org/2016/12/30/
506734040/as-a-rough-year-ends-we-turn-to-the-cosmos-for-some-perspective

 

https://www.youtube.com/watch
?v=Rx7erWZ8TjA - The Economist, Aug. 14, 2015

 

http://www.theguardian.com/science/2014/mar/23/
primordial-gravitational-waves-tantalising-cosmic-birth-big-bang

http://www.nytimes.com/2014/03/18/
science/space/detection-of-waves-in-space-buttresses-landmark-theory-of-big-bang.html

http://www.theguardian.com/science/2014/mar/14/
gravitational-waves-big-bang-universe-bicep

http://www.nytimes.com/2014/02/11/
science/space/the-archaeology-of-the-stars.html

 

https://www.theguardian.com/science/2013/mar/21/
planck-telescope-light-big-bang-universe 

 

http://www.theguardian.com/science/2006/oct/03/
nobelprizes.highereducation 

 

http://www.usatoday.com/tech/science/space/2006-03-16-
big-bang-expansion_x.htm

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Kuiper belt        USA

 

https://solarsystem.nasa.gov/solar-system/kuiper-belt/overview/

 

 

https://www.npr.org/2019/01/01/
681414470/4-billion-miles-from-the-sun-a-spacecraft-sends-early-pictures-of-a-tiny-planet

 

 

 

 

https://www.npr.org/2018/12/31/
675722234/way-beyond-pluto-an-icy-world-is-ready-for-its-close-up

 

https://www.nytimes.com/2018/12/30/
science/nasa-new-horizons-kuiper-belt.html

 

https://www.nytimes.com/2018/08/29/
science/nasa-new-horizons.html

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 Gravitational waves:

discovery hailed as breakthrough of the century        11 February 2016

 

Scientists announce discovery

of clear gravitational wave signal,

ripples in spacetime

first predicted by Albert Einstein

https://www.theguardian.com/science/2016/feb/11/
gravitational-waves-discovery-hailed-as-breakthrough-of-the-century

 

 

 

 

 

LIGO Hears a Ripple in Space-Time

By DENNIS OVERBYE, JONATHAN CORUM and JASON DRAKEFORD | Feb. 11, 2016 | 4:36

 

About a hundred years ago,

Einstein predicted

the existence of gravitational waves,

but until now, they were undetectable.

http://www.nytimes.com/video/science/
100000004200661/what-are-gravitational-waves-ligo-black-holes.html

 

 

 

 

 

http://www.nytimes.com/2016/02/12/
science/ligo-gravitational-waves-black-holes-einstein.html

http://www.npr.org/sections/thetwo-way/2016/02/11/
466286219/in-milestone-scientists-detect-waves-in-space-time-as-black-holes-collide

http://www.npr.org/sections/13.7/2016/02/11/
466372736/growing-old-with-einstein-the-long-wait-for-detection-of-gravitational-waves

https://www.theguardian.com/science/2016/feb/11/
gravitational-waves-discovery-hailed-as-breakthrough-of-the-century

https://www.theguardian.com/science/2016/feb/09/
gravitational-waves-everything-you-need-to-know

https://www.theguardian.com/science/video/2016/feb/11/
gravitational-waves-discovery-changes-everything-video

 

 

 

 

big bang > Gravitational waves discovery        2014

http://www.theguardian.com/science/2014/mar/23/
primordial-gravitational-waves-tantalising-cosmic-birth-big-bang

http://www.theguardian.com/science/2014/mar/17/
gravitational-waves-bicep-inflation-big-bang

 

 

 

 

 

 

 

 

 

 

 

 

 

 

creation of the cosmos        USA

http://www.npr.org/sections/13.7/2015/09/09/
438630784/moving-from-creation-of-the-cosmos-to-human-life

 

 

 

 

big crunch        UK

https://www.youtube.com/watch?v=
Rx7erWZ8TjA - The Economist, Aug. 14, 2015

 

 

 

 

Big Rip        UK

https://www.youtube.com/watch?v=
Rx7erWZ8TjA - The Economist, Aug. 14, 2015

http://www.theguardian.com/science/2015/jul/02/
not-with-a-bang-but-with-a-big-rip-how-the-world-will-end

 

 

 

 

dark ages

 

 

 

 

cosmic microwave background radiation

 

 

 

 

the original blaze of creation

 

 

 

 

cosmos

 

 

 

 

cosmology

 

 

 

 

cosmic

 

 

 

 

 

 

 

 

 

 

 

 

 

 

space        UK

http://www.theguardian.com/technology/gallery/2014/jan/13/
universe-space-sun-2013-pictures

 

http://www.theguardian.com/science/2006/oct/19/
spaceexploration.usnews

 

 

 

 

space        USA

http://www.nytimes.com/2015/05/03/
books/review/beyond-our-future-in-space-by-chris-impey.html

 

 

 

 

The Guardian > Series > A month in space        UK

https://www.theguardian.com/science/series/space-monthly 

 

 

 

 

space odyssey        UK

http://www.guardian.co.uk/science/gallery/2012/oct/20/
voyager-mission-nasa-space-pictures

 

 

 

 

space odyssey        USA

http://www.theguardian.com/science/2015/mar/15/
voyager-1-and-2-space-journey-nasa

 

 

 

 

space market >  small satellites        USA

http://www.nytimes.com/2014/03/17/
technology/start-ups-aim-to-conquer-space-market.html

 

 

 

 

 

 

 

 

 

 

 

 

 

 

deep space        USA

http://www.npr.org/sections/thetwo-way/2017/02/15/
515261463/space-poop-problem-solvers-take-home-cash-prizes-from-nasa

 

 

 

 

outer space

 

 

 

 

outer space > Lyman-alpha blobs        USA

http://www.npr.org/2016/09/21/
494593614/astronomers-find-clues-in-the-case-of-the-glowing-space-blobs

 

 

 

 

far-off solar system        USA

https://www.npr.org/2018/10/03/
653666274/scientists-find-what-could-be-a-history-making-moon

