until we can have a surface-to-orbit transport safe/effective/cheap enough to lift the waste to orbit, then, presto, send the whole kit and kaboodle into the Sun.
The problem is that if *any* of your waste rockets explodes, you get a fallout plume worse than just about any conceivable nuclear reactor accident.
Encasing nuclear waste to survive a train wreck is one thing. Encasing it to survive a thousand tonnes of rocket fuel exploding, or re-entry if your rocket fails just the wrong way, is quite another.
While the chance of any given rocket failing is quite low, you're not going to get it below about 1% or so. If you're dealing with *all* waste by launching it into space, you're going to have accidents.
I say bury it in the continental shield, which has been geologically stable for the past 3 billion years or so.
too bad he didn't answer the bandwidth Q. Can anyone here give a calculated estimate on how much bytes the google farm pushes around per day ?
If by "calculated estimate" you mean "blind guess", sure:).
Assume 1e9 people with access/exposure to it. Assume 1e-3 of these use it regularly, and assume 1e1 uses per day per user. That's 1e7 calls to Google per day. Assuming 1e3 bytes per search, that's 1e10 bytes per day. (At 1e5 seconds per day, that's 1e5 bytes per second, or 1e6 bytes per second if peak time has 10 times the load).
So 10 gigabytes per day, with one megabyte per second at peak load.
None of the links in the story provide any useful information at all, as far as I can see. The first is for a "Mileage marathon society" which doesn't appear to have any information about a particular recent contest. The second is for the location at which the event was held; the third links to a blank page inside Shell with some plugin that doesn't work in my Mozilla. Searching Shell for "Mileage Marathon" produces lots of results in other languages and from 1998-99, but nothing topical.
A few links in, there's more information. Here are the contest rules:
They have to do 6 laps of a 1.64 mile course with a minimum _average_ speed of 15 miles per hour. The vehicle with the lowest fuel consumption wins.
The vehicles have people in them, which puts a lower limit on their size. Engine technology can be anything that qualifies as a heat engine and runs on unleaded gasoline.
Because we (the people paying attention to it) also think it's neat.
Why are newspapers and sites like slashdot following it? Presumably because they think enough readers are interested in it to justify the page space. This is no different from any other human-interest story.
You could also wax poetic about it being an inspiring story of determination triumphing over adversity. Take your pick.
If you, personally, aren't interested - more power to you. Don't read the article. The time wasted by skipping it is negligeable.
Guess what? It doesn't have those "features" for a reason! MySQL was meant to be fast and small, that's it.
The problem is that without row-level locking, the "fast" part kind of goes away when you start getting substantial traffic.
I'm told that's in development. It still seems like a bit of a kludge, as the original architecture was built without intent to support things like this.
I don't see why sites don't switch to Postgres when they run into the locking problem. Machines are powerful enough now that processing power isn't the problem it was when mySQL was invented. Why not use tools in the domains where they're best suited?
I thought it was just me at first, but do any books that get a rating that is not 9 get posted? I went to the book section and checked out the most recent reviews. Of the last nine books reviewed, eight of them got a nine, and the other got five stars (out of five I assume). The two book reviews before that (both in the Java meets XP subject) got 7's.
Evidently people only feel the need to write a review for books they found very good:).
This is probably for the best. A book being bad or mediocre isn't surprising - it's the good books that are hard to find.
The only exception I can think of would be a book that you'd otherwise expect to be good (e.g. the O'Reilly on MP3s, which is an outdated overview of MP3 playing and ripping programs, as opposed to the detailed analysis of the guts of an MP3 codec that I'd expected).
Some of the people who access from, say, a library, may have no other access. If you block sites that discuss, say, breast cancer, you are threatening their lives, in an indirect and probably non-actionable kind of way.
By this argument, charging money for a newspaper is also threatening lives, as people who can't afford a newspaper might miss an article about breast cancer.
I don't buy it. Information about truly important matters is always freely accessible by a variety of means. Internet access is not a vital part of life.
You have also failed to explain why, if we presume that unfiltered internet access *is* vital to well-being, it's the business or library's responsibility to supply it.
Filters suck. We know this, and chances are the people using the filters know this too. They're used anyways, to show "due diligence". This is a very, very important thing to show to avoid getting sued into oblivion. Whether the filters work or not is immaterial.
I don't care what justifications you create. They don't excuse the actions. This isn't murder, this isn't grand theft corporation. But it's on the next tier down.
Censorship that is justifiable must be able to say and prove what it is censoring. Reasonable and trusted people must be able to check, and if you want to limit the number of people who are allowed to check you had better have an excruciatingly good reason. (Weaponizing anthrax comes to mind.)
