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Apologies for being so inactive. Work really kills a lot of your motivation to do other things.
I’ve only felt like doing short posts of late and as some of you may have noticed, the posts I tend to do here are long. Anyway, I still engage in scientific discussion when the chance arises and typed this one out recently – thought I would share it. I typed this on my phone by the way, so forgive any grammar/syntax/punctuation errors.
Damn this is getting frustrating. Time to drop some knowledge bombs.
Antimatter is NOT dark matter. Dark matter is matter that we have not discovered and have literally no idea about – hence dark. We know it exists because it affects light and other properties in the universe in a way that currently known matter cannot describe (i.e more light curvature than one would expect given how much known matter there is – hence that means there’s more “stuff” out there than we know). Dark energy is used to describe the accelerated expansion of the universe. Remember, what’s dark mean? It meabs we don’t know. So we expect expansion to be slowing down but it’s actually increasing so there must be some energy we don’t know about. Those of you that actually UNDERSTAND Einstein’s equation E=mc^2 will know energy and mass are the interchangeable, so dark energy and dark matter are essentially the same thing.
Now ANTImatter is not dark. What does that mean? We KNOW about it. What is matter made up of? Particles. So antimatter is a broad term for a whole bunch of particles called antiparticles. Every particle theoretically has an antiparticle with the same mass but opposite charge, therefore when they come into contact with each other they annihilate each other and cause decay (into other forms of energy/particles). Carl Anderson discovered the POSITRON. It is the antiparticle of the ELECTRON. Both are known to exist and scientists can create them at will. No, it’s not the end of the world. Positrons ONLY annihilate electrons. All elementary particles have a known antiparticle.
Further reading for you if you’re interested is CP Violation which explains why there’s more matter than antimatter in the universe.
Boom. Science bitches.
On a side note, I think I will begin every scientific explanation I give with “Time to drop some knowledge bombs” and end it with “Boom. Science bitches.” from now on. Sound good?
I just want to do a quick post here so I won’t go into too much detail or include all arguments.
There seems to be some sort of wired-in expectation that things should be more or less symmetrical. Let’s not get too into supersymmetry here – though I should point out that the supersymmetry theory (SUSY) took a hit recently from results at the LHC. BSmeson decay was set to one in every 300 million Bsmesons, close to what the standard model predicts. Those of you that are more science savvy will probably understand why this is a hit to SUSY but basically it’s like god of gaps argument. It is an ever-receding range of likelihood; if BSmeson decay ends up being the rate predicted by the standard model, there’s no space for SUSY any more. As I said above, one in 300 million is getting pretty close, so the possibility of SUSY being successful just got smaller.
Anyway, back on topic. We seem to think things should be basically symmetrical. You can see this on a spiritual scale, with the concept of karma. There’s even that sort of mentality where if you’ve done something wrong, you can assuage your guilt through good deeds (altruism). On a more scientific note, people have an expectation that the universe is perfectly balanced. Everything was “perfect” because if it wasn’t, the universe wouldn’t have formed the way it did. Everything was “perfect” for the conditions of life. We can get a little more technical and even claim the universe is perfectly “even”, as shown by the cosmological principle which suggests homogeneity.
Let’s take a look at this assumption of “perfect balance”. Well, first of all, people often quote homogeneity wrong. The universe is not completely even, nor symmetrical. That much would be obvious if you actually put some thought into it yourself instead of quoting homogeneity. The average density (as well as other factors) of the universe is the same no matter where you look, but it’s not completely uniform.
Next up, the matter-antimatter imbalance. People are often asking “if antimatter exists, where is it all?” or “how come we live on planets made of matter instead of antimatter?”. Well, let me put to rest any doubts you have about the existence of antimatter. It is real, and created on a daily basis at facilities such as the LHC. As for the imbalance? The leading theory is CP violation. Again, I don’t want to get too deep into another theory but basically CP symmetry postulates that all negative equivalents of particles should have the exact same properties (but reversed) as their positive counterparts. CP violation (or CP symmetry violation) is basically the violation of that rule. There’s quite a lot of evidence for CP violation and it can be reproduced in experiments to show that antiparticles do not, in fact, replicate their positive counterparts. Specific to the matter-antimatter imbalance is the fact that antimatter has a much shorter decay rate. Basically, it disappears faster than matter does, which is why we’re left with a predominantly matter filled universe (though I do have some evidence that could suggest antimatter clusters; I’ll save that for another post).
Finally, let’s go to the very beginning. After the Big Bang spread a cloud of cosmic gas, gravity acted to cause these to cluster and form stellar bodies. But think about it for a second. If this matter were spread perfectly evenly throughout the universe, then gravity would act on each individual particle with the exact same force in every direction. There could be no formation of anything unless there was an imbalance, an imperfection in this uniformity.
The reality? Our universe was born imperfect, and that’s why we exist today.