 

 

 

 

spaceport        UK

http://www.theguardian.com/science/2005/apr/10/
spaceexploration.usnews1 

 

 

 

 

reach the edge of the solar system        UK

http://www.guardian.co.uk/science/2012/oct/21/
voyager-mission-leave-solar-system

 

 

 

 

the solar system’s outer reaches        USA

https://www.nytimes.com/2018/12/30/
science/nasa-new-horizons-kuiper-belt.html

 

 

 

 

craft

 

 

 

 

space plane > US X-37B        UK

http://www.guardian.co.uk/science/2010/dec/01/
space-vehicle-earth

 

 

 

 

space facility        UK

http://www.guardian.co.uk/science/2008/nov/26/
esa-space-facility-harwell-earth-observation

 

 

 

 

spacesuit        USA

http://www.npr.org/sections/thetwo-way/2017/02/15/
515261463/space-poop-problem-solvers-take-home-cash-prizes-from-nasa

 

 

 

 

space program        USA

http://www.nytimes.com/2010/02/09/
opinion/09tue1.html

 

 

 

 

space policy        USA

http://www.nytimes.com/2010/06/29/
science/space/29orbit.html

 

 

 

 

space travel        USA

http://www.nytimes.com/2015/05/03/
books/review/beyond-our-future-in-space-by-chris-impey.html

 

 

 

 

space fan

 

 

 

 

space obsessives

 

 

 

 

space race        UK

https://www.theguardian.com/science/audio/2019/may/07/
the-new-space-race

 

 

 

 

space elevator        UK

http://www.theguardian.com/science/2006/sep/03/
spaceexploration.theobserver

 

 

 

 

 

 

 

 

 

 

 

 

 

 

orbiting debris        UK

http://www.theguardian.com/science/2014/may/09/
space-debris-junk-gravity-congress

 

 

 

 

space debris        UK

http://www.theguardian.com/science/2014/mar/10/
australian-scientists-zap-debris-with-lasers

 

http://www.guardian.co.uk/science/across-the-universe/2013/may/13/
skylab-40th-anniversary-space-debris

 

http://www.guardian.co.uk/science/across-the-universe/2012/oct/04/
astronomy-space

 

 

 

 

space debris        USA

http://www.npr.org/sections/thetwo-way/2016/12/09/
505020386/japan-sends-long-electric-whip-into-orbit-to-tame-space-junk

 

http://www.npr.org/sections/thetwo-way/2015/12/30/
461482971/watch-the-stuff-weve-left-in-space

 

 

 

 

space junk        UK

http://www.theguardian.com/science/2014/may/09/
space-debris-junk-gravity-congress

 

 

 

 

space junk        USA

https://www.nytimes.com/2020/02/26/
science/mev-1-northrop-grumman-space-junk.html

 

http://www.npr.org/sections/thetwo-way/2016/12/09/
505020386/japan-sends-long-electric-whip-into-orbit-to-tame-space-junk

 

http://www.usatoday.com/tech/science/space/2006-01-19-
space-junk_x.htm

 

 

 

 

space trash        USA

http://www.usatoday.com/tech/science/space/2007-03-15-
spacejunk_N.htm

 

 

 

 

wayward satellites        USA

http://www.nytimes.com/2014/02/28/
us/dale-gardner-astronaut-who-helped-corral-wayward-satellites-dies-at-65.html

 

 

 

 

graveyard of space        USA

http://www.nytimes.com/2014/06/15/
science/space/calling-back-a-zombie-ship-from-the-graveyard-of-space.html

 

 

 

 

 

 

 

 

 

 

 

 

 

 

spacecraft        UK

http://www.theguardian.com/science/2015/mar/15/
voyager-1-and-2-space-journey-nasa

 

 

 

 

spacecraft (sing / plur)        USA

http://www.npr.org/2017/09/13/
550711289/saturns-strangest-sights-as-captured-by-a-doomed-spacecraft

http://www.npr.org/sections/thetwo-way/2017/05/25/
530002348/juno-spacecraft-reveals-spectacular-cyclones-at-jupiters-poles

 

http://www.nytimes.com/2015/01/20/
science/nasa-spacecraft-get-a-closer-look-at-pluto-and-ceres-whatever-they-may-be.html

 

http://www.nytimes.com/2014/11/15/
world/europe/spacecraft-on-comet-drills-for-data-as-its-power-fades.html

 

http://www.nytimes.com/2013/09/13/
science/in-a-breathtaking-first-nasa-craft-exits-the-solar-system.html

 

http://www.usatoday.com/tech/science/space/2008-05-25-
mars-lander_N.htm

 

 

 

 

spaceflight > solar sailing        USA

https://www.nytimes.com/2019/07/31/
science/lightsail-solar-sail.html

 

 

 

 

close in on N        USA

http://www.nytimes.com/2015/01/20/
science/nasa-spacecraft-get-a-closer-look-at-pluto-and-ceres-whatever-they-may-be.html

 

 

 

 

lander        UK

http://www.theguardian.com/science/2014/nov/14/
rosetta-philae-lander-hop-comet

 

 

 

 

spaceship        USA

http://www.nytimes.com/2014/03/02/world/europe/
valery-kubasov-79-dies-thawed-cold-war-in-space.html

 

 

 

 

unmanned spaceship

 

 

 

 

supply ship

 

 

 

 

mother ship / mothership        UK

http://www.theguardian.com/science/2003/dec/19/
spaceexploration.research1 

 

 

 

 

USA > NASA Voyager ships        UK

https://www.theguardian.com/science/2012/oct/21/
voyager-mission-leave-solar-system

https://www.theguardian.com/science/gallery/2012/oct/20/
voyager-mission-nasa-space-pictures 

 

 

 

 

Voyager 1 - launched in 1977

http://www.theguardian.com/science/2015/mar/15/
voyager-1-and-2-space-journey-nasa

