The theory of dark matter

in #science8 years ago

The dark; for a long time we’ve suspected it’s up to no good, only existing to provide a hiding place for goblins, vampires and random pieces of lego.

But it turns out that pretty much the entire universe is made up of stuff that we cannot see, cannot interact with and have no idea what it is.

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In fact, things we can see only make up a pathetic 5% of existence. So if you think your room looks messy now, think what it would be like if you caught a glimpse of the other 95%. Yet we stumble through life like drunk, deaf moles, barely taking in a fraction of everything around us and somehow still manage to come up with space travel, cancer treatments and frozen yoghurt.

So what is the huge amount of other stuff? Where did it come from? Can I poke it and will it care if I do? Does the dark matter?

The problem with the universe is that it’s getting too fat and we need to find a way to account for this. Once we had realized that the universe was expanding, we came up with two possible outcomes. First, that the density of matter and energy would eventually halt the continuous expansion initiated by the big bang and then the universe would collapse, disappearing back into a “big crunch” singularity.

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The second option was that it would keep expanding forever but the expansion would slow down by smaller and smaller increments. The trouble was, when we pointed the Hubble telescope at distant supernovae, not only did we accidently catch them in the shower, but we realized that in the past the universe expanded slower than it did now.

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That means not only is gravity not slowing our expansion, something must be speeding it up; we named this “something” dark energy. Dark Energy makes up 70% of the universe and dark matter makes up 25% but these two things, despite their name, didn’t appear as part of the same concept – we needed each one to account for different phenomena. For dark energy,

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it was the swelling belly of the universe, but dark matter was needed to explain the unusually large mass of galaxies.

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Jacobus Kapteyn and Jan Oort,

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after forming the ministry of unusual names became astronomers and theorized the idea of dark matter but it was Swiss Astrophysicist Fritz Zwicky

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Who after also leaving the ministry of unusual names, made the first formal theory about its existence in 1933. Zwicky was looking at a distant cluster of galaxies and worked out that the motion of the galaxies at the edge of the cluster was much faster than it
mathematically should Be.

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Where was all this extra gravitational pull coming from – there must a huge mass we aren’t able to observe. So the idea of dark matter was born; matter which has mass, therefore gravity, but almost no other interaction with baryonic matter, which is what physicists call normal matter, because they just have to have to come up with a funky word for everything.

Alright then, so there is this huge amount of stuff hiding in the cupboard. Or, more accurately, we’re stuck in a tiny cupboard and we have no idea what’s in the rest of the house. So do we know anything at all about dark matter?

Well yeah, we do. We know that it’s primordial, meaning it came from the big bang, since there’s no realistic way for it to be continuously created.

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Alright, that’s a start. But then if it was all from the big bang and it still exists now, then it must also be stable, otherwise it would have changed into something else.

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So we assume dark matter conserves something called parity, meaning that it can’t decay into ordinary matter. The simplest theory is that all dark matter is of just one type called a WIMP; weakly interacting massive particle.

So, they’re heavy but they are extremely anti-social, rarely interacting with their own kind, let alone with baryonic matter. But try as we might, we’ve yet to see a particle of dark matter.

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But who wants a world full of WIMPs? Bogdan Dobrescu and Don Lincoln

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have discussed the idea of complex dark matter, these are dark particles that interact with themselves in the same way that ordinary matter does. So it sounds like dark matter could just be a mirror of baryonic matter, with all the same rules and regulations. But we know that this can’t be exactly true, the similarities must end at some point because we see that the mass given by dark matter around galaxies is spread out in a sphere, rather than a flattened disk that our galaxies Have.

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But like ours, it could have hot and cold particles. Baryonic are cold matter but we also have hot matter, better known as neutrinos – these move close to light speed and have almost zero mass.

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Dark matter could have a similar spread with hot and dark particles; which sounds like an erotic sci-fi film, the cold dark particles would be the WIMPs we discussed earlier.

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The question is; are we ever going to find any evidence for this? There are a number of different experiments currently going on. Some are just hoping to observe that incredibly rare interaction between baryonic and dark matter, by creating an extremely insulated space where very little of the regular rays, waves and particles pass through,

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Creating all their noise, and making it difficult to see if any dark interactions are happening.

