This lady was Bright but not bright : the next morning she again joined that flight : So then two made the date : and then four, and then eight : And her spouse got one hell of a fright!
The GDP of the United States is around 14.5 trillion dollars. Taking an average historical growth rate of 3.2% per year, the cumulative GDP of the US from 2011 to 2050 is 1144 trillion dollars.
Therefore, your supposedly preposterous cost represents around 10% of GDP over the period.
Not to mention that the cost given is for the entire world. Given that the US represents about 20% of the world's energy use, the real figure is more like 2% of US GDP.
> At $100 per bbl that's $8.5 billion per day or, by 2050 $120 trillion, almost exactly the same cost as you've given above.
The real differentiator is that you'd be spending most of that money at home building your new energy infrastructure, instead of forking it over to corrupt middle-eastern despots to build air-conditioned palaces in the sand, as you do now. Hell of a lot better stimulus program too than the bank bailout, Iraq war, and all the other lobby-induced nonsense the US government likes to lose a trillion on every year or so.
That thing needs some sort of protective cover for the screen... how about a hinged lid? Oh yeah, and while you're at it stick a keyboard inside the lid, then you'd really have something!:-)
I did not know that people could survive such heat
Bah. A decent sauna is around 200 degrees Fahrenheit, and is good for you. I've spend plenty of quarter-hours at this temperature. US sauna are all dialed pitifully low for insurance reasons.
260F is just enough hotter than 200F that it wouldn't be pleasant anymore, but certainly not lethal in the short term. Drink enough fluids to replace the sweat and you'll be fine.
Love those ballpark estimates... so that 500-sheet pack I brought home the other day weighed more than my wife? I must have had a lot of spinach that day.
Science may have had little use for it, but what was accomplished in terms of international cooperation is really quite impressive.
Maybe so. The point, however, is that this sort of thing could have been accomplished just as well by spending the same amount of money on any comparably complex international project - preferably one that, unlike the ISS, had some actual value, be it scientific, ecologic, humanitarian, whatever.
Amazing things could have been done with this kind of money and international cooperation. Instead we got a white elephant in orbit, proving nothing so much as our ability to throw good money (ISS) after bad (Shuttle) into the pockets of the aerospace-military-industrial complex.
Somebody please rewind the last 30 years of the US manned space program. It's been far worse in terms of fizzle-per-gigabuck than anyone's worst nightmares could have envisioned in 1979. It makes me weep.
IIRC, SkySails expect amortisation of the system's cost within 3 years, at the hefty prices they intend to sell them for. This is taking into account ongoing maintenance etc. You can find all this info on their website.
they know that upward forces contribute nothing to propulsion.
Geez, make me spell it out will you? Upward force can be used to lift the ship out of the water so as to reduce drag. Drag opposes propulsive forces, so the upward force makes propulsion more efficient. I'd call that a contribution.
Anyway, this is merely a side effect. The kite does make a ship's ride smoother though, which is a valid argument for passenger vessels.
d00d, a modern traction kite is to a spinnaker like a modern wind turbine to a 16th-century windmill. These are airfoils, and yes you can go upwind with them - ask any competent kitesurfer. Rest assured though that you are not alone in your confusion.
A traction kite develops more power per area than a sail for 3 reasons: 1. no spillage (reduction in effective area due to heeling); 2. stronger winds at higher altitudes (where SkySails is flying, winds are roughly double those near ground, generating 4 times as much force); 3. higher airspeed (up to another factor of 2) than ship speed when working (looping or figure-8ing) the kite.
Taken together, these mean that traction kites can have *way* (as in, up to a factor of 20 or so) higher power density than *efficient* sails. A spinnaker is not an efficient sail.
SkySail's projections are in fact rather conservative - these are German engineers after all. They've convinced me - in fact they've got my money riding on them.