 

http://www.theguardian.com/science/across-the-universe/2013/sep/13/
voyager-1-solar-system-great-explorers

http://www.nytimes.com/2013/09/13/
science/in-a-breathtaking-first-nasa-craft-exits-the-solar-system.html

http://www.theguardian.com/science/2013/sep/12/
voyager-1-leaves-solar-system

 

 

 

 

robot spacecraft

 

 

 

 

spacecraft / space probe

http://www.nytimes.com/2014/08/07/
science/space/spacecraft-pulls-alongside-comet.html

http://www.theguardian.com/science/2014/aug/05/
rosetta-spacecraft-rendezvous-rubber-duck-comet

 

http://www.theguardian.com/science/2013/nov/11/saturn-
cassini-photograph

http://www.nytimes.com/2013/09/13/
science/in-a-breathtaking-first-nasa-craft-exits-the-solar-system.html

 

http://www.usatoday.com/tech/science/space/2006-01-19-
new-horizons-launch_x.htm

 

https://www.theguardian.com/books/2003/nov/10/
science.scienceandnature 

https://www.theguardian.com/science/2003/dec/27/
spaceexploration.research

 

 

 

 

Supernova acceleration probe    Snap

 

SNAP,

the SuperNova/Acceleration Probe,

is an experiment designed

to learn the nature of dark energy

by precisely measuring

the expansion history of the universe.

 

At present scientists cannot say

whether dark energy has a constant value

or has changed over time,

or even whether dark energy is an illusion,

with accelerating expansion

being due to a gravitational anomaly instead.

https://science.jpl.nasa.gov/projects/SNAP/

 

https://science.jpl.nasa.gov/projects/SNAP/

 

 

 

 

the probe's

high-speed entry into the atmosphere

 

 

 

 

Mariner 2

 

Mariner 2 was the world's

first successful interplanetary

spacecraft.

 

Launched Aug. 27, 1962,

on an Atlas-Agena rocket,

Mariner 2 passed within

about 34,000 kilometers (21,000 miles)

of Venus,

sending back valuable new information

about interplanetary space

and the Venusian atmosphere.

 

Mariner 2 recorded

the planet's temperature

for the first time,

revealing its very hot atmosphere

of about 500 degrees Celsius

(900 degrees Fahrenheit).

 

The spacecraft's

solar wind experiment

was the first to measure

the density, velocity, composition

and variation over time of the solar wind.

https://www.nasa.gov/multimedia/imagegallery/image_feature_964.html 

 

 

 

 

11m radio dish

 

 

 

 

on-board spectograph

 

 

 

 

space capsule / NASA's Stardust spacecraft

https://stardustnext.jpl.nasa.gov/index.html 

 

 

http://www.usatoday.com/tech/science/space/2006-01-15-
stardust_x.htm

http://www.nytimes.com/2006/01/15/
science/space/15cnd-stardust.html

 

 

 

 

space capsule > privately funded SpaceX Dragon capsule        2012

http://www.guardian.co.uk/science/2012/may/31/
spacex-dragon-spacecraft-return-journey-earth

 

 

 

 

 

 

 

 

 

 

 

 

 

 

fly

 

 

 

 

flyby        USA

http://www.usatoday.com/tech/science/space/2006-01-11-
stardust-return_x.htm

 

 

 

 

flight

 

 

 

 

maiden flight

 

 

 

 

man spaceflight

 

 

 

 

space walk / spacewalk        USA

http://www.npr.org/sections/thetwo-way/2017/02/15/
515261463/space-poop-problem-solvers-take-home-cash-prizes-from-nasa

 

http://www.npr.org/2015/11/08/
454932716/what-it-s-like-to-walk-in-space

 

http://www.usatoday.com/tech/science/space/2007-02-04-
spacewalk_x.htm

 

http://www.usatoday.com/tech/science/space/2006-07-06-
discovery-shuttle_x.htm

 

 

 

 

spacewalker

 

 

 

 

take a space walk

 

 

 

 

height

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

moon        UK

http://www.guardian.co.uk/science/2013/jul/15/
neptune-moon-discovered

 

 

 

 

alien moons        USA

http://www.npr.org/sections/thetwo-way/2016/04/13/
473380087/hot-on-the-trail-of-alien-moons

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

planet        UK

 

https://www.theguardian.com/science/2016/may/10/
new-planets-discovered-nasa-kepler-space-telescope

 

 

 

 

 

 

 

minor planet        USA

 

https://www.npr.org/2018/12/31/
675722234/way-beyond-pluto-an-icy-world-is-ready-for-its-close-up

 

 

 

 

 

 

 

planetary system        UK

 

http://www.theguardian.com/science/2015/jan/27/
ancient-planetary-system-kepler-444-milky-way-galaxy

 

 

 

 

 

 

 

planetarium        USA

 

http://www.npr.org/sections/ed/2015/11/09/
444167132/a-galaxy-far-far-away-right-there-on-the-ceiling

 

 

 

 

 

 

 

 

 

 

 

 

 

 

at the boundary of Earth and space        USA

http://www.usatoday.com/tech/science/space/2006-10-26-
hubble-fate_x.htm

 

 

 

 

constellation        USA

http://www.nytimes.com/slideshow/2009/09/09/
science/0909HUBBLE_2.html

 

 

 

 

constellation of Libra

 

 

 

 

constellation > Centaurus        USA

http://www.nytimes.com/interactive/2016/08/24/
science/space/proxima-centauri-nearest-exoplanet.html

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Eyewitness

Centaurus constellation,

463m light years from Earth

G

pp. 20.21

Wednesday February 14 2007

http://digital.guardian.co.uk/guardian/2007/02/14/pdfs/gdn_070214_ber_20_15807114.pdf

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

quasar        USA

 

http://www.npr.org/sections/thetwo-way/2016/02/23/
467826553/solving-the-mystery-of-the-disappearing-quasar

 

http://www.usatoday.com/tech/science/space/2007-09-24-
hidden-galaxies_N.htm

 

 

 

 

 

 

 

 

 

 

 

 

 

