Yes, it is a picture of the entire universe when it was 400,000 years old taken today from the earth. But in the same way we take pictures with photo cameras, the object which the picture was taken of is 3D but the resulting picture itself is 2D. In the case of the CMB, we can think of the picture as follows: for each latitude and longitude on the earth, you point a camera straight up and record the CMB photons coming from that direction. Then, for each point on the surface of the earth (2D) you have a number - and that's the picture. These photons are coming from a very distant place in the universe and started traveling to us a very long time ago; and the energy of those photons is proportional to the amount of energy there was at that point in the universe when the photon started its trip towards the earth. Then that picture is telling us what the distribution of matter-energy was 400,000 years after the big bang.
You are perfectly right that the picture is like the internal surface of a sphere, and I've seen balloons with the CMB painted on it, which is probably the best representation of the picture. However, we like to have things on flat paper, and for that we need a projection from the surface of the sphere to a flat space. This is equivalent to the projections used to represent world maps on flat surfaces. I'm not sure what the particular projection used for CMB is.
Another interesting fact is that that picture is not the "actual" picture taken: it has been through two processes. In fact, originally it looks like this. This is due to the well-known doppler effect. We are moving with respect to the CMB photons, so the photons coming from the direction we're moving into seem to be more energetic than the photons coming from the opposite direction. This fact allows us to measure the speed we're moving through the CMB which happens to be about 600km/s.
After correcting for the doppler effect, what's left is this. In fact, the universe was extremely homogeneous 400,000 year after the big bang. However if one looks carefully it is possible to detect inhomogeneities in that picture, as small as 1 in 10^5. Those inhomogeneities is what actually is represented in the pictures as the one I showed in the previous post.
The decoupling of matter and radiation is an extremely interesting event that happened 400,000 years after the big bang. Its nature makes it the oldest possible observable event, and interestingly enough, thanks to experiments as COBE and WMAP we have very pretty pictures of that event.
Are you suggesting we should let "stupid" (poor, maybe?) people die from starvation or diseases in order to boost progress? I'm afraid there's something I'm not understanding, since I cannot believe such an offensive comment got modded insightful. People with no economical resources who need to get the advantages of the socialist welfare you're talking about are not poor because they're stupid. They have less opportunities for good nutrition and education because they are born poor. So if you want to have less "stupid" people, we should give more opportunities and education to those sectors of society. Not giving them the resources to reproduce won't solve the problem because we live in a system that makes a big fraction of population poor.
And you should read some more history. The only socialism in the nazi party is in the name.
Now the next big step would be to come up with the best strategy. I didn't RTFA but I guess it'll take years for someone to summarize that gigantic tree in a set of general rules...
According to what you're saying, I could *legally* sniff all unencrypted traffic getting to my wireless card. IANAL but I guess there's a limit in "any broadcast transmission", and wifi is out.
Experiments like these will eventually force us to confront the fact that punishing people for their "moral choices" is inconsistent with our scientific knowledge.
A very interesting point indeed. In fact I've been thinking about it some time ago, but I'm not sure I agree with your conclusion.
I like to think of the world as a deterministic one. There is an astonishing degree of predictability in both scientific research and everyday life. The mere fact that there is a temporal correlation of events (I'm looking at you, I blink, and you're still there) suffices me to think that to a very good approximation, reality is predetermined. The question remains of whether humans are predictable or not, but for the sake of argument, let me assume it is true.
Although (hypothetically) being a deterministic system, a human being is a self adapting system. As a computer, we take some input and process it to "decide" what to do, in order to maximize profit in some personal definition. On the other hand, society as a whole is a self adapting system as well, which sets some rules and punishes the "wrongdoers" among other things, to maximize some profit too.
In other words, who cares if I have free will to do what I would? Society needs something from me, and knows that when I'm given some input (I get punished, for example), I behave in a way useful to society (a.e. I don't steal, so order is preserved). With that in mind, punishment makes sense even in a deterministic reality (but this fact is predetermined as well, I know...)
you're kidding, aren't you? If you're not, I'm sorry for you. Fortunately the world is changing, in the sense you seem to fear so much. I'm afraid of people like you, who consider that we are not prepared to handle information, and it's your, the government's, or whoever's duty to hide it from us to keep society working. And related to that, maybe regarding the free as in free spech side of Open Source, I hope that the idea that sharing and cooperating is good transcends the computer software world, so when we teach our children to share they don't get so confused when they see what's going on in the outside world.
I am already getting bored with all these articles about robots, isn't there anything worthy going on in the IT world besides robots that can do human-like things?
