How can you be so sure that there is little we can do to stop it? The fact that we can't prove that we're responsible for global warming doesn't prove that we're not. And if you do a proper risk assessment, like this guy does in his series of videos that are very much worth viewing despite his silly hats, you'll find that the smart thing to do is to try and do something about it.
Did you really understand that video? I watched it a while ago and there are somethings I just don't understand. Primarily, why is it that if we act on global warming and we are wrong it sends the world into a global depression, but if global warming is true and we act everyone is happy? Wouldn't the cost be the same regardless of whether or not global warming is true? Seems to me that both rows in column A must lead to global depression, but maybe you understood something different.
Your line of thought sounds like "the Earth is going to hell but we might not be responsible so let's just see where this goes". Consider the possibility that we are responsible, and/or (they don't even have to be connected) the possibility that we can do something about it.
I cannot speak for anyone else, but I look at it like this: If global warming is true and we want to do something about then we need to understand the cause. It doesn't matter if the cause is natural or man-made, either way we need to know the cause to determine the correct solution. If you don't really know the cause then you can't really know what the best solution should be or if a given solution will even work.
Machining is the most expensive way to produce a metal part.
No, the cheapest process for metal forming depends on the application. For large quantities there are often cheaper processes than machining, but that is not necessarily true for a 'one-off'. Likewise other factors such as material, complexity, tolerances, lead-time, etc can drive an engineer away from casting or stamping. Machining is the logical choice in many applications.
Why would you be forced to use it? Just don't switch to that input, or whatever mechanism they provide to activate it. It's a TV, I'm not buying one without many and varied inputs.
But then you paying for hardware that you don't actually use, where if the hardware wasn't included in the TV the base price could be lower. I hate paying for things that I don't use. My cell phone is a prime example, because I don't/can't use half the features it has. But I still had to pay for the hardware/software to support said features, because they just don't offer basic phones anymore.
Where I work we deal with both EAR and ITAR equipment. Since I have been here I have seen a lot of different points of view. Currently, as I understand it, we treat any mechanical or un-programmed electrical hardware as EAR. Unless there are special circumstances (i.e. specific customer requirements).
Electrical hardware doesn't become ITAR unless it has ITAR software/firmware on it. Sub-assembly and top level drawings are EAR unless they call out a piece of hardware that is ITAR. Once a lower level drawing calls out an ITAR item all higher level assembly drawings have to be ITAR as well. While, an ITAR assembly drawing can call out either ITAR or EAR items, an EAR assembly can only call out EAR items in the BOM.
These guys are doing -nothing- of consequence. The Koran comes off of a web press in the tens of thousands, just like any other book these days. So all they are doing ultimately is making a bit more business for some printer. It isn't as though they are destroying some special, ancient Koran that has historical and cultural significance, they are just burning a mass produced book. If they can't see the futility of that, well then that makes them the retards.
This exactly right! Nothing of value will be lost! Islam can still be practiced, new books can be printed, and the world will go on.
The amount of media and negative feedback this guy is getting is ridiculous for something so trivial.
Everyone talking about a burning a bible or a America Flag should go ahead and do that, for the same reason; nothing of value will be lost. But keep in mind it makes you no better than this Pastor.
If people were really serious about finding a peaceful response they could. Would it really be so fucking hard to have a print a new Koran day on 9/11 to offset all the books that get burned? But then again that might take some effort and tolerance of other peoples point of view.
There is certainly a limit to how much solar power can be collected. However, 1 kW/m^2 is a substantial amount of power, if we could get there. Take for example the high power electronics suites in UAVs. These electroncis require large amounts of power and therefore must be cooled accordingly. Now when the aircraft is running on the ground a unique cooling problem exists because only partial cooling capacity is available. This is further complicated by solar thermal loading on the ground which can exceed 1 kW/m^2. In some cases the solar loading can approach the nominal electronics power dissipation, which could drive the need for almost twice the cooling capacity. The point being that solar radiation is a significant problem at UAV power scales. There would significant opportunity if we could harness a 100% of that energy.
Seriously? Anyone who has developed airborne systems using COTS hardware has encountered this issue with spinning media.
It is not just airborne applications...ground vehicles are just as challenging, and I am sure ship-board electronics are also a challenge. I know of ground vehicle applications where the entire unit had to be mounted on isolators just to support the use of rotating media. Without isolators the qualification vibration levels would 1) prevent the harddrives from probably running the software, and 2) would cause the drives to fail mechanically (after only hours of testing).