Um, in order to be censorship, this must significantly hamper the ability of the users involved to access information/speech, yes?
They can look up anything they please at *home*.
How is the work filtering policy censoring what they have access to?
The company presumably has terms of service along the lines of "the company's computers are to be used for work-related purposes only". Where's the problem?
There are easier ways to melt metal, even at home. Thermite, for example, should appeal to people who like fireworks.
The problem with thermite is that the resulting metal is going to be horribly impure (yes, I've made thermite, many times).
Other than having to sit around for several minutes instead of a few seconds, I don't see how the microwave melting method is harder.
A bigarsed propane jet, on the other hand, would be quite convenient and probably cheaper (electric heating is expensive even when perfectly efficient, and the microwave method was noted as losing much of the supplied energy). A friend has been melting aluminum with this method (why it hasn't burst into flames in his face, I don't know - don't try this at home).
Yes, that's the issue: the mold is more complex than for other methods.
I agree that this is true for metal clay, but for anything else it sounds like about the same amount of work. Slathering on clay paste isn't terribly difficult or time-consuming.
Re. metal clay - it seems to me that this would be "cooked" only enough to sinter the metal grains together, as opposed to fusing them (and in the process melting your figure). This would result in a weaker resulting object. Is this correct, or am I missing something about the casting process?
It's simple: in Japan, Europe, Australia, New Zealand etc... you only pay to call someone, not to receive a call. I understand most Americans are reluctant to give out their cellphone numbers because you pay to receive calls as well. This is stupid.
I'm not sure about that. Firstly, I don't use all of the monthly minutes on my phone. So an incoming call costs me nothing (up to a point). Secondly, cost is 10 cents *Canadian* per minute up here/on my provider, so I could talk for an hour straight for the cost of a submarine sandwich. My conversations are typically 2 minutes or so (arranging to see people in person or conveying quick information), so quantity of calls is simply not a factor.
The real reason I don't give out my cell number much is that there's a select few people who I want to be able to bug me at any minute of the day. Everyone else can just email me.
So I don't think the cost argument holds, in my location and within my peer group at least.
Fine, when it stops costing me money. Ever heard of metered bandwidth? His constitutional right to freedom of speech ends when I have to pay for it.
The problem is that unless you receive thousands of messages per day, the bandwidth consumed by spam emails is utterly negligeable compared to the bandwidth you consume doing things like reading Slashdot. Thus, I doubt an argument based on bandwidth costs would fly.
My own argument is that I have to spend time identifying and deleting these things. You could argue that this represents time I could have been spending working, and apply an hourly rate to that for something larger than bandwidth costs would work out to, or if you wanted to be a real bastard you could tally up the total amount of time you waste on spam per year, multiply that by your estimate life span, and then look up how much court settlements have been valued at for other circumstances where someone loses that part of their life (e.g. by exposure to a health hazard that shortens their lifespan).
I doubt the second approach would fly either, but it would certainly be fun to try, and a lot more lucrative;).
A colour laser print will look decent, and should last if you laminate it. These services will be fairly cheap, and should be available at the local large photocopy shop.
For a nicer picture, if I recall correctly, sublimation printing produces an image that looks a lot like a photograph, but I haven't seen the output from a sublimation printer in years, so my memory could be off.
Lastly, you could just make a printout at fantastically high resolution and re-photograph with an ordinary camera to get a photo that will last decades or longer with minimum fuss. Be sure to use a tripod for this, as small movements will blur the image.
Lastly, the most practical solution for the future is probably just to carry both digital and analog cameras. Use the digital camera for most things, and take a handful of old-fashioned pictures for the images you want to be there for your great-grandkids to see.
As mentioned above, I haven't followed the higher-end printing options for a while. Does anyone have more up-to-date information on this?
I'm not sure how the use of an intelligent router would eliminate the need for the expensive systems to stream the audio. Wouldn't moving the software for streaming onto the router make for a more expensive router and still require the expense a box outside of the router anyway?
My guess? This is a smart cacheing system.
The ZDnet article makes much reference to bandwidth congestion as a major stumbling block to streaming media. As a user will always get the same data back when requesting a media stream, you could set up smart router/proxies to cache, oh, the first few blocks of all media clips and the entire contents of the last N requested clips (up to a space limit). Assuming many users are listening to the same clip in the same general timeframe, you only have to stream the clip to the cacheing router once (instead of many times), saving bandwidth and load on your source box. Non-media traffic is routed as usual.
Or this could be something completely different. But a smart router/transparent proxy type of deal seems to be the most beneficial thing to develop.
It appears, depressingly, that modern physics is telling us that FTL travel is not possible, and never will be.
