Well, it seems that you may not understand much of what you are talking about. First off, the 10 or 50 000 V quoted on tasers is the peak unloaded voltage (it's 50 kV for the M26 taser) . With a load like a human body it is more like 5000 V peak (1500 V average). Typically a lethal current is in the 100 mA range (sustained), and that is 100 mA through the heart. The M26 taser has an average current of around 3.6 mA. You've mentioned 500 000 ohms and that is actually close the resistance of dry skin. Also, the power output of a taser is about 7.4 W (the ADVANCED TASER M26 uses 8 AA batteries). Since the device is power limited, higher voltage results in lower current, so higher voltages are safer.
So it's your contention that all of the poor in the USA could just work a little harder and they could all become middle class or something? Unfortunately the functioning of the system requires the poor. If the poor as a whole start making more money you get a magical thing called inflation.
I see lots of arguing about the cost of the power, but isn't this a test facility? As far as I'm concerned, this is an R&D project more than it is an effort to increase electricity production in Ontario (in the short term). I don't think there are plans to open up a whole bunch of these facilities at $0.42/kWh, though I guess I could be wrong. If you're going to criticize this power station for that reason, then I think there are a lot of projects that are a lot more worth of criticism. I worked in a nuclear fusion research facility in Saskatoon for a couple of years on a Tokamak, and let me tell you that that little multi-million dollar machine has produced all of zero electricity. I have a friend who works for AECL on advanced fission fuel technology and the stuff he's working on is not intended for electricity production for years. Why not criticize these as they're also being paid for by tax payers. I think some people are being a little short sighted.
Stuck at 15% with nothing above that on the horizon? Spectrolab has constructed photovoltaic cells that are 36% efficient (4 years ago). I've read of >40% in multiple-junction research lab cells. Of course these type of cells are prohibitively expensive right now, but they are certainly "on the horizon" so to speak.
I believe that the powertrain warranty is 5 years/60 000 miles (engine/transmission/transaxle/front/rear-wheel drive system). Up here it is 5 years/100 000 km. The general warrany is 3 years/36 000 miles (60 000 km).
The hybrid with the highest mileage is a Canadian taxi that is a 2001 Prius and has over 400 000 km. There are also a number of them with over 300 000 km. The Prius is also the most common taxi vehicle next to the Crown Victoria where I live (Winnipeg, Canada) and they've been driving around all day for years. I don't see any stats to back up the claim that small engines only last 100 000 km, but I have plenty of anecdotal evidence to the contrary.
It isn't impossible as far as we know, just extremely difficult. The reason for a large machine like ITER is that empirically derived scaling laws of confinement and fusion power output point to a machine with the parameters of ITER being able to achieve Q ~ 10 given current technology or at least technology that can be developed within the timeline of ITER's construction.
It probably wasn't in Montreal. As far as I know, The Daily Show is carried on Comedy Central and CTV in Canada. I believe that it is made obvious on the CTV airing that it is a political satire show.
I'm not even sure anyone knows where the first commercial fusion reactor will be built. ITER is not a prototype power station let alone a commercial one. It is merely to demonstrate the scientific and technical feasibility of fusion power. ITER is not going to be used for power production. Ideally ITER will be proceeded by DEMO, a prototype power plant.
Well, I've worked on a tokamak and we've had disruptions (loss of confinement) and it does basically nothing. There's a limited risk of damage to the machine.
Yep, I've read the same thing. When you actually factor in the use of coal for generating electricity(and subsequent release of mercury), CFLs and incandescents are pretty comparable.
I think that a controlled reaction is implied. An out of control fusion reaction is "fairly" simple; a hydrogen bomb is an easy example.
I would say that an individual starting a large scale nuclear fusion reaction is unlikely for at least 100 years. Considering magnetic confinement fusion, the technology is so expensive and obtaining a plasma with the performance necessary for fusion is so difficult that it requires billions of dollars and hundreds of personnel to construct and operate a modern tokamak that can perform a non-trivial amount of fusion. Additionally, with magnetic confinement fusion it would be very difficult to have a reaction that is out of control. The reaction is so difficult to maintain that small changes to things like the plasma position and impurity content quickly quench the reaction. If any damage to the vacuum vessel caused a leak, the incoming atmosphere, which is on the order of a million times more dense than the plasma, would also quench the reaction and disrupt the plasma. Also, the machines are built to handle disruptions, which in the worst case is where the entire plasma hits the wall of the chamber. Though it may cause some damage to the first plasma facing components (typically graphite tiles in advanced tokamaks), this is unlikely to cause any damage to the actual vacuum vessel which is stainless steel.
