Search found 1911 matches

by Charlie!
Sat Sep 17, 2011 6:58 pm UTC
Forum: Science
Topic: Expansion & Infinity
Replies: 4
Views: 1197

Re: Expansion & Infinity

A thread on a very similar topic was recently closed. That should be a hint that just starting another one is not the best plan.

The more fundamental problem is that what you are doing is numerology, not science, and isn't going to yield physically meaningful results.
by Charlie!
Thu Sep 15, 2011 7:32 pm UTC
Forum: Science
Topic: Favorate classical discovery?
Replies: 5
Views: 1478

Re: Favorate classical discovery?

Measurements of the speed of light are pretty impressive, and the later connection to electromagnetism by Maxwell was cool too. Also, this guy sounds awesome: In 1021, Alhazen (Ibn al-Haytham) published the Book of Optics, in which he presented a series of arguments dismissing the emission theory in...
by Charlie!
Thu Sep 15, 2011 5:21 pm UTC
Forum: Science
Topic: Time Without Change
Replies: 69
Views: 8015

Re: Time Without Change

Don't bother reading any books on my account - I just figured you'd look it up on wikipedia. If you'd like to promise me to read things, though, you might read this article and any you find necessary to understand it. Anyhow, in spacetime, a totally non-interacting system would just look like a coll...
by Charlie!
Thu Sep 15, 2011 6:26 am UTC
Forum: Science
Topic: Time Without Change
Replies: 69
Views: 8015

Re: Time Without Change

On valid spaces, I take that you mean, say, the four-dimensional configuration of my house is a valid one, as was the configuration ten minutes ago, and that these are two of many valid configurations. That we could do some trippy things to the four-dimensional space that is my house if we were mov...
by Charlie!
Tue Sep 13, 2011 6:40 pm UTC
Forum: Science
Topic: Question from a theist on universal beginnings and entropy
Replies: 290
Views: 23970

Re: Question from a theist on universal beginnings and entro

If you want to call god "a thing which allows violation of 2nd law of thermodynamics" then go to town with that. That's a little better. Not quite the most familiar of gods, but I can back it, and am just as sure that it doesn't exist as I am of Jesus ; ) Oh come now, the second law is vi...
by Charlie!
Tue Sep 13, 2011 3:34 am UTC
Forum: Science
Topic: Time Without Change
Replies: 69
Views: 8015

Re: Time Without Change

From my reading, coordinate time is extrapolated from the recordings of proper time clocks. If proper time clocks have been suspended, how could I measure coordinate time to demonstrate it's still passing? So the t-coordinate could either be changing or not changing, and you wouldn't know, right? S...
by Charlie!
Tue Sep 13, 2011 3:08 am UTC
Forum: Science
Topic: Time Without Change
Replies: 69
Views: 8015

Re: Time Without Change

Time, as in a coordinate, doesn't care about change. A coordinate in what sense? Longitude is, as a coordinate, dependent on the shape of the earth. Likewise, time is dependent on space. If space were to freeze then so would time - they're not independent, but intimately connected. Analogies are tr...
by Charlie!
Mon Sep 12, 2011 4:09 pm UTC
Forum: Science
Topic: Time Without Change
Replies: 69
Views: 8015

Re: Time Without Change

Time, as in a coordinate, doesn't care about change. A coordinate in what sense? Longitude is, as a coordinate, dependent on the shape of the earth. Likewise, time is dependent on space. If space were to freeze then so would time - they're not independent, but intimately connected. Analogies are tr...
by Charlie!
Sun Sep 11, 2011 12:24 am UTC
Forum: Science
Topic: Measurement in QM
Replies: 6
Views: 1071

Re: Measurement in QM

It should be mentioned that what Charlie! just gave is basically the Everett interpretation. And yeah, it is the most elegant interpretation of quantum mechanics, which is why it is so popular. But it has a lot of counter-intuitive and weird consequences. It's also the "subjective collapse&quo...
by Charlie!
Sat Sep 10, 2011 7:05 am UTC
Forum: Science
Topic: Creating Acellular Organ Scaffolds
Replies: 22
Views: 3442