Actually, our existing understanding of physics suggests several interesting possible approaches to FTL travel. These are already being studied to some extent; time will show whether they're practical or not.
We also have enough gaps in our understanding to leave room for potential methods of FTL travel. We just know that it isn't terribly easy, if it is possible.
I think that is the most likely explanation. No civilizations make routine interstellar trips simply because it is so expensive.
That's one possibility.
Another is that life is uncommon enough that even frequent-FTL-travelling civilizations wouldn't be near enough to us to have found us.
Another is that the active lifetime of civilizations tends to be short enough that nobody happened to be alive (or at least interested in contacting people) during our history to contact us.
Or a combination of the above.
It will be interesting when we finally have enough information to be reasonably sure which is the case.
They spice up our water/air/primordial-soup with some pre-life cake mix and then fly away. They tell all their friends to come and visit when they get the chance, you know, just to look in and see how things are going. Well, then we get visited by aliens for the next few billions years (assume they have long life spans, or collective memories).
Seems this scenario gets rid of all of his improbable probabilities.
...And instead gives the improbable scenario of aliens stopping by tens or hundreds of millions of times over the Earth's history. This would take a significant expenditure of resources, to little end (especially since the hypothetical ant-farm alien could have seeded a barren world in their own system or otherwise closer to home for convenient visiting). It would also require lots and lots of patience and dedication that would probably be more entertainingly spent elsewhere.
The ones at my old high school were especially badly maintained. When we finally switched to PCs, I wrote a TSR that used palette shifting to fade text in and out like the dying monitors on the Icons we had to use earlier:).
Much nicer games than the PCs initially had, though.
The version of gcc that the admin recently installed converts "xor" to "^" in the *preprocessing* stage, apparently.
This made for Much Fun when I accessed a field called "xor" in a structure. It took me a while to figure out exactly why it was producing an apparently-nonsensical error with quoted code that didn't match anything in my source....
You'd think that, in context, it would realize that this was a field identifier.
The previous version, which I'd started development under, didn't make a peep.
Atmosphere isn't really the main problem; it's gravity. It is far more efficient to climb up the gravity well on wings than it is to blast up it on a rocket.
Yes, but "climbing" is a negligeable part of the thrusting you need to do. Most of your thrusting is tangential thrusting to get to orbital speed - and you need 8 km/sec whether you're orbiting at 300 km or a foot above the surface of the Earth. Getting to 300 km altitude takes almost no energy by comparison (3 MJ/kg versus about 30 MJ/kg for orbit). Getting to 100 km "for free" saves even less (1 MJ/kg).
Flying on wings does nothing to help you gain tangential velocity.
But you do have to lift a weight into orbit, of which most is not the payload but the vehicle. Reducing the weight of vehicle to be lifted increases the payload for the same amount of thrust.
The weight you have to lift is mostly _fuel_. The amount of fuel you have to carry is the same whether you're starting from the ground or starting from 100 km up. Starting from 100 km up does not reduce the weight of your rocket, and so does not reduce the stresses your rocket must withstand when boosting to gain tangential velocity.
How are you proposing to reduce the craft stresses, given this? If you have the same weight, and the same amount of thrust... you have the same stresses.
Most of the literature I've seen discussing this kind of technique assumes subsonic climb to altitude, subsonic fuelling (at maybe Mach 0.8) and a subsonic ferry mode - in other words, the jets wouldn't be powerful enough to reach supersonic speeds. Thus, the only time the aircraft would experience significant atmospheric friction would be for a short period during the boost phase and during reentry.
This is not proposed because launching from high altitude is magically more efficient for all rockets - it's proposed because the SSTO designs being considered are all much smaller than the space shuttle, and so have non-negligeable atmospheric effects, making it *only* possible to launch them from high altitude.
As strength to weight ratios get better for smaller craft, this lets less of the non-fuel mass be structure and more of the non-fuel mass be cargo. The fuel to non-fuel mass ratio is pretty much the same as for large rockets (or worse, if you're burning kerosene instead of hydrogen).
It's not so much the speed, it's the altitude and the fact that your takeoff weight is reduced. If the tanker and craft separate at 100 km, it's much easier for a small craft to make orbit.
For a small craft, yes (this is the idea behind the Pegasus, among other things).
However, anything that has to lift substantial amounts of payload will be large enough for the atmosphere to be mostly irrelevant (the benefit only comes when your rocket is small enough for its cross-sectional mass *not* to be greater than the atmosphere's at low altitudes).
The small craft needs less undercarriage because it doesn't take off with any weight, and has less structure because you only have to worry about fuel in it when you are flying- the lift of the wings holds the fuel from snapping the wings.