If we consider some as of yet undiscovered method of performing nuclear fusion then I suppose it could be possible to have a seemingly stable reaction become out of control and dangerous. Something like Spiderman 2 is far from the reality of any current fusion method.
Unfortunately for many, science has been plagued by some spectacular frauds lately . The result is that skepticism runs high, especially when you follow an experiment and cannot reproduce the results and then the original scientist who claimed the results simply says you aren't doing it right and hides behind intellectual property rights to avoid revealing their "secret". I've been following this bubble fusion for a while now (I work in magnetic confinement fusion) and it seems to have all the warning signs of a fraud. I've read too many sketchy things about this scientist refusing to share his raw data, restricting access to his lab when someone calls into question the validity of the results and a number of other things that throw up a red flag. Maybe it will turn out to be true, but IMO Taleyarkhan is behaving in a very strange manner for someone claiming such a great discovery.
However, it is also crucial to acheive a self-sustaining reaction, something not yet done.
Actually, it is not necessary to have a self-sustaining reaction to have a viable fusion based power source. High power amplification (Q) of 50 or even 1000 would be suitable. In fact, from what I've recently read on ITER and plans for future machines they would actually prefer a finite Q since it introduces another method of control into the system. The actual Q required will depend on the plant efficiency.
You are right about the Q achieved to date. The highest equivalent Q achieved in the JET is something like 1.16 and it is 1.25 in the JT-60U tokamak. The equivalent Q is determined from the measured deuterium-deuterium fusion and the (equivalent) Q for a deuterium-tritium fuel is extrapolated. This is done because using tritium in experiments is problematic since these two machines are either not designed to handle tritium (JT-60U) or would prefer not to contaminate their machine due to the extreme care that must be taken after tritium experiments (JET). These two machines have demonstrated plasma performance that is better than breakeven. One can only hope that ITER is able to achieve higher Q with deuterium-tritium fuel.
I once saw Lance Burton make a car disappear. A CAR!!! I interpret that to mean that he can actually make cars disappear at will. It allows me to work towards my goal of making cars disappear. Once I get that down, I'm moving on to levitation a la David Blaine.
Seriously, a car disappeared. I saw it. Since I can't explain exactly how it happened, I have to assume it was some biological power as yet undiscovered by science. I mean, it just couldn't be a trick.
In the very first post he questioned whether gravity accelerates all objects at the same rate. That is what I am arguing against. The acceleration of an object in a gravitational field is independent of it's mass. Basically the poster appears to be questioning the equivalence principle and stating that he and his physics teacher (high school I assume) have somehow mathematically demonstrated that it doesn't hold. The only statement in the article about acceleration in a gravitational field is "As an explanation for the nature of gravity, general relativity relies on a key assumption: that gravity accelerates all objects at the same rate - regardless of their mass or composition. This idea is called the equivalence principle."
It is my contention that he was confusing the collision time being different for two objects and somehow interpreting this as meaning that objects are not accelerated at the same rate. He may not mean that, but what he really means is confusing and by using incorrect math it is hard to follow what point he is trying to make. By pointing out that he and his physics teacher put together some sort of hypothetical trials suggests they have found something new.
Obviously the actual collision time with the earth depends on the mass of the falling objects mass. The correct acceleration to use in order to calculate the fall time would be a = g + g*m_o/M_E where m_o is the object mass and M_E the earth mass. For anything near the size of a person this correction factor will be on the order of 10^-23 times the acceleration due to gravity of ~9.8m/s^2.
Even if you didn't make any typos in transferring what you did, it is still wrong. First, the force of gravity between the two objects is changing in time, therefore you cannot use the force between them when they are 10 m apart and apply it to the entire time that they are moving together. Another thing that is possibly just a typo is that the gravitational force is inversely proportional to the square of the distance between the bodies.
