So that's why all the quantum physics articles are written from the perspective of a senior/grad student in quantum theory. The articles all seem to jump over the introductory level and right into the higher math.
There's a few things going on here that are related in different ways.
1) The single-top isn't the only quark being produced, it's actually produced with a bottom quark at the same time. Usual top quark production is in pairs, one top quark one anti-top quark, but single-top is different; a top quark is produced with a anti-bottom quark.
2) The top quark decays before it can hadronize. That is, it decays before it can pick up a partner quark. This is completely allowed in the Standard Model, but I'm a bit sketchy on the details. I think it behaves as though it was attached with the other quark it was produced with.
The fine article says that this results limits the number of possible quarks. Can someone give an explanation (or even the outline of one) at a level that someone with a B.S. in physics can understand?
One of the things single-top is sensitive to is the coupling strength of the top and bottom quarks via the weak force. The value of this coupling is tightly constrained if one assumes that there are only six quarks (ie. there are three generations of matter). The fact that they measured it and it's within the six quark ballpark means that it is very likely that there isn't another pair of quarks waiting to be discovered.
The basic idea is that if the top and bottom coupling strength is measured to be less than the value we expect for six quarks then that means that some of that coupling strength actually goes to a different, seventh or eighth, quark. But I'm grossly simplifying things here for the general slashdot crowd.
This is not a major discovery, but it is another important showing off of the 'standard model' working very well at the energies we have so far probed.
Single-top is, however, one of the backgrounds in the search for the Higgs boson. For Fermilab to discover the Higgs, they have to discover single-top first.
Emphases mine... I am not convinced this isn't a faked signal. With that possibility having a chance of one in four million, how many millions of collisions have they done in the past 15 years? Far more than 4 million, I would suspect.
You aren't quite grasping what he means by one in four million. This wasn't a single event we are talking about here.
The way the statistics work is that you would have to run the entire Fermilab experiment four million times to get what they see from a fake signal. It's a cumulative probability over all the events ever recorded at Fermilab.
...and another thing. Look at that diagram showing a muon went here and a neutrino went there - how in the world did they detect that neutrino, I ask? I bet it zipped right through their detector without so much a pausing to say hello.
They didn't detect it directly. The key to 'detecting' the neutrino is to count up everything else in the remnants collision and notice that it recoils off of something that you didn't detect. It acts as though what you can see in your detector is violating the conservation of energy. But in reality there's an undetectable neutrino zipping through the detector. So you calculate how much energy and in which direction such a neutrino would travel in order to conserve energy, and that's where they get that little diagram.
Arbitary codes like this and One time pads have been proven (when done correctly) to be absolutely secure, whereas all encryption in theory is insecure (the only exception is quantum encryption)
The thing is, quantum encryption is a one time pad system. It's a secure way of distributing the one time pad.
WebKit itself is doing 100/100 on Acid3. One would assume that Chrome would be performing similarly as it is based on WebKit, especially when this 100/100 result was achieved in March of 2008. Is Chrome based on an older fork of WebKit? Or is something else going on here?
I know that there are a lot of vehicles emitting GPS signals...
GPS does not work that way. The GPS receiver doesn't actually send any radio frequencies, it only receives signals from the GPS satellites that tell the receiver how long it took the signal to reach you, and from that calculate your position.
So, instead of looking for a GPS signal (which would be coming from a satellite, not any GPS receiver), you are looking for radio frequency that is broadcasting what location the GPS receiver detects. Systems like OnStar do this via the cell phone network, but it could conceivably be carried over just about anything. Or the device could just store the history of locations on the device itself and the cops just hope to retrieve it later. The latter would be near undetectable as one would have to look for the RF emitted by running electronics in order to detect it.
Tor is an anonymizing network, it's not end-to-end encryption.
With the use of Hidden services, it is. If you connect to a Hidden service on Tor, the last hop in the Tor network is to the server your connecting to and it is end-to-end encrypted.