When you're boosting, both gravity and airfoils are irrelevant - the dominant force by far is the several gravities of thrust being supplied by your engines. The thrust-induced stresses are the same whether you're on the launchpad or flying free, or in the atmosphere or out of it (aside from exhaust expansion in the rocket nozzle). So no matter what you do your rocket has to be braced enough to take a very heavy axial load.
So, I'm having trouble seeing how launching dry would reduce your structural requirements. As soon as you fuel up, you'll have all of the stresses you would on take-off (because you need as much fuel as you would have on take-off, assuming a rocket large enough for atmospheric effects to be negligeable).
Only whilst its in the atmosphere. But staying in the atmosphere costs fuel and it quickly becomes uneconomic, except at low speeds. Rockets deliberately leave the atmosphere as quickly as possible for a reason.
Assuming a magical scramjet that could work at very high speeds in very thin air, it would be more efficient to stay within the atmosphere for most of your boost. The problem is that we don't have this ultra-scramjet yet. I agree that during rocket-based boosting leaving the atmosphere provides an advantage.
Even with the magic scramjet, it might or might not be possible to boost enough in the atmosphere to make it worth carrying the jet. Beyond a certain point friction heating will be bad enough that no heat shielding material can take it in steady-state conditions. Things are *almost* this bad on re-entry as it is (the calculations are a fun exercise, and nicely explain why the shuttle's underside is graphite coated with tungsten carbide).
An interesting thought experiment, whatever the result ends up being.
Pathfinder takes a nice approach: put both jets and rockets onto the ship, and take off without oxidizer. The ship would use the jets to fly up to a tanker, which would provide the oxidizer. The ship would then separate from the tanker, point up and light the rockets. Since no oxidizer is carried to get through the majority of the atmosphere, the total weight of the ship is much less (it needs less structure to hold oxidizer, because it uses less oxidizer). The oxidizer is carried up by a tanker, which is airbreathing, and the net effect is to be much more efficient. You could argue whether or not to carry the rockets and jets both, or just to carry rockets, and enough oxidizer to get up to tanking altitude.
The problem with this is that your speed when fueling from the tanker will be slow enough that you'll get questionable gains from this system. The tanker will, at best, be travelling around 1 km/sec (and that's in the Mach 2-3 range). Your shuttle needs to get to 8 km/sec. Burn time is directly proportional to delta-V, so you save very little even with a very fast tanker.
I also question how much of a problem the atmosphere is. For small craft, it's a very big deal, but for craft large enough that their cross-sectional weight is much, much greater than that of the air column they plow through, atmospheric drag isn't a concern. This is especially true given that most of the boosting happens at great altitude (less atmosphere to worry about).
The big advantage to an air-breathing rocket is a huge specific impulse boost (as your rocket fuel needs no oxidizer). However, getting rockets to work at extremely-hypersonic speeds is an unsolved problem, and if your jets can only be used at (relatively) low speeds, you again don't get much benefit (and have to drag the extra weight of the jet engines along).
Getting from ground to orbit is an interesting problem with no easy solutions visible in the near future.
I think that vastly increased use of such passive reclamation systems is about the only way that tomorrows electronic devices can manage to simultaneously get smaller AND significantly more powerful.
I think the near future will be fuel cells instead of batteries. Fuel-cell powered cell phones are already in development; the problem for mass-production is finding cheap enough materials, if I understand correctly.
In the far future, even absurdly powerful devices will draw very little power. Display and RF (or modulated-light) communication would be the main power drains. You could recharge these adequately by having induction coils scattered about like coffee holders (or coasters), so that your palmtop (or equivalent) would recharge whenever you set it down.
Ambient RF and environmental heat and motion have little enough capturable power to not be worth the bother. If your device is low enough power to benefit from this, a Li battery will last for weeks and a fuel cell for months.
Bio-engineering is nifty stuff. From intro undergraduate DSP if the brain doesn't treat each ear independently (kind of like stereo vision) I wonder if the brain is doing any covolution or difference between the signals to increase sensitivity.
It definitely does compare signals. This is where a large part of our perception of where a sound is loacated comes from (the rest is from sound interacting with the external part of the ear, which ends up attenuating different frequency bands by different amounts depending on the angle of incidence, if I remember correctly).
Slashdot Mirror
until we can have a surface-to-orbit transport safe/effective/cheap enough to lift the waste to orbit, then, presto, send the whole kit and kaboodle into the Sun.
The problem is that if *any* of your waste rockets explodes, you get a fallout plume worse than just about any conceivable nuclear reactor accident.