As far as isolators go they are no free lunch. They can damp high energy or high frequency vibration but the trade off is very large displacements at low frequencies. So ultimately the space the unit requires is larger and that is never desirable.
TRIM was added to fix this problem by letting the OS tell the drive when blocks become unused but it only works on very recent drives and new operating systems. You are out of luck on that front if your running XP or a Linux kernel older than 2.6.33 but on the upside the problem only affects write speed.
For Intel Drives the new SSD Toolbox supports Trim on older OSes. I have been using it with WinXP...though that probably doesn't help anyone on Linux.
Since neither the summary nor the article has been kind enough to expand on "300 times more thermally conductive than normal polyethylene", I figured I'd look it up. Thermal Conductivity of some common Materials: Polyethylene HD: 0.42 - 0.51 W/mK Aluminium: 250W/mK Copper: 401 W/mK
Best case scenario: 153 W/mK or 61% as conductive as aluminium, 38% as conductive as copper. Not exactly impressive for a heat sink
You are assuming that pure aluminum is used for design. I work in the aerospace industry and the electronics chassis/heatsink we develop are usually made of alloy aluminum (6061 for machined parts and 5052 for sheet-metal).
The thermal conductivity for 6061 and 5052 around 160 W/mK and 140 W/mk, respectively. So this new material would have approximately the same single axis conductivity as an aluminum 6061 heatsink but at a fraction of the weight.
If this material were readily available today, I can think of several applications were I could use this material.
I am sure there are plenty of applications out there that can take advantage of this new hardware. I run finite element and computational fluid dynamics software at work and both are capable of using the 8 cores in my work PC (dual quad core).
The really sad part though is that for the FEA software I can only use 2 cores because the vendor requires customers to buy a separate HPC license for every processor/core beyond 2.
I have had the throttle stick more than once. Both times in a full size (US full size - 6000 lbs) van, that is rear wheel drive. It had front disc brakes and rear drums. Drums are shit, and they cannot over-come the ~180 HP V8. Yea if you are cruising along at low RPM and you push both the gas and the brake you might be able to stop the engine. But usually when the throttle stick it takes a moment a react and if the engine drops into a low gear and builds high RPMs (to where maximum power output is) it becomes much harder to get the vehicle stopped.
The first time the throttle stuck I went through a stop sign with the front wheels pretty much locked up, but the rear wheels were still propelling the vehicle forward. I was able to get it in neutral and then kill the engine, but that was after I already negotiated the intersection. It is scary shit when you only have 1-2 seconds to react and hitting the brakes the 'normal' first reaction only helps a little bit.
Your post is spot on. Except I would add that the questioning has to be done, by both sides, with the common goal of finding the truth. If one side is only discrediting the other side to push a self-serving agenda, then the system can't work.
I'm sure there is significant engineering effort involved in creating something like a personal jetpack, but he's still jumping out of a plane at altitude and essentially gliding with a bit of a boost from his jet engines along the way.
Engineering is about solving problems with practical solutions. You are assuming he didn't consider what it would take get of the ground using the jet pack. But I would assume he did look at the issue, and found that it would significantly increase the cost, weight, and risk by launching from the ground.
If his end goal is just to fly around, then to solve the problem of take-off he probably reasoned the best solution was to use existing aircraft to get to the proper altitude. Then just figure out how to get in/out of the aircraft with his equipment. Sounds like a smart engineering decision to me.
Well what I had in mind is a flat plate (say, aluminum) with water channels in it. On this plate there are two or three protrusions that match the main chip locations that need cooling that are milled to physically contact the chips just like discreet heat sinks would.
Similar to what you have described, a conduction cooling plate has been used extensively in the military embedded electronics industry. You take an aluminum/copper block of metal and machine the face so that it "touches" multiple components on the circuit card. It doesn't actually touch the components, because of the mechanical tolerances, generally putty or a complaint gap pad are used to interface between the heatsink and the package.
This results is a very robust heatsink. It can conduct a significant amount of heat from the card and also stiffens the assembly making the card more resistant to vibration and shock.
