Hacker News new | ask | show | jobs
by pdonis 3778 days ago
This isn't really correct. Expansion of space is not the same thing as accelerated expansion of space. Aaccelerated expansion is indeed due to something "pushing" objects apart--that something is called "dark energy". But expansion itself, apart from the effects of dark energy, does not push on anything; it doesn't exert any force that moves objects apart or works against gravity. So thinking of ordinary expansion (apart from accelerated expansion) as "creating space" in between objects isn't really correct. It's unfortunate that so many pop science treatments use this way of speaking, since it leads to the incorrect inference I've just described.
1 comments

The space is expanding and its expansion rate is accelerating. Dark energy is not pushing objects apart, it is causing the acceleration of expansion of space.

What you said isn't even pop science, it is blatantly wrong.

https://en.wikipedia.org/wiki/Metric_expansion_of_space

https://en.wikipedia.org/wiki/Dark_energy

And the money quote:

It is called "dark" because it is not interacting with normal matter, but only with the space time structure.

from http://physics.stackexchange.com/a/206217

> What you said isn't even pop science

What I said was an attempt to explain how the basic model cosmologists use works in layman's terms. It wasn't intended to be "pop science" or even "real science"; that would be building the model, not trying to explain how it works.

The references you give are not "real science" either. Try looking in a cosmology textbook or a peer-reviewed paper. Or, even better, work out the science for yourself instead of arguing from authority.