Tracker data and.torrent transfer would be good uses for this channel, but not the raw data. I'm surprised TPB doesn't have it already set up.
1. Entanglement. Is this a fact or a theory? Looking on web I found only few experiments with some possible loopholes. I found the principle hard to grok.
2. Heisenberg principle. It mainly states that observing an object you are changing the state of the object. The Heisenberg example from wikipedia is using a photon for measuring the position of an electron and the photon is changing the position of electron. What is happening if you are using a smaller particle that is not impacting the electron so much? Are you going to change the constant? Looks mostly like a limitation from a time when the atom was considered to be indivisible.
The Wikipedia entries are written from the perspective of a physicist, so they aren't going to be much use to laypeople.
1. Entanglement: It is fact. If you send a photon through a certain type of non-linear crystal, two photons will emerge that are entangled quantum mechanically. To truly understand this requires some knowledge of quantum mechanics, a basic introduction to QM and entanglement can be found here and here if you care to learn more.
2. Heisenberg principle: You inadvertently stumbled onto the problem yourself, kinda. When trying to measure the position of the electron, you use a high energy photon and this photon. When this high energy photon interacts with the electron it alters the velocity of the electron, so you know less about the velocity of the electron. When trying to measure the velocity of the electron, you use a low energy photon. This low energy photon measures the velocity well, but it moves the electron a little bit, so you don't know its position. This issue is the essence of the Heisenberg uncertainty principle.
At the end of the lecture, a little old lady at the back of the room got up and said: "What you have told us is rubbish. Web development is really Ruby supported on the back of Rails."
The developer gave a superior smile before replying, "What is Rails standing on?"
We can. In fact, it's been done. This isn't the real goal of the project, though:
"This Windows to the Universe Citizen Science Event is designed to encourage learning in astronomy!"
They're trying to increase awareness of astronomy and the detrimental effects of light pollution. If it just gets people aware it's worth it. I might just do it myself so I have a measure of how much light pollution there really is in my backyard.
You lost me there. I downloaded the source for their native Qt/Mac implementation and the./configure script had the audacity to force me to 'accept' the GPL as my license be for it would let me compile! A company that confused about the GPL should reevaluate distributing software under the GPL in the first place. I can understand putting the GPL in a.dmg or an.pgk that Installer.app forces you to click, that's just a silly developer putting the GPL somewhere it doesn't belong, but when a company goes out of it's way to make you type the letter 'a' stating you accept the GPL in a configure script is pushing the bounds of sanity. I sent them an email that I'm sure got promptly tossed aside. I had the full intention of accepting the GPL in the terms of the license itself, not artificial additional terms Trolltech feels they can enforce on me.
I recently installed the Free Software version of Qt/Mac on my computer, and was dismayed to find that I had to 'accept' the GPL before it would let me compile and install. This is contrary to the GPLv2 license itself, which states (taken directly from the LICENSE.GPL file included with my download):
"5. You are not required to accept this License, since you have not
signed it. However, nothing else grants you permission to modify or
distribute the Program or its derivative works. These actions are
prohibited by law if you do not accept this License. Therefore, by
modifying or distributing the Program (or any work based on the
Program), you indicate your acceptance of this License to do so, and
all its terms and conditions for copying, distributing or modifying
the Program or works based on it."
The text of the GPL in the section is very clear, and requiring users to 'accept' the GPL prior to being able to simply install GPL software is completely unnecessary. The Free Software Foundation is very clear on this point: "The license does not require anyone to accept it in order to acquire, install, use, inspect, or even experimentally modify GPL'd software" from http://www.gnu.org/philosophy/enforcing-gpl.html
Sneezing in an airport is not the same as having a electronic board with batteries attached to it.
Your comparisons are awful and you are just turning a blind eye to the real problem.
Typical liberal trying to play the victim and get some attention from the media.
Typical conservative playing the "Typical Liberal" card. Ad hominem works both ways, and I didn't post anonymously.