However, the solution tends to be very specific. The heatsink typically will only work for that specific card, and if any components are changed/moved the heatsink needs to be modified. This can be very costly. Of course a more generic design could be made to fit multiple cards, but as it becomes more generic the benefits this approach are diminished.
The notable thing about his approach is that once you get the heat off the card and to the cold-wall there are many options for removing the heat from there. For example the cold-wall could actually be a large heatsink fin-array, and that heatsink could be cooled by either air or water.
I'm sure there's actually probably a better substance than water for the purpose
No water is the probably the best solution. As already mentioned it has excellent thermal properties, in particular a very high specific heat. But also it is cheap and readily abundant, perfect for a home project.
I would suggest putting more effort into controlling the heat flow into and out of the water. During the day try to maximize the solar heating of the water, so that you can get it to the highest temperature. Maybe changing the color of the container so it absorbs more solar energy. If you can lift the container move it to a place where it won't loose heat to the ground.
At night try insulating undesired heat paths. For example, insulate the top of the container to prevent heat transfer back into the air. While making sure you have good contact between the sides of the water container and the ground, any air gaps will create unwanted thermal resistance. Or maybe you want that thermal resistance so that the heat is released at a slower rate, keeping things warm through the whole night.
I was just giving example, I am not 100% sure I understand you setup. But the basic idea should the same nonetheless.
I don't think they even showed the whole test, or they did it wrong. The MIL-STD-810 drop test is actually 26 total drops. Once on each face, edge, and corner.
They didn't show if they actually measure 4' or just eye-balled it. Also, they were dropping onto some kind of surface, but not directly on the ground. That can have a large influence on the amount of energy transferred to the laptop during the test. Where I work when we do a drop test we do it on a bare concrete floor, and there is fixture to ensure the exact height is used.
My suspicion is something in the range or Cubic Kilometers per Second instead of CFM and if we're talking that much, what impact on our weather is there going to be with such a large fan running all the time?
Converting Cubic Feet per Minute to Cubic Kilometers per Second. By any chance do your work for NASA?
Stopping distance is independent of the mass of the vehicle. Speed, being quadratic, is a huge factor. And mu, which depends on the tires and the road is also important.
This is what they teach in high school physics, and if you ask why race cars use larger tires you will get some BS answer about tire wear or rules. However, if you Google 'Tire Load Sensitivity', you will see that mu is not constant. Instead as the tire load increase so does the coefficient of friction, up to a point. Then the coefficient of friction will peak and then as the load continues to increase the coefficient of friction begins to decrease.
During braking load is transferred from the rear wheels to the front wheels, this effectively redistributes the amount of grip available for braking. The redistribution in grip actually results in a net loss in grip, maximum grip occurs for most vehicles when all the tires share the total vehicle load evenly. The more load that is transferred the more grip is lost during braking. The amount of load transfer is dependent on wheel base, mass, and CoG height.
If a vehicle's performance could be summed up into two simple equations, there would be a lot race engineers out of a job
I'm living in Tokyo at the moment, and my (rather cheap) apartment comes with broadband (fibre) bundled as part of the rent. I just did a speed test and I'm getting 52mbit down, 10mbit up. Absolutely no monthly limits.
What is "rather cheap", because here in the Midwest rather cheap is like $350/mo, and you don't get shit for internet. Of course you can buy cable internet or DSL for another $30-$60 a month. So is a cheap apartment in Tokyo $410/mo?
Yes, because plastic is a muuch better conductor for heat than say, copper.
It really depends on the design. You can account for a low conductivity material by increasing surface area and still dissipate the same amount of heat for a given temperature delta. In this case size isn't really an issue and neither is spreading resistance (typically a concern for the common CPU heatsink, hence it is made of Copper). So there are probably lower cost/thermal-conductivity materials that could work just as effectively as copper.
You are confusing risk with experience. Obviously, someone who drives more frequently will have more experience. However, regardless of experience or skill there are plenty of shitty drivers on the road. If you get into a accident, even if it is not your fault, it is still an accident and it costs the insurance companies money.
From their point of view accidents cost them money, regardless of the skill of the drivers involved, and by reducing time spend driving the risk of getting into accident is also reduced.
Certainly, a better driver will be able to avoid many dangerous situations, but there are some very poor drivers who could cause an accident with even the most diligent drivers.
Bottom line the only guaranteed way to not get into a car accident is not to drive. If you drive you are exposed to the risk of an accident. You can mitigate the risk by being a better driver, but the more you drive the more risk you assume.
