Please create an account to participate in the Slashdot moderation system


Forgot your password?
Check out the new SourceForge HTML5 internet speed test! No Flash necessary and runs on all devices. ×

Submission + - Ask Slashdot: Physics of Water 1

bwayne314 writes: We have been having a debate at the lab about mechanics of water and leaky bottles that I am hoping you slashdotters might be able to put to rest.

One group claims that capping a bottle or tube with water residue on the seal will cause some water molecules to remain in the seal and allow liquid from the container to leak out (under certain conditions, like shipping) despite being tightly closed. They call this phenomenon, "creating a river" and opening and drying of the the seal on such a bottle would prevent a leak.

The other faction thinks that any bottle that leaks, simply has a poorly fitting seal and that closing a wet bottle with a proper seal should push any water residue either into or out of the bottle. The distinction here is that there should not be a difference between capping a bottle that is dry vs. capping one that is wet.

So what happens on a molecular level in this situation and who is correct?

Submission + - New Fabric Blocks Sound But Lets Light Through (

Zothecula writes: Heavy curtains made from thick material such as velvet are often needed to keep noise out of indoor environments, but Swiss researchers have come up with another option. The Empa researchers, in collaboration with textile designer Annette Douglas and silk weavers Weisbrod-Zurrer AG, have developed lightweight, translucent curtains which are five times more effective at absorbing sound than their conventional counterparts.

Comment Re:Look at the DroboPro (Score 1) 609

I'll second that - while I don't use a drobo - it's on the purchase list.

I'm highly technically competent - I use an opensolaris fileserver with ZFS and some terabyte drives - and sure, I can expand it and do all kinds of cool things - but in the end, I could get the same features I get there (the ones I actually use) out of a drobo, with less hassle.

With my fileserver I have to know a bunch of stuff about how to manipulate it to expand it... with a Drobo, you have to watch some blinkenlights and just pop in bigger drives when you need to grow. It locks dives when you shouldn't remove them, and is dead simple to use. From all my research, it's unparalleled in the ease of use department for joe average.

Comment Re:Battery usage of Flash (Score 1) 850

Again though - if they want to say "your app shall not consume more than ## battery units per ## time unit" then fine. if that outlaws most flash apps, that's fine too.

a) it should also outlaw things that aren't flash that have the same problem
b) if I DO make a flash/java/unity/whatever program that doesn't have this problem, then apple should be fine with it.

Comment Re:Institutional Traders Don't Enter Trades Like T (Score 1) 643

Well, I(nor does anyone right now, really) have no idea of the details of the trading platform being used (if, indeed, its even relevant). However, I've never seen (nor heard of, nor have the folks who I've talked to who have worked with institutional investing) a system where you type in the amount of stock you want and then put a letter after it.

Comment Re:Terrible Idea (Score 1) 409

I would imagine a great panic since neither country has publicized any weapon other than a nuclear capable ICBM and our intelligence probably would confirm this. This is a stupid comparison. Obviously an ICBM from Russia/China is a nuke. And obviously our missile defense shield would eliminate a single ICBM threat not requiring a full nuclear retaliatory action.

Continuing our game.. now I'm imagining I'm Iran. I think I want to nuke someone.. oh wait our nuclear launch vehicles were just blown the fuck up an hour later. What the hell just happened? Oh that's right, the Americans have a 60 minute counter to our stupidity. So we're out of nukes now, time to invade Israel with conventional warfare because we should respond to the American action? I doubt it. More like we deny we were going to nuke anyone and blame the US for terrorist actions against our country.

And as for inspecting our weapons. We only need justify our weapons claims to those who hold an equal threat of invading/annihilating our own soil. Iran does not fall into this category. Iran can either choose to believe the public intel or test it's luck against it. Which do you think they will choose?

Comment Any game can tie data to user response (Score 1) 443

those trainers existed because a local engine could be cracked. Tying data to the server changes everything. Even moving a small part of that engine to the server would cause a major problem for the cracker.

Have fun building a trainer for a racing game when the local client is entirely dependent upon the server for the positions of the other cars.

Comment Re:Prime directive (Score 1) 648

I don't know. Maybe FTL travel was developed as a military technology for galactic-scale battles or something like that.

Again, this runs into the whole problem with how ridiculously far apart everything is astronomically. If you want to develop FTL for military purposes, this presupposes that you've already found an enemy to fight where FTL would be an advantage. Presumably, any non-FTL-capable race will be just like us: they won't have any idea if other intelligent beings even exist, so they wouldn't know where to go to find these new enemies. The only exception here is if two races developed independently on two different planets either in neighboring systems, or in the same system somehow, and learned about each other's existence somehow.

The fundamentals of modern physics were developed in the first half of the 20th century with two world wars.

