Off topic a bit, I'm just curious where you're from. We've talked on here quite bit over the years. Anyway, to respond to your questions and comments:
I said: >> that wacky Trump dude were threatening to nuke my country, pointing out his big nuclear button, that would make me a bit more nervous than Obama's approach did. Trump seems like the kind of guy who just might decide, against the advice of his advisers, to go ahead and send a flight of three B-52s... >> It might not be a good idea
You asked: > why you proclaim such barbaric actions. Are you a barbarian?... > Sorry, mad pigs like you, who demand bombing another country back into the stone age
Where I'm from, if someone says "I'd be nervous that a wacky person might", that's not demanding that they do it. That's saying it's a wacky (crazy) thing to do, and the thought ought to make people nervous (worried). "Not a good idea" means one should NOT do it.
I said: >> it would be easy for the US
You asked: >> Why? NK is on another continent. What the fuck does the US care
When hammering nails, it's easy to hit your thumb with the hammer. Why? What the fuck would you want to do that for?
I believe asking nicely is what Obama did. Nice fellow, Obama.
I don't know how much Trump had to do with this.
Remember North Korea is smaller than Hewlett-Packard, they the US could easily destroy NK; we don't mostly because of politics. I know that if *I* were Kim Jong-un, and that wacky Trump dude were threatening to nuke my country, pointing out his big nuclear button, that would make me a bit more nervous than Obma's approach did. Trump seems like the kind of guy who just might decide, against the advice of his advisers, to go ahead and send a flight of three B-52s loaded up with 60 cruise missiles to go ahead and eliminate most of the major buildings in North Korea.
Keep in mind, North Korea has much less industry (gdp) than Birmingham, Alabama; Jacksonville; or Memphis. It would be easy for Trump to just wake up one morning and decide "I'm tired of little Rocket Man. Let's blow up North Korea today and be done with it". It might not be a GOOD idea, but it would be easy for the US to do. Trump just might do something that Obama and Bush wouldn't do.
It may be that Trump asked nicely AFTER he grabbed them by the crotch. That's more Trump's MO, just asking nicely isn't really his thing - even when he should.
Without knowing, I can only listen to what the people who are in a better position to know have to say.
I went off on a tangent at the end there. Obviously code review doesn't guarantee or prove anything.
Other techniques CAN guarantee, or prove, certain things about the code, and it doesn't have to be time-consuming or expensive. Heck just using a strongly typed language guarantees certain things that aren't guaranteed in languages without strong typing.
>The whole 'provably correct code' disappeared from reality as soon as I was half a step beyond academia.
It did at one point. Maybe around 1988 or so. In the 1970s programmers were people with degrees in math, so there was a lot more correctness. As math majors, they had done plenty of mathematical proofs, so the idea of knowing that you're getting the right answer made sense to my mom's generation.
We've had a phase of "sloppy" programming for a while now, but over that time our tools have improved immensely. Static analysis, which can automatically prove certain things about code, is coming back into style. New tools, and possibly new languages, may allow for a degree of reliability that wasn't feasible in 1988.
To give two examples, functional programming, which is currently in production use, can readily prove certain things. The most basic is using a functional language by itself proves that every function has no side effects - the only thing it does is return a value, which is determined entirely by the arguments passed to the function. Starting with those guarantees, it's fairly easy for tools to prove some other useful things about the function. Another example is that SQL schemas allow you to fairly easily make certain guarantees about the system. I do that at times and it's faster than not enforcing guarantees, because I don't have to debug problems caused by assumptions not actually being true. SQL *can* be used to make "we hope it works" systems, but in some cases that takes longer. It can be faster for me to apply rules which guarantee things, rather than tracing down problems related to assumptions.
I have hope that better and better tools and processes will be developed, and I'd like to help develop them. So far I've started by applying practices such as code review in organizations that didn't previously do it. We've found that code review / peer review reduces bugs enough to make it worthwhile. As a bonus it is a great training tool - programmers learn from each other practical approaches that apply directly to your codebase - because they ARE your codebase.
I was thinking along similar lines before I read your post. I'm about to head back to school for my masters and put some thought into which area I wanted to study. Partly, I want to retire as early as I can, which means making good money first. There is a huge demand for AI professionals, leading to high salaries. It just doesn't interest me much, though.
In my case I think it's partially because I've been on a software quality kick the last few years. If aerospace engineering was done like software engineering, planes would crash every day. It doesn't have to be like that. We can do it right, the first time. The attitude of "it seems like it pretty much worked when I tried it, let's ship it" gets on my nerves.