You have a lot more faith in the system than I do. I had a typo in my driver's license that was never caught. Any organization that would use my driver's license infomration would just keep propagating the typo. Next time I got the ID renewed I 'corrected' the typo, because you have to update all your information, but apparently they thought my correction was a typo, because the misspelling was still there on the new ID.
When I was younger I assumed my step father's last name, but I never legally changed my name. I used that on bank accounts, college administration, and even filed my taxes with it. Although the IRS sent me a letter and told me that I needed to use my legal last name if I wanted my re-fund. I think at one point I had 3 or 4 variations of my name floating around.
As for social security numbers, at one point in time my wife had two different SSNs. She is a permanent resident so I am sure that is where the confusion originated from. But I still remember it clearly, one day she asked me which SSN she should use. Bewildered I asked her what she meant, as I had never heard of someone having more than one SSN. She showed me two government issued SS cards, and I told her to call the social security office and ask them what to do. On the phone they flat out said it was impossible for her to have two SS Cards and that she was mistaken. They didn't correct the issue until she actually went to the office in person and showed them both cards. They basically were like WTF, we have never seen this before.
None of it really surprised me though because I don't have a lot of faith in the system. I have seen a lot of small stuff go unnoticed when there was no malicious intent. I am sure a malicious individual could do just about anything given enough motivation.
Still, Stross called it a risky, waste of taxpayer money that would only benefit the wealthy and bailout VCs who'd sunk money into the money-losing company.
What is with this small thinking? It seems like a lot of 'green' ideas are presented in terms of money losers. I don't understand how that can be true when no one ever trys to figure out the environmental costs (literal costs).
It easy to say that Tesla makes less than they spend, therefore they should go under. But what if they were to succeed, and how much better would the environment be?
Conversely, what if they fail? How much money would it take to create an equally 'healthy' environment?
Unless someone can answer these questions how can they say it is truly a money loosing investment?
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How can you be so sure that there is little we can do to stop it? The fact that we can't prove that we're responsible for global warming doesn't prove that we're not. And if you do a proper risk assessment, like this guy does in his series of videos that are very much worth viewing despite his silly hats, you'll find that the smart thing to do is to try and do something about it.
Did you really understand that video? I watched it a while ago and there are somethings I just don't understand. Primarily, why is it that if we act on global warming and we are wrong it sends the world into a global depression, but if global warming is true and we act everyone is happy? Wouldn't the cost be the same regardless of whether or not global warming is true? Seems to me that both rows in column A must lead to global depression, but maybe you understood something different.
Your line of thought sounds like "the Earth is going to hell but we might not be responsible so let's just see where this goes". Consider the possibility that we are responsible, and/or (they don't even have to be connected) the possibility that we can do something about it.
I cannot speak for anyone else, but I look at it like this: If global warming is true and we want to do something about then we need to understand the cause. It doesn't matter if the cause is natural or man-made, either way we need to know the cause to determine the correct solution. If you don't really know the cause then you can't really know what the best solution should be or if a given solution will even work.
we could have sent up thirty Hubble telescopes ($5B).
Just sayin'.
Maybe nobody knew there was a $50 billion discount for buying Hubbles in bulk? ;-)
Machining is the most expensive way to produce a metal part.
No, the cheapest process for metal forming depends on the application. For large quantities there are often cheaper processes than machining, but that is not necessarily true for a 'one-off'. Likewise other factors such as material, complexity, tolerances, lead-time, etc can drive an engineer away from casting or stamping. Machining is the logical choice in many applications.
Why would you be forced to use it? Just don't switch to that input, or whatever mechanism they provide to activate it. It's a TV, I'm not buying one without many and varied inputs.
But then you paying for hardware that you don't actually use, where if the hardware wasn't included in the TV the base price could be lower. I hate paying for things that I don't use. My cell phone is a prime example, because I don't/can't use half the features it has. But I still had to pay for the hardware/software to support said features, because they just don't offer basic phones anymore.
Where I work we deal with both EAR and ITAR equipment. Since I have been here I have seen a lot of different points of view. Currently, as I understand it, we treat any mechanical or un-programmed electrical hardware as EAR. Unless there are special circumstances (i.e. specific customer requirements).