What you really want to do is calculate the acceleration of A and of B due to C when they are both the same distance r from C. You'll quickly see that the acceleration of A and B are identical. The acceleration of either of A or B is:
a_A = a_B = G*m_C/r^2
Also, the thing in the situation of the earth that is important as far as the fall time goes is that the earth is so massive compared with any objects which are typically considered that the object is essentially stationary. There is an equal and opposite force on the earth due to a falling object, but since the earths mass is so tremendous (5.97 x 10^24 kg) it basically does not move and so the fall time winds up being essentially identical. The situation you are describing has two objects of comparable mass so that both objects undergo comparable accelerations in such a case the fall times between AC and BC can be noticeably different.
If you aren't making a joke, then your physics teacher should be fired.
As has already been posted, due to the equivalence of inertial mass and gravitational mass, the object mass in the equation you have posted cancels. Also, if you really did do an experiment then I would question your methods. How did you account for air resistance. A 1992 article in Physical Review Letters details an experiment performed in an ultra-high vacuum where the universality of the free fall acceleration of objects in a gravitational field was verified to a few parts in 10^10. I'm assuming that this experiment was considerable more accurate than yours.
Of course, I hope that you are making a joke of some sort.
Thanks for the tip, but I don't see what you've changed. But hopefully your post helps you to feel smarter. I'm also having some trouble with gyrokinetic theory as it applies to plasmas. Could you help me with that as well?
On a side-note - Stockwell Day is a bit of a dingleberry - a creationist who believes the earth was created 5000 years ago....the sharp swing to the right has begun in Canada....looks like the terrorists are winning when our freedoms start to get whittled away, bit by bit....
This legislation was first introduced by the liberals last year, so it isn't just because of the more right wing conservatives.
I've done several checkstops as an Auxilliary and it is routine to check license, registration and insurance. It dependd how busy it id, but if there id time it's done.
Where does the article mention carbon dating? What is the relevance of your statement?
Can you provide a scientific reference to your statement regarding potassium-argon dating?
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Well, it seems that you may not understand much of what you are talking about. First off, the 10 or 50 000 V quoted on tasers is the peak unloaded voltage (it's 50 kV for the M26 taser) . With a load like a human body it is more like 5000 V peak (1500 V average). Typically a lethal current is in the 100 mA range (sustained), and that is 100 mA through the heart. The M26 taser has an average current of around 3.6 mA. You've mentioned 500 000 ohms and that is actually close the resistance of dry skin. Also, the power output of a taser is about 7.4 W (the ADVANCED TASER M26 uses 8 AA batteries). Since the device is power limited, higher voltage results in lower current, so higher voltages are safer.
So it's your contention that all of the poor in the USA could just work a little harder and they could all become middle class or something? Unfortunately the functioning of the system requires the poor. If the poor as a whole start making more money you get a magical thing called inflation.
I see lots of arguing about the cost of the power, but isn't this a test facility? As far as I'm concerned, this is an R&D project more than it is an effort to increase electricity production in Ontario (in the short term). I don't think there are plans to open up a whole bunch of these facilities at $0.42/kWh, though I guess I could be wrong. If you're going to criticize this power station for that reason, then I think there are a lot of projects that are a lot more worth of criticism. I worked in a nuclear fusion research facility in Saskatoon for a couple of years on a Tokamak, and let me tell you that that little multi-million dollar machine has produced all of zero electricity. I have a friend who works for AECL on advanced fission fuel technology and the stuff he's working on is not intended for electricity production for years. Why not criticize these as they're also being paid for by tax payers. I think some people are being a little short sighted.
Stuck at 15% with nothing above that on the horizon? Spectrolab has constructed photovoltaic cells that are 36% efficient (4 years ago). I've read of >40% in multiple-junction research lab cells. Of course these type of cells are prohibitively expensive right now, but they are certainly "on the horizon" so to speak.
I believe that the powertrain warranty is 5 years/60 000 miles (engine/transmission/transaxle/front/rear-wheel drive system). Up here it is 5 years/100 000 km. The general warrany is 3 years/36 000 miles (60 000 km).
