Monday, October 05, 2015

Some Links

The Truth About Ancient Greece

If you happen to be Jewish and press the wrong button on the time machine.
18) The Michelson-Morley and Sagnac experiments attempted to measure the change in speed of light due to Earth’s assumed motion through space. After measuring in every possible different direction in various locations they failed to detect any significant change whatsoever, again proving the stationary geocentric model.
(from a list of 200 proofs of the geocentric model of the universe)
A detailed critique of recycling.






15 Comments:

At 2:14 PM, October 05, 2015, Blogger Roger said...

It is true that the Michelson-Morley experiment was intended to detect the motion of the Earth, and it failed to detect that motion. It became the crucial experiment for relativity, but relativity does allow a belief in a stationary Earth, because motion is relative.

 
At 2:32 PM, October 05, 2015, Blogger David Friedman said...

What I thought was beautiful about that "proof" was that it took a real experiment of great importance in the history of science, accurately described it, and then offered a simple explanation that interpreted it as evidence for a different claim from the one it actually supported. A much easier claim to understand.

 
At 2:36 PM, October 05, 2015, Anonymous Anonymous said...

Regarding recycling - I'm not sure I understand why landfill is considered anything other than deferred recycling. If your concern is preserving limited resources, why is it better to recycle resources in order to slow the rate that new resources must be extracted, rather than putting the already used resources in storage to possibly use in the future if and when doing so becomes cheaper than extracting new resources?

 
At 6:00 PM, October 05, 2015, Blogger William Newman said...

"relativity does allow a belief in a stationary Earth, because motion is relative"

Relativity (either Galilean or Einstein) says that uniform translation is relative. (So e.g. when two objects with negligible gravitational or other interaction are coasting past each other in space there is no experimental basis for preferring to say that one object is stationary or the other object is stationary or that some other frame of reference is stationary and that both objects are moving in that frame.) However under both those kinds of relativity other kinds of motion, like arbitrarily accelerated motion or rotational motion, are not relative. (So e.g. when a spaceship is accelerating past an object which is coasting, we might or might not choose to analyze the coasting object as stationary, but we simply cannot properly analyze the accelerating spaceship by treating it as a stationary frame of reference, because treating an accelerated frame as stationary would cause our analysis to take leave of reality: various of our usual experiments which work in stationary frames will come out differently in the accelerating spaceship.) You might nonetheless say relativity "allow[s] a belief" in a stationary Earth (despite its rotation and the orbital motion around the Sun), but it is only in some artificial extreme sense, not what would ordinarily be meant by that phrase, and this isn't a characteristic of relativity, but of human extremism. (Sufficient extremism allows people to believe almost anything almost regardless of what evidence suggests, whether the theory in question is relativity or paternity or climate history.) Relativity doesn't prevent observations that can distinguish between rotating Earth and stationary Earth (e.g. Foucault pendulum, or the fit of the observed motion of the Moon to simple equations instead of twisted equations with epicycle-flavored ad hoc parameters) or distinguish between Earth and other planets orbiting the Sun vs. the Sun traveling around the Earth, the planets moving in a twisted epicyclic dance, small bodies like asteroids doing even weirder stuff when they happen to make close approaches to planets, and small precisely instrumented bodies like GPS satellites and interplanetary probes reporting the very small gravity-and-acceleration-and-motion corrections for time under Einstein's equations when the probes are accelerating very slightly and also moving relative to the rest of the experimental setup (like the antennas back on Earth) at some small fraction of the speed of light.

 
At 8:17 AM, October 06, 2015, Anonymous Power Child said...

One of my criticisms of Zionism used to be that the area today known as Israel will eventually be pushed up into the air in a mountain range as Africa converges with Europe, and may become uninhabitable.

 
At 9:33 AM, October 06, 2015, Blogger Roger said...

David, there is considerable academic dispute on this point. Physics textbooks describe the MM experiment as the crucial one for special relativity, while philosophy of science textbooks deny that there is ever a crucial experiment in the history of science. The philosophers explain away the MM experiment by saying that it has other interpretations. I side with the physicists, but it is true that you need to combine MMX with other info to get the good conclusions.

 
At 2:32 PM, October 06, 2015, Anonymous Patrick said...

William Newman:
"when a spaceship is accelerating past an object which is coasting, we might or might not choose to analyze the coasting object as stationary, but we simply cannot properly analyze the accelerating spaceship by treating it as a stationary frame of reference, because treating an accelerated frame as stationary would cause our analysis to take leave of reality: various of our usual experiments which work in stationary frames will come out differently in the accelerating spaceship"

This is exactly what general relativity does allow. You can freely shift between relatively accelerated reference frames, replacing the acceleration with an appropriate gravitational field. Having done this properly, all local experiments will have consistent explanations regardless of your frame, it's just that some experimenters will conclude that they're being accelerated in one direction, while others will (equivalently) conclude that there is gravity pulling them in the other.

 
At 7:43 PM, October 06, 2015, Blogger William Newman said...

Patrick, that is not precisely what general relativity does allow. Experiments in the accelerating spaceship will come out differently from the coasting spaceship. General relativity does relate gravitational effects and uniform acceleration effects, guaranteeing that sufficiently local experiments ("local" in the sense of not involving less-local effects like tidal stresses) will come out the same in a uniformly accelerating spaceship as in a gravitational field of the same strength. But that is not enough to justify the kinds of general claims that you are trying to hang on it.

