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Interesting article, I was hoping that dark matter would prove to be observable in our solar system. I'm more curious about dark energy though. Hopefully in m

Interesting article, I was hoping that dark matter would prove to be observable in our solar system. I'm more curious about dark energy though. Hopefully in my lifetime, we can figure out what dark energy is. I'm curious what dark energy does to time since it accelerates the expansion of space. The next golden age of science resides in our understanding of the unknown matter and energy that we are currently observing.

InclinedPlane 12y ago
It's highly likely that within the next decade or two we will have a very good idea about what dark matter is actually made of and have direct observational evidence of it. The most likely candidate for dark matter is a hypothesized supersymmetric particle that happens to be weakly interacting, there are several good candidates for such. But these particles should be detectable in future particle colliders and should give rise to characteristic signals in x-ray/gamma ray emissions from galaxies as well as perhaps being directly detectable in "dark matter wind" type experiments (which leverage the significant difference in speed relative to the galactic disk the Earth experiences at different times of the year). Dark energy is still a rather large mystery, but it's possible someone will make a big breakthrough at some point.
- lurcio 12y ago
  Dark Matter, or dark energy: i can't but think its this era's ether. That is, an impasse waiting for a sizeable conceptual clarification/shake up.
  - InclinedPlane 12y ago
    That's a common sentiment among people who aren't terribly familiar with the scientific background for dark matter. I would urge you to go take a look at the wikipedia entry on dark matter and read through it, it's a good overview of a lot of the lines of evidence. The fact is that scientists have always been reluctant to believe in the existence of some exotic, new form of matter that hasn't been seen or directly detected, but in trying to disprove its existence or to prove that it's really just something else they've consistently, time after time, been stuck with that as the only option that explains the evidence. And there is quite a lot of evidence, from cosmological simulations to gravitational lensing studies to galactic rotational curves and so much more. If dark matter is what we think it probably is then it would actually make for a fairly elegant explanation. The overwhelmingly likely story is that dark matter is a kind of "supersymmetric" particle which requires very high energy conditions to create, conditions which do not generally exist much anymore, and which interacts very weakly or not at all with electromagnetic and strong nuclear forces. Highly energetic conditions were quite common in the early period of the Universe just after the big bang though, and if it were at all possible for such weakly interacting particles to exist then they would have been created in abundance, sapping a lot of the total mass/energy away from the Universe as they "fell out" of the energetic soup of the Universe. Eventually the Universe would have cooled enough to cause creation of such particles to halt, after which it would have gone on to create the more ordinary matter we know today (photons, electrons, protons, etc.) Fortunately we're likely to get a lot more data on the subject in the next few decades. As I mentioned our capabilities of directly testing the existence of dark matter particles are increasing to the point where within one to two decades we will likely have direct confirmation of their existence. I put the chances of dark matter being something other than a weakly interacting massive particle to be fairly low, though not impossible of course. As for dark energy, the evidence for the accelerating expansion of the Universe is much newer and the hypotheses attempting to explain it much more circumspect, I wouldn't be surprised if it turned out to be something other than the crude guesses we've made at present.
meric 12y ago
Layman here, I can't help but notice the similarities of how 19th century scientists describe an aether with magical properties to help plug holes in their theories to dark matter. 1. "Dark matter is a hypothetical kind of matter that cannot be seen with telescopes but accounts for most of the matter in the Universe." 2. "It is hypothesized to be matter that does not react to light." 3. "Astrophysicists hypothesized dark matter because of discrepancies between the mass of large astronomical objects determined from their gravitational effects and the mass calculated from the observable matter (stars, gas, and dust) that they can be seen to contain." 4. "dark matter — that exerts a well-understood gravitational force but neither absorbs nor emits light, and doesn’t collide (as far as we can tell) with protons, neutrons or electrons. So while normal matter (in pink, below) slows down and can even stick together when it runs into other normal matter, dark matter (in blue, below) just passes right through both itself and all other forms of matter." It sounds to me like a kind of Aether 2.0.
- tjradcliffe 12y ago
  In the sense that dark matter is a theoretical entity that is invoked to explain a particular set of astronomical observations, this is a fair comparison. Late 19th century critics of aether might have compared it to caloric (a theoretical entity that explained a particular set of thermodynamic observations.) Caloric turned out not to exist. By the same token, we might compare dark matter to neutrinos, which were a theoretical entity invoked to explain a particular set of observations on radioactivity (the shape of the beta spectrum.) Neutrinos turned out to exist. As such, while the comparison to aether is superficially apt, it is not something we can draw any conclusions from, because the comparison to the neutrino is equally apt. Science is the discipline of publicly testing ideas by systematic observation, controlled experiment and Bayesian inference. It is not the discipline of testing ideas by making analogies to other ideas. There is a reason for this: making analogies to other ideas has consistently proven to be almost completely useless for creating knowledge of reality, while the discipline of science has been wildly successful. Nor are the properties of caloric, aether, neutrinos or dark matter "magical". They are merely the ones required of an entity that is able to explain our observations in each instance. In the case of caloric it turned out to have self-contradictory properties, when the full deductive closure of the theory was teased out. In the case of aether it turned out to have properties that made predictions that were false. In the case of neutrinos the required properties made predictions that were true. In the case of dark matter: we don't know yet, and the only way we will ever know is if we continue on with our program of systematic observation, controlled experiment and Bayesian inference. There is no other way to know.

