I would like to know if there is an agreed upon explanation within the field of physics as to why more dark energy than normal energy was created during the creation of the Universe.

More is unknown than is known. We know how much dark energy there is because we know how it affects the universe's expansion. Other than that, it is a complete mystery. But it is an important mystery. It turns out that roughly 68% of the universe is dark energy. Dark matter makes up about 27%. The rest - everything on Earth, everything ever observed with all of our instruments, all normal matter - adds up to less than 5% of the universe. Come to think of it, maybe it shouldn't be called "normal" matter at all, since it is such a small fraction of the universe. From Dark Energy, Dark Matter.

I've learned that an equal amount of matter and antimatter was created during the early stages of the creation of the Universe and that more matter than antimatter was left after they interacted with one another and this is why we live in a 'matter' Universe instead of an 'antimatter' Universe.

So, this leads me to ask if an equal amount of matter and antimatter was created during the creation of the Universe, why wasn't an equal amount of normal energy and dark energy created during the early stages of the creation of the Universe?


4 Answers 4


It is not currently known why there is more dark matter than normal matter because no one knows what dark matter is yet. Dark matter is like normal matter in that it pulls space together with gravity.

Dark energy, on the other hand, was not created at the beginning of the universe, but is rather a property of space. Empty space has dark energy at the same density throughout the universe. If the universe is expanding then there is more space as time goes on. If there is more space there is more dark energy. Dark energy makes up the majority of the energy now, because the expansion of the universe has gotten large.

Dark energy in fact has the opposite effect of mass (and normal energy, $E=mc^2$) and pushes space apart. The more dark energy the faster this expansion happens. In current models, dark energy will continue to increase and outweigh other types of energy even more than it already does.

Distribution with age of universe

It is also worth noting that photons which contribute to the total amount of normal energy in the universe undergo a redshift and decrease their total amount of energy. This pushes the ratio even more heavily in favor of a dark energy-dominated universe.

Source of image: https://universe-review.ca/R15-17-relativity10.htm

  • $\begingroup$ But the energy lost by photons undergoing redshift isn't related to the increase in dark energy... is it? $\endgroup$
    – Michael
    Mar 2, 2023 at 19:35

It's not true that more dark energy was created during the Big Bang than normal energy. The energy density of dark energy now is greater than that of normal energy (which I interpret as the energy density of radiation + matter), but it wasn't the case in the past. If you look at the definition of dark energy, you'll see that what's special about it is that its energy density is constant as space expands. Comparatively matter's energy density goes down, and radiation's energy density goes down even faster.

Which means that if you run time backwards, you'll eventually get to a point where the energy density of matter and dark energy were equal, and if you go back even further, then matter dominates over dark energy. Shortly after the big bang it was even the case that radiation dominated over matter. Therefore the question "why was more dark energy created during the creation of the universe than normal energy?" is not well-posed.

You could flip the question around and ask why was more normal energy created than dark energy. The answer to that is we don't know, since we don't have laws that hold during the Big Bang. In the same way, we can't answer questions about what exactly ocurred during the Big Bang.


Antimatter has certain conserved charges equal and opposite to that of matter, and this explains their initial balance. (Some of these conservation laws likely failed somewhat in the early Universe, but that's a big topic.) For example, an antiproton has the opposite electric charge and baryon number as a proton, and a positron has the opposite electric charge and lepton number as an electron. There is no analogous conservation-based argument to relate quantities of baryonic matter and dark energy.


The ratio of dark energy needs more explanation. The universe has been expanding and this expansion is currently accelerating.

Now dark energy is very unique, because it is being created as we speak. As the universe expands, the energy density of normal matter and even dark matter decreases.

This is not the case with dark energy. As the universe expands, the dark energy density stays constant. This is very important. More and more dark energy is being created, and as the universe expands, the energy density of matter and dark matter gets diluted.

That is, since the dark energy density is constant (at least this appears to be the case) the expansion of the universe creates new dark energy from nowhere.

Does the fact that energy is not conserved in cosmology open the possibility of new matter/atoms being created in the universe?

This means, that the relative dark energy content of the (observable) universe increases (relative to the matter and dark matter energy density), and the relative energy content of matter and dark matter decreases.

So the answer to your question is that at the beginning of the universe, the relative dark energy content might have been very little.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.