"You can freely shift between relatively accelerated reference frames, [...] all local experiments will have consistent explanations regardless of your frame". I see two problems with this. First, relativity is more nearly about experiments coming out the same regardless of your frame than about "having consistent explanations regardless of your frame." (What would it take for no possible "consistent explanation" to exist in some frame of reference? If we have sufficient mental and muscular and intestinal fortitude, can't we can have a consistent explanation of a bullet's flight nearby even if we're doing a triple backflip in a Vomit Comet overhead at same time? It would just be a messy explanation involving the more-or-less-epicycles that would be needed to relate the arbitrarily complicated motion of our frame back to a well-behaved inertial frame of motion in which the fundamentally simple equations governing the simple motion of the bullet remained simple. Just because with sufficient determination you can find a messy but consistent explanation doesn't mean that the tbiaVC frame is the same kind of well-behaved inertial frame of reference as the one that the bullet is coasting in.) Notice that even in the simplest cases of accelerated motion the results of many experiments will be different depending on how the experiment is aligned with the direction of acceleration/gravitation. That is deeply unlike the ordinary relativistic notion of a frame which is indistinguishable from a stationary frame: one property of a such a stationary frame is its rotational invariance. Second, you also seem to have slipped in an implicit assumption that acceleration is necessarily uniform and linear. Admittedly that assumption isn't necessarily violated in my spaceship example. It is, however, an incorrect assumption in the situation in your original claim ("does allow a belief in a stationary Earth, because motion is relative") because the rotational motion of the Earth creates a pattern of accelerations which, unlike the presumably-uniform acceleration in the spaceship example, is not indistinguishable from an ordinary gravitational pull. So fixing on how in some special cases general relativity lets some kinds of accelerated frames look like frames subject to gravitational pull doesn't do much to justify a claim that relativity can correctly be paraphrased as [all] motion [and in particular the Earth's rotational motion] is relative.

"Finally, there is even a philosophy which says that one cannot detect any motion except by looking outside. It is simply not true in physics. True, one cannot perceive a uniform motion in a straight line, but if the whole room were rotating we would certainly know it, for everybody would be thrown to the wall—there would be all kinds of 'centrifugal' effects. That the earth is turning on its axis can be determined without looking at the stars, by means of the so-called Foucault pendulum, for example. Therefore it is not true that 'all is relative'; it is only uniform velocity that cannot be detected without looking outside." --- http://www.feynmanlectures.caltech.edu/I_16.html

(That passage continues to discuss philosophy and conceptual possibilities, but if all you're concerned about is what holds true experimentally, you can get the essence by stopping there.)

 
At 8:40 PM, October 06, 2015, Anonymous Mark Bahner said...

"I'm not sure I understand why landfill is considered anything other than deferred recycling."

Paper and cardboard are major components of recycling. It's not possible to recycle paper and cardboard if they're contaminated with food waste, grease, oil, and so on.

So while it's possible to dig up paper waste to burn it, recycling landfilled paper and cardboard isn't really an option.

 
At 4:58 PM, October 07, 2015, Blogger gurugeorge said...

Hehe, nice to see you taking a leaf from Scott Alexander's book David. Occasional lists of links re. whatever you happen to be interested in, would always be welcome :)

 
At 11:33 AM, October 08, 2015, Anonymous Anonymous said...

Humor is always a surprise. A man who does not have any presupositions cannot be surprised.

 
At 7:19 PM, October 08, 2015, Blogger Unknown said...

It is easier for most of us to separate our metals into one bin than to separate one specific metal into a bin. If a local facility then separates the aluminum from the other metals, recycles it, and sends the rest to landfill, is there a benefit. Consider that this allows the creation of a special landfill for metal - a convenient place to mine in the future, if it starts to make financial sense. (Similarly for glass and plastic mines.)

 
At 7:19 PM, October 08, 2015, Blogger Unknown said...

It is easier for most of us to separate our metals into one bin than to separate one specific metal into a bin. If a local facility then separates the aluminum from the other metals, recycles it, and sends the rest to landfill, is there a benefit. Consider that this allows the creation of a special landfill for metal - a convenient place to mine in the future, if it starts to make financial sense. (Similarly for glass and plastic mines.)

 
At 2:51 PM, October 09, 2015, Blogger Tibor said...

Paper/cardboard, metal and plastics. This is pretty much what I am used to recycle - what there are trash bins for around. I always thought that recycling paper is probably not worth it though, I am a bit surprised that it is. Then again, if you bring a lot of it, garbage companies pay you for it...which is a good indicator that it is worth it unless they get some subsidy for buying it from you or something.

Sometimes you also see "bio waste" containers, but I doubt anyone is recycling half-eaten pizzas and mouldy vegetables, I think this is used to be burned and thus create electricity (unfortunately, in the EU, biomass is also highly subsidized and farmed, which makes little sense economically AND environmentally, even such partisan organizations as Greenpeace are against that, but there is a vested interest of the firms that do this sort of thing and they have a good lobby in Brussels), I cannot imagine it to have any use otherwise (you could create compost, but it will be of little value if you have all sort of things in it, quality compost is not that easy to make).

I am surprised that glass is not worth recycling though and a little bit suspicious of that claim. First of all, you need glass shards to make new glass the way it is being produced nowadays (of course, you could simply crush say 1% of your production instead or something). Secondly, beer bottles come with a deposit which is refunded at the shop - even in countries where there are no mandatory laws for that, which suggests strongly that it is cheaper to do this than to keep making new bottles. Of course, this is not really recycling, but re-use. I also always wondered why the beer bottles come with a deposit (basically always) whereas the wine bottles never do.

 
At 5:58 AM, October 12, 2015, Anonymous Daublin said...

I really like the "deferred recycling" perspective.

Mark, for paper and cardboard, it's important to consider that (a) they are biodegradable, and (b) trees are a renewable resource. So I don't think the case for recycling paper and cardboard is very strong.

 

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