While AI isn't exactly "it seems like it pretty much works", it tends to lean much more in that direction than the systems I want to create, systems about which I can say "this is known to be absolutely correct; it has been mathematically proven correct".
âoeIf we want to be serious about quality, it is time to get tired of finding bugs and start preventing their happening in the first place.ââ" Alan Page
> What part of "Of course there are other problems with larger props, such as larger weight" wasn't clear t
What apparently isn't clear to you is that cubed is quite a bit larger than squared.
2x longer props on 2x longer arms require 4x the weight. 4x the weight in turn requires props double in size again. Longer props on longer arms can't be a solution to the thrust to weight ratio being too low because longer arms make the problem WORSE, not better.
To paraphrase what you said:
Too much weight for a given amount of thrust can be solved with larger props. Of course there are other problems with larger props, such as larger weight.
So your solution for "it's too heavy (given the thrust)" is to make it even heavier. Making it heavier does not and cannot solve the problem of it being to heavy. "Not enough thrust" is the same thing as "too heavy", because the actual problem is that the thrust is less than the weight. Going bigger makes that problem worse, much worse.
> This is nonsense. If you want to fit larger props on a quad, you make the mounting beams longer.
A longer beam must be thicker and wider in order to have the same strength. An arm twice as long, twice as thick, and twice as wide is roughly eight times heavier. The longer arm also is a longer moment arm producing a larger bending force at the point of attachment. That requires the central part of the frame to be stronger, and therefore heavier. You just end up making the entire craft bigger and heavier.
Making it bigger overall has one huge problem - the weight is proportional to any given dimension CUBED, while the lift is only proportional to disc area - rotor radius SQUARED. The larger you go, the more it doesn't work.
That's why three-inch toy quadcopters are in every store, even convenience stores, while people fly around in HELIcopters, not quadcopters. Because cubing the weight while only squaring the lift doesn't work past about 350mm, and even at that size you only get a few minutes of flight time.
Notice helicopters fly for about four hours, quads about 8 minutes. That's because the ratio of lift to power (fuel) needed is horrible in a quad. They are, however, fun and cheap to build small ones where more motors and rotors is cheaper than the complex mechanical linkage required by a helicopter. I've used one of my quads to pull my plane out of a tree.
Might be time to take said book down off the shelf again and refresh your memory.
The drag equation is:
D = Cd * A *.5 * (r * V^2)
R is density. Density on Mars is 1/100 that on Earth, so when you say:
>To get the airfoils rotating at 10x speed... the motor is required to be outputting up to 100x the normal power.
That would be correct if density were constant. Reduce density by 99% and you also reduce drag (and therefore power) by 99%. Required motor power is therefore increased by 100x to get additional velocity, yet DEcreased by the exact same amount, by the same reduced density which necessitated the increased speed. Motor power needed on Mars equals that needed on Earth. Here's a perhaps simpler explanation of why:
The airfoil (rotor in this case) is tilted backward compared to the relative flow. We can divide that angle into two components - the vertical and the horizontal. It's producing lift upward, and also backward. That backward lift is the induced drag. Since the primary form of drag IS lift, directed backward, anything that reduces lift will proportionally reduce induced drag. Because again, drag IS lift. It's the backward component of lift due to the backward tilt of the blade.
We've focuses on induced drag, which is likey to be the main form of drag. Parasitic drag, skin friction, is also very roughly proportional to density, though that gets very complicated very quickly. We'd need Slashdot to support MathML in order to even start discussing it. Even then, after someone mentioned boundary layer turbulence someone else would mention golf ball dimples and the whole thing would turn into a guessing game.
I'm not the one who said that, but I do have enough understanding of the physics of props to explain why it should likely be largely true for helicopters. "Drones" (quadcopters) would likely run into a problem.
You have probably played around with sticking your hand out a car window and angling it so that it flies up. You've probably noticed that if you angle it too much toward the vertical, the airflow pushed your hand backward with considerable force. Props are of course angled similarly, so that some of the oncoming air is forced downward, creating lift, and the greater the angle, the more drag, or backward force is created. It is the job of the motor to overcome that drag. A more dense fluid has more drag, and so requires more motor power to maintain the same speed. So the required motor power is equal (and working opposite to) the drag.