How is it not the same? It's a broad over generalization and overreaction based on the facts. And it was one battery.
My analogies do suck, but when people are being prosecuted because investigations don't turn up guilt to the original charge, they are exactly what's going on. You do something innocuous that someone thinks is suspicious, then you are prosecuted for just being suspicious.
"The real problem" as you so blatantly put it (without stating the problem for clarification) is that we have made the choice to be safe instead of the choice to be safe and free.
We could execute her for being stupid, if that's what you want. We could throw her in jail for... for what exactly? A Hoax? She didn't intend for it to be a hoax. Innocuous intent protects speech-like actions.
I think you are correct up until you reference the girl in the airport. In all honesty she invited lethal force. She was lucky they didnt use it.
She is stupid and deserves to be punished severely.
Have you seen the device? It was a proto-board with 5 LEDs, resistors and a 9V battery. While I can understand the initial reaction to the device as being proper (it's wierd, check it out!) but when you start punishing people severely for something that was not intended to create a panic of any sort you are inviting punishment for all sorts of actions. Sneeze in an airport? They might arrest you for having a hoax biological weapon. That taffy looks a little suspicious and he has batteries in his carry-on, it must be C4! And when it turns out not to be, your still charged with having a hoax bomb.
"In Germany, they came first for the Communists, And I didn't speak up because I wasn't a Communist;
And then they came for the trade unionists, And I didn't speak up because I wasn't a trade unionist;
And then they came for the Jews, And I didn't speak up because I wasn't a Jew;
And then . . . they came for me . . . And by that time there was no one left to speak up." - Martin Niemöller
Suspicion and investigation are fine (to an extent). It's when you talk about summary execution and charging every person that you investigate of terrorism with a 'hoax' that you've really tossed out the freedoms that America used to stand for.
This wouldn't exactly do the torrent community any favors, but if I were running a torrent client from a campus LAN, I'd block inbound connections from IPs not on my campus. If they cant see me sharing, they cant sue me.
That's exactly what the network topology is like at the University of Illinois, all incoming connections that aren't on campus are automatically firewalled, unless you convince everyone in your dorm room to agree to move you to the 'Mostly Closed' network, where a few major ports (22,80,ect.) are open to incoming traffic. Each computer does get it's own public IP, though.
I heard some fellow undergraduates of mine give a talk on "quantum encryption" last year. It took me a while to notice, but quantum 'encryption' isn't really encryption at all. It is just a secure way to distribute to exactly two people the same random data. You then leverage this security to make a one-time use pad that's (almost) as practically secure as it theoretically is. You still have to keep the pad a secret at both ends, but the transmission is foolproof.
$1000 is not much. I've been doing research quite a long time on what should I buy, to get the best possible view both for planets and deep-sky. You know - usually for deeps skies a newton with huge mirrors is good, while they are not applicable for planets, because newtons cannot produce big magnification with enough detail. While for planet viewing the refractors are the best, because they can produce big magnifications without the distortions of newtonians. But refractors have too small aperture to collect enough light for comfortable deep-sky viewing.
The best balance in this big_mirror/refractor conflict is an apochromatic refractor.
You seem uninformed on the caveats of refractor vs. reflector designs. You have the basic ideas right, but your reasoning is a bit flawed, let me try.
Refractors are a lensed design, the problem with lenses is that they do not bend all colors the same amount, that is their refractive index varies by wavelength. To correct this most telescopes use a achromatic doublet, which converges most colors except for the near purple end of the spectrum, resulting in a purple haze around the object your viewing. Recently the concept of an apochromatic has reached the consumer, in which a doublet or triplet with exotic glasses are used to focus much more of the visible spectrum than achromatic reflectors. This results in a perfect image with no obstructions in the objective (I'll get to this in a moment). However, the exotic glasses are extremely expensive, resulting in a small aperture for the money.