 

physicist        UK

http://www.guardian.co.uk/science/2013/apr/03/
dark-matter-space-station-physics

 

 

 

 

Albert Einstein    1879-1955        UK

https://www.theguardian.com/theguardian/1955/apr/19/
fromthearchive

 

 

 

 

theory

 

 

 

 

quantum mechanics

 

 

 

 

infrared light

 

 

 

 

 

 

 

 

 

Studies of Universe’s Expansion

Win Physics Nobel

 

October 4, 2011

The New York Times

By DENNIS OVERBYE

 

Three astronomers won the Nobel prize on Tuesday for discovering that the universe is apparently being blown apart by a mysterious force that cosmologists now call dark energy. They are Saul Perlmutter of the Lawrence Berkeley National Laboratory in Berkeley, Calif., Brian P. Schmidt of the Australian National University in Weston Creek, Australia, and Adam G. Riess of the Space Telescope Science Institute and Johns Hopkins University in Baltimore.

They were the leaders of two competing teams of astronomers who were trying to use the exploding stars known as Type 1a supernovae as cosmic lighthouses to measure the expansion of the universe. They were hoping to measure how fast the universe, which has been expanding since its fiery birth in the Big Bang 14 billion years ago, was slowing down, and thus to find out if its ultimate fate was to fall back together in what is called a Big Crunch or not. Instead, they reported in 1998, it was inexplicably speeding up, a conclusion that nobody would have accepted if not for the fact that both groups wound up with the same answer.

At the time, “We were a little scared,” Dr. Schmidt said. Subsequent cosmological measurements have confirmed that roughly 70 percent of the universe by mass or energy consists of this antigravitational dark energy.

The most likely explanation for this bizarre behavior is a fudge factor Albert Einstein introduced into his equations in 1917 to stabilize he universe against collapse and then abandoned as his greatest blunder. “Every test we have made has come out perfectly in line with Einstein’s original cosmological constant in 1917,” Dr. Schmidt said.

Quantum theory predicts that empty space should exert a repulsive force, like dark energy, but one that is 10 to the 120th power times stronger than what the astronomers have measured, leaving some physicists mumbling about multiple universes.

Lawrence M. Krauss, a cosmologist at Arizona State University said, “The discovery that the universe is dominated by the energy of empty space has changed everything in cosmology. Nothing could, literally, not be more exciting, because now we know nothing is almost everything!”

In the years since then the three astronomers have shared a number of awards.

Dr. Perlmutter, who led the Supernova Cosmology Project out of Berkeley, will get half of the prize of 10 million Swedish kronor ($1.4 million). The other half will go to Dr. Schmidt, leader of the rival High-Z Supernova Search Team, and Dr. Riess, who was the lead author of the 1998 paper in The Astronomical Journal, in which the dark energy result was first published. They will get their prizes in Stockholm on Dec. 10.

 

 

This article has been revised

to reflect the following correction:

Correction: October 4, 2011

An earlier version of this article

incorrectly stated the publication

in which Adam G. Riess's 1998 paper

on dark energy appeared.

It was The Astronomical Journal, not Science.

The article also stated incorrectly

the amount of the prize.

It is 10 million Swedish kronor ($1.4 million).

Studies of Universe’s Expansion Win Physics Nobel,
NYT,
4.10.2011,
http://www.nytimes.com/2011/10/05/
science/space/05nobel.html

 

 

 

 

 

A Whisper, Perhaps,

From the Universe’s Dark Side

 

November 25, 2008

The New York Times

By DENNIS OVERBYE

 

Is this the dark side speaking?

A concatenation of puzzling results from an alphabet soup of satellites and experiments has led a growing number of astronomers and physicists to suspect that they are getting signals from a shadow universe of dark matter that makes up a quarter of creation but has eluded direct detection until now.

Maybe.

“Nobody really knows what’s going on,” said Gordon Kane, a theorist at the University of Michigan. Physicists caution that there could still be a relatively simple astronomical explanation for the recent observations.

But the nature of this dark matter is one of the burning issues of science. Identifying it would point the way to a deeper understanding of the laws of nature and the Einsteinian dream of a unified theory of physics.

The last few weeks have seen a blizzard of papers trying to explain the observations in terms of things like “minimal dark matter” or “exciting dark matter,” or “hidden valley” theory, and to suggest how to look for them in particle accelerators like the Large Hadron Collider, set to begin operation again outside Geneva next summer.

“It could be deliriously exciting, an incredibly cool story,” said Nima Arkani-Hamed of the Institute for Advanced Study in Princeton, N.J., who has been churning out papers with his colleagues. “Anomalies in the sky tell you what to look for in the collider.”

On Thursday, a team of astrophysicists working on one of the experiments reported in the journal Nature that a cosmic ray detector onboard a balloon flying around the South Pole had recorded an excess number of high-energy electrons and their antimatter opposites, positrons, sailing through local space.

The particles, they conceded, could have been created by a previously undiscovered pulsar, the magnetized spinning remnant of a supernova explosion, blasting nearby space with electric and magnetic fields. But, they say, a better and more enticing explanation for the excess is that the particles are being spit out of the fireballs created by dark matter particles colliding and annihilating one another in space.

“We cannot disprove that the signal could come from an astrophysical object. We also cannot eliminate a dark matter annihilation explanation based upon current data,” said John P. Wefel of Louisiana State University, the leader of the team, adding, “Whichever way it goes, for us it is exciting.”

The results came on the heels of a report earlier this fall from Pamela, a satellite built by Italian, German, Russian and Swedish scientists to study cosmic rays. Pamela scientists reported in talks and a paper posted on the Internet that the satellite had recorded an excess of high-energy positrons. This, they said, “may constitute the first indirect evidence of dark matter particle annihilations,” or a nearby pulsar.

Antimatter is rare in the universe, and so looking for it is a good way of hunting for exotic phenomena like dark matter.