You may have noticed that the same thing happens in water. Because water is more dense and vicious than air, water creates a greater force at a given angle - both greater lifting force and greater drag force.
We call the drag created by the angle "induced drag". There are complex formulas for drag and lift, which involve something called the Reynolds number, but as it happens when calculating the ratio of drag to lift the other numbers cancel out and drag is directly proportional to lift for a given foil, as density and speed changes. You can intuitively imagine that if you hold a flat board in a flow, at exactly 45 degree angle to the flow half the force will be up and half drag backward. That isn't exactly correct due to flow separation and complex stuff, but the intuitive understanding is that the magnitude of the forces is related is true. Something more dense, like water, will have more force - more drag and more lift. Lower density will give less drag and less lift.
Lower density means less lift AND less drag, proportionately. The required motor power is exactly equal to the drag. So the required motor power is reduced as drag and lift are reduced. Thus required power is directly proportional to lift - the thin atmosphere gives less lift, and needs less motor to overcome drag.
So just moving a helicopter from Earth to Mars we find that the lift (at a constant RPM) is too small, and the Earth motor is way oversized for the need. To make it fly on Mars, we need the prop to generate more lift BUT we don't mind a lot more drag - we have plenty of motor to overcome drag. We can easily generate more lift (and drag) by making the prop larger, spinning it faster, or increasing its "pitch" (the small dimension of the prop, from top to bottom on a helicopter). In particular, larger props generate a lot more lift and So it's easy to get lift equal to the weight of the craft - our motor was designed to overcome the proportional drag. drag. Larger props are also considerably more efficient, having a better radio of lift to drag.
Quadcopters have a problem when you want to make the props bigger. Quads of course have four props, and if they are large enough to be efficient the ends of the props nearly touch at the center of the craft. You can't go larger without the ends of the props hitting each other. To put much larger props on a quad, you'd need them at different heights, going over and under each other. Even if you do that, the prop can't be longer than the width of the frame, because the tip of one prop would hit the axle of the others.
This is just a first approximation to show it is generally a reasonable idea to simply put bigger or props on for lower density atmosphere, or just let the same props spin faster since they have less drag. Practical issues arise such as building the prop to be stiff enough given the extra length.
The fine summary says it's the size of a softball, which is inches in diameter (9cm). It's also four pounds (1.8kg). A typical hobby shop drone of that size would be maybe 100 grams.
My hobby shop "heavier than air" vehicle is 100cm and 500 grams. Keep in mind mine is 10x longer, 10x wider, and 10x taller, so it should be about 1000x the weight.
The article you linked to mentioned there was a recall. "The changes are designed to automatically prevent the vehicle from moving under certain circumstances, even if the driver doesn't select 'park'", the article said. That's precisely the change I posted about.
> Even assuming all that were true, isn't it pretty fucking humiliating to admit that a dozen russians with broken english and a 5 figure budget were SO much more effective than the $Billions worth of marketing people on Hillary's side doing the exact same shit (including plenty of foreigners)?
That argument also doesn't make sense because the Russian ads were trolling both ways, trying to stir up discord, pitting Americans against each other. They ran Black Lives Matter ads, ads on both sides of the gun control debate, etc. Nearly half their ads were the same type of things the Hillary campaign was saying. Rather than compete with the United States, Russia would rather compete with the Divided States.
The Russians were trying to make black people mad with #BLM stuff, Hillary was trying to make black mad with #BLM stuff. Russia wanted a bunch of ultra-feminist women angry at men, Hillary wanted a bunch of ultra-feminist women angry at men. There's no "Russians beat Hillary", the Russians were running slightly more extreme versions of the same type of ads Hillary was running half the time.
The Russians know we're stronger when we're united. They don't have to fight against us if they can get us to fight against ourselves.
They want Mexicans coming in waving the Mexican flag chanting "Viva Mexico" while working-class Americans get angry and scared. What the Russians don't want is the United States to be United, proud new Americans working alongside those who have been here longer. They want to divide us - chop us up into black America, women vs men, rich vs poor, etc. None of that involves beating Hillary. A lot of it involves taking a lesson from Hillary.
> thinks auto-pilot is like aircraft autopilot in the movies. Note that real aircraft pilots only use it for mid-flight, not at or around super-busy airports
Going off on a tangent here, but modern airliners actually auto-land as common procedure. 30 years ago they didn't.
Heck, even my $250 model plane can auto-land, after automatically taking off. It uses open source software on a $30 controller board to do so.