BTW, the current kite on the Beluga Skysails is 160 m^2, about 10x the size of a large kitesurfing kite but only 2/3 the size of a tennis court. This size will ultimately be used on superyachts and fishing boats; for tankers and container ships Skysails is following an engineering roadmap that doubles kite area every year or so. With current technology they expect to max out at 2500-5000 m^2, which is indeed near the size of a football (as in: soccer) field, hence the confusion.
I recommend the SkySails website for lots of good information. Disclaimer: I have 50 kiloeuros riding on these guys.
The problem is that the [wings] will add more weight to the craft
Paragliders are flying steerable, ram-air self-inflating airfoils that carry 30 times their own weight to a low-speed landing at a 10:1 glide ratio. These parafoils have been scaled up to carry half-ton payloads so far; there is no reason to believe they couldn't be scaled up further. Skydivers' parafoils are less efficient (lower glide ratio, higher airspeed) but more robust, and deployable at free-fall speeds.
A parafoil-based landing system for spacecraft would trace its ancestry to the Apollo-era parachute reentry systems. This is no accident: after all, the design constraints (safety, low weight, etc.) haven't changed. What has improved a lot in recent years is our ability to design and build highly efficient ram-airfoils.
Amen. Add to the gripe list the travesty of making the friggin things pulse and flicker merrily to indicate... sleep mode. These days both my socks are doing night duty as blackout covers for the pointless lightshow on my Mac and cell phone, respectively.
Often times you can learn a lot about real world science from these authors (albiet some what dated now, as many areas of science have long since surpassed the knowledge possessed when these stories were originally written), something that I find lacking in modern day science fiction.
You should really take a harder look at modern SF then - IMO there is more solid science-based work out there now than ever before. Ignore the SF/fantasy bookshelf in your average bookstore, it's full of crap (and let's face it, it was full of crap back in the 60s). Ignore novels, they're written (rather: expanded from short stories) only because that's where the money is, then as now. Ignore anything with a movie or TV tie-in (shudder).
What you want to look at is recent short stories and novellas. A good place to start are Gardner Dozois' "Year's Best Science Fiction" anthologies; you can get the last 10 years' worth used for about $5 apiece on Amazon. Not all stories in there are good, but it's unbeatable at giving you a who's who of current authors, and you'll quickly find your favorites among them.
Among current "credible SF" authors, I would add to the suggestions already made by others: Greg Egan, David Marusek, Nancy Kress, Ted Chiang. These just of the top of my head; there are others. Many of them have their own web sites these days, with sample stories online. I think you'd be pleasantly surprised at how far the field has developed if you'd give it a serious try.
Because/. unfortunately still doesn't have a "stupid" mod. It took this guy longer to post his trivial question to/. than it would have taken to google/wiki for the answer. What would you call this?
check it out, TFA even comes with/.ish comments pre-attached on page 2! No need to post, folks, nothing to see here, move on... (scrolls down 1057 posts) doh!
Until it comes up with this I'll stick with IMDB, thank you. Reviews for blockbusters are a dime a dozen, and showtimes on another continent do nothing for me.
Let's see - 100'000 km at 7.5 grams per meter, makes 750 tons. (try that in imperial, heh:-) Allowing for taper, let's say 2'000 tons. In other words: not much at all.
Slashdot Mirror
This lady was Bright but not bright : the next morning she again joined that flight : So then two made the date : and then four, and then eight : And her spouse got one hell of a fright!
Oldies but goodies.
iOS far outsells Android
What have you been smoking?
We're already moving to cabled systems instead of radio broadcasts.
Errrrr... for the past decade we've been moving back to wireless. Where have you been?
The GDP of the United States is around 14.5 trillion dollars. Taking an average historical growth rate of 3.2% per year, the cumulative GDP of the US from 2011 to 2050 is 1144 trillion dollars.
Therefore, your supposedly preposterous cost represents around 10% of GDP over the period.
Not to mention that the cost given is for the entire world. Given that the US represents about 20% of the world's energy use, the real figure is more like 2% of US GDP.