Another indication that something funny is happening on the dark side of the universe is evident in maps of the cosmic background radiation left over from the Big Bang. Those maps, produced most recently this year by the Wilkinson Microwave Anisotropy Probe satellite, show a haze of what seem to be charged particles hovering around the Milky Way galaxy, according to an analysis by Douglas Finkbeiner of the Harvard-Smithsonian Center for Astrophysics.

Adding to the mix and mystery, the European Space Agency’s Integral satellite detected gamma rays emanating from the center of the Milky Way, suggesting the presence of positrons there, but with much lower energies than Pamela and Dr. Wefel’s experiments have seen.

What all this adds up to, or indeed whether it all adds up to anything at all, depends on which observations you trust and your theoretical presumptions about particle physics and the nature of dark matter. Moreover, efforts to calculate the background level of high-energy particles in the galaxy are beset with messy uncertainties. “The dark matter signal is easy to calculate,” Dr. Kane said. “The background is much harder.”

Dark matter has teased and obsessed astronomers since the 1930s, when the Caltech astronomer Fritz Zwicky deduced that some invisible “missing mass” was required to supply the gravitational glue to hold clusters of galaxies together. The idea became respectable in the 1970s when Vera C. Rubin of the Carnegie Institution of Washington and her collaborators found from studying the motions of stars that most galaxies seemed to be surrounded by halos of dark matter.

The stakes for dark matter go beyond cosmology. The most favored candidates for its identity come from a theory called supersymmetry, which unifies three of the four known forces of nature mathematically and posits the existence of a realm of as-yet-undiscovered particles. They would be so-called wimps — weakly interacting massive particles — which feel gravity and little else, and could drift through the Earth like wind through a screen door. Such particles left over from the Big Bang could form a shadow universe clumping together into dark clouds that then attract ordinary matter.

The discovery of a supersymmetric particle would also be a boost for string theory, the controversial “theory of everything,” and would explicate the nature of a quarter of the universe. But until now, the dark matter particles have mostly eluded direct detection in the laboratory, the exception being a controversial underground experiment called Dama/Libra, for Dark Matter/Large Sodium Iodide Bulk for Rare Processes, under the Italian Alps, where scientists claimed in April to have seen a seasonal effect of a “dark matter wind” as the Earth goes around its orbit.

The sky could be a different story. Dark matter particles floating in the halos around galaxies would occasionally collide and annihilate one another in tiny fireballs of radiation and lighter particles, theorists say.

Dr. Wefel and his colleagues have been chasing sparks in the sky since 2000, when they flew an instrument known as ATIC, for Advanced Thin Ionization Calorimeter, around Antarctica on a balloon at an altitude of 23 miles, looking for high-energy particles known as cosmic rays raining from space.

In all they have made three flights, requiring them to spend the winter at the National Science Foundation’s McMurdo Station, which Dr. Wefel described as very pleasant. “It’s not bad until a storm moves in. You put your hand out till you can’t see it. Then you go out and start shoveling snow,” he explained.

The Nature paper includes data from the first two balloon flights. It shows a bump, over theoretical calculations of cosmic ray intensities, at energies of 500 billion to 800 billion electron volts, a measure of both energy and mass in physics. One way to explain that energy bump would be by the disintegration or annihilation of a very massive dark particle. A proton by comparison is about one billion electron volts.

Dr. Wefel noted, however, that according to most models, a pulsar could generate particles with even more energy, up to trillions of volts, whereas the bump in the ATIC data seems to fall off at around 800 billion electron volts. The ATIC results, he said, dovetail nicely with those from Pamela, which recorded a rising number of positrons relative to electrons, but only up to energies of about 200 billion electron volts.

Reached in China, where he was attending a workshop, Neal Weiner of New York University, who is working with Dr. Arkani-Hamed on dark matter models, said he was plotting ATIC data gleaned from the Web and Pamela data on the same graph to see how they fit, which was apparently very well.

But Piergiorgio Picozza, a professor at the University of Rome and the Pamela spokesman, said in an e-mail message that it was too soon to say the experiments agreed. That will depend on more data now being analyzed to learn whether Pamela continues to see more positrons as the energy rises.

Moreover, as Dr. Kane pointed out, Pamela carries a magnet that allows it to distinguish electrons from positrons — being oppositely charged, they bend in opposite directions going through the magnetic field. But the ATIC instrument did not include a magnet and so cannot be sure that it was seeing any positrons at all: no antimatter, no exotic dark matter, at least at those high energies.

But if he is right, Dr. Wefel said that the ATIC data favored something even more exotic than supersymmetry, namely a particle that is lost in the fifth dimension. String theory predicts that there are at least six dimensions beyond our simple grasp, wrapped up so tightly we cannot see them or park in them. A particle in one of these dimensions would not appear to us directly.

You could think of it as a hamster running around on a wheel in its cage. We cannot see the hamster or the cage, but we can sort of feel the impact of the hamster running; according to Einsteinian relativity, its momentum in the extra dimension would register as mass in our own space-time.

Such particles are called Kaluza-Klein particles, after Theodor Kaluza and Oscar Klein, theorists who suggested such an extra-dimensional framework in the 1920s to unify Einstein’s general theory of relativity and electromagnetism.

Dr. Wefel’s particle would have a mass of around 620 billion electron volts. “That’s the one that seems to fit the best,” he said in an interview. The emergence of a sharp edge in the data, he said, “would be a smoking gun” for such a strange particle.

But Dr. Arkani-Hamed said that Kaluza-Klein particles would not annihilate one another at a fast enough rate to explain the strength of the ATIC signal, nor other anomalies like the microwave haze. He and his colleagues, including Dr. Weiner, Dr. Finkbeiner and Tracy Slatyer, also of Harvard, drawing on work by Matthew Strassler of Rutgers, have tried to connect all the dots with a new brand of dark matter, in which there are not only dark particles but also a “dark force” between them.