Reflectors, by contrast, are a mirrored design. Mirrors bend all light the same amount, so they do not have the chromatic problems. The issue with reflectors is that the secondary mirror has to be in the path of the light that hits the primary mirror, so there is a "shadow" of the secondary mirror and it's supports on the primary mirror. This does not create a hole in the image, but the secondary and it's supports do diffract light around them, resulting in stars that have a spike around them. The Hubble is a reflector design, and shares these diffraction spikes. Reflectors also suffer from coma distortion.
What it comes down to then is Aperture vs Obstructions.
Aperture (the size of the primary focusing element): Reflectors have much larger apertures than similarly priced refractors. A higher aperture allows you to see darker of objects, it allows you to use a higher magnification and increases how much detail is present at higher magnifications.
Obstructions: These lower the amount of light getting to the primary mirror and cause diffraction in the image. The reduction in light is acceptable for reflectors as they have a large unobstructed aperture. The issue is diffraction with bright objects, mainly planets and stars. For stars, it simply causes a starburst pattern in the image, but for planets the diffraction of the circular secondary becomes important because planets are extended objects with details. With stars this circular diffraction simply increases the brightness of the sky surrounding the star, but for planets this slightly blurs the image of the planet which some feel is unacceptable.
The telescopes you've listed are in the $10,000 and above range, very far above the poster's $1000 budget. I couldn't even find a mounted 80mm semi-apo (the minimum aperture I'd suggest for planetary viewing, let alone deep sky) for under $1000. For sub-$1000, a reflector wins over a refractor hands down simply because there are no apos in this price range. The aperture of a reflector simply destroys the possible advantages an refractor in this range due to the chromatic aberration on planets, plus you can do deep sky observing with a sub-$1000 reflector and still be happy with the planets you can see.
I went through the same thing. I was fresh to amateur astronomy and didn't know what to do. My first warning: Don't spend to little on a telescope. $180 for a StarBlast is the lowest I'd pay for anything decent (and it is, I drool over it as a quick 'plop down and observe' scope from time to time). Second Warning: Astrophotography is insanely expensive. As in 10+ times your budget. Don't do it. If you really want to do astrophotography take a camera, put it on a tripod, point at the sky, set it as wide as you can and expose for 15 seconds for digital, a few hours for film. The results are quite nice.
Here's what my own experiences have taught me: Get a Dobsonian. With $1000 you can get a 10"-12" Dobsonian and still have tons of room for accessories. A dobsonian is very portable compared to a refractor and with near zero setup and takedown using it is much easier than a refractor too. 10" is a lot of aperture and you won't catch the "aperture fever" for something bigger for a while. The scope I eventually got is an OrionXT10 Intelliscope, but you may not want the computerization with your budget.
I found the people at Cloudy Nights very, very helpful. They have reviews of lots of products as well as their forums and they tend to specialize in getting the most out of your money.
As far as books go, I use Nightwatch by Terence Dickinson every night I observe just for the charts. Star Watch by Philip Harrington goes well with Nightwatch as good place to find new objects for the beginner. A lot of people suggest Turn Left at Orion, but I fount it to be a bit slow and the charts lacking in lower magnitude stars for their size.
Slashdot Mirror
So that's why all the quantum physics articles are written from the perspective of a senior/grad student in quantum theory. The articles all seem to jump over the introductory level and right into the higher math.
To be pedantic, Physics killed Goose.
"Guns don't kill people; Physics kills people!" —Dick Soloman
There's a few things going on here that are related in different ways.
1) The single-top isn't the only quark being produced, it's actually produced with a bottom quark at the same time. Usual top quark production is in pairs, one top quark one anti-top quark, but single-top is different; a top quark is produced with a anti-bottom quark.
2) The top quark decays before it can hadronize. That is, it decays before it can pick up a partner quark. This is completely allowed in the Standard Model, but I'm a bit sketchy on the details. I think it behaves as though it was attached with the other quark it was produced with.
One of the things single-top is sensitive to is the coupling strength of the top and bottom quarks via the weak force. The value of this coupling is tightly constrained if one assumes that there are only six quarks (ie. there are three generations of matter). The fact that they measured it and it's within the six quark ballpark means that it is very likely that there isn't another pair of quarks waiting to be discovered.