Electrical hardware doesn't become ITAR unless it has ITAR software/firmware on it. Sub-assembly and top level drawings are EAR unless they call out a piece of hardware that is ITAR. Once a lower level drawing calls out an ITAR item all higher level assembly drawings have to be ITAR as well. While, an ITAR assembly drawing can call out either ITAR or EAR items, an EAR assembly can only call out EAR items in the BOM.
These guys are doing -nothing- of consequence. The Koran comes off of a web press in the tens of thousands, just like any other book these days. So all they are doing ultimately is making a bit more business for some printer. It isn't as though they are destroying some special, ancient Koran that has historical and cultural significance, they are just burning a mass produced book. If they can't see the futility of that, well then that makes them the retards.
This exactly right! Nothing of value will be lost! Islam can still be practiced, new books can be printed, and the world will go on.
The amount of media and negative feedback this guy is getting is ridiculous for something so trivial.
Everyone talking about a burning a bible or a America Flag should go ahead and do that, for the same reason; nothing of value will be lost. But keep in mind it makes you no better than this Pastor.
If people were really serious about finding a peaceful response they could. Would it really be so fucking hard to have a print a new Koran day on 9/11 to offset all the books that get burned? But then again that might take some effort and tolerance of other peoples point of view.
Because highways with speed limits are safe and you should feel free to talk, phone, text, eat, put on make-up, etc?
How about people just assume that every drive, no matter how seemingly safe, was actually dangerous and required their full attention.
There is certainly a limit to how much solar power can be collected. However, 1 kW/m^2 is a substantial amount of power, if we could get there. Take for example the high power electronics suites in UAVs. These electroncis require large amounts of power and therefore must be cooled accordingly. Now when the aircraft is running on the ground a unique cooling problem exists because only partial cooling capacity is available. This is further complicated by solar thermal loading on the ground which can exceed 1 kW/m^2. In some cases the solar loading can approach the nominal electronics power dissipation, which could drive the need for almost twice the cooling capacity. The point being that solar radiation is a significant problem at UAV power scales. There would significant opportunity if we could harness a 100% of that energy.
Seriously? Anyone who has developed airborne systems using COTS hardware has encountered this issue with spinning media.
It is not just airborne applications...ground vehicles are just as challenging, and I am sure ship-board electronics are also a challenge. I know of ground vehicle applications where the entire unit had to be mounted on isolators just to support the use of rotating media. Without isolators the qualification vibration levels would 1) prevent the harddrives from probably running the software, and 2) would cause the drives to fail mechanically (after only hours of testing).
As far as isolators go they are no free lunch. They can damp high energy or high frequency vibration but the trade off is very large displacements at low frequencies. So ultimately the space the unit requires is larger and that is never desirable.
TRIM was added to fix this problem by letting the OS tell the drive when blocks become unused but it only works on very recent drives and new operating systems. You are out of luck on that front if your running XP or a Linux kernel older than 2.6.33 but on the upside the problem only affects write speed.
For Intel Drives the new SSD Toolbox supports Trim on older OSes. I have been using it with WinXP...though that probably doesn't help anyone on Linux.
Since neither the summary nor the article has been kind enough to expand on "300 times more thermally conductive than normal polyethylene", I figured I'd look it up.
Thermal Conductivity of some common Materials:
Polyethylene HD: 0.42 - 0.51 W/mK
Aluminium: 250W/mK
Copper: 401 W/mK
Best case scenario: 153 W/mK or 61% as conductive as aluminium, 38% as conductive as copper. Not exactly impressive for a heat sink
You are assuming that pure aluminum is used for design. I work in the aerospace industry and the electronics chassis/heatsink we develop are usually made of alloy aluminum (6061 for machined parts and 5052 for sheet-metal).
The thermal conductivity for 6061 and 5052 around 160 W/mK and 140 W/mk, respectively. So this new material would have approximately the same single axis conductivity as an aluminum 6061 heatsink but at a fraction of the weight.
If this material were readily available today, I can think of several applications were I could use this material.
I am sure there are plenty of applications out there that can take advantage of this new hardware. I run finite element and computational fluid dynamics software at work and both are capable of using the 8 cores in my work PC (dual quad core).
The really sad part though is that for the FEA software I can only use 2 cores because the vendor requires customers to buy a separate HPC license for every processor/core beyond 2.