If it wasn't clear above, they just introduced this bill in House of Representatives. Rand Paul is a Senator. The bill has a long way to go before Paul would be looking at it.
They've just now introduced the bill. There's no evidence they even mentioned it to Rand Paul yet. They should, and I'm sure they will.
Rand Paul understands the issues around encryption and says clearly that weakening the encryption would not only be stupid, but have Constitutional issues as well.
He authored seven budget bills. I don't have time to check all of them, but I was curious enough to check two. Maybe you'll want to check the others. I checked fiscal year 2015 and 2017. Both of those are balanced budget plans. Care to check a couple others and let me know what you find?
Bill probably knows this already, but for those who don't, the federal government plans spending over a 10-year period, for two reasons. First, this slightly reduces the extent of "buy it this year, pay for it three years later" that happens - the budget proposals show costs over the next ten years. Also, it provides some predictability and stability. A "budget cut" doesn't mean an agency gets less money than it got last year, it means their increase is less than the increase that they've been planning on over the last 10 years.
Like all federal budget proposals, those written by Speaker Ryan were over a 10-year period, and balanced the budget over that time frame. To make THIS YEAR balance would require a sudden 40% cut to every agency, based on the plans they'd been given over the last ten years.
> Have even put my own jokes into code and docs. Not sorry.
I've done that myself. One particular case stands out in my mind. As I recall it was in a comment, or perhaps within an "if false" statement, something that couldn't possibly affect how the program runs. However, the file ended up being used in a way that I didn't intend or predict, and the presence of the joke caused a significant outage.
"Triggered" is the word people use derisively. The wording almost sounds like Carlos was encouraged to write something he didn't mean, and worded it in such a way to show derision for what he was being asked to say. Like the forced "confessions" that dictators film of hostages.
Either Carlos is ignorant enough that he self-flamed his own statement, or he felt compelled to engage in some virtue-signaling that he didn't actually believe.
Yes, this is a continuation of an effort that began when some in Congress thought that the FBI was lying to them about their efforts to force Apple to crack a phone.
The reps who introduced this bill are:
Rep. Zoe Lofgren (D-Calif.) introduced the legislation along with Reps. Ted Lieu (D-Calif.), Jerrold Nadler (D-N.Y.), Matt Gaetz (R-Fla.), Thomas Massie (R-Ky.) and Ted Poe (R-Texas).
Reps involved starting in April were:
Zoe Lofgren (D-Calif.), Darrell Issa (R-Calif.), Jerrold Nadler (D-N.Y.), Jim Sensenbrenner (R-Wis.), Ted Lieu (D-Calif.), Ted Poe (R-Texas), Jared Polis (D-Col.), Matt Gaetz (R-Fla.), Suzan DelBene (D-Wash.) and Jim Jordan (R-Ohio).
Virtually all congresscritters vote on all the bills without ever reading most of them, especially budgets. I only know of one representative in Congress who has ever read a federal budget. Paul Ryan WROTE, not just read, multiple federal budgets. For any and every congresscritter, I can find areas where we disagree as to the best policy. Ryan is no exception, I don't fully agree with anyone, on everything. He is also by far the best informed, smartest person we've had in Congress in many years. And squeaky clean on ethics. Whikle he doesn't always come to the same conclusions I do, his conclusions are based on *really* knowing his stuff, knowing wtf he's talking about. Frankly, me disagreeing with Paul Ryan about federal policy is like me disagreeing with Stephen Hawking about physics theories - we both have our own opinions; one of us knows wtf they are talking about it, and it isn't me.
Paul Ryan's departure will hurt the country when he's replaced with another "we have to pass the bill to find out what's in it" person.
I read the article you had linked to. Which didn't say anything about a laughing partner or anything like that, as I recall. If you don't think that article spins it the way they should, I suppose don't use that link next time.
I spent about 10 minutes or so reading most of your latest link, and I still don't see any mention of a bail bondsman either.
Slashdot Mirror
Off topic a bit, I'm just curious where you're from. We've talked on here quite bit over the years. Anyway, to respond to your questions and comments:
I said: ...
>> that wacky Trump dude were threatening to nuke my country, pointing out his big nuclear button, that would make me a bit more nervous than Obama's approach did. Trump seems like the kind of guy who just might decide, against the advice of his advisers, to go ahead and send a flight of three B-52s
>> It might not be a good idea
You asked: ...
> why you proclaim such barbaric actions. Are you a barbarian?
