The nice thing about cosmological theories is the the time scales involved make the theories unfalsifiable.
One of the latest theories is that the universe is cyclic.
- A sort of a Big Bang,
- Expansion,
- A Big Suck,
- Compression.
followed by another kind of a Big Bang, and so on ad infinitum.
But why that should be so is outside the realm of the knowable.
Two articles caught my eye this morning.
One of the great mysteries of modern physics is why antimatter did not destroy the universe at the beginning of time.
To explain it, physicists suppose there must be some difference between matter and antimatter – apart from electric charge. Whatever that difference is, it’s not in their magnetism, it seems.
Physicists at CERN in Switzerland have made the most precise measurement ever of the magnetic moment of an anti-proton – a number that measures how a particle reacts to magnetic force – and found it to be exactly the same as that of the proton but with opposite sign. The work is described in Nature.
“All of our observations find a complete symmetry between matter and antimatter, which is why the universe should not actually exist,” says Christian Smorra, a physicist at CERN’s Baryon–Antibaryon Symmetry Experiment (BASE) collaboration. “An asymmetry must exist here somewhere but we simply do not understand where the difference is.”
The Milky Way and Andromeda galaxy won’t collide for next 4 billion years. But but a recent discovery of a massive halo of hot gas close to Andromeda Galaxy may mean that our galaxies are already touching. Astrophysicist Nicholas Lehner from University of Notre Dame, led a group of scientists using the Hubble Space Telescope to detect an enormous halo of hot, ionized gas about 2 million light years in diameter around the galaxy.
The Andromeda Galaxy and Milky Way are the largest member of a ragtag group of some 54 galaxies, called the Local Group. Andromeda, with almost a trillion stars — twice as many as the Milky Way — shines 25% brighter and can simply be seen with the naked eye from outlying and rural skies. If the recently discovered halo spreads at least a million light years in our direction, our two galaxies are way MUCH closer to touching than previously thought.
Tags: Cosmology
The k2p blog 