The booster idea is more or less necessary. Parachutes don't stop you, they merely slow you down. You've still got a decent amount of speed going when you hit the ground. It's hard enough on your knees doing that with just your own weight. You're not going to want to do that with a bulky pressure suit, air tank, and whatever other protective and stabilization gear you need to get you through a Mach 3 freefall. Re-entry typically land in water to cushion the fall, but then you're not going to be buoyant like a large, hollow capsule. You can either eject that crap to land separately (like a paratrooper), use a parawing and glide in (but then you have a high running speed instead of a falling speed), or use retro-rockets to slow you down beyond the ability of the parachute.
Except you don't, because this company is not proposing an orbital re-entry system. What they want to design is for someone at a fixed position, 100km up, so basically the same flight envelope as SpaceShipOne/Two. There's not enough energy there to really be an issue. You just need to lock those limbs down so they don't flail around.
Actually, we are there. We could build a space dive suit right now (or about a year down the line with sufficient funding once all the engineering legwork is done). It's just not that tough to get down from 100 kilometers. You really don't have all that much energy to dissipate. Just make a suit with locking joints to prevent the wearer's limbs from being broken off, use a cryogenic oxygen tank to cool the suit as it boils off, and you're golden. Now being at 100km with an initial velocity of 8.5km/s is a different matter entirely. The only way we could do that with our current technology is some form of breakaway re-entry pod.
but by breaking it up, the mass of the particles entering the lower atmosphere would be drastically smaller.
That is true, but it really doesn't matter all that much if 1.0e9 tons hit you in the form of a few large fragments or a million small ones. The energy is still the same (you can do basic arithmetics, can you?), and, e.g., the production of toxic nitrogen oxides from the atmosphere heating wouldn't be significantly diminished, especially if all the asteroid fragment energy is expended in the atmosphere rather than in a single impact site. The former effect you're mentioning (as well as I did) is much more important.
Of course it matters. The energy from the Tunguska airburst is estimated to be as high as 130PJ. The largest thermonuclear detonation, the Tsar Bomba, was 210PJ. The Earth receives around 440PJ of sunlight every second of every day. Even your ten megaton asteroid traveling at 30km/s only amounts to about 9EJ, or roughly twenty seconds worth of sunlight. The energy from an asteroid impact isn't even a drop in the bucket in the grand scheme of things. The power density is what matters, the peak amplitude of that shock wave. If you have a single, large chunk, you're going to have a single large airburst and a massive amount of localized damage, or a large crater that spews large amounts of particulate into the atmosphere causing global weather shifts. If you break that up into thousands of little chunks, those are still going to cause a lot of damage, but now you have a dozen cities on fire, rather than one region completely wiped off the map and a dust cloud that drops you into a new ice age. It's a terrible disaster, but it's no longer an extinction level event.
It refers to the fact that the chip is still using a 19nm process. i.e. the transistors are still 19nm on each side
Nope. It just means they're 19nm on their short edge. The length of their long edge is unbounded. Specifically, the 1X manufacturing process was 19nm x 26nm, while the 1Y process is 19nm x 19.5nm. It's not twice the density, but it is more dense.
Logic transistors still have plenty of life left in them, however NAND flash is a very different beast. The technology works by storing a static charge in a floating gate. The effect of the charge can be measured remotely, but to store the charge, you must use high voltage to bridge the gap across the insulator. This is damaging, which is why flash memory has a limited number of write cycles. The smaller you make the gate, the less charge the gate is able to store, making it harder to read, and the more leaky it is, making it have a shorter life span between refreshes. While the theoretical limit is not known, it's going to be much larger than that of logic transistors, and many believe we will reach it within the next few processing nodes.
Moore's Law applies to the number of transistors in a chip. Just because you have found an increase in performance that did follow Moore's Law for a while does not mean that Moore's Law is somehow about flash memory.
If Moore's Law is about transistors on a chip, and NAND flash is a bunch of floating gate transistors on a chip, wouldn't logic follow that Moore's Law applied to NAND flash as well?
Singing is an art. You could be spouting gibberish that no one could potentially understand and still convey emotion and meaning. That does not make it an "everyday use". You're not going to go down to the local market and order a pound of salami in Gaelic (well you could, but people would look at you strangely).
What "everyday uses" for it are there? That's like trying to find "everyday uses" for classical Latin or Gaelic. No one uses that as a primary language, so why force the language for primary uses?