The basic idea is that if the top and bottom coupling strength is measured to be less than the value we expect for six quarks then that means that some of that coupling strength actually goes to a different, seventh or eighth, quark. But I'm grossly simplifying things here for the general slashdot crowd.
Single-top is, however, one of the backgrounds in the search for the Higgs boson. For Fermilab to discover the Higgs, they have to discover single-top first.
You aren't quite grasping what he means by one in four million. This wasn't a single event we are talking about here.
The way the statistics work is that you would have to run the entire Fermilab experiment four million times to get what they see from a fake signal. It's a cumulative probability over all the events ever recorded at Fermilab.
They didn't detect it directly. The key to 'detecting' the neutrino is to count up everything else in the remnants collision and notice that it recoils off of something that you didn't detect. It acts as though what you can see in your detector is violating the conservation of energy. But in reality there's an undetectable neutrino zipping through the detector. So you calculate how much energy and in which direction such a neutrino would travel in order to conserve energy, and that's where they get that little diagram.
First we had Fanbois; but they went out of control and we were forced to create the AntiFanbois.
But the AntiFanbois too went out of control, and here we see the development of the Anti-Anti-Fanboi.
I fear this arms race will never end.
The thing is, quantum encryption is a one time pad system. It's a secure way of distributing the one time pad.
You jest, but WebKit is at 100/100 on Acid3 and passes the smooth animation requirement as well.
You mean something like this?
Totally destroy yes, but it might also increase it's value.
WebKit itself is doing 100/100 on Acid3. One would assume that Chrome would be performing similarly as it is based on WebKit, especially when this 100/100 result was achieved in March of 2008. Is Chrome based on an older fork of WebKit? Or is something else going on here?
GPS does not work that way. The GPS receiver doesn't actually send any radio frequencies, it only receives signals from the GPS satellites that tell the receiver how long it took the signal to reach you, and from that calculate your position.
So, instead of looking for a GPS signal (which would be coming from a satellite, not any GPS receiver), you are looking for radio frequency that is broadcasting what location the GPS receiver detects. Systems like OnStar do this via the cell phone network, but it could conceivably be carried over just about anything. Or the device could just store the history of locations on the device itself and the cops just hope to retrieve it later. The latter would be near undetectable as one would have to look for the RF emitted by running electronics in order to detect it.
With the use of Hidden services, it is. If you connect to a Hidden service on Tor, the last hop in the Tor network is to the server your connecting to and it is end-to-end encrypted.
.torrent transfer would be good uses for this channel, but not the raw data. I'm surprised TPB doesn't have it already set up.
Tracker data and
1. Entanglement: It is fact. If you send a photon through a certain type of non-linear crystal, two photons will emerge that are entangled quantum mechanically. To truly understand this requires some knowledge of quantum mechanics, a basic introduction to QM and entanglement can be found here and here if you care to learn more.
2. Heisenberg principle: You inadvertently stumbled onto the problem yourself, kinda. When trying to measure the position of the electron, you use a high energy photon and this photon. When this high energy photon interacts with the electron it alters the velocity of the electron, so you know less about the velocity of the electron. When trying to measure the velocity of the electron, you use a low energy photon. This low energy photon measures the velocity well, but it moves the electron a little bit, so you don't know its position. This issue is the essence of the Heisenberg uncertainty principle.
At the end of the lecture, a little old lady at the back of the room got up and said: "What you have told us is rubbish. Web development is really Ruby supported on the back of Rails."
The developer gave a superior smile before replying, "What is Rails standing on?"
"You're very clever, young man, very clever," said the old lady. "But it's Rails all the way down!"
How is it not the same? It's a broad over generalization and overreaction based on the facts. And it was one battery.
My analogies do suck, but when people are being prosecuted because investigations don't turn up guilt to the original charge, they are exactly what's going on. You do something innocuous that someone thinks is suspicious, then you are prosecuted for just being suspicious.
