...provided you don't mind a ball and chain for 24 months. If a sexy new phone comes out, another carrier starts offering a better deal (as Three did with the £13/mo deal) or you have a financial crisis, then that contract could cost you.
When I priced up my Note II, contract vs. purchase, there was not much overall difference to the total cost (of course, the deliberately convoluted tariffs make it almost impossible to compare).
What really put me off another contract was that, with my previous on-contract HTC phone, whenever there was an Android update, you first had to wait for HTC to implement it, then you had to wait for T-Mobile to implement it. Also, I wanted to give the Three network a go for a few months to see what it was like (conclusion: works for me).
Here in the UK, we often get ripped off for computers, software and electronics (usually priced as $1=£1*) so its nice to know that there are some things where we have it better than the USA.
Currently paying £13 per month for 200 minutes of voice, 5000 texts and pseudo-unlimited data (HSPA+ in most places). One-month rolling contract, bring-your-own phone. (I don't use much voice - it would be another £12/month for 2000 minutes). Bundled phone contracts are still the norm (at the end of the contract you can usually keep the phone and negotiate a reduced rate) but all the carriers offer SIM-only plans.
(* some of which is down to sales tax, but not all).
Does IE7 support the IE box model? I'm not sure, I'll have to get back to you on that one.
I did stop and think about that question a bit. Its not silly. IE7 can run in standards-compliant mode (CSS box-model) or legacy mode (IE box-model), depending on the doctype. The question is whether IE7 supports the "box-sizing" property in standards compliant mode, to enable the IE7 box model (which some people find more logical) without all the other IE quirks.
The CSS property you're looking for is box-sizing. If you want modern browsers to use IE's box model where the width includes border and padding, use the value 'border-box'.
Yes - but is it supported by IE7...
If you want to yell at someone, yell at those folks still XP and IE8 (or earlier).
Unfortunately, such folks fall into categories like "clients", "customers" or "target audience" and its not such a good idea to tell them "piss off and come back when you've got a decent web browser".
This does all get better the further IE6/7/8 fade into history - if I were starting a site today I could at least ignore IE6/7 - but I'm still seeing significant hits from IE8.
Then new things come along: I was having trouble with 'background-size' recently (handy if you want to use 2x res images to look good on 'retina'-type displays) and I've yet to find a browser that properly supports page-break controls on printouts (yes, I know people who like to print out web pages to read later).
I'd look on it from the perspective of "encapsulation": One person should be able to design what was in the box without knowing how it was going to be placed on the page, a second person should be able to place it on the page and align it with other elements without affecting anything inside.
That would work best if the primary size of the box included the inner margin/padding and border (which the box designer 'needs to know'), but excluded the outer margin (which the 'page designer' needs to match with other elements).
As for the border - the most flexible solution would probably be to have a separate 'inner border' and 'outer border' and leave it up to the designer to ensure that the border fit within the margin/padding if desired: the 'box designer' might want the inner border to match the ambient colour of the image and maybe slightly print the photo to 'seal' it; the page designer might want a fancy frame outside the box.
Unfortunately graphic (website) designers are completely shit at using it. Even simply understanding when they should use an ID and when they should use a class seems to a'splode their brain, "huh, what is wrong with using this same id a bajillion times in the page".
If CSS did what it said on the tin - separated content from style and layout - then graphic designers wouldn't have to bother their little heads about this sort of thing because they wouldn't need to touch the semantically-marked-up HTML.
Unfortunately, (a) CSS doesn't do what it says in the tin - changing the layout inevitably needs including exactly the right permutation of DIVs in the markup because CSS doesn't have any way of doing what every half-decent DTP package since PagerMaker 1.0 can do: defining a series of frames and specifying how text should flow between them - and (b) anybody who thinks style can be completely separated from content has spent too long reading & writing rigidly structured technical documents.
Don't even try telling them that "redtext" is not a good classname.
Hell no! Any idiot knows that a classname should be something semantic, like "rubric".;-)
Bad craftspeople have a definite tendency to blame their tools
...and bad software designers have an even more definite tendency to blame their users. Usability/clarity and appropriateness for the intended user base (in this case, graphic designers) is part of good tool design.
CSS smacks of being a hammer designed by someone who has never seen a nail.
Anyone who has used JQuery will know how their power exceeds the original intention
...anybody who has used jQuery will know how powerful they could have been if only browsers had implemented them completely and consistently.