They didn't ding him for using too much bandwidth. They did so because he freely admitted to their tech that he was running servers, and nearly ever consumer-grade internet subscription does not allow customers to run servers. They required him to upgrade to a business account if he was to continue running his servers.
I can dig a few inches down in my yard and hit clay. Fire it in a blast oven, and you get a ceramic. Cement is nothing more than limestone. You mix it with water, let it absorb carbon dioxide from the atmosphere, and you get calcium carbonate, which is the same composition as limestone. Concrete is just cement mixed with filler, like crushed rock.
No you won't. Lift must be balanced. If you lose one motor, you also lose its opposite. If you're using these things to haul cargo, which means you're not running it anywhere near a 2:1 thrust to weight ratio, and you're going to crash. You're right back to the single point of failure you were with the swashplate.
The quadrotors are simpler. I'll give you that. There is no swashplate, nor servos to control the swashplate, of course no rudder control simply means you can no longer control yaw.
More stable? More agile? Both of those statements are completely false. The use of a swashplate means your lift is continuously variable from one side of the disc to the other. It's trivial to shift your center of lift directly over top your center of gravity, and produce stable flight. Further, a traditional helicopter only ever operates at one RPM. You bring the rotor up to speed, and then you vary the throttle as necessary to maintain that speed. That means your changes in thrust are nearly instantaneous, as you only have to wait for your servos to change the pitch of your swashplate. On a quadrotor, you have to wait for your individual electric motors to spool up, which takes considerably more time since you're fighting momentum, rather than taking advantage of it. Take a look at some of the 3D acrobatic displays performed by hobbyists with traditional RC helicopters, and then rethink whether any quadrotor could even come close to their agility.
No one would ever use an Arduino for anything in large scale production. An Arduino costs $35 last I checked, but its constituent components amount to around $5 when bought individually.
Turbines do not scale well, and if you're trying to put 4-6 of them at a few horsepower each on a quadrotor, you're going to get absolutely shit for efficiency. If you try to couple all the rotors into a single turbine at a few tens of horsepower, you're still going to get shit for efficiency, and now it's not going to be controllable. Forget all that, it doesn't make sense to use quadrotors in the first place. Disc loading really does matter when you're lugging shit around, and those small rotor discs mean unnecessarily high disc loading.
1) The idea of using quadcopters smacks of following a fad to get views and sound trendy. The reality is that quadcopters are horribly inefficient and unreliable.
The idea smacks of someone who is already trying to drum up venture capital and hasn't yet talked to an engineer, or even a skilled hobbyist. It makes the concept sound very disingenuous.
Could anyone see any future for this sort of set up in cities for local parcel delivery?
No, because any first year physics student who actually understands the implication of calculus and Newtonian mechanics could tell you that you don't use quadrotors for payload or endurance.
What is needed for quadrotors is to stop using god damned quadrotors. If you want longer duration flight, you need to get that disc loading down, which means one big rotor instead of a bunch of small ones.
Why would stability be any more difficult than a traditional helicopter? It's not like the center of gravity needs to be perfectly aligned with the center of the rotors. We have this thing called a swashplate. The rotor blades are hinged, and the free end rides on the swashplate. Move the plate up, your angle of attack decreases, and you have less thrust. Move it down, and you have more thrust. Pitch it, and you generate uneven thrust across the rotor disc. You can use this to shift that center of thrust across a wide area, compensating for a significant variation in CG. It does of course mean you have to build proper helicopter mechanisms, rather than a crappy variable-speed quadrotor.
That doesn't mean quadrotors are in any way good for a commercial product. Quadrotors mean you don't need the complex gearboxes and swashplates of a traditional helicopter. You just get four cheap propellers and cheap electric motors, a speed controller, and strap them onto a bunch of sticks. The barrier for entry is very low, meaning hobbyists can get into it with little skill or ability. If you actually have trained engineers to design it, and trained machinists to built the intricate workings of a traditional helicopter, there is no value in a quadrotor. I can't help but summarily write off any company trying to bring such a product to market, since whoever holds the reigns has no background in basic physics.
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the booster idea is stupid.