That theory was called “a delightful castle in the sky” by Dr. Kane, who said he was glad it kept Dr. Arkani-Hamed and his colleagues busy and diverted them from competing with him. Dr. Kane and his colleagues favor a 200 billion-electron-volt supersymmetric particle known as a wino as the dark matter culprit, in which case the Pamela bump would not extend to higher energies.

Dr. Wefel said he had not kept up with all the theorizing. “I’m just waiting for one of these modelers to say here is the data, here is the model,” he said. “Fit it out. I’m not sure I’ve seen it yet.”

Dr. Picozza said that it was the job of theorists to come up with models and that they were proliferating.

“At the end of the story only one will be accepted from the scientific community, but now it is too early,” he said in an e-mail message.

Sorting all this out will take time, but not forever.

Pamela is expected to come out with new results next year, and the first results from the Fermi Gamma-ray Space Telescope, launched last summer, should also be out soon. Not to mention the Large Hadron Collider, which will eventually smash together protons of seven million electron volts. It is supposed to be running next summer.

“With so many experiments, we will soon know so much more about all of this,” Dr. Weiner said. “In a year or two, we’ll either not be talking about this idea at all, or it will be all we’re talking about.”

A Whisper, Perhaps, From the Universe’s Dark Side,
NYT,
25.11.2008,
http://www.nytimes.com/2008/11/25/science/25dark.html

 

 

 

 

 

How Did the Universe

Survive the Big Bang?

In This Experiment,

Clues Remain Elusive

 

April 12, 2007

The New York Times

By KENNETH CHANG

 

An experiment that some hoped would reveal a new class of subatomic particles, and perhaps even point to clues about why the universe exists at all, has instead produced a first round of results that are mysteriously inconclusive.

“It’s intellectually interesting what we got,” said Janet M. Conrad, professor of physics at Columbia University and a spokeswoman for a collaboration that involves 77 scientists at 17 institutions. “We have to figure out what it is.”

Dr. Conrad and William C. Louis, a physicist at Los Alamos National Laboratory, presented their initial findings in a talk yesterday at the Fermi National Accelerator Laboratory, outside Chicago, where the experiment is being performed.

The goal was to confirm or refute observations made in the 1990s in a Los Alamos experiment that observed transformations in the evanescent but bountiful particles known as neutrinos. Neutrinos have no electrical charge and almost no mass, but there are so many of them that they could collectively outweigh all the stars in the universe.

Although many physicists remain skeptical about the Los Alamos findings, the new experiment has attracted wide interest. The Fermilab auditorium was filled with about 800 people, and talks were given at the 16 additional institutions by other collaborating scientists. That reflected in part the hope of finding cracks in the Standard Model, which encapsulates physicists’ current knowledge about fundamental particles and forces.

The Standard Model has proved remarkably effective and accurate, but it cannot answer some fundamental questions, like why the universe did not completely annihilate itself an instant after the Big Bang.

The birth of the universe 13.7 billion years ago created equal amounts of matter and antimatter. Since matter and antimatter annihilate each other when they come in contact, that would have left nothing to coalesce into stars and galaxies. There must be some imbalance in the laws of physics that led to a slight preponderance of matter over antimatter, and that extra bit of matter formed everything in the visible universe.

The imbalance, some physicists believe, may be hiding in the dynamics of neutrinos.

Neutrinos come in three known types, or flavors. And they can change flavor as they travel, a process that can occur only because of the smidgen of mass they carry. But the neutrino transformations reported in the Los Alamos data do not fit the three-flavor model, suggesting four flavors of neutrinos, if not more. Other data, from experiments elsewhere, have said the additional neutrinos would have to be “sterile” — completely oblivious to the rest of the universe except for gravity.

The new experiment is called MiniBooNE. (BooNE, pronounced boon, is a contraction of Booster Neutrino Experiment. “Booster” refers to a Fermilab booster ring that accelerates protons, and “mini” was added because of plans for a second, larger stage to the research.)

MiniBooNE sought to count the number of times one flavor of neutrino, called a muon, turned into another flavor, an electron neutrino. The experiment slams a beam of protons into a piece of beryllium, and the cascade of particles from the subatomic wreckage includes muon neutrinos that fly about 1,650 feet to a detection chamber, a tank 40 feet in diameter that contains 250,000 gallons of mineral oil.

Most of the neutrinos fly through unscathed, but occasionally a neutrino crashes into a carbon atom in the mineral oil. That sets off another cascade of particles, which is detected by 1,280 light detectors mounted on the inside of the tank.

From the pattern of the cascades, the physicists could distinguish whether the incoming neutrino was of muon flavor or electron. To minimize the chances of fooling themselves, they deliberately did not look at any of the electron neutrino events until they felt they had adequately understood the much more common muon neutrino events. They finally “opened the box” on their electron neutrino data on March 26 and began the analysis leading to their announcement yesterday.

For most of the neutrino energy range they looked at, they did not see any more electron neutrinos than would be predicted by the Standard Model. That ruled out the simplest ways of interpreting the Los Alamos neutrino data, Dr. Conrad and Dr. Louis said.

But at the lower energies, the scientists did see more electron neutrinos than predicted: 369, rather than the predicted 273. That may simply mean that some calculations are off. Or it could point to a subtler interplay of particles, known and unknown.

“It’s tantalizing,” said Boris Kayser, a Fermilab physicist not on the MiniBooNE project. “It could be real. But this remains to be established.”

Dr. Louis said he was surprised by the results. “I was sort of expecting a clear excess or no excess,” he said. “In a sense, we got both.”

    How Did the Universe Survive the Big Bang? In This Experiment,
    Clues Remain Elusive, NYT, 12.4.2007,
    http://www.nytimes.com/2007/04/12/science/12neutrino.html

 

 

 

 

 

The universe gives up

its deepest secret

It is the invisible material
that makes up most of the cosmos.
Now, scientists have created
the first image of dark matter

 

Published: 08 January 2007
The Independent
By Steve Connor, Science Editor
 

 

One of the greatest mysteries of the universe is about to be unravelled with the first detailed, three-dimensional map of dark matter - the invisible material that makes up most of the cosmos.

