## Search found 1911 matches

Tue Oct 18, 2011 1:54 am UTC
Forum: Science
Topic: Ball probability. As in, testicles.
Replies: 21
Views: 4510

### Re: Ball probability. As in, testicles.

krogoth wrote:Can we maybe say how much we would have drank over our current lifetime? Rather than just one glass, as said before, still quite a few Olympic swimming pools light.

Dainbramage beat you to it
Mon Oct 17, 2011 8:27 pm UTC
Forum: Science
Topic: Wait, can free will exist?
Replies: 247
Views: 26439

### Re: Wait, can free will exist?

Can we test for determinism and randomness? If theoretically, the first test comes back "negative for determinism" and the second comes back "negative for randomness" then what conclusion would we make? Imagine that you could repeatably generate some system at some point in time...
Mon Oct 17, 2011 6:50 am UTC
Forum: Science
Topic: Physics homework help
Replies: 11
Views: 1659

### Re: Physics homework help

Just google "electron mass," pretty much. Any thoroughly precise report on the electron mass will include a standard deviation - uncertainties are a key part of science. The National Institute of Standards and Technology (NIST) is a go-to authority on stuff like this, so you could throw &q...
Mon Oct 17, 2011 1:39 am UTC
Forum: Science
Topic: 2D Collision with Spinning
Replies: 3
Views: 1183

### Re: 2D Collision with Spinning

The exact problem is tough - the coefficient of friction really applies to finite collision times of elastic objects. However, you might be able to approximate. The general template looks like this: (momentum transfer from friction) = (Force)*(time), and (Force) = (coefficient of friction)*(normal f...
Sun Oct 16, 2011 8:19 pm UTC
Forum: Science
Topic: Is this an accurate interpretation of quantum mechanics?
Replies: 5
Views: 1265

### Re: Is this an accurate interpretation of quantum mechanics?

So it's "intuitive" in that it is easy to imagine. But it's not intuitive because it doesn't give you an intuitive picture of what is really happening.
Sun Oct 16, 2011 7:24 am UTC
Forum: Science
Topic: Ball probability. As in, testicles.
Replies: 21
Views: 4510

### Re: Ball probability. As in, testicles.

... says someone who answered the question for the most conservative interpretation. Fixed :P EDIT - aww, ninja'd by LaserGuy. Ninja'd bit tiny'd. What would the liberal interpretation look like? Well, if humans are roughly water-neutral and all our blood flows through our testicles at some point (...
Sat Oct 15, 2011 10:50 pm UTC
Forum: Science
Topic: Ball probability. As in, testicles.
Replies: 21
Views: 4510

### Re: Ball probability. As in, testicles.

Human males usually have about 36 mL worth of testicles, so assuming water content of 70%, we get 25.2 mL. Then saying that the water (and only the water) got perfectly redistributed around the earth in the years after death, it goes into 1.4 *10^9 cubic km = 1.4*10^24 cc of water. So 1.4 going into...
Sat Oct 15, 2011 9:24 pm UTC
Forum: Science
Topic: Is this an accurate interpretation of quantum mechanics?
Replies: 5
Views: 1265

### Re: Is this an accurate interpretation of quantum mechanics?

Nope.

I'll edit or post in a fuller explanation later, but the main gist is that there's no need for "moving back and forth," and Hilbert space should be pictured the same as real space.
Fri Oct 14, 2011 1:23 am UTC
Forum: Fictional Science
Topic: Alchemy (transmutation of elements)
Replies: 36
Views: 12775

### Re: Alchemy (transmutation of elements)

Yeah, my first thought was rare earths too. Rare earth magnets means easy generators and motors, as well as mag-lev trains. Also, successful alchemy may ironically be most "successful" by getting replaced by chemistry faster. Transmutation of elements would make it clearer what elements ar...
Thu Oct 13, 2011 10:47 pm UTC
Forum: Science
Topic: How do we see the CMBR?
Replies: 18
Views: 2391