I mean, my problem is, slashdot is getting boring! I need something to read about while I'm at work! How am I gonna be productive like that? Oh, wait...
What you say is exactly true. Einstein added the cosmological constant so that the universe was static (which was very reasonable at that time, what kind of crazy would think the universe was expanding or contracting??) Later, it was discovered by observing that galaxies fly away from us that the universe does actually expand, and Einstein regretted his mistake: he could have predicted one of the major breakthroughs in the 20th century. But the universe seem to be expanding much faster than it should, considering the amount of matter we see in the universe. There was something missing... People thought that the forgotten cosmological constant would be handy, it just causes the universe to accelerate its expansion. But what is that cosmological constant? Well, some people suggest it is just a quantum effect, vaccum energy. But their theory is the worst disagreemt between theory and observations in the history of physics: their prediction is off by more than 120 orders of magnitude. Nevertheless, even tough the idea of cosmological constant lacks of first principles fundaments, it fits very well the observation, especially Cosmic Microwave Background anisotropies and the growth of perturbations in the universe. But that's not the only possible explanation of the accelerating expansion. There are many people working on alternative theories of gravitation, usually in many dimentions (DGP theory among others) that say that Einstein's gravity is correct at small distancies, but at cosmological distancies is weaker allowing the faster expansion. Another less esotherical theory, by Rocky Kolb, one of the fathers of modern cosmology, is that there are "nonlinear" effects due to the perturbations in the matter density field: he tries to solve Einstein's theory by suggesting that there are some wrong assumptions in the current predictions of gravitation.
Oh, by the way, 10% is not so bad in cosmology. We're just entering the "precision cosmology era"... 10 years ago, the deviations were of the order of 200% so you get an idea:)
I agree partially with your argument. I think that the bottom line of science is not provable. For example, the simple fact of describing space-time with 4 numbers is no verifiable, it doesn't have any physical consecuencies. Or interpreting the wave function in quantum mechanics as a distribution of probabilities. Per se, that's not verifiable either, and there are even other equally valid interpretations. All of that comes to the concept of paradigm. We as scientists accept as a group "working assumptions" which seem valid and seem to be a useful. What do I mean by useful? I mean that they provide motivation for experiments and theoretical research. When those assumptions go dry, that is, when they are not useful anymore, they are challenged by other different assumptions, and if they're proved useful in the sense before, scientists finally take them. But in the end, they're just useful assumptions.
But my point is different, I think that science's purpose is to understand HOW things work so we can make verifiable predictions for the future. It doesn't matter if the assumptions are right or wrong. What science wants is to make bridges and to know if they're gonna break or not. Science is our refined technique for making tools, a technique that let us evolve into what we are now. But that's it, science doesn't care at all about why things are the way they are. Or about making people happy. Or about fulfilling the spiritual needs of every human being.
And that's what religion is about. It's not about explaining the unexplainable, but just one way of developing our spiritual half. And I think that is really important. But ID people are trying to apply religion where it doesn't apply, they are trying to explain why the world is as we see it, and the Kansas board of education is trying to call it science. The Kansas board people are plain stupid, I feel sorry for them. And the religious people behind ID are just wasting time, they fail to realize the true meaning of religion. And there were many like them in the history of humanity. I hope they will understand their role and importance for each one of us, and help us be complete human beings.
This is just my opinion, I wanted to share it with you...
there is a hunter who wakes up one day in his house, walks out, and sees the sun just above the horizon. So he decides to go hunting. He unavoidably walks three miles to the south, then four miles to the west. He finds a bear and kills it... (sigh). Well, the questions are: 1) how far is the hunter's house from the dead bear. 2) what date is it. 3) what is the dead bear's colour.
I don't exactly understand what you you're interested in... is it just the first derivative? Ok it goes like that:
log f=(1/x) log(x) ---> f'/f=((1/x)log(x))'=(1-log(x))/x^2 --->
f'(x)=x^(1/x) (1-log(x))/x^2
if you want to know where it peaks, well, f'(x)=0 when log(x)=1, that is, when x=e
I just calculated it on a paper napkin, so it might have some mistake... but the idea should be clear
well, that's exactly the point. The equation is saying that mass and energy are two manifestations of the same reality. So it is harder to change the speed of a 10kg rest mass object if it's moving since the kinetic energy adds inertia (mass) to the object. Just to be the third pedantic one: m=m0/sqrt(1-v^2/c^2)
Slashdot Mirror
Yes, it is a picture of the entire universe when it was 400,000 years old taken today from the earth. But in the same way we take pictures with photo cameras, the object which the picture was taken of is 3D but the resulting picture itself is 2D. In the case of the CMB, we can think of the picture as follows: for each latitude and longitude on the earth, you point a camera straight up and record the CMB photons coming from that direction. Then, for each point on the surface of the earth (2D) you have a number - and that's the picture. These photons are coming from a very distant place in the universe and started traveling to us a very long time ago; and the energy of those photons is proportional to the amount of energy there was at that point in the universe when the photon started its trip towards the earth. Then that picture is telling us what the distribution of matter-energy was 400,000 years after the big bang.