The hybrid with the highest mileage is a Canadian taxi that is a 2001 Prius and has over 400 000 km. There are also a number of them with over 300 000 km. The Prius is also the most common taxi vehicle next to the Crown Victoria where I live (Winnipeg, Canada) and they've been driving around all day for years. I don't see any stats to back up the claim that small engines only last 100 000 km, but I have plenty of anecdotal evidence to the contrary.
It isn't impossible as far as we know, just extremely difficult. The reason for a large machine like ITER is that empirically derived scaling laws of confinement and fusion power output point to a machine with the parameters of ITER being able to achieve Q ~ 10 given current technology or at least technology that can be developed within the timeline of ITER's construction.
It probably wasn't in Montreal. As far as I know, The Daily Show is carried on Comedy Central and CTV in Canada. I believe that it is made obvious on the CTV airing that it is a political satire show.
I'm not even sure anyone knows where the first commercial fusion reactor will be built. ITER is not a prototype power station let alone a commercial one. It is merely to demonstrate the scientific and technical feasibility of fusion power. ITER is not going to be used for power production. Ideally ITER will be proceeded by DEMO, a prototype power plant.
Well, I've worked on a tokamak and we've had disruptions (loss of confinement) and it does basically nothing. There's a limited risk of damage to the machine.
Yep, I've read the same thing. When you actually factor in the use of coal for generating electricity(and subsequent release of mercury), CFLs and incandescents are pretty comparable.
I think that a controlled reaction is implied. An out of control fusion reaction is "fairly" simple; a hydrogen bomb is an easy example.
I would say that an individual starting a large scale nuclear fusion reaction is unlikely for at least 100 years. Considering magnetic confinement fusion, the technology is so expensive and obtaining a plasma with the performance necessary for fusion is so difficult that it requires billions of dollars and hundreds of personnel to construct and operate a modern tokamak that can perform a non-trivial amount of fusion. Additionally, with magnetic confinement fusion it would be very difficult to have a reaction that is out of control. The reaction is so difficult to maintain that small changes to things like the plasma position and impurity content quickly quench the reaction. If any damage to the vacuum vessel caused a leak, the incoming atmosphere, which is on the order of a million times more dense than the plasma, would also quench the reaction and disrupt the plasma. Also, the machines are built to handle disruptions, which in the worst case is where the entire plasma hits the wall of the chamber. Though it may cause some damage to the first plasma facing components (typically graphite tiles in advanced tokamaks), this is unlikely to cause any damage to the actual vacuum vessel which is stainless steel.
If we consider some as of yet undiscovered method of performing nuclear fusion then I suppose it could be possible to have a seemingly stable reaction become out of control and dangerous. Something like Spiderman 2 is far from the reality of any current fusion method.
Unfortunately for many, science has been plagued by some spectacular frauds lately . The result is that skepticism runs high, especially when you follow an experiment and cannot reproduce the results and then the original scientist who claimed the results simply says you aren't doing it right and hides behind intellectual property rights to avoid revealing their "secret". I've been following this bubble fusion for a while now (I work in magnetic confinement fusion) and it seems to have all the warning signs of a fraud. I've read too many sketchy things about this scientist refusing to share his raw data, restricting access to his lab when someone calls into question the validity of the results and a number of other things that throw up a red flag. Maybe it will turn out to be true, but IMO Taleyarkhan is behaving in a very strange manner for someone claiming such a great discovery.
However, it is also crucial to acheive a self-sustaining reaction, something not yet done.
Actually, it is not necessary to have a self-sustaining reaction to have a viable fusion based power source. High power amplification (Q) of 50 or even 1000 would be suitable. In fact, from what I've recently read on ITER and plans for future machines they would actually prefer a finite Q since it introduces another method of control into the system. The actual Q required will depend on the plant efficiency.
You are right about the Q achieved to date. The highest equivalent Q achieved in the JET is something like 1.16 and it is 1.25 in the JT-60U tokamak. The equivalent Q is determined from the measured deuterium-deuterium fusion and the (equivalent) Q for a deuterium-tritium fuel is extrapolated. This is done because using tritium in experiments is problematic since these two machines are either not designed to handle tritium (JT-60U) or would prefer not to contaminate their machine due to the extreme care that must be taken after tritium experiments (JET). These two machines have demonstrated plasma performance that is better than breakeven. One can only hope that ITER is able to achieve higher Q with deuterium-tritium fuel.
