Ask a physicist anything. (7)

[Wiccan_Child]

It depends. Some ads are paid per-click, some are paid per-view. And if the ads are never loaded, the ad agency doesn't pay out.

So personally I do not run ad blockers unless I'm visiting a website that either has really annoying ads, or that I despise on moral grounds (e.g. the Huffington Post, which effectively uses slave labor).

I can't say I'm a massive fan of the Huffington either - its stance of pseduscience and alternative medicine is... troublesome. It'd be nice to put it down to "Oh, they don't decide what gets posted", except, they do.

 

[Chalnoth]

My Chrome Version of AdBlocker has this setting
"Show ads everywhere except for these domains..."

Oh, it does that now? I am definitely going to check that out...

 

[Zippy the Wonderslug]

What website was it? Or is it *cough* adult *cough*...

I didn't think we could post sites on this forum, but since I now despise the place, here it is.

http://gameknot.com

It's basically just a Chess site for stupid losers like myself.

Somehow, I felt like I was accepted there but only for a brief moment in time.

 

[GrowingSmaller]

IFAIK the only known way to decrease entropy is evolution. Is that true?

 

[Wiccan_Child]

IFAIK the only known way to decrease entropy is evolution. Is that true?

Short answer: no, entropy is easy to decrease. Thermodynamics generally causes an overall increase (and closed systems will always increase), but local decreases are certainly possible.

Long answer:
Nope, pretty much any process can decrease entropy. The Second Law of Thermodynamics only tells us that the entropy of a closed system tends to a maximum - that is, the average entropy (analogous to 'disorder') of the entire system will, over time, increase. But just because there's a global increase, doesn't mean there can't be a local decrease.

Take the Solar System. The Sun's activities dwarf anything else going on, and its processes make it increasingly entropic - its entropy is increasing. However, there are local areas of decreasing entropy, and evolution is indeed an example of this.

So my stunningly poorly-explained point is that systems will tend towards higher levels of entropy, and closed system always will, overall, tend to a maximum entropy, but even the latter can have local instances of decreasing entropy - the only requirement is that, overall, entropy increases.

 

[GrowingSmaller]

Ok thanks for the effort. So what are the other mechanisms called, if not "evolution"?

 

[Chalnoth]

Ok thanks for the effort. So what are the other mechanisms called, if not "evolution"?

Putting your foot on the gas pedal of a car, for one.

Though I should mention that these things only decrease entropy for a specific subset. Overall entropy is always increased. In fact, things like evolution or driving a car increase overall entropy faster than not doing anything.

 

[Wiccan_Child]

Ok thanks for the effort. So what are the other mechanisms called, if not "evolution"?

No no, every process is capable of causing a localised decrease in entropy. Pretty much any human construction, especially complex electronics, constitutes a lowering of entropy.

They don't have a name, because pretty much every general process may (or may not) decrease entropy.

 

[AV1611VET]

Say there's a glass of distilled water, filled to the brim; and has one distilled ice cube floating in it.

In the ice cube is a marble.

Question:

When the ice cube melts, will it release the marble and cause overflow; or does the weight of the marble cause more displacement of water, compensating for the level of the water?

 

[Nabobalis]

Say there's a glass of distilled water, filled to the brim; and has one distilled ice cube floating in it.

In the ice cube is a marble.

Question:

When the ice cube melts, will it release the marble and cause overflow; or does the weight of the marble cause more displacement of water, compensating for the level of the water?

The ice cube should sink but as soon as it was added to the glass it would displace the water in the glass and cause it to spill. It is based purely on the volume of the objects added.

 

[Wiccan_Child]

Say there's a glass of distilled water, filled to the brim; and has one distilled ice cube floating in it.

In the ice cube is a marble.

Question:

When the ice cube melts, will it release the marble and cause overflow; or does the weight of the marble cause more displacement of water, compensating for the level of the water?

Without the marble, the water level would stay the same - the volume of water displaced by the cube is the same weight as the cube, so when it melts that weight (and, thus, volume) in water replaces the original displaced water, so it must also be of the same volume, so the water level stays the same.

The marble replaces some ice, and because it's so heavy, it sinks below the waterline (the ice cube would orientate to put the marble as low as possible). Thus, when released by the melting cube, it can only displace a maximum of its own volume of water - its weight no longer matters. The ice cube, having less ice, cannot compensate for the extra water that's been displaced, so I theorise that the water level would go down.

So the marble displaces more water by dragging the ice cube down, but as there's a) less ice to fill the displaced water, and b) more water displaced, the water level must go down. The 'missing' volume is made up by the weight of the marble, which ceases to matter when the ice cube releases it.

 

[AV1611VET]

Without the marble, the water level would stay the same - the volume of water displaced by the cube is the same weight as the cube, so when it melts that weight (and, thus, volume) in water replaces the original displaced water, so it must also be of the same volume, so the water level stays the same.

The marble replaces some ice, and because it's so heavy, it sinks below the waterline (the ice cube would orientate to put the marble as low as possible). Thus, when released by the melting cube, it can only displace a maximum of its own volume of water - its weight no longer matters. The ice cube, having less ice, cannot compensate for the extra water that's been displaced, so I theorise that the water level would go down.

So the marble displaces more water by dragging the ice cube down, but as there's a) less ice to fill the displaced water, and b) more water displaced, the water level must go down. The 'missing' volume is made up by the weight of the marble, which ceases to matter when the ice cube releases it.

Thank you, sir!

And congrats on yet another generation coming up!

Your thread has got to be a record here!

 

[Wiccan_Child]

Thank you, sir!

And congrats on yet another generation coming up!

Your thread has got to be a record here!

Well, second only to the numbers threads

 

[AV1611VET]

Your thread has got to be a record here!

Well, second only to the numbers threads

I meant where discussion is concerned.

You know -- constructive.

 

[Zippy the Wonderslug]

Pop question.

Why are tires on all cars not that very long in width?

It would seem that, at the very least, a three foot wide tread on them would be so much better than what we have today.

Is there some type of maximum efficiency to account for this?

I know a three foot wide tire would probably look fairly ugly, and super heavy on our modern cars, but hey, if it could save thousands of lives because of the increased traction, why not make this a new standard?

Thanks ahead for any response.

 

[Wiccan_Child]

Pop question.

Why are tires on all cars not that very long in width?

It would seem that, at the very least, a three foot wide tread on them would be so much better than what we have today.

Is there some type of maximum efficiency to account for this?

I know a three foot wide tire would probably look fairly ugly, and super heavy on our modern cars, but hey, if it could save thousands of lives because of the increased traction, why not make this a new standard?

Thanks ahead for any response.

Probably for the same reason that they don't make entire airplanes out of the same material they make the black box from - too heavy and too expensive. Plus there's probably such a thing as too much traction - you'd spend far more fuel maintaining your speed if there was greater friction.

We humans exchange safety for convenience. The proper solution isn't to make tires thicker (which would only exacerbate fuel costs, rubber usage, etc), but to ban cars altogether.

 

[Zippy the Wonderslug]

So why not just make tires bigger in addition to compensate for the extra wide treads?

I would love driving 15 feet off the ground to feel safer.

 

[GrowingSmaller]

Ty for answering the quesitonds on entropy. May god find a way to honor you in this life and the next.

 

[Zippy the Wonderslug]

^ Wow. Nice thank you response.

That was intense.

 

[Cactus Jack]

What keeps animals from talking like humans?