I have had the throttle stick more than once. Both times in a full size (US full size - 6000 lbs) van, that is rear wheel drive. It had front disc brakes and rear drums. Drums are shit, and they cannot over-come the ~180 HP V8. Yea if you are cruising along at low RPM and you push both the gas and the brake you might be able to stop the engine. But usually when the throttle stick it takes a moment a react and if the engine drops into a low gear and builds high RPMs (to where maximum power output is) it becomes much harder to get the vehicle stopped.
The first time the throttle stuck I went through a stop sign with the front wheels pretty much locked up, but the rear wheels were still propelling the vehicle forward. I was able to get it in neutral and then kill the engine, but that was after I already negotiated the intersection. It is scary shit when you only have 1-2 seconds to react and hitting the brakes the 'normal' first reaction only helps a little bit.
Your post is spot on. Except I would add that the questioning has to be done, by both sides, with the common goal of finding the truth. If one side is only discrediting the other side to push a self-serving agenda, then the system can't work.
I'm sure there is significant engineering effort involved in creating something like a personal jetpack, but he's still jumping out of a plane at altitude and essentially gliding with a bit of a boost from his jet engines along the way.
Engineering is about solving problems with practical solutions. You are assuming he didn't consider what it would take get of the ground using the jet pack. But I would assume he did look at the issue, and found that it would significantly increase the cost, weight, and risk by launching from the ground.
If his end goal is just to fly around, then to solve the problem of take-off he probably reasoned the best solution was to use existing aircraft to get to the proper altitude. Then just figure out how to get in/out of the aircraft with his equipment. Sounds like a smart engineering decision to me.
Well what I had in mind is a flat plate (say, aluminum) with water channels in it. On this plate there are two or three protrusions that match the main chip locations that need cooling that are milled to physically contact the chips just like discreet heat sinks would.
Similar to what you have described, a conduction cooling plate has been used extensively in the military embedded electronics industry. You take an aluminum/copper block of metal and machine the face so that it "touches" multiple components on the circuit card. It doesn't actually touch the components, because of the mechanical tolerances, generally putty or a complaint gap pad are used to interface between the heatsink and the package.
This results is a very robust heatsink. It can conduct a significant amount of heat from the card and also stiffens the assembly making the card more resistant to vibration and shock.
However, the solution tends to be very specific. The heatsink typically will only work for that specific card, and if any components are changed/moved the heatsink needs to be modified. This can be very costly. Of course a more generic design could be made to fit multiple cards, but as it becomes more generic the benefits this approach are diminished.
The notable thing about his approach is that once you get the heat off the card and to the cold-wall there are many options for removing the heat from there. For example the cold-wall could actually be a large heatsink fin-array, and that heatsink could be cooled by either air or water.
I'm sure there's actually probably a better substance than water for the purpose
No water is the probably the best solution. As already mentioned it has excellent thermal properties, in particular a very high specific heat. But also it is cheap and readily abundant, perfect for a home project.
I would suggest putting more effort into controlling the heat flow into and out of the water. During the day try to maximize the solar heating of the water, so that you can get it to the highest temperature. Maybe changing the color of the container so it absorbs more solar energy. If you can lift the container move it to a place where it won't loose heat to the ground.
At night try insulating undesired heat paths. For example, insulate the top of the container to prevent heat transfer back into the air. While making sure you have good contact between the sides of the water container and the ground, any air gaps will create unwanted thermal resistance. Or maybe you want that thermal resistance so that the heat is released at a slower rate, keeping things warm through the whole night.
I was just giving example, I am not 100% sure I understand you setup. But the basic idea should the same nonetheless.
I don't think they even showed the whole test, or they did it wrong. The MIL-STD-810 drop test is actually 26 total drops. Once on each face, edge, and corner.
They didn't show if they actually measure 4' or just eye-balled it. Also, they were dropping onto some kind of surface, but not directly on the ground. That can have a large influence on the amount of energy transferred to the laptop during the test. Where I work when we do a drop test we do it on a bare concrete floor, and there is fixture to ensure the exact height is used.
My suspicion is something in the range or Cubic Kilometers per Second instead of CFM and if we're talking that much, what impact on our weather is there going to be with such a large fan running all the time?
Converting Cubic Feet per Minute to Cubic Kilometers per Second. By any chance do your work for NASA?