> At $100 per bbl that's $8.5 billion per day or, by 2050 $120 trillion, almost exactly the same cost as you've given above.
The real differentiator is that you'd be spending most of that money at home building your new energy infrastructure, instead of forking it over to corrupt middle-eastern despots to build air-conditioned palaces in the sand, as you do now. Hell of a lot better stimulus program too than the bank bailout, Iraq war, and all the other lobby-induced nonsense the US government likes to lose a trillion on every year or so.
That thing needs some sort of protective cover for the screen... how about a hinged lid? :-)
Oh yeah, and while you're at it stick a keyboard inside the lid, then you'd really have something!
I did not know that people could survive such heat
Bah. A decent sauna is around 200 degrees Fahrenheit, and is good for you. I've spend plenty of quarter-hours at this temperature. US sauna are all dialed pitifully low for insurance reasons.
260F is just enough hotter than 200F that it wouldn't be pleasant anymore, but certainly not lethal in the short term. Drink enough fluids to replace the sweat and you'll be fine.
assume a sheet of paper to be roughly 100 grams
Love those ballpark estimates... so that 500-sheet pack I brought home the other day weighed more than my wife? I must have had a lot of spinach that day.
So, by not taking data now, the LHC staff are really saving themselves some time
Which is an excellent example of the value of slacking.
Science may have had little use for it, but what was accomplished in terms of international cooperation is really quite impressive.
Maybe so. The point, however, is that this sort of thing could have been accomplished just as well by spending the same amount of money on any comparably complex international project - preferably one that, unlike the ISS, had some actual value, be it scientific, ecologic, humanitarian, whatever.
Amazing things could have been done with this kind of money and international cooperation. Instead we got a white elephant in orbit, proving nothing so much as our ability to throw good money (ISS) after bad (Shuttle) into the pockets of the aerospace-military-industrial complex.
Somebody please rewind the last 30 years of the US manned space program. It's been far worse in terms of fizzle-per-gigabuck than anyone's worst nightmares could have envisioned in 1979. It makes me weep.
IIRC, SkySails expect amortisation of the system's cost within 3 years, at the hefty prices they intend to sell them for. This is taking into account ongoing maintenance etc. You can find all this info on their website.
they know that upward forces contribute nothing to propulsion.
Geez, make me spell it out will you? Upward force can be used to lift the ship out of the water so as to reduce drag. Drag opposes propulsive forces, so the upward force makes propulsion more efficient. I'd call that a contribution.
Anyway, this is merely a side effect. The kite does make a ship's ride smoother though, which is a valid argument for passenger vessels.
This is essentially a giant spinnaker.
d00d, a modern traction kite is to a spinnaker like a modern wind turbine to a 16th-century windmill. These are airfoils, and yes you can go upwind with them - ask any competent kitesurfer. Rest assured though that you are not alone in your confusion.
A traction kite develops more power per area than a sail for 3 reasons:
1. no spillage (reduction in effective area due to heeling);
2. stronger winds at higher altitudes (where SkySails is flying, winds are roughly double those near ground, generating 4 times as much force);
3. higher airspeed (up to another factor of 2) than ship speed when working (looping or figure-8ing) the kite.
Taken together, these mean that traction kites can have *way* (as in, up to a factor of 20 or so) higher power density than *efficient* sails. A spinnaker is not an efficient sail.
SkySail's projections are in fact rather conservative - these are German engineers after all. They've convinced me - in fact they've got my money riding on them.
Ships aren't rigid.
Which is why the kite attaches to the *tow point* at the bow. Ships are already reinforced and designed to take massive loads at that point.
Upward force doesn't contribute as much to propulsion as lateral force.
So all those hydrofoil designers are off their rockers?
Besides, having an upward component to the force doesn't mean there isn't plenty of lateral pull.