Meanwhile, anybody who has used CSS will wonder what the hell the original intention was, given the arcane kludges needed to produce popular web-page layout effects easily achieved using evil tables and frames, the lack of 'constants' to set standard colours and measurements.You know there's something wrong with a standard when Microsoft's broken box-model implementation makes more sense. However, that's not the fault of the selectors.
Its as if the designers* of CSS had never looked at a web site, used a DTP package, used styles in a WP package, let alone played with a Java layout manager to get ideas about what might work and/or be useful.
(* probably unfair - I'm sure it was a mixture of committee syndrome and the notion that you can define a standard without producing a reference implementation rather than individual failings).
The real problem is that the innovator who really stole all their ideas from other people, has failed to realize that their own User Interface has become a mature technology.
However, its worth remembering that Microsoft are not the only ones to jump on the tabletization bandwagon whether their users like it or not.
Gnome 3, Ubuntu Unity have had similar castigation for their new 'post PC' interfaces. However, what with Linux being open source and not having the GUI joined at the hip to the rest of the OS this is less of a problem for Linux users.
Apple have also received flak for the fairly limited tabletization that they've done with OS X.
Problem is, we're in a tablet bubble, coming at a time when everybody who wants a regular PC already has one and PC specs are no longer rising fast enough to make them obsolete after 18 months. I like tablets, think they raise some interesting new possibilities and are great for some uses - but the current attitude is "the solution is mobile technology - now, what was the problem again?".
There's no reason to assume the whole vehicle isn't mirrored.
If they were then, at the typical international airport, you'd notice the large ring of car wrecks around the rental garage. Moving the steering wheel is a helpful hint to remind you to drive on the other side of the road. Swapping the brake and accelerator pedals would be a recipe for unpleasantness.
You're bigoted against adults, as this is age discrimination plain and simple. Adults should be able to play with toys, and it should be legal to market something as a toy for adults only.
You know that shop just off Main Street, with the blacked-out windows?
(Trying not to think of the consequences of using super-strong magnets to fake... other types of piercings.)
I may not buy magnets because some parents are stupid enough to give high power magnets to kids?
RTFA. The recall is for a particular type of magnetic toy, not "high power magnets" per se. Its one thing to sell potentially dangerous items - its another thing to package them as toys*.
Also - as someone has pointed out elsewhere - there is a particular problem with older kids using these to make fake tongue piercings - so its not just parents giving them to babies and toddlers who will swallow anything.
Plus - this threat isn't immediately obvious. There have been magnetic toys since the year dot - but not ones that were (a) small enough to swallow and (b) still powerful enough to clamp your intestines together.
Remember that when idiots scramble their intestines, the cost of fixing the mess will still make its way through to your tax and/or medical insurance bill.
* I remember a 1930s book of science experiments for kids that included such gems as making a carbon arc torch from the graphite rods out of batteries using - wait for it - a variable resistor made from two stones in a dish of salty water to cut 110V mains down to 50V**. What could possibly go wrong? They did tell you to wear sunglasses.
**Not only did they skip Health and Safety assessments in those days, I suspect they skipped the "will it actually work?" assessments, too.
You do know that its possible for both parents and businesses to share responsibility for things like this?
You seem eager to heap responsibility and blame on parents, but hey, businesses should be able to pursue the mighty buck wherever it leads, without consequences. Sounds fair.
Parents should watch what their kids are doing, and not give in to pestering - but that doesn't make it right for supposedly reputable businesses to lurk in the bushes poised to spring out and take advantage as soon as a parent makes a mistake.
As far as I know, in-app purchases require you to put in your password.
....and as has been repeatedly pointed out there have often been loopholes in this, such as systems that cache the password for 15 minutes, or systems that 'cry wolf' by asking for passwords for (e.g.) free apps and updates, so parents get complacent. Plus, your average kid may be smart enough to shoulder-surf when you enter your password, but still dumb enough to be fooled into spending money without realising.
The UK Government will be examining whether free to download apps are putting unfair pressure on kids to pay up for additional content within the game through in-app purchases.
Let's help them with that so they can get on with the important job of searching the Pope's quarters for suspicious crucifixes and rosaries...
0. Kids are generally easier to con and less responsible than adults. That's why we don't let them drive, drink, vote or have credit cards.