I once saw Lance Burton make a car disappear. A CAR!!! I interpret that to mean that he can actually make cars disappear at will. It allows me to work towards my goal of making cars disappear. Once I get that down, I'm moving on to levitation a la David Blaine.
Seriously, a car disappeared. I saw it. Since I can't explain exactly how it happened, I have to assume it was some biological power as yet undiscovered by science. I mean, it just couldn't be a trick.
In the very first post he questioned whether gravity accelerates all objects at the same rate. That is what I am arguing against. The acceleration of an object in a gravitational field is independent of it's mass. Basically the poster appears to be questioning the equivalence principle and stating that he and his physics teacher (high school I assume) have somehow mathematically demonstrated that it doesn't hold. The only statement in the article about acceleration in a gravitational field is "As an explanation for the nature of gravity, general relativity relies on a key assumption: that gravity accelerates all objects at the same rate - regardless of their mass or composition. This idea is called the equivalence principle."
It is my contention that he was confusing the collision time being different for two objects and somehow interpreting this as meaning that objects are not accelerated at the same rate. He may not mean that, but what he really means is confusing and by using incorrect math it is hard to follow what point he is trying to make. By pointing out that he and his physics teacher put together some sort of hypothetical trials suggests they have found something new.
Obviously the actual collision time with the earth depends on the mass of the falling objects mass. The correct acceleration to use in order to calculate the fall time would be a = g + g*m_o/M_E where m_o is the object mass and M_E the earth mass. For anything near the size of a person this correction factor will be on the order of 10^-23 times the acceleration due to gravity of ~9.8m/s^2.
Even if you didn't make any typos in transferring what you did, it is still wrong. First, the force of gravity between the two objects is changing in time, therefore you cannot use the force between them when they are 10 m apart and apply it to the entire time that they are moving together. Another thing that is possibly just a typo is that the gravitational force is inversely proportional to the square of the distance between the bodies.
What you really want to do is calculate the acceleration of A and of B due to C when they are both the same distance r from C. You'll quickly see that the acceleration of A and B are identical. The acceleration of either of A or B is:
a_A = a_B = G*m_C/r^2
Also, the thing in the situation of the earth that is important as far as the fall time goes is that the earth is so massive compared with any objects which are typically considered that the object is essentially stationary. There is an equal and opposite force on the earth due to a falling object, but since the earths mass is so tremendous (5.97 x 10^24 kg) it basically does not move and so the fall time winds up being essentially identical. The situation you are describing has two objects of comparable mass so that both objects undergo comparable accelerations in such a case the fall times between AC and BC can be noticeably different.
If you aren't making a joke, then your physics teacher should be fired.
As has already been posted, due to the equivalence of inertial mass and gravitational mass, the object mass in the equation you have posted cancels. Also, if you really did do an experiment then I would question your methods. How did you account for air resistance. A 1992 article in Physical Review Letters details an experiment performed in an ultra-high vacuum where the universality of the free fall acceleration of objects in a gravitational field was verified to a few parts in 10^10. I'm assuming that this experiment was considerable more accurate than yours.
Of course, I hope that you are making a joke of some sort.
Also, liberal can be both an adjective and a noun, according to Merriam-Webster anyway. I just thought you'd like to know.
Thanks for the tip, but I don't see what you've changed. But hopefully your post helps you to feel smarter. I'm also having some trouble with gyrokinetic theory as it applies to plasmas. Could you help me with that as well?
...and this legislation hasn't even been introduced, let alone passed.
On a side-note - Stockwell Day is a bit of a dingleberry - a creationist who believes the earth was created 5000 years ago....the sharp swing to the right has begun in Canada....looks like the terrorists are winning when our freedoms start to get whittled away, bit by bit....
This legislation was first introduced by the liberals last year, so it isn't just because of the more right wing conservatives.
I've done several checkstops as an Auxilliary and it is routine to check license, registration and insurance. It dependd how busy it id, but if there id time it's done.
They also do that when they do a checkstop. Did you complain to your MP the last time you went through a checkstop?
Where does the article mention carbon dating? What is the relevance of your statement? Can you provide a scientific reference to your statement regarding potassium-argon dating?