You are perfectly right that the picture is like the internal surface of a sphere, and I've seen balloons with the CMB painted on it, which is probably the best representation of the picture. However, we like to have things on flat paper, and for that we need a projection from the surface of the sphere to a flat space. This is equivalent to the projections used to represent world maps on flat surfaces. I'm not sure what the particular projection used for CMB is.
Another interesting fact is that that picture is not the "actual" picture taken: it has been through two processes. In fact, originally it looks like this. This is due to the well-known doppler effect. We are moving with respect to the CMB photons, so the photons coming from the direction we're moving into seem to be more energetic than the photons coming from the opposite direction. This fact allows us to measure the speed we're moving through the CMB which happens to be about 600km/s.
After correcting for the doppler effect, what's left is this. In fact, the universe was extremely homogeneous 400,000 year after the big bang. However if one looks carefully it is possible to detect inhomogeneities in that picture, as small as 1 in 10^5. Those inhomogeneities is what actually is represented in the pictures as the one I showed in the previous post.
The decoupling of matter and radiation is an extremely interesting event that happened 400,000 years after the big bang. Its nature makes it the oldest possible observable event, and interestingly enough, thanks to experiments as COBE and WMAP we have very pretty pictures of that event.
Are you suggesting we should let "stupid" (poor, maybe?) people die from starvation or diseases in order to boost progress? I'm afraid there's something I'm not understanding, since I cannot believe such an offensive comment got modded insightful. People with no economical resources who need to get the advantages of the socialist welfare you're talking about are not poor because they're stupid. They have less opportunities for good nutrition and education because they are born poor. So if you want to have less "stupid" people, we should give more opportunities and education to those sectors of society. Not giving them the resources to reproduce won't solve the problem because we live in a system that makes a big fraction of population poor.
And you should read some more history. The only socialism in the nazi party is in the name.
Now the next big step would be to come up with the best strategy. I didn't RTFA but I guess it'll take years for someone to summarize that gigantic tree in a set of general rules...
You must be new around here, aren't you?
According to what you're saying, I could *legally* sniff all unencrypted traffic getting to my wireless card. IANAL but I guess there's a limit in "any broadcast transmission", and wifi is out.
A very interesting point indeed. In fact I've been thinking about it some time ago, but I'm not sure I agree with your conclusion.
I like to think of the world as a deterministic one. There is an astonishing degree of predictability in both scientific research and everyday life. The mere fact that there is a temporal correlation of events (I'm looking at you, I blink, and you're still there) suffices me to think that to a very good approximation, reality is predetermined. The question remains of whether humans are predictable or not, but for the sake of argument, let me assume it is true.
Although (hypothetically) being a deterministic system, a human being is a self adapting system. As a computer, we take some input and process it to "decide" what to do, in order to maximize profit in some personal definition. On the other hand, society as a whole is a self adapting system as well, which sets some rules and punishes the "wrongdoers" among other things, to maximize some profit too.
In other words, who cares if I have free will to do what I would? Society needs something from me, and knows that when I'm given some input (I get punished, for example), I behave in a way useful to society (a.e. I don't steal, so order is preserved). With that in mind, punishment makes sense even in a deterministic reality (but this fact is predetermined as well, I know...)
Actually you didn't catch another typo. It should read: "Microsoft Launches Sad Effort to Fight Privacy". Now it's fixed!
In Soviet Russia.... music plays you!
you're kidding, aren't you? If you're not, I'm sorry for you. Fortunately the world is changing, in the sense you seem to fear so much. I'm afraid of people like you, who consider that we are not prepared to handle information, and it's your, the government's, or whoever's duty to hide it from us to keep society working.
And related to that, maybe regarding the free as in free spech side of Open Source, I hope that the idea that sharing and cooperating is good transcends the computer software world, so when we teach our children to share they don't get so confused when they see what's going on in the outside world.
croto
I am already getting bored with all these articles about robots, isn't there anything worthy going on in the IT world besides robots that can do human-like things?
I mean, my problem is, slashdot is getting boring! I need something to read about while I'm at work! How am I gonna be productive like that? Oh, wait...