1. Yes - they're disingenuously called "free-to-play" games and every app store is heaving with them. Technically you can enjoy the game without paying, but they're specifically designed to tempt you to open your wallet. Particularly insidious are the ones with both an imaginary in-game economy and the option of spending real money, where the two concepts can easily get blurred enough to fool a kid. A parent wouldn't necessarily pot this if they 'checked out' the game for a few minutes.
2. Evidence - the industry wouldn't be doing this if they weren't making more money from in-app purchases than by charging a fair, one-off price for the game.
3. Solution - the Govenment doesn't want to get any further into video game censorship than it already is, but we already have age-rating systems. Any game with in-app purchases should be marked as "Funded by in-app purchases and not suitable for under 16s" and make use of whatever parental controls exist on the platform. Games could be exempted if they could demonstrate that they had adequate mechanisms to allow parents to cap spending, and had payments disabled by default. (Giving a kid a limited budget to manage is not a bad thing, but they need training wheels!)
4. Next steps - don't bother: by the time you finish grinding out your report, customer pressure will have forced all the reputable app stores and age-rating schemes to fix this: Apple have already improved labelling of games with in-app purchases.
5. Conclusion - even the solutions in (3) and (4) won't solve this problem - there's too much money in it - but they might help responsible people avoid this trap. Sadly, we'll still see a lot of potentially good gameplay wrecked by greed for in-app purchases.
Now, let's have a quick look for stains in Mr Holmes' underpants.
Why teach a crappy, relatively more difficult language like Java to children?
And this is how any attempt to teach kids to program gets killed - every "expert" immediately jumps in and screams about how not using [insert favourite trendy programming language] will melt kids' brains and ruin them for life.
For kids' first experiences in programming it doesn't. fucking. matter. Get them enthused about programming and you can start hitting them with good practices and formalities if and when they decide to study computer science further (what subject [i]doesn't[/i] change beyond recognition when you start to study it at degree level?) The ones with any aptitude will recognise good practices and understand new paradigms when they're shown them - the ones with no aptitude will at least have learnt more about how computers work that they otherwise would have done. Anyway, by the time these kids get to college, functional programming will be "considered harmful" in favour of the latest trendy paradigm.
The difficult thing about a project like this will be getting the gameplay right so that it is both fun and educational. Crack that, and modifying it to use Python, Haskell, Javascript, Lisp, ADA, GW-BASIC, INTERCAL or Elvish Perl will be simple.
Of course, everybody knows that magic is written in FORTH.
My shoulders don't fit into the width of a cattle-class seat. I could certainly lose some weight about my belly, but I'd need some bits sawn off my skeleton to fit comfortably.
But I'm not getting a discount for the < 90% of a seat I'm left to occupy.
Nor did your oppressor get a refund for having to spend the flight with an armrest embedded in their belly. Its not like you have to be Jabba the Hut to have difficulty fitting into a cattle class seat.
And I think it would be quite fair if he paid an extra 15% to account for that.
Except you're also assuming that 100% of the ticket cost is attributable to weight/fuel and are ignoring aircraft maintenance, flight & ground crew wages, ticketing, security, insurance, airport facilities, interest payments, administration, executive bonuses, advertising and whatever else it takes to run an airline.
Also, far as I can tell, air fares are a commodity item and bear sod all relation to the actual costs of providing the service.
Simple. Because it costs the airline more to move 180lbs than it does 100lbs. Simple way of pricing tickets, you and all your luggage
...along with 1/300th ( assuming there are 300 passengers) of the airplane, fuel and flight crew, plus a couple of extra weights to represent all the non-fuel related costs of running an airline...
step on a scale and you're charged a per lb rate for your ticket.
...at which point you'll find that the portion of the fare attributable to the difference in personal weights isn't really worth the huge complications this sort of charging will cause.
Alternatively, if you're going to add a weight surcharge, allocate seating space in proportion to how much people are paying.
Slashdot Mirror
Contracts still make a lot of sense.
...provided you don't mind a ball and chain for 24 months. If a sexy new phone comes out, another carrier starts offering a better deal (as Three did with the £13/mo deal) or you have a financial crisis, then that contract could cost you.
When I priced up my Note II, contract vs. purchase, there was not much overall difference to the total cost (of course, the deliberately convoluted tariffs make it almost impossible to compare).
