Astrophysicist Estimates Diameter Of The Universe

The diameter of the Universe has been estimated at 156 billion light years by astrophysicist Neil Cornish (Montanna State University). The results were published in Physical Review Letters last week.


The estimate was reached by estimating both the time that light has been traveling from the most distant galaxies we can see, and then factoring in the expansion of the space in between galaxies that has happened since the Big Bang.

How can the most distant galaxies be both 13.7 billion years old, and yet 156 billion light-years apart? Did they travel faster than light? Space.com asked Neil Cornish:

"The problem is that funny things happen in general relativity which appear to violate special relativity (nothing traveling faster than the speed of light and all that).
"Let's go back to Hubble's observation that distant galaxies appear to be moving away from us, and the more distant the galaxy, the faster it appears to move away. The constant of proportionality in that relationship is known as Hubble's constant.
"One seemingly paradoxical consequence of Hubble's observation is that galaxies sufficiently far away will be receding from us at a velocity faster than the speed of light. This distance is called the Hubble radius, and is commonly referred to as the horizon in analogy with a black hole horizon.
"In terms of special relativity, Hubble's law appears to be a paradox. But in general relativity we interpret the apparent recession as being due to space expanding (the old raisins in a rising fruit loaf analogy). The galaxies themselves are not moving through space (at least not very much), but the space itself is growing so they appear to be moving apart. There is nothing in special or general relativity to prevent this apparent velocity from exceeding the speed of light. No faster-than-light signals can be sent via this mechanism, and it does not lead to any paradoxes."

For more information, see Universe Measured: We're 156 Billion Light-Years Wide!; reference from KurzweilAI.net.

Scroll down for more stories in the same category. (Story submitted 5/25/2004)

Follow this kind of news @Technovelgy.

| Email | RSS | Blog It | Stumble | del.icio.us | Digg | Reddit |

Would you like to contribute a story tip? It's easy:
Get the URL of the story, and the related sf author, and add it here.

Comment/Join discussion ( 7 )

Related News Stories - (" Misc ")

Is There A Subterranean Ocean?
'A vast, limitless expanse of water, the end of a lake if not of an ocean, spread before us, until it was lost in the distance.'- Jules Verne, 1864.

The Robotic Shopping Cart Of The Future
'...the machine would carry his bag in its soft plastic jaws and follow him as faithfully as a well-trained hound.'- John Brunner, 1975.

Arctic Resource Jackpot An Old Wish
By inducing climate change, new resources are revealed.

Marie Curie's Papers Still Radioactive
And the half-life of radium's most common isotope is 1,601 years.

 

Google
  Web TechNovelgy.com   

Technovelgy (that's tech-novel-gee!) is devoted to the creative science inventions and ideas of sf authors. Look for the Invention Category that interests you, the Glossary, the Invention Timeline, or see what's New.

 

 

 

 

 

Current News

3D Printed Artificial Muscles Are Stronger Than Yours
Bots don't need to work out.

Fog Computing (AKA Edge Computing) Ad Hoc Networks
'The tiny devices chirped their impulse codes at one another...'

Dubai Scorpion Police Hoverbike Ready To Pull Young Kirk Over
'Is there a problem, officer?'

HEXA Robotic Help For Plants
Then some unknown race had chanced upon the dreamers and decided to "help them out."

Korean Tesla Model S Video 'Excelsior' Is Indeed Our Motto
'Improving man by bringing him close to Nature, while they combine the sensations of coasting with the interest of seeing the country well...'

DIY Robot Shoots You In The Face
'...there were automatic guns that fired ligamine darts.'

A Bayesian Approach to Safe Imitation Learning For AIs and Robots
Um, how about that pension for the humans who serve as the models for robot behavior?

Qoobo Headless Robotic Therapy Cat Was Anne McCaffrey's Idea
'...used as surrogates in intense dependency cases.'

Autonomous Cars Talk To Each Other At MCity
'My cars talk to one another.'

PUFFER Robots - From Philip K DIck's Second Variety?
'Across the ground something small and metallic came, flashing in the dull sunlight of midday.'

Russian Space Garden
'We saw the gardens, flooded with artificial sunlight...'

Targeted Neuroplasticity Training For 'Downloading Skills'
'I know kung-fu.'

U of M's MCity To Feature Asimov's Automatobuses
Should you turn autonomous buses off?

Crazyflie Drone Swarm Technology
'...Programmed to hang in space in a hexagonal grid pattern.'

Our GodBot, Who Art In Cyberspace
Vaal hungers! We must serve him.

easyJet Short-Haul Electric Jets
Have a little faith, will you? They're working on it.

More SF in the News Stories

More Beyond Technovelgy science news stories

Home | Glossary | Invention Timeline | Category | New | Contact Us | FAQ | Advertise |
Technovelgy.com - where science meets fiction™

Copyright© Technovelgy LLC; all rights reserved.