Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Kryptid on 12/07/2008 22:13:36

Exotic matter has several different meanings, so I'll clarify what I mean. When I refer to exotic matter, I'm speaking of matter or particles with a negative net mass and energy (such as 15 kilograms or 15 joules or something) instead of the postive net mass and energy that we see in 'normal' matter.
Here is some more information: http://en.wikipedia.org/wiki/Exotic_matter (http://en.wikipedia.org/wiki/Exotic_matter)
For the sake of simplicity, I will abbreviate exotic matter as "exomatter" and "exoparticles".
Theoretically speaking, the Casimir Effect arises from quantum vacuum fluctuations composed of virtual particles. Between two closelyspaced metal plates, there are fewer virtual particles than outside of the plates. Since these virtual particles do contain energy, then the energy outside of the plates is higher than between the plates. The net result is for the plates to be pushed together by the higher pressure outside of them.
Now on to exomatter.
Quantum vacuum fluctuations are said to be composed of all different types of subatomic particles that can exist, in all possible enegy levels, right? Now let's create a thought experiment. Imagine a universe where exomatter does indeed exist. Since exoparticles exist there, and since the quantum vacuum fluctuations in that universe must contain all possible particles in all possible energy states, then shouldn't it contain virtual exoparticles too?
What would happen if we tried to duplicate the Casimir Effect in this hypothetical universe? When we put two closelyspaced plates together, they exclude vacuum fluctuations, both postive energy (particles) and negative energy (exoparticles). We've already seen what excluding positive energy from the plates does. Now let's take the postive energy out of the equation for a moment and think only about the negative energy. When we exlude some amount of negative energy from within the plates, the amount of energy between the plates becomes "less negative" than outside of them. In essence, the pressure inside of the plates is greater than outside of them and they feel a repulsion instead of an attraction. Now put both kinds of energy together. Since the vacuum would contain roughly equal amounts of particles and exoparticles, shouldn't the two forces cancel each other out, resulting in no Casimir Effect?
If this is the case, then could the existence of the Casimir Effect in our Universe be seen as proof that there are no virtual exoparticles within the quantum vacuum fluctuations to cancel out the pressure of the normal virtual particles? If they don't exist in these fluctuations, then doesn't that mean that they don't exist anywhere in our Universe at all?
I just find the concept of negative mass exomatter to be very interesing and I think it would be neat if it existed and could be utilized for technological purposes.

I find this a convincing argument for the nonexistence of exomatter.

There is an imbalance of matter/antimatter so why should there be equal amounts of matter & exomatter? If matter is predominant then the plates will still get closer.

There is an imbalance of matter/antimatter so why should there be equal amounts of matter & exomatter? If matter is predominant then the plates will still get closer.
That imbalance seems to be only present in real matter and antimatter particles, not virtual particles and antiparticles that are in vacuum fluctuations.
Plus, I believe that the strength of the Casimir Effect can be calculated to a relatively high degree of accuracy using equations that take the positive energy of vacuum fluctuations into consideration. Surely if there was some negative energy exomatter component at work, the equations would not be as accurate as they are?

Surely if there was some negative energy exomatter component at work, the equations would not be as accurate as they are?
Not necessarily.
Take the sequence 2, 8, 32, 128
You would assume that each successive value is arrived at by multiplying the previous value by 4. But you would arrive at the same values if you multiplied the previous value by 8 & then divided the product by 2. Apply that to what you said in your reply and it is apparent that the positive pressure could be twice as strong as we think and there is a negative force halving its effect.
Although my example uses very basic arithmetic, there is no reason why it can't apply it more complex maths.

There are many different ways to model the vacuum in order to explain the Casimir Effect:
1) You could hypothesize that the vacuum contains about amount of positive energy predicted by theory with no negative energy to mitigate it, resulting in the observed amount of Casimir force.
2) As you said, the vacuum could contain twice the amount of positive energy predicted in hypothesis #1 with a component of negative energy that balances out 1/2 of it to produce the observed net amount of Casimir force.
3) By extension, the vacuum could also contain three times the amount of positive energy predicted in hypothesis #1 with a component of negative energy double that predicted in hypothesis #2 that balances out 2/3 of the positive energy to produce the observed net amount of Casimir force.
4) By extension again, the vacuum could also contain four times the amount of positive energy predicted in hypothesis #1 with a component of negative energy triple that predicted in hypothesis #2 that balances out 3/4 of the positive energy to produce the observed net amount of Casimir force.
5 and beyond) Etc. etc...
Given that hypothesis #1 is the simplest because it agrees with the observed strength of the Casimir force without invoking an extra amount of positve energy as well as an undiscovered negative energy component, that means that Occam's Razor favors it and makes it the more likely hypothesis.

