I think the "predicted delay" was actually made after the observation. Easy to make a prediction that matches observation, but in the end it's probably model dependent.
I think most of the finite element/multiphysics packages started as research projects, either in university or government labs (some military, some conventional). For studying e.g. electromagnet design, heat deposition by currents/EM radiation e.g. microwave studio. Most of the radioactivation and nuclear shielding simulations used by the nuclear industry for designing radiation shielding are or were academic projects (e.g. MARS, FLUKA, MCNPX).
Someone has invented a neutrino telescope:-
http://icecube.wisc.edu/http://antares.in2p3.fr/
But the angular resolution is awful and the energy threshold is very high. So this only detects neutrinos from really super powerful cosmic stuff like black holes colliding.
To be pedantic, the most powerful CW proton accelerator in the world is IIRC at Paul Scherrer Institute. Most powerful pulsed source is SNS at Oak Ridge both produce about a MW I think. LHC is highest luminosity which is different.
Also increase in oil price, food price. This foreshadows much bigger political instability to come as oil prices go up. Lots of literature on his (see peak oil stuff).
I would say dictatorship is considerably more stable than democracy - that's why most nations end up with dictatorships rather than democracies. It's only when people are wealthy enough to worry about who is ruling them that democracy can do okay.
Nb: In UK we've been in a state of emergency for the last 10 years, which has allowed the government to suspend habeas corpus, i.e. permit detention without trial. Formally this was illegal due to the European Convention on Human Rights (ECHR) except in state of emergency. The ECHR, though it has the word European in, was actually invented by the Brits in post WWII era.
As an accelerator physicist (who doesn't know how to do slashdot formatting)
The basic physics is in a sort of golden age right now. Every 10-20 years we have discovered one or more new *fundamental forms of matter* - like discovering a new sort of electron or whatever (think 6 quarks, 6 leptons). Every 10-20 years we have discovered a new unification theory or fundamental law of physics - like maxwell did with unification of electricity and magnetism, or newton did with unification of planetary motion and gravitational motion (think gluons, W+-, Z0). So I think the idea that basic physics is not discovering things is wrong.
What is problematic is the amount of resources required to access the physics of each thing is steadily increasing. We aren't getting (much) better at building particle accelerators, we are just throwing more money at the problem. So it costs 10 billion euros to access LHC scale physics, making developing anything practical from it basically impossible. The reason we don't have a light source in every lab is that the cost of accessing the GeV energy scale is 0.5 billion euros. We do have a few per continent, but it doesn't look like it will become possible anytime soon to make this cheaper.
Some technologies provide us with hope. Superconducting magnets are getting cheaper. Wakefield type accelerators may make things cheaper (though they look horribly inefficient). But for the foreseeable future, there will be no synchrotron ray guns or neutrino radios because the cost of making a high intensity xray or neutrino beam is just too much...
The whole article is based on the premise that EITHER you have risk of accidental launch EX-OR you have risk of failure to launch deliberately. That patently isn't true and you can make trivial example code to show that this is the case.
This is war and shit happens. You go into someone's house with a few thousand guns and someone's gonna get shot. Let's think about whether we should go into the house next time...
I really hope the ILC gets the go ahead But you would not build it until you know the Higgs mass (if the Higgs exists) because you want to work with e+e- collisions on the centre of mass. Until you can prove the Higgs mass is in the design range of the machine, you simply wouldn't built. So I think that story is yarbles.
The detector is fascinating because it can be used to look at a different class of object that may or may not exist. For example, any object that interacts weakly but not electromagnetically would be visible. So if one were to imagine dark matter, for example, was weakly interacting, it might allow a direct observation of dark matter objects.
nb ANTARES is another one they talk about to be built under the mediterranean. There a major background is biological - algae growing on the detectors and stuff(!)
Well... actually kids never were 'kids'. They used to work down a mine or in a farm for 12 hours every day from as early an age as possible. It's only in recent times that we've had enough wealth that kids can spend their time mucking around
Given the vast alternative resources available to the US, why do this before building large scale solar and wind plants? Is it really going to be cheaper than (say) paving large areas of desert with ever-cheaper solar cells? Or building the really large wind-farm projects in the many available on/off shore locations? As technology advances, these alternatives have got cheaper and cheaper..
Renewables have a big problem - solar and wind are unreliable. It is simply inconceivable that electricity supplies can fail when it is cloudy and/or not windy. If you want to build renewables you need to also build gas-fired plants (usually, other possibilities exist) as a backup. That makes things look very expensive
The actual cost has been estimated a few times, although the renewables folks include the cost of nuclear decommissioning but not the cost of backup generators, and sometimes not the initial capital cost (building a windfarm); and the nuclear folks usually don't bother to include the cost of decommissioning. So in the end it is difficult to make a realistic comparison. But I think it usually comes out that renewables are more expensive by about a factor 2; and still have carbon emissions and security-of-supply issues caused by backup generators.