Astronomers announced yesterday that they have achieved the apparently impossible task of creating a picture of something that has defied every attempt to detect it since its existence was first postulated in 1933.

Scientists have known for many years that there is more to the universe than can be seen or detected through their telescopes but it is only now that they have been able to capture the first significant 3D-image of this otherwise invisible material.

Unlike the ordinary matter of the planets, stars and galaxies, which can be seen through telescopes or detected by scientific instruments, nobody has seen dark matter or knows what it is made of, though calculations suggest that it is at least six times bigger than the rest of the visible universe combined.

A team of 70 astronomers from Europe, America and Japan used the Hubble space telescope to build up a picture of dark matter in a vast region of space where some of the galaxies date back to half the age of the universe - nearly 7 billion years.

They used a phenomenon known as gravitational lensing, first predicted by Albert Einstein, to investigate an area of the sky nine times the size of a full moon. Gravitational lensing occurs when light from distant galaxies is bent by the gravitational influence of any matter that it passes on its journey through space.

The scientists were able to exploit the technique by collecting the distorted light from half a million faraway galaxies to reconstruct some of the missing mass of the universe which is otherwise invisible to conventional telescopes.

"We have, for the first time, mapped the large-scale distribution of dark matter in the universe," said Richard Massey of the California Institute of Technology in Pasadena, one of the lead scientists in the team. "Dark matter is a mysterious and invisible form of matter, about which we know very little, yet it dominates the mass of the universe."

One of the most important discoveries to emerge from the study is that dark matter appears to form an invisible scaffold or skeleton around which the visible universe has formed.

Although cosmologists have theorised that this would be the case, the findings are dramatic proof that their calculations are correct and that, without dark matter, the known universe that we can see would not be able to exist.

"A filamentary web of dark matter is threaded through the entire universe, and acts as scaffolding within which the ordinary matter - including stars, galaxies and planets - can later be built," Dr Massey said. "The most surprising aspect of our map is how unsurprising it is. Overall, we seem to understand really well what happens during the formation of structure and the evolution of the universe," he said.

The three-dimensional map of dark matter was built up by taking slices through different regions of space much like a medical CT scanner build a 3-D image of the body by taking different X-ray "slices" in two dimensions.

Data from the Hubble telescope was supplemented by measurements from telescopes on the ground, such as the Very Large Telescope of the European Southern Observatory in Chile and the Japanese Subaru telescope in Hawaii.

Details of the dark matter map were released yesterday at the annual meeting of the American Astronomical Society in Seattle and published online by the journal Nature. The map stretches half way back to the beginning of the universe and shows that dark matter has formed into "clumps" as it collapsed under gravity. Other matter then grouped around these clumps to form the visible stars, galaxies and planets.

"The 3-D information is vital to studying the evolution of the structures over cosmic time," said Jason Rhodes of the Jet Propulsion Laboratory in Pasadena.

Astronomers have compared the task of detecting dark matter to the difficulty of photographing a city at night from the air when only street lights are visible.

Scientists said the new images were equivalent to seeing a city, its suburbs and country roads in daylight for the first time. Major arteries and intersections become evident and a variety of neighbourhoods are revealed.

"Now that we have begun to map out where dark matter is, the next challenge is to determine what it is, and specifically its relationship to normal matter," Dr Massey said. "We have answered the first question about where the dark matter it, but the ultimate goal will be to determine what it is."

Various experiments on Earth are under way to try to find out what dark matter is made of. One theory is that it is composed of mysterious sub-atomic particles that are difficult to detect because they do not interact with ordinary matter and so cannot be picked up and identified by conventional scientific instruments. Comparing the maps of visible matter and dark matter have already pointed to anomalies that could prove critical to the understanding of what constitutes dark matter.

    The universe gives up its deepest secret, I, 8.1.2007,
    http://news.independent.co.uk/world/
    science_technology/article2134891.ece

 

 

 

 

 

Steve Connor:

The mystery that has endured

since Big Bang

 

Published: 08 January 2007
The Independent

 

For anyone who has been mesmerised by the sheer number of stars that make up a clear night sky, it seems incredible that what we can see, even with a telescope, is but a small fraction of what is actually out there. In fact, more than 80 per cent of the material of the universe is invisible to even the best instruments.

It is called "dark" matter because, unlike the "bright" matter of the visible stars, galaxies and planets, it is invisible, even though its gravitational presence can be felt. What dark matter is made of, however remains a mystery.

Fritz Zwicky, a Swiss astronomer, was the first to postulate the existence of dark matter in 1933 when he observed clusters of galaxies beyond our own Milky Way. Zwicky said that these distant galaxies were moving too fast to be held together by the gravity of the visible stars they contain.

Confirmation of Zwicky's idea came in the 1970s when astronomers measured the speed at which stars moved inside and on the outer edges of galactic discs. To their surprise, the outer stars were travelling just as fast as the inner stars. Gravitational theory suggested that the outermost stars should be travelling more slowly.

The only reasonable explanation was that each galaxy had up to 10 times more mass than could be seen. This extra material was creating the additional gravity that kept the outer stars from slowing down.

The latest findings from the Hubble space telescope, released at the American Astronomical Society in Seattle yesterday, suggest that dark matter forms an invisible "scaffold" around which the ordinary matter of the stars and galaxies have formed. The map of dark matter has been likened to a three-dimensional X-ray of the skeleton on which the "flesh" of the visible universe is hung.

Knowing the whereabouts of the dark matter is critical to understanding how galaxies formed and how they began to accumulate into clusters over the 13.7 billion years since the Big Bang.

Critically, comparing the distribution maps of bright and dark matter may point to important differences between them. Several experiments on Earth are designed to capture the elusive subatomic particles that may account for the missing mass.

Many scientists now feel that we are on the verge of discovering what it is that has formed such an immense part of the universe.

