Crosswords2 mins ago
There's nothing out there ?
Did I hear correctly that Astronomers have discovered a vast expanse of space , where there is literally no stars ?
If correct how do they know this , given the enormity of the space as obvioulsy they cannot have scritinise the whole of this area ?
If correct how do they know this , given the enormity of the space as obvioulsy they cannot have scritinise the whole of this area ?
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One could travel between galaxies at the speed of light for millions of years and not meets a soul.
Really, I am convinced all these enormous celestial postulations are mere guesses, either that or they forgot to take the dust cap of their telescope.
A billion galaxies with one billion stars each????? Considering that the outer reaches of space are expanding at a greater rate than the speed of light we will never know just what is out there. One billion galaxies may just be a drop in the ocean in the complete(?) outer space.
Astronomers are expected to have answers on these subjects so they invent numbers to keep the punters happy and justify the public funding.
Really, I am convinced all these enormous celestial postulations are mere guesses, either that or they forgot to take the dust cap of their telescope.
A billion galaxies with one billion stars each????? Considering that the outer reaches of space are expanding at a greater rate than the speed of light we will never know just what is out there. One billion galaxies may just be a drop in the ocean in the complete(?) outer space.
Astronomers are expected to have answers on these subjects so they invent numbers to keep the punters happy and justify the public funding.
No you heard wrong.There are enormous amount of space with no stars (between the Galaxies). What you HEARD was astronomers discovered an enormous hole in the Universe, nearly a billion light-years across, empty of both normal matter such as stars, galaxies and gas, as well as the mysterious, unseen �dark matter.�
Here is how they did it: It is as simle as measuring the energy of light,
The answer lies in dark energy, which became a dominant force in the Universe very recently, when the Universe was already three-quarters of the size it is today. Dark energy works opposite gravity and is speeding up the expansion of the Universe. Thanks to dark energy, CMB photons that pass through a large void just before arriving at Earth have less energy than those that pass through an area with a normal distribution of matter in the last leg of their journey.
In a simple expansion of the universe, without dark energy, photons(light) approaching a large mass -- such as a supercluster of galaxies -- pick up energy from its gravity. As they pull away, the gravity saps their energy, and they wind up with the same energy as when they started.
But photons passing through matter-rich space when dark energy became dominant don't fall back to their original energy level. Dark energy counteracts the influence of gravity and so the large masses don�t sap as much energy from the photons as they pull away. Thus, these photons arrive at Earth with a slightly higher energy, or temperature, than they would in a dark energy-free Universe.
Conversely, photons passing through a large void experience a loss of energy.
Here is how they did it: It is as simle as measuring the energy of light,
The answer lies in dark energy, which became a dominant force in the Universe very recently, when the Universe was already three-quarters of the size it is today. Dark energy works opposite gravity and is speeding up the expansion of the Universe. Thanks to dark energy, CMB photons that pass through a large void just before arriving at Earth have less energy than those that pass through an area with a normal distribution of matter in the last leg of their journey.
In a simple expansion of the universe, without dark energy, photons(light) approaching a large mass -- such as a supercluster of galaxies -- pick up energy from its gravity. As they pull away, the gravity saps their energy, and they wind up with the same energy as when they started.
But photons passing through matter-rich space when dark energy became dominant don't fall back to their original energy level. Dark energy counteracts the influence of gravity and so the large masses don�t sap as much energy from the photons as they pull away. Thus, these photons arrive at Earth with a slightly higher energy, or temperature, than they would in a dark energy-free Universe.
Conversely, photons passing through a large void experience a loss of energy.
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