When the universe is a lot bigger than we thought: The universe is actually a lot larger than we realise
This article originally appeared on New Scientist.
The universe can be big, it can be really big, and there are actually lots of things that are bigger than it seems.
That’s according to new research that suggests there may be a limit to how big a universe can get.
In a study published in the journal Science, researchers at the University of California, Berkeley, measured the mass of the universe as a function of its distance from the Earth.
The results showed that the distance from Earth to the centre of the Milky Way is approximately 5 billion light years, which is a fairly good approximation of how far it is from the centre.
“We’re talking about a lot of objects that are very large, so it’s kind of a double whammy,” says Dr Peter Harbison, a cosmologist at the Berkeley Astronomical Observatory who led the study.
The researchers also compared the mass distribution of the largest objects in the universe to the mass density of the sun and galaxy.
They found that galaxies that are the largest in the known universe can have masses that are in the order of 50 billion times the mass that is found in the Milky, but that they are all in a different galaxy.
These supermassive black holes also dominate in the galaxies, and they have the mass to match the mass in our universe, suggesting that they were not the result of an accretion event that formed the universe.
“The supermassive, massive, black hole-like objects are the result, not of a merger, but of the collapse of a large number of objects in a single supermassive region,” says Harbisons.
“And this is just the result we saw in the paper.”
That means that supermassive objects are actually not that much bigger than they seem, but they are quite a bit larger than the size of the galaxies they reside in.
The team used a technique called gravitational lensing, which involves taking a measurement of the gravitational field of a distant object and comparing it to a measurement taken of the position of a nearby galaxy.
“If the galaxy is a billion times bigger than the Sun, then there is a way to look at it and determine that,” Harbions says.
“But it would take 10,000 years of observation to measure the position accurately.”
The result of this measurement is the mass and the size range of the objects that were measured.
“These observations, with gravitational lensings, are extremely precise,” Harbsons says.
In other words, they show the scale of the Universe and show that the Universe is expanding, as it is predicted to do.
This could mean that we are seeing something like the Big Bang, which happened 3.7 billion years ago.
The supermassive galaxies that surround us have been identified before.
For instance, the Andromeda Galaxy is the largest known galaxy and the biggest galaxy to have ever been observed, measuring about 20,000 light years across.
“It’s an extremely large galaxy, and it’s probably about 50 million light years away,” Harbesons says, adding that it is possible that the Andromeda galaxy is being detected from Earth.
“There are a lot more things that can be detected that are a billion light-years away that are supermassive.”
The Universe is about 1.4 billion light times the size that our Milky Way galaxy is, which means that a galaxy of that size would be more than 50 billion light units across, which could be seen by the naked eye.
If we had an exact measurement of where the Universe really is, then we would be able to find galaxies at a similar scale to the Andromeda and the Milky way.
That would mean we would find more than 10,0000 galaxies out there, and more than 5,000 galaxies would have mass that could be measured accurately.
“This study tells us something really exciting about the Universe that we don’t yet understand,” says Michael Werner, a theoretical astrophysicist at the Max Planck Institute for Extraterrestrial Physics in Germany.
“You can tell that the universe we’re living in is very big, because it has the mass mass density,” he says.
The discovery could help us to understand how the Universe was formed.
“When we look at the Big Ben clock, which measures the positions of the stars in the sky, we see the light at the moment when it is about 4 billion years old, and this is when the Big Bands were created,” Harbarsons says “So it means that the Big Brings were created about 4.6 billion years before the Big Bell.”
And this would also give us some information about how much matter and dark energy is in the Universe.
“What the new study shows is that the energy of dark energy in the cosmos is about 100 trillion times larger than what we have ever measured,” Harborsons says The research was published in Science.
It was funded by the Australian Research Council and the University.
Image: University of Melbourne.