The booster idea is more or less necessary. Parachutes don't stop you, they merely slow you down. You've still got a decent amount of speed going when you hit the ground. It's hard enough on your knees doing that with just your own weight. You're not going to want to do that with a bulky pressure suit, air tank, and whatever other protective and stabilization gear you need to get you through a Mach 3 freefall. Re-entry typically land in water to cushion the fall, but then you're not going to be buoyant like a large, hollow capsule. You can either eject that crap to land separately (like a paratrooper), use a parawing and glide in (but then you have a high running speed instead of a falling speed), or use retro-rockets to slow you down beyond the ability of the parachute.
Except you don't, because this company is not proposing an orbital re-entry system. What they want to design is for someone at a fixed position, 100km up, so basically the same flight envelope as SpaceShipOne/Two. There's not enough energy there to really be an issue. You just need to lock those limbs down so they don't flail around.
Actually, we are there. We could build a space dive suit right now (or about a year down the line with sufficient funding once all the engineering legwork is done). It's just not that tough to get down from 100 kilometers. You really don't have all that much energy to dissipate. Just make a suit with locking joints to prevent the wearer's limbs from being broken off, use a cryogenic oxygen tank to cool the suit as it boils off, and you're golden. Now being at 100km with an initial velocity of 8.5km/s is a different matter entirely. The only way we could do that with our current technology is some form of breakaway re-entry pod.
One gigaton, not ten megaton, but energy scales linearly with mass, so it's 2000 seconds, or still only about half an hour worth of sunlight.
but by breaking it up, the mass of the particles entering the lower atmosphere would be drastically smaller.
That is true, but it really doesn't matter all that much if 1.0e9 tons hit you in the form of a few large fragments or a million small ones. The energy is still the same (you can do basic arithmetics, can you?), and, e.g., the production of toxic nitrogen oxides from the atmosphere heating wouldn't be significantly diminished, especially if all the asteroid fragment energy is expended in the atmosphere rather than in a single impact site. The former effect you're mentioning (as well as I did) is much more important.
Of course it matters. The energy from the Tunguska airburst is estimated to be as high as 130PJ. The largest thermonuclear detonation, the Tsar Bomba, was 210PJ. The Earth receives around 440PJ of sunlight every second of every day. Even your ten megaton asteroid traveling at 30km/s only amounts to about 9EJ, or roughly twenty seconds worth of sunlight. The energy from an asteroid impact isn't even a drop in the bucket in the grand scheme of things. The power density is what matters, the peak amplitude of that shock wave. If you have a single, large chunk, you're going to have a single large airburst and a massive amount of localized damage, or a large crater that spews large amounts of particulate into the atmosphere causing global weather shifts. If you break that up into thousands of little chunks, those are still going to cause a lot of damage, but now you have a dozen cities on fire, rather than one region completely wiped off the map and a dust cloud that drops you into a new ice age. It's a terrible disaster, but it's no longer an extinction level event.
It refers to the fact that the chip is still using a 19nm process. i.e. the transistors are still 19nm on each side
Nope. It just means they're 19nm on their short edge. The length of their long edge is unbounded. Specifically, the 1X manufacturing process was 19nm x 26nm, while the 1Y process is 19nm x 19.5nm. It's not twice the density, but it is more dense.
Logic transistors still have plenty of life left in them, however NAND flash is a very different beast. The technology works by storing a static charge in a floating gate. The effect of the charge can be measured remotely, but to store the charge, you must use high voltage to bridge the gap across the insulator. This is damaging, which is why flash memory has a limited number of write cycles. The smaller you make the gate, the less charge the gate is able to store, making it harder to read, and the more leaky it is, making it have a shorter life span between refreshes. While the theoretical limit is not known, it's going to be much larger than that of logic transistors, and many believe we will reach it within the next few processing nodes.
Moore's Law applies to the number of transistors in a chip. Just because you have found an increase in performance that did follow Moore's Law for a while does not mean that Moore's Law is somehow about flash memory.
If Moore's Law is about transistors on a chip, and NAND flash is a bunch of floating gate transistors on a chip, wouldn't logic follow that Moore's Law applied to NAND flash as well?
Singing is an art. You could be spouting gibberish that no one could potentially understand and still convey emotion and meaning. That does not make it an "everyday use". You're not going to go down to the local market and order a pound of salami in Gaelic (well you could, but people would look at you strangely).
What "everyday uses" for it are there? That's like trying to find "everyday uses" for classical Latin or Gaelic. No one uses that as a primary language, so why force the language for primary uses?
Sadly, HEV suits are still rare and hard to come by.
