games for pc
Home » Science

More philosophical meanderings

by October 20, 2009 3 Comments

My mom writes in a comment:

I think I would like to know what the consequences are of discovering or measuring dark matter. Also, does what you are doing have any relation whatsoever to things like the Hubble telescope or general space travel that people seem to be doing more and more of? Might your discoveries, for instance, give us an idea of the future of the universe as we know it?
xox MOM

These are good questions. What would be the consequences of discovering dark matter? When people ask me this question, one of the first things that I have to emphasize is that there are no foreseeable applications to my research. Nothing obviously useful will come out of it, unlike, for example, research in quantum computing or more applied fields. Now, there's always the chance that something we develop in trying to detect dark matter could be useful to society (for example, there are a number of ideas to use technologies developed in this field for detecting nuclear weapons at border crossings), but I believe that justifying this research by appealing to possible applications is dishonest.

The only reason I have for searching for dark matter is to increase our ("Mankind's" with a capital M) understanding of the universe. 23% of the universe is dark matter, and 85% of all the matter is dark. There are two aspects to this. The first is humanity's standard musings over "why are we here? how did we get here?" Dark matter is a key component to the evolution of the universe, influencing the expansion rate of the universe and the way matter first clustered to form stars and then planets. If it didn't exist in the way that it does, the Earth would probably not exist and neither would this blog. I'm touching up on religion again, here, which interestingly enough seems to happen quite a lot in this blog.

The second aspect that interests me is that I just think it's cool to know more about the way the universe works. Why is there more matter than antimatter in the universe (another great physics question, as naively we might expect identical amounts in which case we would have all disappeared in a puff of energy a long long time ago)? What was the big bang? Does dark matter really take the form we think it does (I sort of like the fact that we can predict the existence of a particle and then go out and find it, which has happened many times in the past)?

To answer my mom's other questions, this is very closely related to the Hubble telescope in the sense that a lot of the evidence for dark matter comes from telescopes like Hubble, and that telescopes have a chance to detect dark matter in a completely different way from us. Not so much space travel, which in my mind isn't so interesting.

The picture is a simulation of structure formation in the universe. All the filaments and bright sports are made of dark matter (Courtesy http://www.casca.ca/ecass/issues/1997-DS/West/ and interestingly enough titled "hugh.gif")

    

    Subscribe via RSS

  • Dianna Pax

    I enjoyed reading this! It's so difficult to find others who have a love of cosmology. Thank you.

    I do have a few questions, if it's ok to ask in this forum: What are some of the(seriously considered)hypotheses on the component(s)of dark matter? How are they testable? Has there been any evidence yet to suggest that any of the proposed ideas are correct?

    Or, can you suggest a great book/paper to answer some of these questions?

    Thanks again!

  • Geof Cornish

    Touching on religion ? Great, but it seems like it's more a question of the existence of matter, time, and scientific facts.
    Faith, (ones belief system or faith tradition) spirituality, (the feelings of being in touch with the infinite, belonging, or potential in oneself) and religion (the institution as it is perceived or organizationally structured with churches and humans) are very different matters.
    Let science discover everything it will and can, I mean... Bring It On ! and then lets make the greatest minds of thinkers and theologians really work for their livings .... not sit in haughty detached, arrogance. Thomas Aquinas brought Aristototelean logic to feudal Christianity. and eventually science leapt forward. We should all appreciate and love science for all of the life, joy, and new vigor it regularly adds to the discussions. It is the very act of discussing that helps us all learn ... but when will we learn that the mystery will never end.....ever !

  • Hugh

    Hi Dianna,
    There are a number of seriously considered hypotheses for the nature of dark matter. In the long term, I may try to talk about them in more detail but they include things like the "WIMPs" that I am looking for. Basically as the evidence for the existence of dark matter continues to grow, theorists have begun postulating the existence of particles that could solve the mystery. For example, one popular theory is "supersymmetry." The idea in supersymmetry is that every particle we know has a partner that happens to be very heavy. The electron would have a supersymmetric partner, the "selectron." Quarks would have "squarks" as partners. These theoretical partners could be stable and have the right mass to be the dark matter - we just haven't been able to make them yet because our terrestrial particle accelerators don't have enough energy. Of course, this is only one theory.

    Can these theories be tested? Yes and no. Experiments like mine are seeking to directly detect a dark matter particle, and if we found one, then we'd start being able to say something about its nature. If we don't find one, then at the very least we can rule out particular theories. The problem is there's always the chance that we'll get unlucky and dark matter will take a form that we can't detect experimentally (at least not in the near future). Then we'll be stuck where we are, knowing something is out there but without any idea how.
    Hugh