> Sorry, mad pigs like you, who demand bombing another country back into the stone age
Where I'm from, if someone says "I'd be nervous that a wacky person might", that's not demanding that they do it. That's saying it's a wacky (crazy) thing to do, and the thought ought to make people nervous (worried). "Not a good idea" means one should NOT do it.
I said:
>> it would be easy for the US
You asked:
>> Why? NK is on another continent. What the fuck does the US care
When hammering nails, it's easy to hit your thumb with the hammer. Why? What the fuck would you want to do that for?
I believe asking nicely is what Obama did. Nice fellow, Obama.
I don't know how much Trump had to do with this.
Remember North Korea is smaller than Hewlett-Packard, they the US could easily destroy NK; we don't mostly because of politics. I know that if *I* were Kim Jong-un, and that wacky Trump dude were threatening to nuke my country, pointing out his big nuclear button, that would make me a bit more nervous than Obma's approach did. Trump seems like the kind of guy who just might decide, against the advice of his advisers, to go ahead and send a flight of three B-52s loaded up with 60 cruise missiles to go ahead and eliminate most of the major buildings in North Korea.
Keep in mind, North Korea has much less industry (gdp) than Birmingham, Alabama; Jacksonville; or Memphis.
It would be easy for Trump to just wake up one morning and decide "I'm tired of little Rocket Man. Let's blow up North Korea today and be done with it". It might not be a GOOD idea, but it would be easy for the US to do. Trump just might do something that Obama and Bush wouldn't do.
It may be that Trump asked nicely AFTER he grabbed them by the crotch. That's more Trump's MO, just asking nicely isn't really his thing - even when he should.
Without knowing, I can only listen to what the people who are in a better position to know have to say.
I went off on a tangent at the end there.
Obviously code review doesn't guarantee or prove anything.
Other techniques CAN guarantee, or prove, certain things about the code, and it doesn't have to be time-consuming or expensive. Heck just using a strongly typed language guarantees certain things that aren't guaranteed in languages without strong typing.
>The whole 'provably correct code' disappeared from reality as soon as I was half a step beyond academia.
It did at one point. Maybe around 1988 or so. In the 1970s programmers were people with degrees in math, so there was a lot more correctness. As math majors, they had done plenty of mathematical proofs, so the idea of knowing that you're getting the right answer made sense to my mom's generation.
We've had a phase of "sloppy" programming for a while now, but over that time our tools have improved immensely. Static analysis, which can automatically prove certain things about code, is coming back into style. New tools, and possibly new languages, may allow for a degree of reliability that wasn't feasible in 1988.
To give two examples, functional programming, which is currently in production use, can readily prove certain things. The most basic is using a functional language by itself proves that every function has no side effects - the only thing it does is return a value, which is determined entirely by the arguments passed to the function. Starting with those guarantees, it's fairly easy for tools to prove some other useful things about the function. Another example is that SQL schemas allow you to fairly easily make certain guarantees about the system. I do that at times and it's faster than not enforcing guarantees, because I don't have to debug problems caused by assumptions not actually being true. SQL *can* be used to make "we hope it works" systems, but in some cases that takes longer. It can be faster for me to apply rules which guarantee things, rather than tracing down problems related to assumptions.
I have hope that better and better tools and processes will be developed, and I'd like to help develop them. So far I've started by applying practices such as code review in organizations that didn't previously do it. We've found that code review / peer review reduces bugs enough to make it worthwhile. As a bonus it is a great training tool - programmers learn from each other practical approaches that apply directly to your codebase - because they ARE your codebase.
I was thinking along similar lines before I read your post. I'm about to head back to school for my masters and put some thought into which area I wanted to study. Partly, I want to retire as early as I can, which means making good money first. There is a huge demand for AI professionals, leading to high salaries. It just doesn't interest me much, though.
In my case I think it's partially because I've been on a software quality kick the last few years. If aerospace engineering was done like software engineering, planes would crash every day. It doesn't have to be like that. We can do it right, the first time. The attitude of "it seems like it pretty much worked when I tried it, let's ship it" gets on my nerves.
While AI isn't exactly "it seems like it pretty much works", it tends to lean much more in that direction than the systems I want to create, systems about which I can say "this is known to be absolutely correct; it has been mathematically proven correct".
âoeIf we want to be serious about quality, it is time to get tired of finding bugs and start preventing their happening in the first place.ââ" Alan Page
> What part of "Of course there are other problems with larger props, such as larger weight" wasn't clear t
What apparently isn't clear to you is that cubed is quite a bit larger than squared.