InclinedPlane 12y ago

It's highly likely that within the next decade or two we will have a very good idea about what dark matter is actually made of and have direct observational evidence of it. The most likely candidate for dark matter is a hypothesized supersymmetric particle that happens to be weakly interacting, there are several good candidates for such. But these particles should be detectable in future particle colliders and should give rise to characteristic signals in x-ray/gamma ray emissions from galaxies as well as perhaps being directly detectable in "dark matter wind" type experiments (which leverage the significant difference in speed relative to the galactic disk the Earth experiences at different times of the year). Dark energy is still a rather large mystery, but it's possible someone will make a big breakthrough at some point.

lurcio 12y ago
Dark Matter, or dark energy: i can't but think its this era's ether. That is, an impasse waiting for a sizeable conceptual clarification/shake up.
- InclinedPlane 12y ago
  That's a common sentiment among people who aren't terribly familiar with the scientific background for dark matter. I would urge you to go take a look at the wikipedia entry on dark matter and read through it, it's a good overview of a lot of the lines of evidence. The fact is that scientists have always been reluctant to believe in the existence of some exotic, new form of matter that hasn't been seen or directly detected, but in trying to disprove its existence or to prove that it's really just something else they've consistently, time after time, been stuck with that as the only option that explains the evidence. And there is quite a lot of evidence, from cosmological simulations to gravitational lensing studies to galactic rotational curves and so much more. If dark matter is what we think it probably is then it would actually make for a fairly elegant explanation. The overwhelmingly likely story is that dark matter is a kind of "supersymmetric" particle which requires very high energy conditions to create, conditions which do not generally exist much anymore, and which interacts very weakly or not at all with electromagnetic and strong nuclear forces. Highly energetic conditions were quite common in the early period of the Universe just after the big bang though, and if it were at all possible for such weakly interacting particles to exist then they would have been created in abundance, sapping a lot of the total mass/energy away from the Universe as they "fell out" of the energetic soup of the Universe. Eventually the Universe would have cooled enough to cause creation of such particles to halt, after which it would have gone on to create the more ordinary matter we know today (photons, electrons, protons, etc.) Fortunately we're likely to get a lot more data on the subject in the next few decades. As I mentioned our capabilities of directly testing the existence of dark matter particles are increasing to the point where within one to two decades we will likely have direct confirmation of their existence. I put the chances of dark matter being something other than a weakly interacting massive particle to be fairly low, though not impossible of course. As for dark energy, the evidence for the accelerating expansion of the Universe is much newer and the hypotheses attempting to explain it much more circumspect, I wouldn't be surprised if it turned out to be something other than the crude guesses we've made at present.

meric 12y ago

Layman here, I can't help but notice the similarities of how 19th century scientists describe an aether with magical properties to help plug holes in their theories to dark matter. 1. "Dark matter is a hypothetical kind of matter that cannot be seen with telescopes but accounts for most of the matter in the Universe." 2. "It is hypothesized to be matter that does not react to light." 3. "Astrophysicists hypothesized dark matter because of discrepancies between the mass of large astronomical objects determined from their gravitational effects and the mass calculated from the observable matter (stars, gas, and dust) that they can be seen to contain." 4. "dark matter — that exerts a well-understood gravitational force but neither absorbs nor emits light, and doesn’t collide (as far as we can tell) with protons, neutrons or electrons. So while normal matter (in pink, below) slows down and can even stick together when it runs into other normal matter, dark matter (in blue, below) just passes right through both itself and all other forms of matter." It sounds to me like a kind of Aether 2.0.

tjradcliffe 12y ago
In the sense that dark matter is a theoretical entity that is invoked to explain a particular set of astronomical observations, this is a fair comparison. Late 19th century critics of aether might have compared it to caloric (a theoretical entity that explained a particular set of thermodynamic observations.) Caloric turned out not to exist. By the same token, we might compare dark matter to neutrinos, which were a theoretical entity invoked to explain a particular set of observations on radioactivity (the shape of the beta spectrum.) Neutrinos turned out to exist. As such, while the comparison to aether is superficially apt, it is not something we can draw any conclusions from, because the comparison to the neutrino is equally apt. Science is the discipline of publicly testing ideas by systematic observation, controlled experiment and Bayesian inference. It is not the discipline of testing ideas by making analogies to other ideas. There is a reason for this: making analogies to other ideas has consistently proven to be almost completely useless for creating knowledge of reality, while the discipline of science has been wildly successful. Nor are the properties of caloric, aether, neutrinos or dark matter "magical". They are merely the ones required of an entity that is able to explain our observations in each instance. In the case of caloric it turned out to have self-contradictory properties, when the full deductive closure of the theory was teased out. In the case of aether it turned out to have properties that made predictions that were false. In the case of neutrinos the required properties made predictions that were true. In the case of dark matter: we don't know yet, and the only way we will ever know is if we continue on with our program of systematic observation, controlled experiment and Bayesian inference. There is no other way to know.