I agree. I was merely pointing out that there is an alternative explanation to that offered.

On a related note, I'd like to mention tachyons. Assuming for the sake of argument that tachyons can exist, then surely quantum vacuum fluctuations must contain virtual tachyons? Are there any observable effects that the presence of virtual tachyons in the vacuum would have on the Casimir Effect or anything else for that matter?

Negative mass? Negative energy? That's waaaay beyond the capabilities of my poor little brain [:(]

Negative mass? Negative energy? That's waaaay beyond the capabilities of my poor little brain [:(]
Think about it in terms of concept and consequences, as opposed to how it melds with common sense. Analogies help, too. If a positive mass bends the "lines" of spacetime towards itself, you might think of a negative mass as bending the "lines" spacetime away from itself. Likewise, a beam of light will be bent towards a positive mass, and away from a negative mass.
I've also seen it suggested that matter and exomatter could meet and annihilate to produce nothingness, since a positive number and a negative number can cancel out to make zero. In theory, that is possible, but only in certain circumstances. Conservation laws would prevent certain kinds of annihilations. For example, you couldn't annihilate an electron and an exotic electron because there would be nothing left behind to carry the negative electric charge that they had (or their lepton number). However, you could annihilate a positron and an exotic electron (or conversely, an electron and an exotic positron) because their electric charges and lepton numbers would cancel out.
I also wonder about the consequences of the gravitational field surrounding a negative mass/exomatter. Since time slows down in a strong gravitational field, what would happen in the "antigravitational" field surrounding a sphere of exomatter? Would time speed up? Would it run backwards? Would it slow down just like in a regular gravitational field?

Negative mass? Negative energy? That's waaaay beyond the capabilities of my poor little brain [:(]
Think about it in terms of concept and consequences, as opposed to how it melds with common sense. Analogies help, too. If a positive mass bends the "lines" of spacetime towards itself, you might think of a negative mass as bending the "lines" spacetime away from itself. Likewise, a beam of light will be bent towards a positive mass, and away from a negative mass.
I've also seen it suggested that matter and exomatter could meet and annihilate to produce nothingness, since a positive number and a negative number can cancel out to make zero. In theory, that is possible, but only in certain circumstances. Conservation laws would prevent certain kinds of annihilations. For example, you couldn't annihilate an electron and an exotic electron because there would be nothing left behind to carry the negative electric charge that they had (or their lepton number). However, you could annihilate a positron and an exotic electron (or conversely, an electron and an exotic positron) because their electric charges and lepton numbers would cancel out.
I also wonder about the consequences of the gravitational field surrounding a negative mass/exomatter. Since time slows down in a strong gravitational field, what would happen in the "antigravitational" field surrounding a sphere of exomatter? Would time speed up? Would it run backwards? Would it slow down just like in a regular gravitational field?
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If this is the case, then could the existence of the Casimir Effect in our Universe be seen as proof that there are no virtual exoparticles within the quantum vacuum fluctuations to cancel out the pressure of the normal virtual particles? If they don't exist in these fluctuations, then doesn't that mean that they don't exist anywhere in our Universe at all?
They don't exist. No point particles exist.
and maybe another observation of casimir will point out that, the entangled energy increases its potential; from the environment.
You are looking at what gravity is........
Electromagnetic radiation can be pictured as waves flowing through space at the speed of light. The waves are not waves of anything substantive, but are ripples in a state of a theoretically defined field. However these waves do carry energy (and momentum), and each wave has a specific direction, frequency and polarization state. Each wave represents a ''propagating mode of the electromagnetic field.''
Each mode is equivalent to a harmonic oscillator and is thus subject to the Heisenberg uncertainty principle. From this analogy, every mode of the field must have 1/2 hf as its average minimum energy. That is a tiny amount of energy in each mode, but the number of modes is enormous, and indeed increases per unit frequency interval as the square of the frequency. The spectral energy density is determined by the density of modes times the energy per mode and thus increases as the cube of the frequency per unit frequency per unit volume. The product of the tiny energy per mode times the huge spatial density of modes yields a very high theoretical zeropoint energy density per cubic centimeter.
Gravity is simply entangled energy between mass and that potential can vary on environment and 'f' of the energy and space.
pretty basic if you look at it with open eyes.