Encasing nuclear waste to survive a train wreck is one thing. Encasing it to survive a thousand tonnes of rocket fuel exploding, or re-entry if your rocket fails just the wrong way, is quite another.
While the chance of any given rocket failing is quite low, you're not going to get it below about 1% or so. If you're dealing with *all* waste by launching it into space, you're going to have accidents.
I say bury it in the continental shield, which has been geologically stable for the past 3 billion years or so.
too bad he didn't answer the bandwidth Q. Can anyone here give a calculated estimate on how much bytes the google farm pushes around per day ?
:).
:).
If by "calculated estimate" you mean "blind guess", sure
Assume 1e9 people with access/exposure to it. Assume 1e-3 of these use it regularly, and assume 1e1 uses per day per user. That's 1e7 calls to Google per day. Assuming 1e3 bytes per search, that's 1e10 bytes per day. (At 1e5 seconds per day, that's 1e5 bytes per second, or 1e6 bytes per second if peak time has 10 times the load).
So 10 gigabytes per day, with one megabyte per second at peak load.
Take this with a grain of salt
That's dated 1997 - are you sure it's current?
No, but I doubt they've substantially changed the rules.
None of the links in the story provide any useful information at all, as far as I can see. The first is for a "Mileage marathon society" which doesn't appear to have any information about a particular recent contest. The second is for the location at which the event was held; the third links to a blank page inside Shell with some plugin that doesn't work in my Mozilla. Searching Shell for "Mileage Marathon" produces lots of results in other languages and from 1998-99, but nothing topical.
A few links in, there's more information. Here are the contest rules:
http://www.shef.ac.uk/~mms/rules.html
They have to do 6 laps of a 1.64 mile course with a minimum _average_ speed of 15 miles per hour. The vehicle with the lowest fuel consumption wins.
The vehicles have people in them, which puts a lower limit on their size. Engine technology can be anything that qualifies as a heat engine and runs on unleaded gasoline.
So why exactly are we paying attention to it.
Because we (the people paying attention to it) also think it's neat.
Why are newspapers and sites like slashdot following it? Presumably because they think enough readers are interested in it to justify the page space. This is no different from any other human-interest story.
You could also wax poetic about it being an inspiring story of determination triumphing over adversity. Take your pick.
If you, personally, aren't interested - more power to you. Don't read the article. The time wasted by skipping it is negligeable.
What's the point? Those ballooners have blown millions of dollars to do this. Why?
Because it's there?
Because they thought it would be fun/cool/neat/whatever?
Because they *wanted* to?
Why wouldn't they? Once you make enough money to cover your daily life, why not spend the rest on something fun?
Also, bear in mind that it's only *one* balloonist in this case. This is the first *solo* circumnavigation.
Guess what? It doesn't have those "features" for a reason! MySQL was meant to be fast and small, that's it.
The problem is that without row-level locking, the "fast" part kind of goes away when you start getting substantial traffic.
I'm told that's in development. It still seems like a bit of a kludge, as the original architecture was built without intent to support things like this.
I don't see why sites don't switch to Postgres when they run into the locking problem. Machines are powerful enough now that processing power isn't the problem it was when mySQL was invented. Why not use tools in the domains where they're best suited?
I thought it was just me at first, but do any books that get a rating that is not 9 get posted? I went to the book section and checked out the most recent reviews. Of the last nine books reviewed, eight of them got a nine, and the other got five stars (out of five I assume). The two book reviews before that (both in the Java meets XP subject) got 7's.
:).
Evidently people only feel the need to write a review for books they found very good
This is probably for the best. A book being bad or mediocre isn't surprising - it's the good books that are hard to find.
The only exception I can think of would be a book that you'd otherwise expect to be good (e.g. the O'Reilly on MP3s, which is an outdated overview of MP3 playing and ripping programs, as opposed to the detailed analysis of the guts of an MP3 codec that I'd expected).
Some of the people who access from, say, a library, may have no other access. If you block sites that discuss, say, breast cancer, you are threatening their lives, in an indirect and probably non-actionable kind of way.
By this argument, charging money for a newspaper is also threatening lives, as people who can't afford a newspaper might miss an article about breast cancer.
I don't buy it. Information about truly important matters is always freely accessible by a variety of means. Internet access is not a vital part of life.
You have also failed to explain why, if we presume that unfiltered internet access *is* vital to well-being, it's the business or library's responsibility to supply it.
Filters suck. We know this, and chances are the people using the filters know this too. They're used anyways, to show "due diligence". This is a very, very important thing to show to avoid getting sued into oblivion. Whether the filters work or not is immaterial.
I don't care what justifications you create. They don't excuse the actions. This isn't murder, this isn't grand theft corporation. But it's on the next tier down.