Stopping distance is independent of the mass of the vehicle. Speed, being quadratic, is a huge factor. And mu, which depends on the tires and the road is also important.
This is what they teach in high school physics, and if you ask why race cars use larger tires you will get some BS answer about tire wear or rules. However, if you Google 'Tire Load Sensitivity', you will see that mu is not constant. Instead as the tire load increase so does the coefficient of friction, up to a point. Then the coefficient of friction will peak and then as the load continues to increase the coefficient of friction begins to decrease.
During braking load is transferred from the rear wheels to the front wheels, this effectively redistributes the amount of grip available for braking. The redistribution in grip actually results in a net loss in grip, maximum grip occurs for most vehicles when all the tires share the total vehicle load evenly. The more load that is transferred the more grip is lost during braking. The amount of load transfer is dependent on wheel base, mass, and CoG height.
If a vehicle's performance could be summed up into two simple equations, there would be a lot race engineers out of a job
I'm living in Tokyo at the moment, and my (rather cheap) apartment comes with broadband (fibre) bundled as part of the rent. I just did a speed test and I'm getting 52mbit down, 10mbit up. Absolutely no monthly limits.
What is "rather cheap", because here in the Midwest rather cheap is like $350/mo, and you don't get shit for internet. Of course you can buy cable internet or DSL for another $30-$60 a month. So is a cheap apartment in Tokyo $410/mo?
Yes, because plastic is a muuch better conductor for heat than say, copper.
It really depends on the design. You can account for a low conductivity material by increasing surface area and still dissipate the same amount of heat for a given temperature delta. In this case size isn't really an issue and neither is spreading resistance (typically a concern for the common CPU heatsink, hence it is made of Copper). So there are probably lower cost/thermal-conductivity materials that could work just as effectively as copper.
You are confusing risk with experience. Obviously, someone who drives more frequently will have more experience. However, regardless of experience or skill there are plenty of shitty drivers on the road. If you get into a accident, even if it is not your fault, it is still an accident and it costs the insurance companies money.
From their point of view accidents cost them money, regardless of the skill of the drivers involved, and by reducing time spend driving the risk of getting into accident is also reduced.
Certainly, a better driver will be able to avoid many dangerous situations, but there are some very poor drivers who could cause an accident with even the most diligent drivers.
Bottom line the only guaranteed way to not get into a car accident is not to drive. If you drive you are exposed to the risk of an accident. You can mitigate the risk by being a better driver, but the more you drive the more risk you assume.
You have a lot more faith in the system than I do. I had a typo in my driver's license that was never caught. Any organization that would use my driver's license infomration would just keep propagating the typo. Next time I got the ID renewed I 'corrected' the typo, because you have to update all your information, but apparently they thought my correction was a typo, because the misspelling was still there on the new ID.
When I was younger I assumed my step father's last name, but I never legally changed my name. I used that on bank accounts, college administration, and even filed my taxes with it. Although the IRS sent me a letter and told me that I needed to use my legal last name if I wanted my re-fund. I think at one point I had 3 or 4 variations of my name floating around.
As for social security numbers, at one point in time my wife had two different SSNs. She is a permanent resident so I am sure that is where the confusion originated from. But I still remember it clearly, one day she asked me which SSN she should use. Bewildered I asked her what she meant, as I had never heard of someone having more than one SSN. She showed me two government issued SS cards, and I told her to call the social security office and ask them what to do. On the phone they flat out said it was impossible for her to have two SS Cards and that she was mistaken. They didn't correct the issue until she actually went to the office in person and showed them both cards. They basically were like WTF, we have never seen this before.
None of it really surprised me though because I don't have a lot of faith in the system. I have seen a lot of small stuff go unnoticed when there was no malicious intent. I am sure a malicious individual could do just about anything given enough motivation.
Still, Stross called it a risky, waste of taxpayer money that would only benefit the wealthy and bailout VCs who'd sunk money into the money-losing company.
What is with this small thinking? It seems like a lot of 'green' ideas are presented in terms of money losers. I don't understand how that can be true when no one ever trys to figure out the environmental costs (literal costs).
It easy to say that Tesla makes less than they spend, therefore they should go under. But what if they were to succeed, and how much better would the environment be?
Conversely, what if they fail? How much money would it take to create an equally 'healthy' environment?
Unless someone can answer these questions how can they say it is truly a money loosing investment?