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One such example is the Large Underground Xenon Experiment.

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Another way may be to use the Large Hadron Collider.

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We won’t be able to observe it directly in the detector but, in these powerful collisions, it’s possible we could find some energy that’s missing, perhaps showing that dark emissions have occurred, accounting for this lost energy.

And when it comes to finding dark energy, well that’s equally problematic and we can
probably only observe its effects on a much grander, galactic scale. The Hobby-Eberly Telescope

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in Texas is hoping to build a 3D map of the early universe and so see more clearly what dark energy’s role was in the development of the universe.

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Who knows how much influence this dark energy and dark matter will prove to have on the world we see around us.

Thanks for reading

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ifps.pics is not an acceptable image citation. I could upload anything to that, even copyrighted material and then source it like you did...

Are you crazy? if I find the images in ifps.pics for me is my source, like others you can see wikipedia and others in images. What's your problem??

He is not crazy. He only wants to try to help you improving the quality of your post.

ifps.pic is cannot be the original source of the pictures. They must be taken from somewhere else and it is valuable to add the 'somewhere else' as a correct reference to the picture. it is like quoting google as a reference.

And please don't be so rude, we are only here to try to help. Our goal is to improve the quality of the #science tag on steemit.

This text makes the promotion of an article by B. Dobrescu and D. Lincoln from June 2015, written for the Scientific American journal. Please cite your references, this is a matter of being fair to the original authors. And please also cite the sources for the pictures...

Finally, let's go back to physics. You do mention several dark matter experiments that actually have results now (LUX for instance). It may be good to update your post to describe that, which will make it slightly up-to-date with respect to current state-of-the-art.

Other crazy! where you find the same text? tell me? i don find any in article by B. Dobrescu and D. Lincoln

In your article The LHC legacy (without any blockchain) - towards a first particle physics challenge on Steemit you have 1 image without source, why are you telling me to add source.
many do not add source in images in steemit!

Other crazy! where you find the same text? tell me? i don find any in article by B. Dobrescu and D. Lincoln

I have never said this was taken from somewhere else. I instead said that with your text, you were promoting an article written by B. Dobrescu and D. Lincoln and that you should put a reference to in your post.

From your answer, I am now puzzled. You are mentioning the name of Dobrescu and Lincoln in your text, you refer to what they wrote 1 year ago, and you claim that you cannot find their article. That sounds very surrealistic to me...

In your article The LHC legacy (without any blockchain) - towards a first particle physics challenge on Steemit you have 1 image without source, why are you telling me to add source.

Concerning my post (I do not see the point to refer to my post when you are the one not putting the sources of all your images), your accusation is futile. I always indicate the sources of all my images. Excepted for what concern images produced by myself. Which is the case for the one you are complaining about...

many do not add source in images in steemit!

And it is not because many are doing it wrong that you should do it wrong too. The steemSTEM team is here to help improving the quality of the #science category, which is why we commented your post :) We are here to help improving the content. Nothing less, nothing more.

About promoting an article written by B. Dobrescu and D. Lincoln
if I'm already talking about them why to put a reference

Concerning you post :
It is just an observation

I will say again, if the image that I add to the article i find in a, b, c, site these sites are my sources. If your criticism is constructive I thank you for you criticism :)

About promoting an article written by B. Dobrescu and D. Lincoln
if I'm already talking about them why to put a reference

For readability, it is nice to have a list of the references at the end of the posts with links to the plain articles. For readers who want to know further.

I will say again, if the image that I add to the article i find in a, b, c, site these sites are my sources.

On some sites like the one you mention, anyone can upload anything, including copyrighted material. All the images you are using can be found on official websites. Therefore, it is preferable to use the sources from there. It is a bit more work for you, but that gives more credibility to your post. At least from the perspective of (some) readers (some of them working on what you are talking about).

dark matter and dark energy as hypotheses will end in the dust bin. unless these are altered to mean non-radiative matter and the highly energetic base state of the vacuum.