Re: Creating Acellular Organ Scaffolds

http://www.google.com/search?q=sodium+d ... hl=en&aq=f

Careful, though - some people are allergic.
by Charlie!
Sat Sep 10, 2011 3:08 am UTC
Forum: Science
Topic: Measurement in QM
Replies: 6
Views: 1071

Re: Measurement in QM

Yeah, calling measurement a thermodynamic process isn't really that helpful. More helpful is the idea of measurement being some interaction that gives you quantum information about the particle (information and entropy being intimately connected). Most helpful of all (to me at least) is the idea tha...
by Charlie!
Sat Sep 10, 2011 1:17 am UTC
Forum: Science
Topic: Why We Can’t Take Expected Value Estimates Literally (Even W
Replies: 15
Views: 2301

Re: Why We Can’t Take Expected Value Estimates Literally (Ev

cpt wrote:
Zamfir wrote:Nope, this is the outcome with 50% of the outcomes on both sides of it.


Do you think that the side of the coin has ever been the outcome of a coin toss?

I've done it a few times with pennies.
by Charlie!
Fri Sep 09, 2011 6:30 pm UTC
Forum: Science
Topic: Why We Can’t Take Expected Value Estimates Literally (Even W
Replies: 15
Views: 2301

Re: Why We Can’t Take Expected Value Estimates Literally (Ev

If the median outcome of getting a flu shot is "swelling, costs money, doesn't prevent the flu," that doesn't mean you shouldn't get the flu shot. Actually, if 50% of the people who get the shot experience swelling and also still get the flu, I'm going to go ahead and say there's no real ...
by Charlie!
Fri Sep 09, 2011 2:35 pm UTC
Forum: Science
Topic: Why We Can’t Take Expected Value Estimates Literally (Even W
Replies: 15
Views: 2301

Re: Why We Can’t Take Expected Value Estimates Literally (Ev

For one-off events, or things you only have a few opportunities to do, it becomes far more helpful to look at the median outcome, the quartile outcomes, and the 5th and 95th percentile outcomes. I don't think that's true. If the median outcome of getting a flu shot is "swelling, costs money, d...
by Charlie!
Thu Sep 08, 2011 8:17 pm UTC
Forum: Science
Topic: Why We Can’t Take Expected Value Estimates Literally (Even W
Replies: 15
Views: 2301

Re: Why We Can’t Take Expected Value Estimates Literally (Ev

The title is inaccurate - it's more like "when we calculate expected values, we can be really inaccurate." If the expected value estimate is correct, of course you should take it literally.
by Charlie!
Thu Sep 08, 2011 2:05 pm UTC
Forum: Science
Topic: Time Without Change
Replies: 69
Views: 8015

Re: Time Without Change

Time, as in a coordinate, doesn't care about change.

Science, which requires things to actually make a difference to the world to be real (i.e. Occam's razor), does care.
by Charlie!
Thu Sep 08, 2011 10:07 am UTC
Forum: Science
Topic: Stealing power through induction?
Replies: 11
Views: 6880

Re: Stealing power through induction?

It was probably something like this:

Image
by Charlie!
Wed Sep 07, 2011 9:10 am UTC
Forum: Science
Topic: correlation strength
Replies: 10
Views: 1498

Re: correlation strength

P-values are calculated by comparing the data to a null hypothesis, which is basically the "nothing interesting happens" model. A small p-value means "something interesting happened."
by Charlie!
Wed Sep 07, 2011 8:58 am UTC
Forum: Science
Topic: The Faucet Question
Replies: 14
Views: 2624

Re: The Faucet Question

Mmm... yes, but there you are referring to the surface tension of individual droplets, not to the surface of the whole stream, aren't you? I don't know, I always thought that a moving fluid doesn't develop surface tension, at least not so much as one that remains still. In fact, I was told that the...
by Charlie!
Wed Sep 07, 2011 12:27 am UTC
Forum: Science
Topic: The Faucet Question
Replies: 14
Views: 2624

Re: The Faucet Question

It look like a balance between pressure waves coming out from the spoon (or my finger, when I tried it) and the restoring force of surface tension. Mmmm... do you think we can talk about surface tension in a stream of falling water? Yes. For example, a thin stream of water will break into droplets ...
by Charlie!
Wed Sep 07, 2011 12:23 am UTC
Forum: Science
Topic: "Intuitive" perspective for quantum entanglement?
Replies: 121
Views: 12466

Re: "Intuitive" perspective for quantum entanglement?

