Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: thedoc on 11/08/2012 04:30:01

Title: Is the Earth immersed in dark energy and dark matter?
Post by: thedoc on 11/08/2012 04:30:01
A B P Lever asked the Naked Scientists:
   
Since dark matter and energy pervade space and since we, our planet, is located in space, and this dark energy/matter causes repulsion of spacetime... are we humans immersed in dark energy/matter ??

A B P Lever

What do you think?
Title: Re: Is the Earth immersed in dark energy and dark matter?
Post by: evan_au on 11/08/2012 11:07:51
Dark Energy
The Nobel Prize committee awarded the Physics prize for discovering that the the expansion of the universe is accelerating; they were not totally convinced that dark energy is the reason for it. (Maybe that leaves room for another Nobel Prize?)

Dark energy is a fairly weak effect, so objects that are bound together by gravity (like our galaxy and our planet) are not going to be affected any time soon. Objects that are bound together by the electromagnetic force (like our bodies) are even less likely to be affected.

Dark Matter
The leading theory is that galaxies (including our own) are embedded in a swirling mass of "cold" dark matter, interacting with visible matter primarily through gravity.

Very sensitive detectors have not yet identified dark matter particles in a repeatable manner, so if they exist, they are very subtle, and unlikely to hurt us.

It is possible that the LHC may have enough energy to generate some new particles predicted by the "supersymmetric" theory; some of these are thought to have properties similar to dark matter. If a large amount of energy from a proton collision disappeared without a trace, that would be a hint that such particles had been created.

http://en.wikipedia.org/wiki/Dark_matter#History_of_the_search_for_its_composition

Conclusion: If the theories are correct, we are immersed in Dark Matter and Dark Energy, but they interact with us so weakly that they won't harm us, and most of humanity can continue to ignore them, like they have through all of history.
Title: Re: Is the Earth immersed in dark energy and dark matter?
Post by: lightarrow on 13/08/2012 13:18:25
A B P Lever asked the Naked Scientists:
   
Since dark matter and energy pervade space and since we, our planet, is located in space, and this dark energy/matter causes repulsion of spacetime... are we humans immersed in dark energy/matter ??

A B P Lever

What do you think?
We are, immersed in dark matter and dark energy, but they have an extremely low density, comparing everyday matter and energy fields; it's for this reason they are significant only for very large regions of space.