It would be interesting to see what the trend is in renewables... I saw an estimate that they will become economically viable about midway between 2010 and 2020, although I can't remember the source. Also it will be interesting to see what the UK government decides in its upcoming review on energy policy with particular attention to nuclear. It is quite likely we will be getting nuclear new build here also.
The fact is, anyone who owns a house and puts a decent amount of work into it or has a family with at least 2 kids will make use of the space in their vehicle.
How big are your kids!?!?
The article talks about a 4:1 entry ratio (10 m applicants for 2.5 m places). This is pretty typical here in the UK. Is this response from/. massive prejudice against china? Or have I missed something?
Actually its pretty straight forward - whack a bunch of protons into a target and neutrons drop out. The protons react with nuclei in the target to produce neutrons (and pions and a whole load of other junk). The protons need to be reasonably high energy (say at least relativistic) to get a good neutron yield.
Usually you use a heavy metal as the target. High nuclear mass so that there are lots of protons and neutrons to collide with, high melting point/tough so you don't damage the target too much when the protons go into it. The target is probably actively cooled or you might want to try a liquid metal target at high intensities so that it cools itself. Watch out that you can build pipes to contain the liquid that aren't destroyed by the incoming proton beam. Then you collimate the neutrons coming out and possibly slow them down using something like carbon.
Lol... know what you mean. You're right, the formula is E^2 = m^2 c^4 + p^2 c^2. But for a typical electron in a hydrogen atom, momentum is about 1/10,000 its rest mass (taking c=1) so these effects are small. Basically E=mc^2 is a good approximation here.
Slashdot Mirror
I think the "predicted delay" was actually made after the observation. Easy to make a prediction that matches observation, but in the end it's probably model dependent.
I think most of the finite element/multiphysics packages started as research projects, either in university or government labs (some military, some conventional). For studying e.g. electromagnet design, heat deposition by currents /EM radiation e.g. microwave studio. Most of the radioactivation and nuclear shielding simulations used by the nuclear industry for designing radiation shielding are or were academic projects (e.g. MARS, FLUKA, MCNPX).
Someone has invented a neutrino telescope:- http://icecube.wisc.edu/ http://antares.in2p3.fr/ But the angular resolution is awful and the energy threshold is very high. So this only detects neutrinos from really super powerful cosmic stuff like black holes colliding.
To be pedantic, the most powerful CW proton accelerator in the world is IIRC at Paul Scherrer Institute. Most powerful pulsed source is SNS at Oak Ridge both produce about a MW I think. LHC is highest luminosity which is different.
Also increase in oil price, food price. This foreshadows much bigger political instability to come as oil prices go up. Lots of literature on his (see peak oil stuff). I would say dictatorship is considerably more stable than democracy - that's why most nations end up with dictatorships rather than democracies. It's only when people are wealthy enough to worry about who is ruling them that democracy can do okay.
Nb: In UK we've been in a state of emergency for the last 10 years, which has allowed the government to suspend habeas corpus, i.e. permit detention without trial. Formally this was illegal due to the European Convention on Human Rights (ECHR) except in state of emergency. The ECHR, though it has the word European in, was actually invented by the Brits in post WWII era.
3) Fermilab pioneered the application of super-conductors for use in building the Tevatron.
Humm... you might want to check that
As an accelerator physicist (who doesn't know how to do slashdot formatting)
The basic physics is in a sort of golden age right now. Every 10-20 years we have discovered one or more new *fundamental forms of matter* - like discovering a new sort of electron or whatever (think 6 quarks, 6 leptons). Every 10-20 years we have discovered a new unification theory or fundamental law of physics - like maxwell did with unification of electricity and magnetism, or newton did with unification of planetary motion and gravitational motion (think gluons, W+-, Z0). So I think the idea that basic physics is not discovering things is wrong.
What is problematic is the amount of resources required to access the physics of each thing is steadily increasing. We aren't getting (much) better at building particle accelerators, we are just throwing more money at the problem. So it costs 10 billion euros to access LHC scale physics, making developing anything practical from it basically impossible. The reason we don't have a light source in every lab is that the cost of accessing the GeV energy scale is 0.5 billion euros. We do have a few per continent, but it doesn't look like it will become possible anytime soon to make this cheaper.
