h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Hi Potholer,

Sorry, didn't follow that at all

It looked like you were describing how a fridge could be built with the motor on the inside. So where would the heat go?

A web search didn't help me out much. Post on my personal space if it's too off-topic.

Gif

Esentially, a fridge with a 100W motor can shift *more* than 100W of heat from the inside to the outside, but that doesn't violate the 2nd law because you couldn't extract more than 100W of useful energy from the heat differential that the fridge created.

(i.e. If you put *every* part of the fridge mechanism except for the hot coils *inside* the insulated part of the fridge, it could still cool the contents, though less efficiently than the conventional layout.)

But isn't the hot coils also the essential part of the fridge? While the rest is just the compressor and such needed to heat the hot coils. And they only create heat because engines do that while working. Or am I wrong?

Andy, I believe in e.s.p. because I have had many experience's of it. But none that I can prove to you or to anyone else. I am not a creationist or a spiritualist. I do not have faith in e.s.p. because it is a very hard to be certain that the interpretation is correct. I also believe in quantum physics.


Alji (Member of The Guild of Wizards U197895)

But not in relativity as far as I can remember.

The hot coils don't make heat, they just let it be taken away by the outside world. All I'm trying to say is that a fridge can *move* more energy from the inside to the outside than it takes to power it.

No I don't believe in relativity and it is not a matter of faith but of 30 years study (on and off) of the subject. And I am not alone in my disbelief but the trouble with science is its dogma. If you want to do research into anything you have to get funding and to get funding you have to follow the herd.

Alji (Member of The Guild of Wizards U197895)

I thought that relativistic time dilation had been measured - atomic clocks in aircraft/satellites, orbit of Mercury, etc?

Gosh, what a lot to catch up on! Doesn't having to work get in the way of the important things?
First, my twopenny's worth on entropy; if entropy in the universe as a whole is increasing the initial entropy of the universe should be zero. This represents a state of maximum order. Complexity is not a state of maximum order (despite what creationists think). A state of maximum order is featureless. Therefore, the current complex state of the universe (including us) has to be a state of nonminimum entropy.
Rational explanation is the ONLY form of explanation. Rationality IS the correct application of rules of explanation. In the absence of a rule that says a therefore b a does not explain b. We do not, of course, have a full list of the rules to work with, but that's part of the fun.

yes, but noggin, dear, being rational all the time would dictate a rather boring existence. and where does that leave chaos theory and fuzzy logic? it doesn't really make much sense to say that a bird in south america can cause a typhoon in japan, although you can explain it through physics. the thing is, once you take all of the mystery out of something, what have you got left?

this is not to say i'm a creationist....i'm not. i believe quite strongly in evolutionary theory. but this extreme dichotomy of head and heart, body and soul, science and religion, has gone too far in the western world. we want to make sense of everything....but what if part of our purpose is to learn to stop trying to make everything fit into little boxes and see the whole?

and camels make perfect evolutionary sense in desert climates.

Among the rules clearly stated in 'Noggin the Nog's Big Book of Rules' are the following.

You can never know all the rules.
You can never know enough about the state of anything to know exactly how the rules are to be applied.
The rules that govern the behaviour of complex systems (eg humans) are too complex to be followed in real time, even if you know what they are, and what the current state of the system is, which you don't {see above}.
High level rule systems (eg human emotions) can be unrecognizably different from the low level rule systems (laws of physics} that underlie them.
Everything is interconnected. So don't put things in little boxes - they won't fit.
Three zillion is a funnier number than four quadrillion.

All extracts by kind permission of Noggin the Nog.

Potholer said > I thought that relativistic time dilation had been measured <

There is another non-relativistic explanation for the orbit of Mercury which involves the rotational speed of the central region of the Sun.
<quote 1>
In recent years, however, a rival explanation has been found in the non-symmetric gravitational field of the sun. Surface oscillations of the sun betray hidden internal rotation, which produces asymmetry in the sun's gravitational field. By applying the distorted field in predicting the orbit of Mercury and the minor planet Icarus, astronomers are more successful than when they use the GR.
<quote 2>

Taking into account quantum physics, two U.S scientists suggest that giant dying stars transform themselves into what they call gravastars, shells of extremely dense matter with exotic space inside.
<quote 3>
Without quantum mechanics, the early theorists made crucial mistakes in envisioning black holes and their relationship with space and time,

Alji (Member of The Guild of Wizards U197895)

Relatively speaking, what about atomic clocks up mountains, or in planes & satellites, or the extended lifetimes of subatomic byproducts of upper atmosphere cosmic ray collisions.