"The real problem" as you so blatantly put it (without stating the problem for clarification) is that we have made the choice to be safe instead of the choice to be safe and free.
We could execute her for being stupid, if that's what you want. We could throw her in jail for... for what exactly? A Hoax? She didn't intend for it to be a hoax. Innocuous intent protects speech-like actions.
I heard some fellow undergraduates of mine give a talk on "quantum encryption" last year. It took me a while to notice, but quantum 'encryption' isn't really encryption at all. It is just a secure way to distribute to exactly two people the same random data. You then leverage this security to make a one-time use pad that's (almost) as practically secure as it theoretically is. You still have to keep the pad a secret at both ends, but the transmission is foolproof.
Reflectors, by contrast, are a mirrored design. Mirrors bend all light the same amount, so they do not have the chromatic problems. The issue with reflectors is that the secondary mirror has to be in the path of the light that hits the primary mirror, so there is a "shadow" of the secondary mirror and it's supports on the primary mirror. This does not create a hole in the image, but the secondary and it's supports do diffract light around them, resulting in stars that have a spike around them. The Hubble is a reflector design, and shares these diffraction spikes. Reflectors also suffer from coma distortion.
What it comes down to then is Aperture vs Obstructions. Aperture (the size of the primary focusing element): Reflectors have much larger apertures than similarly priced refractors. A higher aperture allows you to see darker of objects, it allows you to use a higher magnification and increases how much detail is present at higher magnifications.
Obstructions: These lower the amount of light getting to the primary mirror and cause diffraction in the image. The reduction in light is acceptable for reflectors as they have a large unobstructed aperture. The issue is diffraction with bright objects, mainly planets and stars. For stars, it simply causes a starburst pattern in the image, but for planets the diffraction of the circular secondary becomes important because planets are extended objects with details. With stars this circular diffraction simply increases the brightness of the sky surrounding the star, but for planets this slightly blurs the image of the planet which some feel is unacceptable.
The telescopes you've listed are in the $10,000 and above range, very far above the poster's $1000 budget. I couldn't even find a mounted 80mm semi-apo (the minimum aperture I'd suggest for planetary viewing, let alone deep sky) for under $1000. For sub-$1000, a reflector wins over a refractor hands down simply because there are no apos in this price range. The aperture of a reflector simply destroys the possible advantages an refractor in this range due to the chromatic aberration on planets, plus you can do deep sky observing with a sub-$1000 reflector and still be happy with the planets you can see.
I went through the same thing. I was fresh to amateur astronomy and didn't know what to do. My first warning: Don't spend to little on a telescope. $180 for a StarBlast is the lowest I'd pay for anything decent (and it is, I drool over it as a quick 'plop down and observe' scope from time to time). Second Warning: Astrophotography is insanely expensive. As in 10+ times your budget. Don't do it. If you really want to do astrophotography take a camera, put it on a tripod, point at the sky, set it as wide as you can and expose for 15 seconds for digital, a few hours for film. The results are quite nice.
Here's what my own experiences have taught me: Get a Dobsonian. With $1000 you can get a 10"-12" Dobsonian and still have tons of room for accessories. A dobsonian is very portable compared to a refractor and with near zero setup and takedown using it is much easier than a refractor too. 10" is a lot of aperture and you won't catch the "aperture fever" for something bigger for a while. The scope I eventually got is an Orion XT10 Intelliscope, but you may not want the computerization with your budget.
I found the people at Cloudy Nights very, very helpful. They have reviews of lots of products as well as their forums and they tend to specialize in getting the most out of your money.
As far as books go, I use Nightwatch by Terence Dickinson every night I observe just for the charts. Star Watch by Philip Harrington goes well with Nightwatch as good place to find new objects for the beginner. A lot of people suggest Turn Left at Orion, but I fount it to be a bit slow and the charts lacking in lower magnitude stars for their size.