What really put me off another contract was that, with my previous on-contract HTC phone, whenever there was an Android update, you first had to wait for HTC to implement it, then you had to wait for T-Mobile to implement it. Also, I wanted to give the Three network a go for a few months to see what it was like (conclusion: works for me).
Here in the UK, we often get ripped off for computers, software and electronics (usually priced as $1=£1*) so its nice to know that there are some things where we have it better than the USA.
Currently paying £13 per month for 200 minutes of voice, 5000 texts and pseudo-unlimited data (HSPA+ in most places). One-month rolling contract, bring-your-own phone. (I don't use much voice - it would be another £12/month for 2000 minutes). Bundled phone contracts are still the norm (at the end of the contract you can usually keep the phone and negotiate a reduced rate) but all the carriers offer SIM-only plans.
(* some of which is down to sales tax, but not all).
This is nothing but a fake reality show designed to try and fool people into thinking they're going to mars
or, more likely, a fake fake reality show designed to fool viewers into thinking that the contestants thought they were going to Mars.
(Actually, putting even one "fake" before "reality show" is redundant).
Does IE7 support the IE box model? I'm not sure, I'll have to get back to you on that one.
I did stop and think about that question a bit. Its not silly. IE7 can run in standards-compliant mode (CSS box-model) or legacy mode (IE box-model), depending on the doctype. The question is whether IE7 supports the "box-sizing" property in standards compliant mode, to enable the IE7 box model (which some people find more logical) without all the other IE quirks.
The CSS property you're looking for is box-sizing. If you want modern browsers to use IE's box model where the width includes border and padding, use the value 'border-box'.
Yes - but is it supported by IE7...
If you want to yell at someone, yell at those folks still XP and IE8 (or earlier).
Unfortunately, such folks fall into categories like "clients", "customers" or "target audience" and its not such a good idea to tell them "piss off and come back when you've got a decent web browser".
This does all get better the further IE6/7/8 fade into history - if I were starting a site today I could at least ignore IE6/7 - but I'm still seeing significant hits from IE8.
Then new things come along: I was having trouble with 'background-size' recently (handy if you want to use 2x res images to look good on 'retina'-type displays) and I've yet to find a browser that properly supports page-break controls on printouts (yes, I know people who like to print out web pages to read later).
What box model would be best?
I'd look on it from the perspective of "encapsulation": One person should be able to design what was in the box without knowing how it was going to be placed on the page, a second person should be able to place it on the page and align it with other elements without affecting anything inside.
That would work best if the primary size of the box included the inner margin/padding and border (which the box designer 'needs to know'), but excluded the outer margin (which the 'page designer' needs to match with other elements).
As for the border - the most flexible solution would probably be to have a separate 'inner border' and 'outer border' and leave it up to the designer to ensure that the border fit within the margin/padding if desired: the 'box designer' might want the inner border to match the ambient colour of the image and maybe slightly print the photo to 'seal' it; the page designer might want a fancy frame outside the box.
Unfortunately graphic (website) designers are completely shit at using it. Even simply understanding when they should use an ID and when they should use a class seems to a'splode their brain, "huh, what is wrong with using this same id a bajillion times in the page".
If CSS did what it said on the tin - separated content from style and layout - then graphic designers wouldn't have to bother their little heads about this sort of thing because they wouldn't need to touch the semantically-marked-up HTML.
Unfortunately, (a) CSS doesn't do what it says in the tin - changing the layout inevitably needs including exactly the right permutation of DIVs in the markup because CSS doesn't have any way of doing what every half-decent DTP package since PagerMaker 1.0 can do: defining a series of frames and specifying how text should flow between them - and (b) anybody who thinks style can be completely separated from content has spent too long reading & writing rigidly structured technical documents.
Don't even try telling them that "redtext" is not a good classname.
Hell no! Any idiot knows that a classname should be something semantic, like "rubric". ;-)
Bad craftspeople have a definite tendency to blame their tools
...and bad software designers have an even more definite tendency to blame their users. Usability/clarity and appropriateness for the intended user base (in this case, graphic designers) is part of good tool design.
CSS smacks of being a hammer designed by someone who has never seen a nail.
Anyone who has used JQuery will know how their power exceeds the original intention
...anybody who has used jQuery will know how powerful they could have been if only browsers had implemented them completely and consistently.