Hey, I did not mean string theory! I mean Hilbert Space, a subset of which is describing things vibrationing . So, to rephrase the question, if we have a string trampoline vibrating as an example of Hilbert Space, do we not need "vibrations" in the multi-verse to be able to describe it in...
by Charlie!
Tue Sep 06, 2011 6:32 am UTC
Forum: Science
Topic: Speck of Dust
Replies: 92
Views: 12250

Re: Speck of Dust

in terms of intelligence, a small group of humans can produce systems several orders of magnitude more complex* than an entire galaxy. * by some definition of complexity You are a frog, for certain definitions of "frog," but people don't go around saying that because words mean things to ...
by Charlie!
Mon Sep 05, 2011 10:54 pm UTC
Forum: Science
Topic: The Faucet Question
Replies: 14
Views: 2624

Re: The Faucet Question

Interesting. The waves actually just stand there!

It look like a balance between pressure waves coming out from the spoon (or my finger, when I tried it) and the restoring force of surface tension.
by Charlie!
Sun Sep 04, 2011 8:50 pm UTC
Forum: Science
Topic: "Intuitive" perspective for quantum entanglement?
Replies: 121
Views: 12466

Re: "Intuitive" perspective for quantum entanglement?

Well, as long as the term "an entire universe is created" at each moment/point/observation then I guess there is no problem. As mentioned further up in the thread, saying that the multi-verses do interact at the point of observation is one thing, but we need the maths to back it up. Unles...
by Charlie!
Sat Sep 03, 2011 7:10 am UTC
Forum: Science
Topic: Speck of Dust
Replies: 92
Views: 12250

Re: Speck of Dust

by Charlie!
Fri Sep 02, 2011 9:44 pm UTC
Forum: Fictional Science
Topic: Science Fiction Technobabble Help?
Replies: 5
Views: 2508

Re: Science Fiction Technobabble Help?

1) We have a Fictional Science forum. 2) Yes, for magic-like magic you definitely need humans to be special, or need consciousness to be written into the laws of nature, or something silly like that. And of course it's silly - it's magic. 3) The cosmology section is probably too fictional. If you wa...
by Charlie!
Tue Aug 30, 2011 11:09 pm UTC
Forum: Science
Topic: "Intuitive" perspective for quantum entanglement?
Replies: 121
Views: 12466

Re: "Intuitive" perspective for quantum entanglement?

Technical Ben wrote:How can there be both a greater probability to end up with all heads, yet less outcomes ending up with all heads? I thought the two correlated.

Weighted coin.
by Charlie!
Tue Aug 30, 2011 5:54 pm UTC
Forum: Science
Topic: Question from a theist on universal beginnings and entropy
Replies: 290
Views: 23970

Re: Question from a theist on universal beginnings and entro

doogly wrote:Oh yea, obviously they wouldn't know Griffiths from Sakurai if I were throwing them at them.

Favorite thing of the day.
by Charlie!
Tue Aug 30, 2011 4:35 am UTC
Forum: Science
Topic: "Intuitive" perspective for quantum entanglement?
Replies: 121
Views: 12466

Re: "Intuitive" perspective for quantum entanglement?

But the way MWI is usually presented (as far as I've seen) suggests that an experiment with two outcomes will split into two universes, regardless of the associated probabilities of each outcome. Say you have a spin-1/2 particle. The particle is living in a Hilbert space with dimensions |up> and |d...
by Charlie!
Sun Aug 28, 2011 11:19 pm UTC
Forum: Science
Topic: "Intuitive" perspective for quantum entanglement?
Replies: 121
Views: 12466

Re: "Intuitive" perspective for quantum entanglement?

Where do the probabilities come from in MWI, then? If there are two outcomes from an event, does that mean the expectation is necessarily 50%? How can it possibly make the right predictions in that case? Important question of quantum mechanics: if you're at one spot in possibility-space and the wor...
by Charlie!
Sun Aug 28, 2011 3:57 am UTC
Forum: Science
Topic: "Intuitive" perspective for quantum entanglement?
Replies: 121
Views: 12466

Re: "Intuitive" perspective for quantum entanglement?