Censorship that is justifiable must be able to say and prove what it is censoring. Reasonable and trusted people must be able to check, and if you want to limit the number of people who are allowed to check you had better have an excruciatingly good reason. (Weaponizing anthrax comes to mind.)
Um, in order to be censorship, this must significantly hamper the ability of the users involved to access information/speech, yes?
They can look up anything they please at *home*.
How is the work filtering policy censoring what they have access to?
The company presumably has terms of service along the lines of "the company's computers are to be used for work-related purposes only". Where's the problem?
There are easier ways to melt metal, even at home. Thermite, for example, should appeal to people who like fireworks.
The problem with thermite is that the resulting metal is going to be horribly impure (yes, I've made thermite, many times).
Other than having to sit around for several minutes instead of a few seconds, I don't see how the microwave melting method is harder.
A bigarsed propane jet, on the other hand, would be quite convenient and probably cheaper (electric heating is expensive even when perfectly efficient, and the microwave method was noted as losing much of the supplied energy). A friend has been melting aluminum with this method (why it hasn't burst into flames in his face, I don't know - don't try this at home).
Yes, that's the issue: the mold is more complex than for other methods.
I agree that this is true for metal clay, but for anything else it sounds like about the same amount of work. Slathering on clay paste isn't terribly difficult or time-consuming.
Re. metal clay - it seems to me that this would be "cooked" only enough to sinter the metal grains together, as opposed to fusing them (and in the process melting your figure). This would result in a weaker resulting object. Is this correct, or am I missing something about the casting process?
It's simple: in Japan, Europe, Australia, New Zealand etc... you only pay to call someone, not to receive a call. I understand most Americans are reluctant to give out their cellphone numbers because you pay to receive calls as well.
This is stupid.
I'm not sure about that. Firstly, I don't use all of the monthly minutes on my phone. So an incoming call costs me nothing (up to a point). Secondly, cost is 10 cents *Canadian* per minute up here/on my provider, so I could talk for an hour straight for the cost of a submarine sandwich. My conversations are typically 2 minutes or so (arranging to see people in person or conveying quick information), so quantity of calls is simply not a factor.
The real reason I don't give out my cell number much is that there's a select few people who I want to be able to bug me at any minute of the day. Everyone else can just email me.
So I don't think the cost argument holds, in my location and within my peer group at least.
Fine, when it stops costing me money. Ever heard of metered bandwidth? His constitutional right to freedom of speech ends when I have to pay for it.
;).
The problem is that unless you receive thousands of messages per day, the bandwidth consumed by spam emails is utterly negligeable compared to the bandwidth you consume doing things like reading Slashdot. Thus, I doubt an argument based on bandwidth costs would fly.
My own argument is that I have to spend time identifying and deleting these things. You could argue that this represents time I could have been spending working, and apply an hourly rate to that for something larger than bandwidth costs would work out to, or if you wanted to be a real bastard you could tally up the total amount of time you waste on spam per year, multiply that by your estimate life span, and then look up how much court settlements have been valued at for other circumstances where someone loses that part of their life (e.g. by exposure to a health hazard that shortens their lifespan).
I doubt the second approach would fly either, but it would certainly be fun to try, and a lot more lucrative
A colour laser print will look decent, and should last if you laminate it. These services will be fairly cheap, and should be available at the local large photocopy shop.
For a nicer picture, if I recall correctly, sublimation printing produces an image that looks a lot like a photograph, but I haven't seen the output from a sublimation printer in years, so my memory could be off.
Lastly, you could just make a printout at fantastically high resolution and re-photograph with an ordinary camera to get a photo that will last decades or longer with minimum fuss. Be sure to use a tripod for this, as small movements will blur the image.
Lastly, the most practical solution for the future is probably just to carry both digital and analog cameras. Use the digital camera for most things, and take a handful of old-fashioned pictures for the images you want to be there for your great-grandkids to see.
As mentioned above, I haven't followed the higher-end printing options for a while. Does anyone have more up-to-date information on this?
I'm not sure how the use of an intelligent router would eliminate the need for the expensive systems to stream the audio. Wouldn't moving the software for streaming onto the router make for a more expensive router and still require the expense a box outside of the router anyway?
My guess? This is a smart cacheing system.
The ZDnet article makes much reference to bandwidth congestion as a major stumbling block to streaming media. As a user will always get the same data back when requesting a media stream, you could set up smart router/proxies to cache, oh, the first few blocks of all media clips and the entire contents of the last N requested clips (up to a space limit). Assuming many users are listening to the same clip in the same general timeframe, you only have to stream the clip to the cacheing router once (instead of many times), saving bandwidth and load on your source box. Non-media traffic is routed as usual.