Meanwhile, anybody who has used CSS will wonder what the hell the original intention was, given the arcane kludges needed to produce popular web-page layout effects easily achieved using evil tables and frames, the lack of 'constants' to set standard colours and measurements.You know there's something wrong with a standard when Microsoft's broken box-model implementation makes more sense. However, that's not the fault of the selectors.
Its as if the designers* of CSS had never looked at a web site, used a DTP package, used styles in a WP package, let alone played with a Java layout manager to get ideas about what might work and/or be useful.
(* probably unfair - I'm sure it was a mixture of committee syndrome and the notion that you can define a standard without producing a reference implementation rather than individual failings).
The real problem is that the innovator who really stole all their ideas from other people, has failed to realize that their own User Interface has become a mature technology.
However, its worth remembering that Microsoft are not the only ones to jump on the tabletization bandwagon whether their users like it or not.
Gnome 3, Ubuntu Unity have had similar castigation for their new 'post PC' interfaces. However, what with Linux being open source and not having the GUI joined at the hip to the rest of the OS this is less of a problem for Linux users.
Apple have also received flak for the fairly limited tabletization that they've done with OS X.
Problem is, we're in a tablet bubble, coming at a time when everybody who wants a regular PC already has one and PC specs are no longer rising fast enough to make them obsolete after 18 months. I like tablets, think they raise some interesting new possibilities and are great for some uses - but the current attitude is "the solution is mobile technology - now, what was the problem again?".
There's no reason to assume the whole vehicle isn't mirrored.
If they were then, at the typical international airport, you'd notice the large ring of car wrecks around the rental garage. Moving the steering wheel is a helpful hint to remind you to drive on the other side of the road. Swapping the brake and accelerator pedals would be a recipe for unpleasantness.
You're bigoted against adults, as this is age discrimination plain and simple. Adults should be able to play with toys, and it should be legal to market something as a toy for adults only.
You know that shop just off Main Street, with the blacked-out windows?
(Trying not to think of the consequences of using super-strong magnets to fake... other types of piercings.)
I may not buy magnets because some parents are stupid enough to give high power magnets to kids?
RTFA. The recall is for a particular type of magnetic toy, not "high power magnets" per se. Its one thing to sell potentially dangerous items - its another thing to package them as toys*.
Also - as someone has pointed out elsewhere - there is a particular problem with older kids using these to make fake tongue piercings - so its not just parents giving them to babies and toddlers who will swallow anything.
Plus - this threat isn't immediately obvious. There have been magnetic toys since the year dot - but not ones that were (a) small enough to swallow and (b) still powerful enough to clamp your intestines together.
Remember that when idiots scramble their intestines, the cost of fixing the mess will still make its way through to your tax and/or medical insurance bill.
* I remember a 1930s book of science experiments for kids that included such gems as making a carbon arc torch from the graphite rods out of batteries using - wait for it - a variable resistor made from two stones in a dish of salty water to cut 110V mains down to 50V**. What could possibly go wrong? They did tell you to wear sunglasses.
**Not only did they skip Health and Safety assessments in those days, I suspect they skipped the "will it actually work?" assessments, too.
You do know that its possible for both parents and businesses to share responsibility for things like this?
You seem eager to heap responsibility and blame on parents, but hey, businesses should be able to pursue the mighty buck wherever it leads, without consequences. Sounds fair.
Parents should watch what their kids are doing, and not give in to pestering - but that doesn't make it right for supposedly reputable businesses to lurk in the bushes poised to spring out and take advantage as soon as a parent makes a mistake.
As far as I know, in-app purchases require you to put in your password.
....and as has been repeatedly pointed out there have often been loopholes in this, such as systems that cache the password for 15 minutes, or systems that 'cry wolf' by asking for passwords for (e.g.) free apps and updates, so parents get complacent. Plus, your average kid may be smart enough to shoulder-surf when you enter your password, but still dumb enough to be fooled into spending money without realising.
The UK Government will be examining whether free to download apps are putting unfair pressure on kids to pay up for additional content within the game through in-app purchases.
Let's help them with that so they can get on with the important job of searching the Pope's quarters for suspicious crucifixes and rosaries...
0. Kids are generally easier to con and less responsible than adults. That's why we don't let them drive, drink, vote or have credit cards.