Some technologies provide us with hope. Superconducting magnets are getting cheaper. Wakefield type accelerators may make things cheaper (though they look horribly inefficient). But for the foreseeable future, there will be no synchrotron ray guns or neutrino radios because the cost of making a high intensity xray or neutrino beam is just too much...
The whole article is based on the premise that EITHER you have risk of accidental launch EX-OR you have risk of failure to launch deliberately. That patently isn't true and you can make trivial example code to show that this is the case.
This is war and shit happens. You go into someone's house with a few thousand guns and someone's gonna get shot. Let's think about whether we should go into the house next time...
I really hope the ILC gets the go ahead But you would not build it until you know the Higgs mass (if the Higgs exists) because you want to work with e+e- collisions on the centre of mass. Until you can prove the Higgs mass is in the design range of the machine, you simply wouldn't built. So I think that story is yarbles.
The detector is fascinating because it can be used to look at a different class of object that may or may not exist. For example, any object that interacts weakly but not electromagnetically would be visible. So if one were to imagine dark matter, for example, was weakly interacting, it might allow a direct observation of dark matter objects. nb ANTARES is another one they talk about to be built under the mediterranean. There a major background is biological - algae growing on the detectors and stuff(!)
What ever happened to bein' a kid?
Well... actually kids never were 'kids'. They used to work down a mine or in a farm for 12 hours every day from as early an age as possible. It's only in recent times that we've had enough wealth that kids can spend their time mucking around
The author is Michio Kaku, one of the inventors of string theory, so he bears a hearing.
After all, an inventor of string theory must be an expert on science fiction...
Given the vast alternative resources available to the US, why do this before building large scale solar and wind plants? Is it really going to be cheaper than (say) paving large areas of desert with ever-cheaper solar cells? Or building the really large wind-farm projects in the many available on/off shore locations? As technology advances, these alternatives have got cheaper and cheaper..
Renewables have a big problem - solar and wind are unreliable. It is simply inconceivable that electricity supplies can fail when it is cloudy and/or not windy. If you want to build renewables you need to also build gas-fired plants (usually, other possibilities exist) as a backup. That makes things look very expensive
The actual cost has been estimated a few times, although the renewables folks include the cost of nuclear decommissioning but not the cost of backup generators, and sometimes not the initial capital cost (building a windfarm); and the nuclear folks usually don't bother to include the cost of decommissioning. So in the end it is difficult to make a realistic comparison. But I think it usually comes out that renewables are more expensive by about a factor 2; and still have carbon emissions and security-of-supply issues caused by backup generators.
It would be interesting to see what the trend is in renewables... I saw an estimate that they will become economically viable about midway between 2010 and 2020, although I can't remember the source. Also it will be interesting to see what the UK government decides in its upcoming review on energy policy with particular attention to nuclear. It is quite likely we will be getting nuclear new build here also.
The fact is, anyone who owns a house and puts a decent amount of work into it or has a family with at least 2 kids will make use of the space in their vehicle. How big are your kids!?!?
The assumption of a universal time is necessary for quantum mechanics.
But not quantum field theory
I merely meant that it is inexact.
Fair enough, then say it is inexact. Newtonian gravity is an elegant and powerful theory, by no means crude.
Newtonian gravity is not crude.
The article talks about a 4:1 entry ratio (10 m applicants for 2.5 m places). This is pretty typical here in the UK. Is this response from /. massive prejudice against china? Or have I missed something?
Yeah, but I think CERN has semi-officially given the US the ILC and Fermilab is keenest among the US labs...
Actually its pretty straight forward - whack a bunch of protons into a target and neutrons drop out. The protons react with nuclei in the target to produce neutrons (and pions and a whole load of other junk). The protons need to be reasonably high energy (say at least relativistic) to get a good neutron yield.
Usually you use a heavy metal as the target. High nuclear mass so that there are lots of protons and neutrons to collide with, high melting point/tough so you don't damage the target too much when the protons go into it. The target is probably actively cooled or you might want to try a liquid metal target at high intensities so that it cools itself. Watch out that you can build pipes to contain the liquid that aren't destroyed by the incoming proton beam. Then you collimate the neutrons coming out and possibly slow them down using something like carbon.
Jobs a good 'un!
Lol... know what you mean. You're right, the formula is E^2 = m^2 c^4 + p^2 c^2. But for a typical electron in a hydrogen atom, momentum is about 1/10,000 its rest mass (taking c=1) so these effects are small. Basically E=mc^2 is a good approximation here.
Troll...
Yes. But I'm talking about rest masses - and if you use my formula for anything real, you're in trouble... it's hand waving rather than science