Or this could be something completely different. But a smart router/transparent proxy type of deal seems to be the most beneficial thing to develop.
It appears, depressingly, that modern physics is telling us that FTL travel is not possible, and never will be.
Actually, our existing understanding of physics suggests several interesting possible approaches to FTL travel. These are already being studied to some extent; time will show whether they're practical or not.
We also have enough gaps in our understanding to leave room for potential methods of FTL travel. We just know that it isn't terribly easy, if it is possible.
I think that is the most likely explanation. No civilizations make routine interstellar trips simply because it is so expensive.
That's one possibility.
Another is that life is uncommon enough that even frequent-FTL-travelling civilizations wouldn't be near enough to us to have found us.
Another is that the active lifetime of civilizations tends to be short enough that nobody happened to be alive (or at least interested in contacting people) during our history to contact us.
Or a combination of the above.
It will be interesting when we finally have enough information to be reasonably sure which is the case.
They spice up our water/air/primordial-soup with some pre-life cake mix and then fly away. They tell all their friends to come and visit when they get the chance, you know, just to look in and see how things are going. Well, then we get visited by aliens for the next few billions years (assume they have long life spans, or collective memories).
Seems this scenario gets rid of all of his improbable probabilities.
...And instead gives the improbable scenario of aliens stopping by tens or hundreds of millions of times over the Earth's history. This would take a significant expenditure of resources, to little end (especially since the hypothetical ant-farm alien could have seeded a barren world in their own system or otherwise closer to home for convenient visiting). It would also require lots and lots of patience and dedication that would probably be more entertainingly spent elsewhere.
In summary, I'm doubtful of this scenario.
Ah, Icons.
:).
The ones at my old high school were especially badly maintained. When we finally switched to PCs, I wrote a TSR that used palette shifting to fade text in and out like the dying monitors on the Icons we had to use earlier
Much nicer games than the PCs initially had, though.
Most annoying bug I've encountered recently?
The version of gcc that the admin recently installed converts "xor" to "^" in the *preprocessing* stage, apparently.
This made for Much Fun when I accessed a field called "xor" in a structure. It took me a while to figure out exactly why it was producing an apparently-nonsensical error with quoted code that didn't match anything in my source....
You'd think that, in context, it would realize that this was a field identifier.
The previous version, which I'd started development under, didn't make a peep.
Atmosphere isn't really the main problem; it's gravity. It is far more efficient to climb up the gravity well on wings than it is to blast up it on a rocket.
Yes, but "climbing" is a negligeable part of the thrusting you need to do. Most of your thrusting is tangential thrusting to get to orbital speed - and you need 8 km/sec whether you're orbiting at 300 km or a foot above the surface of the Earth. Getting to 300 km altitude takes almost no energy by comparison (3 MJ/kg versus about 30 MJ/kg for orbit). Getting to 100 km "for free" saves even less (1 MJ/kg).
Flying on wings does nothing to help you gain tangential velocity.
But you do have to lift a weight into orbit, of which most is not the payload but the vehicle. Reducing the weight of vehicle to be lifted increases the payload for the same amount of thrust.
The weight you have to lift is mostly _fuel_. The amount of fuel you have to carry is the same whether you're starting from the ground or starting from 100 km up. Starting from 100 km up does not reduce the weight of your rocket, and so does not reduce the stresses your rocket must withstand when boosting to gain tangential velocity.
How are you proposing to reduce the craft stresses, given this? If you have the same weight, and the same amount of thrust... you have the same stresses.
Most of the literature I've seen discussing this kind of technique assumes subsonic climb to altitude, subsonic fuelling (at maybe Mach 0.8) and a subsonic ferry mode - in other words, the jets wouldn't be powerful enough to reach supersonic speeds. Thus, the only time the aircraft would experience significant atmospheric friction would be for a short period during the boost phase and during reentry.
This is not proposed because launching from high altitude is magically more efficient for all rockets - it's proposed because the SSTO designs being considered are all much smaller than the space shuttle, and so have non-negligeable atmospheric effects, making it *only* possible to launch them from high altitude.
As strength to weight ratios get better for smaller craft, this lets less of the non-fuel mass be structure and more of the non-fuel mass be cargo. The fuel to non-fuel mass ratio is pretty much the same as for large rockets (or worse, if you're burning kerosene instead of hydrogen).
It's not so much the speed, it's the altitude and the fact that your takeoff weight is reduced. If the tanker and craft separate at 100 km, it's much easier for a small craft to make orbit.
For a small craft, yes (this is the idea behind the Pegasus, among other things).