They didn't ding him for using too much bandwidth. They did so because he freely admitted to their tech that he was running servers, and nearly ever consumer-grade internet subscription does not allow customers to run servers. They required him to upgrade to a business account if he was to continue running his servers.
I can dig a few inches down in my yard and hit clay. Fire it in a blast oven, and you get a ceramic. Cement is nothing more than limestone. You mix it with water, let it absorb carbon dioxide from the atmosphere, and you get calcium carbonate, which is the same composition as limestone. Concrete is just cement mixed with filler, like crushed rock.
No you won't. Lift must be balanced. If you lose one motor, you also lose its opposite. If you're using these things to haul cargo, which means you're not running it anywhere near a 2:1 thrust to weight ratio, and you're going to crash. You're right back to the single point of failure you were with the swashplate.
The quadrotors are simpler. I'll give you that. There is no swashplate, nor servos to control the swashplate, of course no rudder control simply means you can no longer control yaw.
More stable? More agile? Both of those statements are completely false. The use of a swashplate means your lift is continuously variable from one side of the disc to the other. It's trivial to shift your center of lift directly over top your center of gravity, and produce stable flight. Further, a traditional helicopter only ever operates at one RPM. You bring the rotor up to speed, and then you vary the throttle as necessary to maintain that speed. That means your changes in thrust are nearly instantaneous, as you only have to wait for your servos to change the pitch of your swashplate. On a quadrotor, you have to wait for your individual electric motors to spool up, which takes considerably more time since you're fighting momentum, rather than taking advantage of it. Take a look at some of the 3D acrobatic displays performed by hobbyists with traditional RC helicopters, and then rethink whether any quadrotor could even come close to their agility.
That's also four electric motors and four speed controllers that must all be in proper functioning order or else the thing crashes.
No one would ever use an Arduino for anything in large scale production. An Arduino costs $35 last I checked, but its constituent components amount to around $5 when bought individually.
Turbines do not scale well, and if you're trying to put 4-6 of them at a few horsepower each on a quadrotor, you're going to get absolutely shit for efficiency. If you try to couple all the rotors into a single turbine at a few tens of horsepower, you're still going to get shit for efficiency, and now it's not going to be controllable. Forget all that, it doesn't make sense to use quadrotors in the first place. Disc loading really does matter when you're lugging shit around, and those small rotor discs mean unnecessarily high disc loading.
1) The idea of using quadcopters smacks of following a fad to get views and sound trendy. The reality is that quadcopters are horribly inefficient and unreliable.
The idea smacks of someone who is already trying to drum up venture capital and hasn't yet talked to an engineer, or even a skilled hobbyist. It makes the concept sound very disingenuous.
Could anyone see any future for this sort of set up in cities for local parcel delivery?
No, because any first year physics student who actually understands the implication of calculus and Newtonian mechanics could tell you that you don't use quadrotors for payload or endurance.
What is needed for quadrotors is to stop using god damned quadrotors. If you want longer duration flight, you need to get that disc loading down, which means one big rotor instead of a bunch of small ones.
Why would stability be any more difficult than a traditional helicopter? It's not like the center of gravity needs to be perfectly aligned with the center of the rotors. We have this thing called a swashplate. The rotor blades are hinged, and the free end rides on the swashplate. Move the plate up, your angle of attack decreases, and you have less thrust. Move it down, and you have more thrust. Pitch it, and you generate uneven thrust across the rotor disc. You can use this to shift that center of thrust across a wide area, compensating for a significant variation in CG. It does of course mean you have to build proper helicopter mechanisms, rather than a crappy variable-speed quadrotor.
That doesn't mean quadrotors are in any way good for a commercial product. Quadrotors mean you don't need the complex gearboxes and swashplates of a traditional helicopter. You just get four cheap propellers and cheap electric motors, a speed controller, and strap them onto a bunch of sticks. The barrier for entry is very low, meaning hobbyists can get into it with little skill or ability. If you actually have trained engineers to design it, and trained machinists to built the intricate workings of a traditional helicopter, there is no value in a quadrotor. I can't help but summarily write off any company trying to bring such a product to market, since whoever holds the reigns has no background in basic physics.
60 tons of cargo is an absolutely immense "blimp". The largest lighter-than-air craft built to date only had a payload of around 10 tons.
So would a mechanism that splattered everyone with banana cream pie be considered a "dirty bomb"?