(Non-baryonic) Dark Matter particles don't collide and don't lose energy through radiation (because then you would be able to see them). The consequence of this is that if you have a bunch of matter that is comprised of x% percent baryonic and y% non-baryonic matter it will evolve differently through time depending on the value of x and y. (baryonic matter tends to clump more for example) Now all you need is a snapshot of the universe at different times and you can calculate how much baryonic and non-baryonic matter there should have been in order for the universe to evolve the way it did.
The cosmic microwave background gives one such snapshot and by mapping the objects 1 Bn lightyears away you are getting a segment of the universe 1 billion years ago. Combining all these data and the laws of physics you get a best estimate for the amount of baryonic and non-baryonic dark matter.
Despite the high temperatures an astronaut would actually freeze to death out there without thermal insulation. His body would still radiate heat and the low density matter would not be able to make up for the lost energy.
That came across cruder than intended. I apologize.
I guess I'm a bit paranoid as quite a few people oppose Dark Matter on philosophical grounds. That is because they find the idea uncomfortable.
Also there's some data that suggests that Dark Matter is indeed real and no reasonable modification of gravity can reproduce some observations. Most notably gravitational lensing data from the Bullet Cluster. Sean Carroll has written an excellent post on this when the results came out last year.
A large group of chimpanzees has produced the collected works of Shakespeare four times faster than the same number of college students, and with fewer spelling errors.
My physics TA (a doctoral student) used to say that this "dark matter" talk reminded him a lot of how we posited an extra planet between Mercury and the Sun because that was the only way to account for Mercury's orbit.
Or the one where people posited an extra planet outside the orbit of Uranus. Never found that one either, right?
The article never really states that intelligence is terribly malleable. This is more of a general impression left with the reader - which is mostly incorrect.
Intelligence may or may not be malleable but what people usually think of as intelligence (the ability to learn, understand things and solve problems) can be improved by effort and practice. That's what the article says and this is supported by the work of the researcher who wrote it. And if you accept that intelligence itself becomes unimportant.
The real jackpot would have been having two habitable planets in the solar system. Or how about a giant planet in the habitable zone with two habitable giant moons? What sort of effect would that have had on our space industry?
There's one problem with that kind of thinking. Finding all technological civilizations in the Galaxy is easier than sending a fleet to the nearest star system. A lot easier. Indeed SKA will be able to detect radio leakage similar to what we are producing from as far as a thousand light years. It will be fully operational in 2020. Noone knows when we'll be able to send a ship to Alpha Centuri but I think it's safe to bet that we won't in the next 50 years.
It's actually very likely that if a civilization has the technical capability to harm us than they already know we are here. If they have the intention too than it's completely certain they already have the galaxy mapped out.
No, it isn't. The problem is that the data favor neither one model nor the other at this time Are you serious? It's one thing to say that neither is ruled out (which is true) and quite another to say both are equally likely (for most people, not really). For example even if MOND was correct we would still need dark matter for cosmological reasons.
we don't have the whole picture and we know it. GR is clearly not sufficient to model gravity, it and QM can not be made to play well together. GR is almost certainly not a completely accurate description of gravity but that doesn't mean that GR + Dark Matter can't explain current observations of galaxy rotation curves or galaxy cluster dynamics.
There are actually good ways to tell if a random number generator is truly random or not. But this study was never meant to do that, it's just a collection of random (no pun intended) statistics.
A disappointment really.
"The bottom line is that I am arguing that the scientific principle involved applies equally in all situations. It is impossible to prove that something or someone (God) in this case does not exist."
But that's not all you said. You seem to imply that becouse there is no definite logical proof both propositions (i.e.: the God of Christian religions exists/doesn't exist) have equal merit from a scientific point of view. Nothing could be further from the truth.
There are ways to look at the question scientifically. You can ask whether christianity could have arisen without Jesus actually rising from the dead. The answer it certainly yes. You can treat the more literal passages of the Bible as scientific hypotheses and see if they hold up. Many of them don't.
Yes in the end you are right, that's not a logical proof that God doesn't exist. If that really is all you claim I'm sure 99% of people here actually agree with you. Even if they are expressing it in a way that makes you think they actually disagree.
But then you do admit that for someone who has no prior beliefs the FSM/dragons/leprechauns or God is fundamentally the same? Because if you do I don't see how you could object to being called superstitious (or worse). Certainly if an adult person told you he had an invisible friend only he could see you'd think something was probably wrong with him? If you do what's the problem?
Science is certainly interested in why in the sense that scientists are trying to reduce complex phenomena to a few simple principles or equations. Science can't be defined by its scope only by its method. That is observation-hypothesis-testing. Vastly simplyfying of course.
But if a question can be explored by proposing and testing hypotheses then it is within the realm of science. It just so happens that most questions central to contemporary religions are not actively studied by scientists. But this could well change in a few decades when biologists start really understanding the physical basis of consciousness.