BTW, the current kite on the Beluga Skysails is 160 m^2, about 10x the size of a large kitesurfing kite but only 2/3 the size of a tennis court. This size will ultimately be used on superyachts and fishing boats; for tankers and container ships Skysails is following an engineering roadmap that doubles kite area every year or so. With current technology they expect to max out at 2500-5000 m^2, which is indeed near the size of a football (as in: soccer) field, hence the confusion.
I recommend the SkySails website for lots of good information. Disclaimer: I have 50 kiloeuros riding on these guys.
The problem is that the [wings] will add more weight to the craft
Paragliders are flying steerable, ram-air self-inflating airfoils that carry 30 times their own weight to a low-speed landing at a 10:1 glide ratio. These parafoils have been scaled up to carry half-ton payloads so far; there is no reason to believe they couldn't be scaled up further. Skydivers' parafoils are less efficient (lower glide ratio, higher airspeed) but more robust, and deployable at free-fall speeds.
A parafoil-based landing system for spacecraft would trace its ancestry to the Apollo-era parachute reentry systems. This is no accident: after all, the design constraints (safety, low weight, etc.) haven't changed. What has improved a lot in recent years is our ability to design and build highly efficient ram-airfoils.
Amen. Add to the gripe list the travesty of making the friggin things pulse and flicker merrily to indicate... sleep mode. These days both my socks are doing night duty as blackout covers for the pointless lightshow on my Mac and cell phone, respectively.
Often times you can learn a lot about real world science from these authors (albiet some what dated now, as many areas of science have long since surpassed the knowledge possessed when these stories were originally written), something that I find lacking in modern day science fiction.
You should really take a harder look at modern SF then - IMO there is more solid science-based work out there now than ever before. Ignore the SF/fantasy bookshelf in your average bookstore, it's full of crap (and let's face it, it was full of crap back in the 60s). Ignore novels, they're written (rather: expanded from short stories) only because that's where the money is, then as now. Ignore anything with a movie or TV tie-in (shudder).
What you want to look at is recent short stories and novellas. A good place to start are Gardner Dozois' "Year's Best Science Fiction" anthologies; you can get the last 10 years' worth used for about $5 apiece on Amazon. Not all stories in there are good, but it's unbeatable at giving you a who's who of current authors, and you'll quickly find your favorites among them.
Among current "credible SF" authors, I would add to the suggestions already made by others: Greg Egan, David Marusek, Nancy Kress, Ted Chiang. These just of the top of my head; there are others. Many of them have their own web sites these days, with sample stories online. I think you'd be pleasantly surprised at how far the field has developed if you'd give it a serious try.
Why TF did the mods moded parent redundant?
/. unfortunately still doesn't have a "stupid" mod. It took this guy longer to post his trivial question to /. than it would have taken to google/wiki for the answer. What would you call this?
Because
Statistically, sub-democracies breed nearly 100% of the terrorists in the world.
Timothy McVeigh
Unabomber
and, lest I be accused of anti-Americanism:
Rote Armee Fraction
Brigade Rosso
Osama bin Laden
Statistically, a pampered upbringing in a wealthy but morally bancrupt society breeds nearly 100% of the terrorists in the world.
You must have gotten your newspeak confused: "sub-democracies" breed freedom fighters. (That sounds just so 1980s, I know.)
check it out, TFA even comes with /.ish comments pre-attached on page 2! No need to post, folks, nothing to see here, move on... (scrolls down 1057 posts) doh!
And neither is redundancy.
Until it comes up with this I'll stick with IMDB, thank you. Reviews for blockbusters are a dime a dozen, and showtimes on another continent do nothing for me.
Hey, don't knock it - you could play tic-tac-toe with one of these babies and still have 7 pixels left for multitasking!
Let's see - 100'000 km at 7.5 grams per meter, makes 750 tons. (try that in imperial, heh :-) Allowing for taper, let's say 2'000 tons. In other words: not much at all.