But if you do not get the born rule 100% of the time, you do not have identical predictions as other interpretations. Which means you aren't an "other interpretation" anymore, you're a distinct theory. Well, you "get" the Born rule in that the Born rule is still what the univers...
by Charlie!
Sun Aug 28, 2011 1:53 am UTC
Forum: Science
Topic: "Intuitive" perspective for quantum entanglement?
Replies: 121
Views: 12466

Re: "Intuitive" perspective for quantum entanglement?

Unfortunately, most observers will not derive the Born rule Well, yeah - most observers are single particles :P Okay, but really - the Born rule will be derived with high probability only if it works. Which is how it should be. And yes, that makes plenty of sense in MWI. From the inside, entangled ...
by Charlie!
Thu Aug 25, 2011 6:45 pm UTC
Forum: Science
Topic: Question from a theist on universal beginnings and entropy
Replies: 290
Views: 23970

Re: Question from a theist on universal beginnings and entro

As for a self-creating universe, that seems to violate the law of non-contradiction, that is, that something cannot be, and not be, at the same time and in the same way. A universe that does not exist has no power of action to create anything. Incidentally, if anyone feels like clarifying this part...
by Charlie!
Thu Aug 25, 2011 7:29 am UTC
Forum: Science
Topic: Question from a theist on universal beginnings and entropy
Replies: 290
Views: 23970

Re: Question from a theist on universal beginnings and entro

Yeah, we dunno. If there was a first mover, why wasn't there a zeroth mover?

In an infinite universe with certain properties, entropy will fluctuate given enough time. But the universe doesn't look like it's infinite.
by Charlie!
Thu Aug 25, 2011 5:52 am UTC
Forum: Science
Topic: What is Energy?
Replies: 21
Views: 3325

Re: What is Energy?

doogly wrote:"Actually I can make this work, cause I am a beast." - Noether (paraphrased)

Agreed - Sanjuricus, check out Noether's theorem - energy is the stuff that is conserved because the laws of physics are constant in time.
by Charlie!
Sat Aug 20, 2011 5:46 am UTC
Forum: Science
Topic: Automotive engineering question
Replies: 23
Views: 4409

Re: Automotive engineering question

Are they deer whistles? I remember my dad put a pair near there once.

"Protrusion" being nonspecific, you probably just mean a little bump, in which case I dunno.
by Charlie!
Fri Aug 19, 2011 9:50 pm UTC
Forum: Science
Topic: The Double Slit Experiment
Replies: 7
Views: 1957

Re: The Double Slit Experiment

Coffee wrote:So they fired chickens, that is, particles, and they got an interfearance pattern?
Who would expect chickens to behave like waves?

Well, they didn't really get an interference pattern. The point isn't that the experiment worked, the point is that it was funny, I think.
by Charlie!
Fri Aug 19, 2011 6:45 pm UTC
Forum: Serious Business
Topic: Is knowledge justified true belief?
Replies: 136
Views: 50246

Re: Is knowledge justified true belief?

But coin flipping is a horrible model for most situations of imperfect knowledge. It is a special case where we can use symmetry to deduce that there are two equal outcomes without hardly any necessary knowledge of the processes that actually govern the movement of the coin. [...] But most situatio...
by Charlie!
Fri Aug 19, 2011 4:52 pm UTC
Forum: Serious Business
Topic: Is knowledge justified true belief?
Replies: 136
Views: 50246

Re: Is knowledge justified true belief?

That comes suspiciously close to the perfect information assumptions that haunt this thread. In fact, probabilities are tied up very closely with im perfect information. For example, say someone flips a coin fairly and slaps it onto the back of their hand. I would assign probabilities 0.5 to heads ...
by Charlie!
Fri Aug 19, 2011 2:34 am UTC
Forum: Science
Topic: Reading Order
Replies: 6
Views: 1270

Re: Reading Order

If you don't already know the material in the more introductory physics books, of course read them first. General relativity is actually pretty separate - if you have a decent grounding in calculus and mechanics and how to work with matrices you're set, just start with something with the word "...

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