However, anything that has to lift substantial amounts of payload will be large enough for the atmosphere to be mostly irrelevant (the benefit only comes when your rocket is small enough for its cross-sectional mass *not* to be greater than the atmosphere's at low altitudes).
The small craft needs less undercarriage because it doesn't take off with any weight, and has less structure because you only have to worry about fuel in it when you are flying- the lift of the wings holds the fuel from snapping the wings.
When you're boosting, both gravity and airfoils are irrelevant - the dominant force by far is the several gravities of thrust being supplied by your engines. The thrust-induced stresses are the same whether you're on the launchpad or flying free, or in the atmosphere or out of it (aside from exhaust expansion in the rocket nozzle). So no matter what you do your rocket has to be braced enough to take a very heavy axial load.
So, I'm having trouble seeing how launching dry would reduce your structural requirements. As soon as you fuel up, you'll have all of the stresses you would on take-off (because you need as much fuel as you would have on take-off, assuming a rocket large enough for atmospheric effects to be negligeable).
Only whilst its in the atmosphere. But staying in the atmosphere costs fuel and it quickly becomes uneconomic, except at low speeds. Rockets deliberately leave the atmosphere as quickly as possible for a reason.
Assuming a magical scramjet that could work at very high speeds in very thin air, it would be more efficient to stay within the atmosphere for most of your boost. The problem is that we don't have this ultra-scramjet yet. I agree that during rocket-based boosting leaving the atmosphere provides an advantage.
Even with the magic scramjet, it might or might not be possible to boost enough in the atmosphere to make it worth carrying the jet. Beyond a certain point friction heating will be bad enough that no heat shielding material can take it in steady-state conditions. Things are *almost* this bad on re-entry as it is (the calculations are a fun exercise, and nicely explain why the shuttle's underside is graphite coated with tungsten carbide).
An interesting thought experiment, whatever the result ends up being.
Pathfinder takes a nice approach: put both jets and rockets onto the ship, and take off without oxidizer. The ship would use the jets to fly up to a tanker, which would provide the oxidizer. The ship would then separate from the tanker, point up and light the rockets. Since no oxidizer is carried to get through the majority of the atmosphere, the total weight of the ship is much less (it needs less structure to hold oxidizer, because it uses less oxidizer). The oxidizer is carried up by a tanker, which is airbreathing, and the net effect is to be much more efficient. You could argue whether or not to carry the rockets and jets both, or just to carry rockets, and enough oxidizer to get up to tanking altitude.
The problem with this is that your speed when fueling from the tanker will be slow enough that you'll get questionable gains from this system. The tanker will, at best, be travelling around 1 km/sec (and that's in the Mach 2-3 range). Your shuttle needs to get to 8 km/sec. Burn time is directly proportional to delta-V, so you save very little even with a very fast tanker.
I also question how much of a problem the atmosphere is. For small craft, it's a very big deal, but for craft large enough that their cross-sectional weight is much, much greater than that of the air column they plow through, atmospheric drag isn't a concern. This is especially true given that most of the boosting happens at great altitude (less atmosphere to worry about).
The big advantage to an air-breathing rocket is a huge specific impulse boost (as your rocket fuel needs no oxidizer). However, getting rockets to work at extremely-hypersonic speeds is an unsolved problem, and if your jets can only be used at (relatively) low speeds, you again don't get much benefit (and have to drag the extra weight of the jet engines along).
Getting from ground to orbit is an interesting problem with no easy solutions visible in the near future.
I think that vastly increased use of such passive reclamation systems is about the only way that tomorrows electronic devices can manage to simultaneously get smaller AND significantly more powerful.
I think the near future will be fuel cells instead of batteries. Fuel-cell powered cell phones are already in development; the problem for mass-production is finding cheap enough materials, if I understand correctly.
In the far future, even absurdly powerful devices will draw very little power. Display and RF (or modulated-light) communication would be the main power drains. You could recharge these adequately by having induction coils scattered about like coffee holders (or coasters), so that your palmtop (or equivalent) would recharge whenever you set it down.
Ambient RF and environmental heat and motion have little enough capturable power to not be worth the bother. If your device is low enough power to benefit from this, a Li battery will last for weeks and a fuel cell for months.
Bio-engineering is nifty stuff. From intro undergraduate DSP if the brain doesn't treat each ear independently (kind of like stereo vision) I wonder if the brain is doing any covolution or difference between the signals to increase sensitivity.
It definitely does compare signals. This is where a large part of our perception of where a sound is loacated comes from (the rest is from sound interacting with the external part of the ear, which ends up attenuating different frequency bands by different amounts depending on the angle of incidence, if I remember correctly).