2x longer props on 2x longer arms require 4x the weight. 4x the weight in turn requires props double in size again. Longer props on longer arms can't be a solution to the thrust to weight ratio being too low because longer arms make the problem WORSE, not better.
To paraphrase what you said:
Too much weight for a given amount of thrust can be solved with larger props. Of course there are other problems with larger props, such as larger weight.
So your solution for "it's too heavy (given the thrust)" is to make it even heavier. Making it heavier does not and cannot solve the problem of it being to heavy. "Not enough thrust" is the same thing as "too heavy", because the actual problem is that the thrust is less than the weight. Going bigger makes that problem worse, much worse.
> This is nonsense. If you want to fit larger props on a quad, you make the mounting beams longer.
A longer beam must be thicker and wider in order to have the same strength. An arm twice as long, twice as thick, and twice as wide is roughly eight times heavier. The longer arm also is a longer moment arm producing a larger bending force at the point of attachment. That requires the central part of the frame to be stronger, and therefore heavier. You just end up making the entire craft bigger and heavier.
Making it bigger overall has one huge problem - the weight is proportional to any given dimension CUBED, while the lift is only proportional to disc area - rotor radius SQUARED. The larger you go, the more it doesn't work.
That's why three-inch toy quadcopters are in every store, even convenience stores, while people fly around in HELIcopters, not quadcopters. Because cubing the weight while only squaring the lift doesn't work past about 350mm, and even at that size you only get a few minutes of flight time.
Notice helicopters fly for about four hours, quads about 8 minutes. That's because the ratio of lift to power (fuel) needed is horrible in a quad. They are, however, fun and cheap to build small ones where more motors and rotors is cheaper than the complex mechanical linkage required by a helicopter. I've used one of my quads to pull my plane out of a tree.
Might be time to take said book down off the shelf again and refresh your memory.
The drag equation is:
D = Cd * A * .5 * (r * V^2)
R is density. Density on Mars is 1/100 that on Earth, so when you say:
>To get the airfoils rotating at 10x speed ... the motor is required to be outputting up to 100x the normal power.
That would be correct if density were constant. Reduce density by 99% and you also reduce drag (and therefore power) by 99%. Required motor power is therefore increased by 100x to get additional velocity, yet DEcreased by the exact same amount, by the same reduced density which necessitated the increased speed. Motor power needed on Mars equals that needed on Earth. Here's a perhaps simpler explanation of why:
The airfoil (rotor in this case) is tilted backward compared to the relative flow. We can divide that angle into two components - the vertical and the horizontal. It's producing lift upward, and also backward. That backward lift is the induced drag. Since the primary form of drag IS lift, directed backward, anything that reduces lift will proportionally reduce induced drag. Because again, drag IS lift. It's the backward component of lift due to the backward tilt of the blade.
We've focuses on induced drag, which is likey to be the main form of drag. Parasitic drag, skin friction, is also very roughly proportional to density, though that gets very complicated very quickly. We'd need Slashdot to support MathML in order to even start discussing it. Even then, after someone mentioned boundary layer turbulence someone else would mention golf ball dimples and the whole thing would turn into a guessing game.
I'm not the one who said that, but I do have enough understanding of the physics of props to explain why it should likely be largely true for helicopters. "Drones" (quadcopters) would likely run into a problem.
You have probably played around with sticking your hand out a car window and angling it so that it flies up. You've probably noticed that if you angle it too much toward the vertical, the airflow pushed your hand backward with considerable force. Props are of course angled similarly, so that some of the oncoming air is forced downward, creating lift, and the greater the angle, the more drag, or backward force is created. It is the job of the motor to overcome that drag. A more dense fluid has more drag, and so requires more motor power to maintain the same speed. So the required motor power is equal (and working opposite to) the drag.
You may have noticed that the same thing happens in water. Because water is more dense and vicious than air, water creates a greater force at a given angle - both greater lifting force and greater drag force.
We call the drag created by the angle "induced drag". There are complex formulas for drag and lift, which involve something called the Reynolds number, but as it happens when calculating the ratio of drag to lift the other numbers cancel out and drag is directly proportional to lift for a given foil, as density and speed changes. You can intuitively imagine that if you hold a flat board in a flow, at exactly 45 degree angle to the flow half the force will be up and half drag backward. That isn't exactly correct due to flow separation and complex stuff, but the intuitive understanding is that the magnitude of the forces is related is true. Something more dense, like water, will have more force - more drag and more lift. Lower density will give less drag and less lift.