Also, I thought that at least some of relativity (like the fixed speed of light in a vacuum) was the unavoidable conclusion of some of Einstein's thought experiments.


As far as earlier comments about trying to make sense of everything, I think most people who try and understand things don't lose their sense of wonder, and I'd rather try to make sense of the world than make nonsense out of it.

There's a book called Unweaving the Rainbow by Dawkins, about how science doesn't remove the magic. Never read it though.

> I'd rather try to make sense of the world than make nonsense out of it. <

Me too. When speaking about the speed of light, you should remember that it is the speed of propagation of light.
Propagation. The act or process of propagating, especially the process by which a disturbance, such as the motion of electromagnetic or sound waves, is transmitted through a medium such as air or water.

Permittivity, also called electric permittivity, is a constant of proportionality that exists between electric displacement and electric field intensity. This constant is equal to approximately 8.85 x 10-12 farad per meter (F/m) in free space (a vacuum). In other materials it can be much different, often substantially greater than the free-space value.
When light travels through a medium it passes through the medium at a slower speed due to the electric permittivity, but as soon as it leaves that medium it is back up to speed again.
e.g.
|< in space, at c >|< in air, at c/x >|< back to space, c again>|

So what if you move the light, what changes? The frequency changes or to put it another way, the number of waves that pass a point every second. So in Einstein's thought experiment about a light passing a spaceship that was traveling near the speed of light what do you think you'd see? Answer - You can't see light that is passing you, the light has to be reflected off something before you can see it.
Say the light was from a laser so there is only one frequency and it is reflected off a mirror into the spaceship so you could measure the speed. The speed would be c inside the ship but the frequency would be red shifted.

Alji (Member of The Guild of Wizards U197895)

I think you should make a new thread about this. I'm sure you got enough material to make it a lengthy one.

Potholer, thanks, I think that's clear now.

Montana, nothing spoils a good bit of desert quite so much as putting a camel in it.

Gif

I am not aware of any experiments testing the theory of time dilation which have failed to show it, so I suspect that at the very least, any debate would have to be between relativity theory and some modified or related theory that explained the observed results at least as well.

It may well be that some existing theories do need a small amount of tweaking, the recent results indicating an unexpected slight deceleration of the Pioneer spacecraft being a case in point. However, I do think that on the whole, science is receptive (though sometimes a little slowly) to well-founded new information that contradicts existing theories, and to new theories that better explain apparently anomolous results.

When it comes to psychic phenomena, it does appear to be the case that for the more repeatable ones, the more rigorously they are studied, the less positive the results.

Smaller oddnesses, such as people or other animals apparently being aware of things happening to a distant loved one, are rather harder to study - only a much more regular manifestation of similar phenomena of the kind that would be amenable to more intensive scrutiny would seem likely to have had significant implication for the evolutionary process.
Without psychic phenomena having an expression of more regular positive value, even if such things do exist, it seems difficult for evolution to work on them.

True, it's not something that you can turn on and off like a light or for a better analogy a T.V. and you are at the mercy of someone else's strong emotion but as I said before, I believe that it is possible. Given the right instruction, most people can get a taste of it. I taught my son how to focus but that is another story.

Alji (Member of The Guild of Wizards U197895)

giford, i, too, think camels are ungainly, maybe even downright ugly, nasty things. however, in a desert climate, their eyelashes keep out the sand, their hooves are made to grip sand, their humps provide both a hydration source and a convienent spot in which to sit (of course, i am speaking here of two humped camels...one humped are better for portage). they can go forever without water, eat desert grasses that no other animal can eat, and they provide milk. okay, so they spit and smell bad. have you ever smelled a yak? or been spit on by a llama? neither of those animals is terribly pleasant up close, either.