The Hubble Space Telescope has been used to evaluate the phenomenon first observed by the uranologist after which it was named : the expansion of the world . It is the most accurate measuring of the charge per unit of expansion yet made , and it confirms something that ’s been bothering astronomers for a while . The universe is likely expanding quicker than our measurements of thecosmic background radiationindicate it should be , suggesting either one of the measurements is faulty , or the expansion is being influenced by an unknown personnel .
As the universe expands , galaxies get further aside . Investigations into the elbow room this is happening have been cardinal to some of the most significant breakthrough in cosmology over the last century , but it seems we ’re not done yet .
We can exactly measure the rate at which a galaxy is moving away from us from how much the wavelength of its illumination has stretched ( make out asred shift ) . appraise the distance is harder , swear on the luminosity of specific star topology andsupernovasknown as “ stock taper ” . compare their brightnesses can bespeak distance .
Using Hubble ’s more exact measurement of sure stock candles , a paper to be published inThe Astrophysical Journalreports the Hubble constant , a measuring stick of the expansion of the cosmos , as 67 ( 42 miles ) kilometers per 2d per megaparsec . This means that for every additional million parsecs ( 3.3 million swooning - years ) away from us a Galax urceolata is , its speed increases by 67 kilometers ( 42 miles ) per second .
The problem is this figure is 9 percent gravid than the value we reckon using observation of the situation short ( 378,000 days being " presently " to cosmologist ) after the Big Bang . This is based on the Planck satellite ’s measure of the cosmic background radiation produce at that time , processed using example of how this should ’ve changed as the universe evolved .
Previous estimates of the current Hubble constant had also been high than that descend from the Planck datum , but there was uncertainty in the measure . Using fresh method to calibrate the brightness of Cepheid variables , the stock candles used to measure relatively nearby galaxies , Hubble decreased its dubiousness range of a function to 2.3 per centum . Getting the Hubble unceasing accurate to within 10 percentage was one of Hubble ’s original goals , so this dramatically exceeds that . With this newfound precision , the chance of the current and early universe expansion coordinate drops to one in 5,000 , which seems a bit low to swear on .
Three steps astronomers used to measure the universe ’s expansion charge per unit : 1 ) Using Hubble to measure the distances of ace called Cepheid variables , via parallax . 2 ) Applying the calibrations from these to Cepheids in nearby galaxy that have recently hosted Type Ia supernovas . 3 ) Knowing the distance to these supernovas , calibrate this to valuate the distances to galaxies so remote we ca n’t see the Cepheids . NASA , ESA , A. Feild ( STScl ) , and A. Reiss ( STScl / JHU )
" Both termination have been test multiple ways , so barring a series of unrelated error , it is more and more likely that this is not a hemipterous insect but a feature of the universe,“saidProfessor Adam Riess of the Space Telescope Science Institute . Riess deal the 2011 Nobel Prize in physics for his discovery that the universe ’s expansion is speed up , not slowing down , leading to the acceptance of the idea of dark energy .
If both measurements are right-hand , then our sympathy of the Torah of physics at enceinte scales needs an service . Several possible explanations have been project , but at this stage , we have little cornerstone for select any of them .
One holds thatdark energy , the violence causing the existence ’s expansion to accelerate , is itself speed . That is , the universe is n’t just rise faster , but growing faster at an increasing rate , like a skier hold up from a soft gradient to a steadily steeper downhill run . yield how little we bang about dismal zip , we ca n’t rule this out .
Another idea posit a currently undetected subatomic particle , dissemble by gravity but immune to the other three fundamental forces . Known as a sterile neutrino , such a corpuscle would move around nigh to the speed of lightness , sham how the macrocosm develop .
The observation could also be explained if astronomers have underrate the interaction between dark matter , which we hump of from the rotation rate of galaxies but do n’t fully interpret , and the straight evident parts of the world .
Each of these possibility , if correct , would interfere with the manakin we apply to apply the information from the former world to today ’s situation . They ’d also keep many theoretical physicist busy for year trying to explain the implications .