The two world wars took up a large part of the first half of the century (and then the Cold War took up even more), but that doesn't mean that every advance during that time was created for the wars. Einstein didn't create the theories of Relativity just so he could build a bomb; theoretical scientists like that (who are much closer to mathematicians) aren't really thinking of practical applications early on. IIRC, he came up with a lot of his stuff while he was still a patent clerk.

Remember, the whole Industrial Revolution was still going on in the early 20th century. That drove lots of advances on its own, without any need for a war.

Even if I like your way of thinking, being a pacifist myself, I really believe it to be wishful thinking. Unfortunately.

Well, for what it's worth, I'm not a pacifist at all. But I only believe violence is necessary to secure peace, because so many people (e.g. violent criminals) easily resort to violence to get what they want at the expense of others. I think any highly advanced race will either simply not have problems with violence (sort of like ants, who only use violence against non-ants, and never against other ants of the same tribe), or will have figured out how to make themselves evolve (with genetic engineering if necessary) past the point where they're predisposed to it.

Finally, as far as galactic-scale battles go, why would anyone have them? Wars are usually over one of two things: resources or ideology (which includes religion). Advanced aliens are very unlikely to have resource wars; with all the uninhabited planets and moons and asteroids out there, and the fact that such aliens are advanced enough for FTL or any decent level of spaceflight, it should be pretty trivial for them to find all the resources they want in their own systems, or in the many uninhabited systems around. Why go engage in a destructive war with someone on a faraway planet if you can get the same thing without a fight somewhere else, probably no farther away? Secondly, advanced aliens are unlikely to be religious and want to convert all the other aliens they can find. They'll have evolved past the need for making up myths to explain the unknown and the afterlife. And finally, what kind of aliens are going to go look for other aliens (who might barely be recognizable as "life" to them) just so they can have a capitalism vs. communism war with them?

Comment Re:I dunno mang, (Score 1) 332

Exactly. If employers want to discourage job hopping, they need to ensure that compensation keeps up with experience. Many companies seem to think that they can continue to offer poor raises and people will stay out of "loyalty". Well, that ship sailed a long time ago. When you get a miserly raise then you hear of someone else being hired on in a similar (or sometimes lower) position for 50% more than what you're getting then you're told raises are being held in the low single digits this year, what exactly are you supposed to do?

Though personally, I don't really like the whole automated raises thing. People should be encouraged to negotiate their raise and justify it each and every year. This would work best for all concerned.

Comment Re:Slaves (Score 1) 306

My anecdote deal with a private company, but I think it is still applicable to people working a government job.

I worked for a 1000+ person manufacturing facility. Everyone on the shop floor was hourly as well as a lot of the office workers. The "Higher Up" office workers were salaried. Salaried was really cool at that company. You didn't clock in and you could just take off when you needed to. Salaried workers would do a 12 hour day and then take off 3 hours early later in the week to take their kids to the doctor. Need a three day weekend? Get your work done earlier and take the day off. Decide you want the day after Christmas off? Ok. Having a salaried position was pretty awesome.

I am pretty sure you can imagine how this turned out. Most of the people were very happy to have this flexibility and worked really hard for the company and were reasonable with their off time. A few people were not. The worst offender was an Engineering manager who took off 77 days during the year. The company responded by saying "Hey, you guys obviously cannot be reasonable about this so salaried employees will now be punching the clock. They will also have vacation days just like hourly. You want 3 hours off? That will cost you a half day."

The moral of the story? Time and attendance isn't "Slavery". It is pretty much necessary. You can try the "Honor System" with employees and many will be pleased but you'll always get those that want to abuse the shit out of it and laugh about making money without working. The idea of every average Joe being a good honest person working for corrupt politicians and CEO's is pretty naive. Put Average Joe in a position where he can screw someone out of money and there is a decent chance he will.

Comment Re:Fuck exceptions for religion (Score 1) 615

I fully agree that a helmet is a great idea. I'm just saying that there is bound to be a lot of things other people also think are great ideas as well that you won't like so much.

Of course, I have heard from others that they prefer NOT to wear a helmet because it increases the chances that they'll end up quadriplegic rather than dieing in an accident. Right or wrong, that's a choice they've made. It is probably cheaper for the taxpayer if they just die rather than requiring rehab and special equipment for decades.

I certainly would not think that refusing medical coverage because someone wasn't wearing a helmet, butcher's glove, plate mail, etc to be a good idea.

It's also incontrovertible that not skydiving will prevent 100% of skydiving related injuries. The same for rock climbing, skateboarding, etc. Many people do things that are not really NECESSARY but do carry a risk of medical expenses. Those who don't are often sedentary, and so have a risk from that.

Slashdot Top Deals

We all like praise, but a hike in our pay is the best kind of ways.