Slashdot Mirror
(Non-baryonic) Dark Matter particles don't collide and don't lose energy through radiation (because then you would be able to see them). The consequence of this is that if you have a bunch of matter that is comprised of x% percent baryonic and y% non-baryonic matter it will evolve differently through time depending on the value of x and y. (baryonic matter tends to clump more for example) Now all you need is a snapshot of the universe at different times and you can calculate how much baryonic and non-baryonic matter there should have been in order for the universe to evolve the way it did. The cosmic microwave background gives one such snapshot and by mapping the objects 1 Bn lightyears away you are getting a segment of the universe 1 billion years ago. Combining all these data and the laws of physics you get a best estimate for the amount of baryonic and non-baryonic dark matter.
Just wait til the writers' strike hits them.
Despite the high temperatures an astronaut would actually freeze to death out there without thermal insulation. His body would still radiate heat and the low density matter would not be able to make up for the lost energy.
As they say: "Give a troll a fish and he'll come back tomorrow. Feed him to the fishes and he'll leave you alone for the rest of your life."
Or in the dark...
For some reason the link got lost: http://cosmicvariance.com/2006/08/21/dark-matter-exists/
That came across cruder than intended. I apologize. I guess I'm a bit paranoid as quite a few people oppose Dark Matter on philosophical grounds. That is because they find the idea uncomfortable.
Also there's some data that suggests that Dark Matter is indeed real and no reasonable modification of gravity can reproduce some observations. Most notably gravitational lensing data from the Bullet Cluster. Sean Carroll has written an excellent post on this when the results came out last year.
My physics TA (a doctoral student) used to say that this "dark matter" talk reminded him a lot of how we posited an extra planet between Mercury and the Sun because that was the only way to account for Mercury's orbit. Or the one where people posited an extra planet outside the orbit of Uranus. Never found that one either, right?
The article never really states that intelligence is terribly malleable. This is more of a general impression left with the reader - which is mostly incorrect. Intelligence may or may not be malleable but what people usually think of as intelligence (the ability to learn, understand things and solve problems) can be improved by effort and practice. That's what the article says and this is supported by the work of the researcher who wrote it. And if you accept that intelligence itself becomes unimportant.
Noone is angry, they are just pointing out your ignorance.
3. The researchers interpreted the theory wrong and journalists hyped it before others had a chance to shoot it down.
The real jackpot would have been having two habitable planets in the solar system. Or how about a giant planet in the habitable zone with two habitable giant moons? What sort of effect would that have had on our space industry?
You can always write "39.5 inches (about 1 meter)". It would be actually helpful to some people, unlike the comparison to excercise balls.
There's one problem with that kind of thinking. Finding all technological civilizations in the Galaxy is easier than sending a fleet to the nearest star system. A lot easier. Indeed SKA will be able to detect radio leakage similar to what we are producing from as far as a thousand light years. It will be fully operational in 2020. Noone knows when we'll be able to send a ship to Alpha Centuri but I think it's safe to bet that we won't in the next 50 years. It's actually very likely that if a civilization has the technical capability to harm us than they already know we are here. If they have the intention too than it's completely certain they already have the galaxy mapped out.
There are actually good ways to tell if a random number generator is truly random or not. But this study was never meant to do that, it's just a collection of random (no pun intended) statistics. A disappointment really.
"The bottom line is that I am arguing that the scientific principle involved applies equally in all situations. It is impossible to prove that something or someone (God) in this case does not exist." But that's not all you said. You seem to imply that becouse there is no definite logical proof both propositions (i.e.: the God of Christian religions exists/doesn't exist) have equal merit from a scientific point of view. Nothing could be further from the truth. There are ways to look at the question scientifically. You can ask whether christianity could have arisen without Jesus actually rising from the dead. The answer it certainly yes. You can treat the more literal passages of the Bible as scientific hypotheses and see if they hold up. Many of them don't. Yes in the end you are right, that's not a logical proof that God doesn't exist. If that really is all you claim I'm sure 99% of people here actually agree with you. Even if they are expressing it in a way that makes you think they actually disagree.
But then you do admit that for someone who has no prior beliefs the FSM/dragons/leprechauns or God is fundamentally the same? Because if you do I don't see how you could object to being called superstitious (or worse). Certainly if an adult person told you he had an invisible friend only he could see you'd think something was probably wrong with him? If you do what's the problem?
Science is certainly interested in why in the sense that scientists are trying to reduce complex phenomena to a few simple principles or equations. Science can't be defined by its scope only by its method. That is observation-hypothesis-testing. Vastly simplyfying of course.
But if a question can be explored by proposing and testing hypotheses then it is within the realm of science. It just so happens that most questions central to contemporary religions are not actively studied by scientists. But this could well change in a few decades when biologists start really understanding the physical basis of consciousness.