A glimpse of a new universe?
At the Institute of Theoretical Astrophysics at UiO scientists are working like detectives in their effort to decipher images taken by Planck. They are trying to find out what happened 14.5 billion years ago.
A small discrepancy can rock old theory
The cosmic microwave background (CMB) is radiation originating from Big Bang itself and has been called the fingerprint of creation.
This is because it is an image of how the universe looked 380 000 years after Big Bang. Before, the universe had been opaque as heavy smog.
The heat after Big Bang made sure light particles didn’t get anywhere because they were crashing with other particles in constant movement.
The universe had to cool down sufficiently for this light to eventually be released.
That happened 380 000 years after Big Bang. Today, with the help of extremely sensitive instruments like Planck we can actually detect this 14.5 billion year old light.
Planck provides the best images of CMB we have managed to create, and somewhere in the vast amount of data the satellite has given us the seed of a new physics might be found.
– A small discrepancy or asymmetry in the images can rock established truths regarding the universe!
– It can open the door for a new brand of physics, says astrophysicist Hans Kristian Kamfjord Eriksen, professor at Institute of Theoretical Astrophysics at The University of Oslo.
He has just ended an ERC-project in regard to the Planck images. Funds from the European Research Council (ERC) are very prestigious.
A wise decision
The institute for Theoretical Astrophysics at UiO has been deeply involved with Planck and is world leading when it comes to research on CMB. Kamfjord Eriksen belives this is because the institute made a very smart decision decades ago.
– The institute made a very smart decision years ago. They asked themselves an important question: What research can we – with our resources – be competitive with on an elite level? The answer was computer power! Today, we have computer resources here at the university that can compete with the best, explains Kamfjord Eriksen.
And we are talking about available computer power.
– Many of the world’s supercomputers have the same problem. They have no free capacity. There are endless cues if you want to process your data. Here at the university, however, we have the privilege of being able to do heavy calculus on grand theories and big data right away. We have for example a 10 times bigger in-house computer capacity than Princeton.
A twisted universe?
The computer power at Oslo University is currently being used to examine the data from Planck and compare it to its predecessor WMAP. That is quite comprehensive work.
– We are one of the few groups working on Planck that use all available data at the same time. That requires a lot of computer power.
Right now they are trying to decide whether a discrepancy can change an old astrophysical principle.
Until now we have been convinced that the universe is ruled by what we call the cosmological principle. And this principle states that the universe is isotropic, which means it’s the same in all directions.
– If you imagine the universe being an ocean and you are out on the ocean in a boat, the cosmological principle states that you will see waves of the same amount and size in all directions, says Kamfjord Eriksen.
However, already in data from the WMAP satellite a few irregularities were detected that contradicted the cosmological principle. Back then this was written off as statistical deviations.
– But data from Planck back up these irregularities and indicate that the universe actually have a preferred direction. If you imagine sitting in your boat again, it will be like seeing a storm to the north of you while it’s completely windless to the south. Maybe the universe is twisted?
Towards a more complicated universe
– This might indicate that the laws of physics on a grand scale are not the same everywhere. Some rules are valid one place while another place might apply by completely different rules.
Does this mean that the cosmological principle is false?
– Too early to tell, but the data we are looking at indicate that some phenomena are more advanced than we previously thought. For example, in the past I didn’t believe in inflation. Now I believe in some form of inflation. Just a lot more complicated than what we believed inflation to be in the past. We are searching for which type of inflation that influenced the early universe.
Inflation is the theory that the universe in a span of a short few seconds, straight after the Big Bang, expanded extremely fast – the expansion is estimated to have increased at least 1078 times. Inflation is used to explain why the universe is so similar in all directions.
Kamfjord Eriksen, however, believes in a more complicated model of inflation and a universe that is not homogenous.
– Personally, I simply believe that the universe is not homogenous, but have variations on a grander scale than we can observe. We only see a sample of the bigger picture.
– This looks strange!
Is it accepted among astrophysics to believe that the universe is not homogenous?
– The believers are growing in numbers. I would guess half of all astrophysics thinks this is hogwash. Maybe a quarter believes in the theory and another quarter again says: We don’t know.
Eriksen thinks its important to remember that nearly all scientific breakthroughs started small.
– All big revelations started with somebody saying: “This looks strange!” Then it’s all a matter of following this discrepancy. See if anything develops from the ideas that the data supports. If not, then you can just start again. That’s science!
Mest lest siste syv dager
If a material full of pores is soaked in a fluid and another fluid is forced into it, how will the invading fluid displace the other one? It took 30 years to verify the answer, which will be useful for CO2 storage.