Lower density means less lift AND less drag, proportionately. The required motor power is exactly equal to the drag. So the required motor power is reduced as drag and lift are reduced. Thus required power is directly proportional to lift - the thin atmosphere gives less lift, and needs less motor to overcome drag.
So just moving a helicopter from Earth to Mars we find that the lift (at a constant RPM) is too small, and the Earth motor is way oversized for the need. To make it fly on Mars, we need the prop to generate more lift BUT we don't mind a lot more drag - we have plenty of motor to overcome drag. We can easily generate more lift (and drag) by making the prop larger, spinning it faster, or increasing its "pitch" (the small dimension of the prop, from top to bottom on a helicopter). In particular, larger props generate a lot more lift and So it's easy to get lift equal to the weight of the craft - our motor was designed to overcome the proportional drag. drag. Larger props are also considerably more efficient, having a better radio of lift to drag.
Quadcopters have a problem when you want to make the props bigger. Quads of course have four props, and if they are large enough to be efficient the ends of the props nearly touch at the center of the craft. You can't go larger without the ends of the props hitting each other. To put much larger props on a quad, you'd need them at different heights, going over and under each other. Even if you do that, the prop can't be longer than the width of the frame, because the tip of one prop would hit the axle of the others.
This is just a first approximation to show it is generally a reasonable idea to simply put bigger or props on for lower density atmosphere, or just let the same props spin faster since they have less drag. Practical issues arise such as building the prop to be stiff enough given the extra length.
That should say "3.5 inches".
Mine is nearly 10 times that length, and ten times the width,
so presumably around 10x the height, yet weighs 75% less.
Apparently they made theirs from solid lead or something.
The fine summary says it's the size of a softball, which is inches in diameter (9cm). It's also four pounds (1.8kg). A typical hobby shop drone of that size would be maybe 100 grams.
My hobby shop "heavier than air" vehicle is 100cm and 500 grams. Keep in mind mine is 10x longer, 10x wider, and 10x taller, so it should be about 1000x the weight.
The article you linked to mentioned there was a recall. "The changes are designed to automatically prevent the vehicle from moving under certain circumstances, even if the driver doesn't select 'park'", the article said. That's precisely the change I posted about.
Paul Ryan wrote seven federal budgets. Can you name another congresscritter who so much as "read* even one budget bill?
Take your time, I'll wait.
> > Hillary was trying to make black mad with #BLM stuff.
Oh bullshit. Fuck your RWNJ projection.
Thank you for your hilarious parody of a mad Clintonite.
> Even assuming all that were true, isn't it pretty fucking humiliating to admit that a dozen russians with broken english and a 5 figure budget were SO much more effective than the $Billions worth of marketing people on Hillary's side doing the exact same shit (including plenty of foreigners)?
That argument also doesn't make sense because the Russian ads were trolling both ways, trying to stir up discord, pitting Americans against each other.
They ran Black Lives Matter ads, ads on both sides of the gun control debate, etc. Nearly half their ads were the same type of things the Hillary campaign was saying. Rather than compete with the United States, Russia would rather compete with the Divided States.
The Russians were trying to make black people mad with #BLM stuff, Hillary was trying to make black mad with #BLM stuff. Russia wanted a bunch of ultra-feminist women angry at men, Hillary wanted a bunch of ultra-feminist women angry at men. There's no "Russians beat Hillary", the Russians were running slightly more extreme versions of the same type of ads Hillary was running half the time.
The Russians know we're stronger when we're united. They don't have to fight against us if they can get us to fight against ourselves.
They want Mexicans coming in waving the Mexican flag chanting "Viva Mexico" while working-class Americans get angry and scared. What the Russians don't want is the United States to be United, proud new Americans working alongside those who have been here longer. They want to divide us - chop us up into black America, women vs men, rich vs poor, etc. None of that involves beating Hillary. A lot of it involves taking a lesson from Hillary.
> thinks auto-pilot is like aircraft autopilot in the movies. Note that real aircraft pilots only use it for mid-flight, not at or around super-busy airports
Going off on a tangent here, but modern airliners actually auto-land as common procedure. 30 years ago they didn't.
Heck, even my $250 model plane can auto-land, after automatically taking off. It uses open source software on a $30 controller board to do so.
