Social Media Sidebar


Please sign up, comment on articles and bring your friends!

Current poll

PlanetTech is asking:

What do you think about our new web site?

Love it, indeed
Really good solution
Same as old one
The old one was better
This is a new option

Quote of the day

People say we're running out of energy. That's only true if we stick with these old 19th century technologies. We are awash in energy from sunlight.


Ray Kurzweil


Hubble Telescope clocks a faster rate of cosmic expansion

Posted in Science on 3rd Jun, 2016 11:28 PM by AlexMuller
The assessment comes from the Hubble Space Telescope, which has significantly refined the rate at which nearby galaxies are observed to be moving from each other. It reinforces the tension between what we see happening locally and what we would expect from the conditions that existed in the early cosmos.
These have implied a much more sedate trajectory for the recession. Science now has a big job on its hands to try to resolve the conundrum, says Adam Riess from the Space Telescope Science Institute (STScI) and the Johns Hopkins University, both in Baltimore, Maryland, US.
"To be honest, with this latest measurement we've really gone beyond what we might call 'tension'; we're missing something in our understanding of the cosmos," the Nobel Laureate told BBC News.
The issue at hand is the so-called Hubble Constant - the value used by astronomers to describe the current expansion. It is a critical number because it helps us gauge the size and age of the Universe.
One way to pin down this value is to measure the distance and velocities of a large number of stars in a good sample of galaxies.
In Dr Riess's new study, to be published shortly in The Astrophysical Journal, this was done with the aid of two classes of very predictable stars.
These are the cepheid variables - pulsating stars that puff up and deflate in a very regular fashion; and a group of exploding objects referred to as a Type 1a supernovae.
Both shine with a known power output, and so by comparing this quantity with their apparent brightness on the sky, it is possible to figure out their separation from Earth and thus, also, the distance to the galaxies that host them.
Some 2,400 cepheids in 19 nearby galaxies were used in the survey, and these helped calibrate roughly 300 Type 1a supernovae, whose particular properties enabled the team to probe a slightly deeper volume of space.
The work gives a number for the Hubble Constant of 73.24 kilometres per second per megaparsec (a megaparsec is 3.26 million light-years). Or put another way - the expansion increases by 73.24km/second for every 3.26 million light-years we look further out into space.
It means basically that the distance between cosmic objects will double in another 9.8 billion years.

Tags: astronomyHubbletelescopephysicsgalaxyuniverse

Read original article » Back to category



Recent headlines

  • Posted in Business on 2017-09-21 08:16:42
    Google signs $1.1bn HTC smartphone more
    Posted in Business on 2017-09-21 08:11:40
    US solar plant costs fall another 30 per cent in just more
    Posted in Science on 2017-09-21 08:04:25
    SpaceX will call global internet satellite network more
    Posted in Software on 2017-09-20 19:05:15
    Google boosts Cloud Natural Language API with more
    Posted in Software on 2017-09-20 18:55:34
    Salesforce to launch $50 million artificial more
Posted in Business on 2013-10-10 01:33
China is working towards a manned lunar mission in more
Posted in Business on 2013-10-20 07:17
Spacex says China is their main competitor for more
Posted in Software on 2013-10-20 06:43
Pirate Bay Browser Clocks 1,000,000 more
Posted in Medicine on 2013-10-10 02:10
Google reportedly investing hundreds of millions into more
Posted in Medicine on 2013-10-14 03:13
Endothelial Cells Can Repair and Regenerate Organs, more
Posted in Science on 01.01.2010
Spacex says China is their main competitor for more
Posted in Science on 01.01.2010
Staring at Your Phone Could Be Making You Short more
Posted in Science on 01.01.2010
Oculus Rift virtual reality headset coming to mobile, more
Posted in Science on 01.01.2010
China is working towards a manned lunar mission in more
Posted in Science on 01.01.2010
Delivering drugs via nanoparticles to target more

Recent Blog Posts

  • Posted by AlexMuller
    Scientists probe Neptune's depths to reveal secrets of more
    Posted by AlexMuller
    New terahertz imaging approach could speed up skin more
    Posted by AlexMuller
    Rebutting the claim that antidepressants do not more
    Posted by AlexMuller
    Artificial neural networks decode brain activity more
    Posted by AlexMuller
    Four Earth-sized planets detected orbiting the more

Login to your Account

Login to your PlanetTech Account here

Remember me

Create a New Account

You just need username and password

The following errors occured:
Verify password:
Remember me