Steve Connor: The mystery that has endured since Big Bang,
I,
8.1.2007,
http://comment.independent.co.uk/commentators/article2134892.ece

 

 

 

 

 

9 Billion-Year-Old ‘Dark Energy’

Reported

 

November 17, 2006

The New York Times

By DENNIS OVERBYE

 

A strange thing happened to the universe five billion years ago. As if God had turned on an antigravity machine, the expansion of the cosmos speeded up, and galaxies began moving away from one another at an ever faster pace.

Now a group of astronomers using the Hubble Space Telescope have discovered that billions of years before this mysterious antigravity overcame cosmic gravity and sent the galaxies scooting apart like muscle cars departing a tollbooth, it was already present in space, affecting the evolution of the cosmos.

“We see it doing its thing, starting to fight against ordinary gravity,” Adam Riess of the Space Telescope Science Institute said about the antigravity force, known as dark energy. He is the leader of a team of “dark energy prospectors,” as he calls them, who peered back nine billion years with the Hubble and were able to discern the nascent effects of antigravity. The group reported their observations at a news conference yesterday and in a paper to be published in The Astrophysical Journal.

The results, Dr. Riess and others said, provide clues and place new limits on the nature of dark energy, a mystery that has thrown physics and cosmology into turmoil over the last decade.

“It gives us the ability to look at changes in dark energy,” he said in an interview. “Previously, we knew nothing about that. That’s really exciting.”

The data suggest that, in fact, dark energy has changed little, if at all, over the course of cosmic history. Though hardly conclusive, that finding lends more support to what has become the conventional theory, that the source of cosmic antigravity is the cosmological constant, a sort of fudge factor that Einstein inserted into his cosmological equations in 1917 to represent a cosmic repulsion embedded in space.

Although Einstein later abandoned the cosmological constant, calling it a blunder, it would not go away. It is the one theorized form of dark energy that does not change with time.

Sean Carroll, a cosmologist at the California Institute of Technology who was not on the team, said: “Had they found the evolution was not constant, that would have been an incredibly earthshaking discovery. They looked where no one had been able to look before.”

The paper by Dr. Riess and his colleagues represents a sort of progress report from the dark side, where astrophysicists have found themselves more and more as they try to understand what is happening to the universe.

This encounter with the invisible began eight years ago, when two competing teams of astronomers were using exploding stars known as Type 1a supernovas as cosmic distance markers to determine the fate of the universe.

Ever since the Big Bang 14 billion years ago, the galaxies and the rest of the universe have been flying apart like a handful of pebbles tossed in the air. Astronomers reasoned that gravity would be slowing the expansion, and the teams were trying to find out by how much and, thus, determine whether all would collapse one day into a “big crunch” or expand forever.

Instead, to their surprise, the two teams, one led by Saul Perlmutter of the University of California, Berkeley, and the other by Brian Schmidt of the Mount Stromlo and Siding Spring Observatories in Australia, found that the universe was speeding up instead of slowing down.

But the ground-based telescopes that the two teams used could track supernovas to distances of just seven billion light-years, corresponding to half the age of the universe, and the effect could have been mimicked by dust or a slight change in the nature of the supernova explosions.

Since then, Dr. Riess, who was a member of Dr. Schmidt’s team, and his colleagues have used the Hubble telescope to prospect for supernovas and dark energy farther out in space or back in time.

The new results are based on observations of 23 supernovas that are more than eight billion years in the past, before dark energy came to dominate the cosmos. The spectra of those distant supernovas, Dr. Riess reported, appear to be identical to those closer and more recent examples. By combining the supernova results with data from other experiments like the NASA Wilkinson Microwave Anisotropy Probe, Dr. Riess and his colleagues could begin to address the evolution of dark energy.

“That’s one of the $64,000 questions,” he said. “Is dark energy changing?”

So far, he said, the results are consistent with the cosmological constant, but other answers are also possible. The possibility that it is the cosmological constant is a mixed blessing. Physicists concede that they do not understand it.

Dr. Carroll of Caltech said, “Dark energy makes us nervous.”

Einstein invented his constant to explain why the universe does not collapse. After he abandoned it, the theory was resuscitated by quantum mechanics, which showed that empty space should be bubbling with staggering amounts of repulsive energy. The possibility that it really exists in the tiny amounts measured by the astronomers has flummoxed physicists and string theorists.

Because it is a property of empty space, the overall force of Einstein’s constant grows in proportion as the universe expands, until it overwhelms everything. Other theories of dark energy like strange force fields called quintessence or modifications to Einstein’s theory of gravity can change in more complicated ways, rising, falling or reversing effects.

Astronomers characterize the versions of dark energy by their so-called equation of state, the ratio of pressure to density, denoted by the letter w. For the cosmological constant, w is minus one.

Dr. Riess and his group used their data to make the first crude measurement of this quantity as it stood nine billion years ago. The answer, he said, was minus one — the magic number — plus or minus about 50 percent. By comparison for more recent times, with many more supernovas observable and thus more data, the value is minus one with an uncertainty of about 10 percent.

“If at one point in history it’s not minus one,” Dr. Riess said, “then we have killed the very best explanation.”

Getting to the precision needed to kill or confirm Einstein’s constant, however, will be very difficult, he conceded. One of the biggest sources of uncertainty is the fact that the Type 1a explosions are not completely uniform, introducing scatter into the observations.

The Hubble is the sole telescope that can pursue supernova explosions deeply enough to chart the early days of dark energy. The recent announcement that the National Aeronautics and Space Administration will send astronauts to maintain and refurbish the Hubble once again, enabling it to keep performing well into the next decade, is a lift for Dr. Riess’s project. A new camera could extend observations to 11 billion or 12 billion years back.

9 Billion-Year-Old ‘Dark Energy’ Reported,
NYT,
17.11.2006,
http://www.nytimes.com/2006/11/17/science/space/17dark.html

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

New York Times (1857-Current file); Dec 17, 1965;

ProQuest Historical Newspapers The New York Times (1851 - 2003)

pg. 1

http://graphics8.nytimes.com/packages/pdf/science/schirragemini.pdf

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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