> For whatever reason people make this mistake all the time
In my Dodge, if I open the door while the car is stopped, it automatically goes into park.
Humans screw up all the time. Good systems are designed so that mistakes that happen "all the time" don't cause your car to drive through a Starbucks.
If it wasn't clear above, they just introduced this bill in House of Representatives. Rand Paul is a Senator. The bill has a long way to go before Paul would be looking at it.
They've just now introduced the bill. There's no evidence they even mentioned it to Rand Paul yet. They should, and I'm sure they will.
Rand Paul understands the issues around encryption and says clearly that weakening the encryption would not only be stupid, but have Constitutional issues as well.
https://www.randpaul.com/news/...
I thought Ron Paul was kinda kooky - I wondered if he was a Coast to Coast AM listener, but I like Rand Paul so far.
He authored seven budget bills. I don't have time to check all of them, but I was curious enough to check two. Maybe you'll want to check the others. I checked fiscal year 2015 and 2017. Both of those are balanced budget plans. Care to check a couple others and let me know what you find?
Bill probably knows this already, but for those who don't, the federal government plans spending over a 10-year period, for two reasons. First, this slightly reduces the extent of "buy it this year, pay for it three years later" that happens - the budget proposals show costs over the next ten years. Also, it provides some predictability and stability. A "budget cut" doesn't mean an agency gets less money than it got last year, it means their increase is less than the increase that they've been planning on over the last 10 years.
Like all federal budget proposals, those written by Speaker Ryan were over a 10-year period, and balanced the budget over that time frame. To make THIS YEAR balance would require a sudden 40% cut to every agency, based on the plans they'd been given over the last ten years.
> Have even put my own jokes into code and docs. Not sorry.
I've done that myself. One particular case stands out in my mind. As I recall it was in a comment, or perhaps within an "if false" statement, something that couldn't possibly affect how the program runs. However, the file ended up being used in a way that I didn't intend or predict, and the presence of the joke caused a significant outage.
I will never put jokes in production code again.
"Triggered" is the word people use derisively. The wording almost sounds like Carlos was encouraged to write something he didn't mean, and worded it in such a way to show derision for what he was being asked to say. Like the forced "confessions" that dictators film of hostages.
Either Carlos is ignorant enough that he self-flamed his own statement, or he felt compelled to engage in some virtue-signaling that he didn't actually believe.
Yes, this is a continuation of an effort that began when some in Congress thought that the FBI was lying to them about their efforts to force Apple to crack a phone.
The reps who introduced this bill are:
Rep. Zoe Lofgren (D-Calif.) introduced the legislation along with Reps. Ted Lieu (D-Calif.), Jerrold Nadler (D-N.Y.), Matt Gaetz (R-Fla.), Thomas Massie (R-Ky.) and Ted Poe (R-Texas).
Reps involved starting in April were:
Zoe Lofgren (D-Calif.), Darrell Issa (R-Calif.), Jerrold Nadler (D-N.Y.), Jim Sensenbrenner (R-Wis.), Ted Lieu (D-Calif.), Ted Poe (R-Texas), Jared Polis (D-Col.), Matt Gaetz (R-Fla.), Suzan DelBene (D-Wash.) and Jim Jordan (R-Ohio).
I'm a conservative. #NeverTrump
Virtually all congresscritters vote on all the bills without ever reading most of them, especially budgets. I only know of one representative in Congress who has ever read a federal budget. Paul Ryan WROTE, not just read, multiple federal budgets. For any and every congresscritter, I can find areas where we disagree as to the best policy. Ryan is no exception, I don't fully agree with anyone, on everything. He is also by far the best informed, smartest person we've had in Congress in many years. And squeaky clean on ethics. Whikle he doesn't always come to the same conclusions I do, his conclusions are based on *really* knowing his stuff, knowing wtf he's talking about. Frankly, me disagreeing with Paul Ryan about federal policy is like me disagreeing with Stephen Hawking about physics theories - we both have our own opinions; one of us knows wtf they are talking about it, and it isn't me.
Paul Ryan's departure will hurt the country when he's replaced with another "we have to pass the bill to find out what's in it" person.
I read the article you had linked to. Which didn't say anything about a laughing partner or anything like that, as I recall. If you don't think that article spins it the way they should, I suppose don't use that link next time.
I spent about 10 minutes or so reading most of your latest link, and I still don't see any mention of a bail bondsman either.