I was going to ask why you waste your time like that... and I realized that I'm two times dumber by replying. Whatever.
when someone invents a gadget to atract teens, preferably girls ;)
Oh, wait, you're right. I guess I should stop the cheap p0rn movies
What you say is exactly true. Einstein added the cosmological constant so that the universe was static (which was very reasonable at that time, what kind of crazy would think the universe was expanding or contracting??) Later, it was discovered by observing that galaxies fly away from us that the universe does actually expand, and Einstein regretted his mistake: he could have predicted one of the major breakthroughs in the 20th century. But the universe seem to be expanding much faster than it should, considering the amount of matter we see in the universe. There was something missing... People thought that the forgotten cosmological constant would be handy, it just causes the universe to accelerate its expansion. But what is that cosmological constant? Well, some people suggest it is just a quantum effect, vaccum energy. But their theory is the worst disagreemt between theory and observations in the history of physics: their prediction is off by more than 120 orders of magnitude. Nevertheless, even tough the idea of cosmological constant lacks of first principles fundaments, it fits very well the observation, especially Cosmic Microwave Background anisotropies and the growth of perturbations in the universe.
:)
But that's not the only possible explanation of the accelerating expansion. There are many people working on alternative theories of gravitation, usually in many dimentions (DGP theory among others) that say that Einstein's gravity is correct at small distancies, but at cosmological distancies is weaker allowing the faster expansion.
Another less esotherical theory, by Rocky Kolb, one of the fathers of modern cosmology, is that there are "nonlinear" effects due to the perturbations in the matter density field: he tries to solve Einstein's theory by suggesting that there are some wrong assumptions in the current predictions of gravitation.
Oh, by the way, 10% is not so bad in cosmology. We're just entering the "precision cosmology era"... 10 years ago, the deviations were of the order of 200% so you get an idea
I agree partially with your argument. I think that the bottom line of science is not provable. For example, the simple fact of describing space-time with 4 numbers is no verifiable, it doesn't have any physical consecuencies. Or interpreting the wave function in quantum mechanics as a distribution of probabilities. Per se, that's not verifiable either, and there are even other equally valid interpretations. All of that comes to the concept of paradigm. We as scientists accept as a group "working assumptions" which seem valid and seem to be a useful. What do I mean by useful? I mean that they provide motivation for experiments and theoretical research. When those assumptions go dry, that is, when they are not useful anymore, they are challenged by other different assumptions, and if they're proved useful in the sense before, scientists finally take them. But in the end, they're just useful assumptions.
But my point is different, I think that science's purpose is to understand HOW things work so we can make verifiable predictions for the future. It doesn't matter if the assumptions are right or wrong. What science wants is to make bridges and to know if they're gonna break or not. Science is our refined technique for making tools, a technique that let us evolve into what we are now. But that's it, science doesn't care at all about why things are the way they are. Or about making people happy. Or about fulfilling the spiritual needs of every human being.
And that's what religion is about. It's not about explaining the unexplainable, but just one way of developing our spiritual half. And I think that is really important. But ID people are trying to apply religion where it doesn't apply, they are trying to explain why the world is as we see it, and the Kansas board of education is trying to call it science. The Kansas board people are plain stupid, I feel sorry for them. And the religious people behind ID are just wasting time, they fail to realize the true meaning of religion. And there were many like them in the history of humanity. I hope they will understand their role and importance for each one of us, and help us be complete human beings.
This is just my opinion, I wanted to share it with you...
abcabc/13=(abc+1000*abc)/13=abc*1001/13=abc*77 nice!
what about this one guys:
there is a hunter who wakes up one day in his house, walks out, and sees the sun just above the horizon. So he decides to go hunting. He unavoidably walks three miles to the south, then four miles to the west. He finds a bear and kills it... (sigh). Well, the questions are: 1) how far is the hunter's house from the dead bear. 2) what date is it. 3) what is the dead bear's colour.
It's one of my favourite riddles.
I don't exactly understand what you you're interested in... is it just the first derivative? Ok it goes like that: log f=(1/x) log(x) ---> f'/f=((1/x)log(x))'=(1-log(x))/x^2 ---> f'(x)=x^(1/x) (1-log(x))/x^2 if you want to know where it peaks, well, f'(x)=0 when log(x)=1, that is, when x=e I just calculated it on a paper napkin, so it might have some mistake... but the idea should be clear
well, that's exactly the point. The equation is saying that mass and energy are two manifestations of the same reality. So it is harder to change the speed of a 10kg rest mass object if it's moving since the kinetic energy adds inertia (mass) to the object. Just to be the third pedantic one: m=m0/sqrt(1-v^2/c^2)