Dark Energy & Matter: Exploring the Big Bang

[Michaela SJ]

Ok, this question is prompted by watching a TV program on the Big Bang - sorry!

Right after inflation, there was a flood of matter/anti-matter. The matter/anti-matter went through a period of annihilation but there was a residual amount of (anti-)matter left that has become our physical universe.

Is it possible that the matter/anti-matter annihilation resulted in what we now know as Dark Energy and there was quantum type particle that resulted from the collisions of the matter/anti-matter that we have not yet seen that is the Dark Matter we 'know' is there but can't see?

 

[Drakkith]

Is it possible that the matter/anti-matter annihilation resulted in what we now know as Dark Energy

Nope. Not as far as we know.

and there was quantum type particle

I don't know what a 'quantum type particle' is supposed to mean. All known fundamental particles are described by quantum physics.

that resulted from the collisions of the matter/anti-matter that we have not yet seen that is the Dark Matter we 'know' is there but can't see?

It's possible that dark matter is a product of decays/annihilations, but we have yet to see it in any of our experiments.

 

[MikeeMiracle]

This should be testable as we can produce anti-matter. Still before we can "test" it we need to determine just what dark matter is and we still only have theories about that.

It always frustrates me seeing media articles about us building a "dark matter" detector. How can you contrust a test to detect something when you do not know exactly what it is you are trying to detect.

 

[Michaela SJ]

One of the big problems many of us non-techies have with the science cognoscenti is that they easily blow off legitimate questions with a pat on the head and 'please go away' attitude.

Drakkith - we do not know what Dark Energy is because it is well, unknown. I asked a legitimate question knowing how E=mc^2 and an amount of matter/anti-matter could result in the very large amount of Dark Energy being touted as there - but, of course, we don't know what it is.

Why couldn't the resultant energy released in a matter/anti-matter collision be a form of energy that we suspect as Dark Energy but can only prophesize?

As for a 'quantum' particle. I didn't know what else to call it. How about I restate my question and ask about an unknown particle that resulted from the incomplete annihilation of a matter/anti-matter collision. Remember the Higgs Boson wasn't 'found' until 2012 and then only because the particle physics community knew what they were looking for it.

MikeeMiracle

...
It always frustrates me seeing media articles about us building a "dark matter" detector. How can you contrust [sic] a test to detect something when you do not know exactly what it is you are trying to detect.

Statements like yours also always frustrate some folk like me.

How many particle accelerators are there around the World looking for things we can only think exist.

Why did we spend hundreds of millions of Dollars to build the LIGO and the Virgo interferometer looking for something we only suspected existed.

There have always been explorers who set off not really knowing what lies just beyond that ever disappearing horizon until something looms in their telescope.

 

[Drakkith]

Drakkith - we do not know what Dark Energy is because it is well, unknown. I asked a legitimate question knowing how E=mc^2 and an amount of matter/anti-matter could result in the very large amount of Dark Energy being touted as there - but, of course, we don't know what it is.

We don't know what dark energy is, but we sure know a lot about what it is not. For starters, dark energy is not energy that you can get from annihilating two particles. This energy is always released in forms that we can observe and measure, and all experiments to date have shown that there is no apparent violation of energy conservation that would happen if some of the energy disappeared into space as dark energy.

As for a 'quantum' particle. I didn't know what else to call it. How about I restate my question and ask about an unknown particle that resulted from the incomplete annihilation of a matter/anti-matter collision.

There is no such thing as an incomplete annihilation event. I think what you're trying to ask is what if there is a small chance that an annihilation, decay, or other interaction event generate an unknown particle. The only answer I can give you is that no such thing has been observed, despite trillions of collisions and annihilation events inside particle colliders and other kinds of detectors over the last fifty-plus years.

 

[Janus]

Ok, this question is prompted by watching a TV program on the Big Bang - sorry!

Right after inflation, there was a flood of matter/anti-matter. The matter/anti-matter went through a period of annihilation but there was a residual amount of (anti-)matter left that has become our physical universe.

Is it possible that the matter/anti-matter annihilation resulted in what we now know as Dark Energy and there was quantum type particle that resulted from the collisions of the matter/anti-matter that we have not yet seen that is the Dark Matter we 'know' is there but can't see?

Think of this way: The period of matter-antimatter annihilation was a one-off event. While it might have added energy to the universe at the time, it wouldn't cause an acceleration in the expansion of the universe since then.
It is like when you throw a ball into the air. During the period of time during which the ball is in your hand, you are increasing its kinetic energy. This is the equivalent of the annihilation period adding energy to the universe. Once you let go, it will continue to climb, but will slow in response to gravity as it does so. Likewise, after the annihilation period you would expect the universe to continue to expand, but the rate of that expansion should slow over time.
What we see in the universe is an expansion rate that it speeding up and not slowing down.( The study that found this out was expecting to measure a slowdown. It was trying to determine if that slowdown was great enough to ever bring the expansion to a complete halt.)

It's like the ball continuing to climb at a faster and faster rate after it leaves our hand. Something beyond the energy our hand imparted to it has to be responsible.

Fpr the accelerating expansion of the universe to be the result of matter-antimatter annihilation, this would have to be on going throughout the age of the universe, and we see no evidence of this being the case.

 

[PeterDonis]

The period of matter-antimatter annihilation was a one-off event. While it might have added energy to the universe at the time

No, it didn't, because energy is locally conserved. What the period of annihilation did was transfer a lot of energy from radiation (i.e., particles like photons) to matter (i.e., baryons and leptons). This resulted in a lot of energy being in the form of rest mass, where before only very little energy was in that from. But the total energy was conserved throughout the process.

 

[kimbyd]

We don't know what dark energy is, but we sure know a lot about what it is not. For starters, dark energy is not energy that you can get from annihilating two particles. This energy is always released in forms that we can observe and measure, and all experiments to date have shown that there is no apparent violation of energy conservation that would happen if some of the energy disappeared into space as dark energy.

This statement isn't strictly true. There is often missing energy in observed reactions, because there are some particles, such as neutrinos, that have a tendency to pass right through matter and are difficult to detect as a result.

The clearest example of such a particle is the neutrino, many of which escape detection in reactions.

The properties of the particles we don't detect can be estimated from the properties of the particles we do detect, however, provided we observe enough collisions. This is one method that might someday yield a detection of the dark matter particle, but current colliders (including the LHC) aren't really sensitive enough in the right ways to detect that sort of thing unless we get incredibly lucky.

All that said, missing mass in collisions really can't explain dark energy for a completely different and more fundamental reason: dark energy isn't a particle. It's one of two things:

1) The Cosmological Constant, which can be interpreted as a constant energy density throughout space-time, or as a simple parameter in General Relativity that states that there is X amount of space-time curvature all the time even if there is no matter or energy (the math let's you interpret it either way).
2) Some sort of field which, in its ground state, has a net energy density. The dark energy is not that field itself, but rather the energy left over when the field is at rest. There may be one or more particles associated with that field, but they're generally not expected to ever be detectable due to the tiny field value.