1. Yes - they're disingenuously called "free-to-play" games and every app store is heaving with them. Technically you can enjoy the game without paying, but they're specifically designed to tempt you to open your wallet. Particularly insidious are the ones with both an imaginary in-game economy and the option of spending real money, where the two concepts can easily get blurred enough to fool a kid. A parent wouldn't necessarily pot this if they 'checked out' the game for a few minutes.
2. Evidence - the industry wouldn't be doing this if they weren't making more money from in-app purchases than by charging a fair, one-off price for the game.
3. Solution - the Govenment doesn't want to get any further into video game censorship than it already is, but we already have age-rating systems. Any game with in-app purchases should be marked as "Funded by in-app purchases and not suitable for under 16s" and make use of whatever parental controls exist on the platform. Games could be exempted if they could demonstrate that they had adequate mechanisms to allow parents to cap spending, and had payments disabled by default. (Giving a kid a limited budget to manage is not a bad thing, but they need training wheels!)
4. Next steps - don't bother: by the time you finish grinding out your report, customer pressure will have forced all the reputable app stores and age-rating schemes to fix this: Apple have already improved labelling of games with in-app purchases.
5. Conclusion - even the solutions in (3) and (4) won't solve this problem - there's too much money in it - but they might help responsible people avoid this trap. Sadly, we'll still see a lot of potentially good gameplay wrecked by greed for in-app purchases.
Now, let's have a quick look for stains in Mr Holmes' underpants.
Python joins the list of excellent languages that have whitespace requirements:
You forgot one
Why teach a crappy, relatively more difficult language like Java to children?
And this is how any attempt to teach kids to program gets killed - every "expert" immediately jumps in and screams about how not using [insert favourite trendy programming language] will melt kids' brains and ruin them for life.
For kids' first experiences in programming it doesn't. fucking. matter. Get them enthused about programming and you can start hitting them with good practices and formalities if and when they decide to study computer science further (what subject [i]doesn't[/i] change beyond recognition when you start to study it at degree level?) The ones with any aptitude will recognise good practices and understand new paradigms when they're shown them - the ones with no aptitude will at least have learnt more about how computers work that they otherwise would have done. Anyway, by the time these kids get to college, functional programming will be "considered harmful" in favour of the latest trendy paradigm.
The difficult thing about a project like this will be getting the gameplay right so that it is both fun and educational. Crack that, and modifying it to use Python, Haskell, Javascript, Lisp, ADA, GW-BASIC, INTERCAL or Elvish Perl will be simple.
Of course, everybody knows that magic is written in FORTH.
The show was just hilariously stupid.
They have done - Series 10 was made by the UK comedy reruns channel "Dave" and broadcast in the UK earlier this year. Google it.
Review: Better than the final series of the original run, but then, that was crap.
My shoulders don't fit into the width of a cattle-class seat. I could certainly lose some weight about my belly, but I'd need some bits sawn off my skeleton to fit comfortably.
Hang on - I think we're at cross purposes here. My point was that the effect of weight on cost of travel is even less than you estimated.
And that maintenance goes up when a fat guy sits there instead of a skinny guy ... for what reason again?
Yes, for what reason indeed? Please do tell.
But I'm not getting a discount for the < 90% of a seat I'm left to occupy.
Nor did your oppressor get a refund for having to spend the flight with an armrest embedded in their belly. Its not like you have to be Jabba the Hut to have difficulty fitting into a cattle class seat.
And I think it would be quite fair if he paid an extra 15% to account for that.
Except you're also assuming that 100% of the ticket cost is attributable to weight/fuel and are ignoring aircraft maintenance, flight & ground crew wages, ticketing, security, insurance, airport facilities, interest payments, administration, executive bonuses, advertising and whatever else it takes to run an airline.
Also, far as I can tell, air fares are a commodity item and bear sod all relation to the actual costs of providing the service.
Simple. Because it costs the airline more to move 180lbs than it does 100lbs. Simple way of pricing tickets, you and all your luggage
...along with 1/300th ( assuming there are 300 passengers) of the airplane, fuel and flight crew, plus a couple of extra weights to represent all the non-fuel related costs of running an airline...
step on a scale and you're charged a per lb rate for your ticket.
...at which point you'll find that the portion of the fare attributable to the difference in personal weights isn't really worth the huge complications this sort of charging will cause.
Alternatively, if you're going to add a weight surcharge, allocate seating space in proportion to how much people are paying.