### Re: How do we see the CMBR?

We are not the center of the universe. You already know this, I bet, but you may not be aware of its many uses :D So when the matter in the universe became mostly transparent, all this radiation suddenly started spreading out freely, from every point, in every direction. It's true that there is an e...
Tue Oct 11, 2011 7:28 pm UTC
Forum: Science
Topic: Giant cuttlefish eats ichthyosaurs
Replies: 9
Views: 2940

### Re: Giant cuttlefish eats ichthyosaurs

Gotta be extra careful of things that you wish were true. As far as I've seen, the only evidence of this is some vertebrae in a "suggestive" formation. But dig up enough fossils and human pareidolia guarantees you something "suggestive."
Sun Oct 09, 2011 8:58 pm UTC
Forum: Science
Topic: Helping an ecologist/wildlife biologist understand physics--
Replies: 7
Views: 1645

### Re: Helping an ecologist/wildlife biologist understand physi

It's hard for a creative thinker to stay motivated in doing such dull labour. Perhaps it helps to know that physics majors are often motivated by the feeling that solving an equation is associated with some fundamental sense of correctness. Hence, the realization that they become skilled in solving...
Sun Oct 09, 2011 6:35 am UTC
Forum: Science
Topic: Helping an ecologist/wildlife biologist understand physics--
Replies: 7
Views: 1645

### Re: Helping an ecologist/wildlife biologist understand physi

Enjoying the idea of physics and enjoying physics are somewhat different. The second is lots of work, sadly. I think one component for enjoying physics is to do so much gut-checking that you get really good at it. By gut-checking I mean solving problems, and every time asking: Are the units right? W...
Tue Oct 04, 2011 7:42 pm UTC
Forum: Science
Topic: "borrowing" energy
Replies: 25
Views: 3827

### Re: "burrowing" energy

I think it's like quantum tunneling. So you can do things that, classically, would have required violation of conservation of energy, but the probability decreases exponentially with the amount of energy * the amount of time. "Uncertainty relation" usually refers to the useful fact about f...
Mon Oct 03, 2011 6:41 am UTC
Forum: Science
Topic: Jack Horner wants to make dinosaurs out of chickens
Replies: 35
Views: 6264

### Re: Jack Horner wants to make dinosaurs out of chickens

It sounds like you're agreeing with me here, that Horner can't make a full dinosaur. Well, yeah. I don't think anyone was seriously suggesting he'd make a full and complete dinosaur by flipping a few genetic switches. I think Izzawlgood in fact denied that he wouldn't (for sufficiently un-true-scot...
Mon Oct 03, 2011 6:35 am UTC
Forum: Science
Topic: Well, this could change things (neutrinos)
Replies: 289
Views: 43814

### Re: Well, this could change things (neutrinos)

YoungStudent wrote:What if they speed up for some time when they change between types?

Makes much less sense than all types travelling faster than c, and doesn't solve the problem of the measurements form the supernova.
Sun Oct 02, 2011 5:25 am UTC
Forum: Science
Topic: Well, this could change things (neutrinos)
Replies: 289
Views: 43814

### Re: A hypothesis

gmalivuk wrote:
Deadcode wrote:What if the neutrinos oscillate between traveling slightly slower than light and slightly faster than light?
That seems even less likely than that neutrinos always travel a bit faster than light, actually.

I suppose you could have different flavors of neutrinos travel at different velocities.
Sun Oct 02, 2011 5:08 am UTC
Forum: Science
Topic: Jack Horner wants to make dinosaurs out of chickens
Replies: 35
Views: 6264

### Re: Jack Horner wants to make dinosaurs out of chickens

If you read the quote I posted above, chickens lack the gene for enamel. So it's a little more work than turning on some genes. I'm not sure why you're pointing this out. I'm not claiming switching on a single gene will make a chicken a T-rex, I'm saying what the article is; that switching on a sin...
Sat Oct 01, 2011 5:57 pm UTC
Forum: Science
Topic: Jack Horner wants to make dinosaurs out of chickens
Replies: 35
Views: 6264

### Re: Jack Horner wants to make dinosaurs out of chickens

I just assume that Horner did not succeeded yet Again, look at the article; there is an image of two chicken skulls, one of which has teeth buds coming from it's beak. This isn't a dino-rooster, but it's a pretty good proof of concept. Of the dozens and dozens of parts of things needed to be done, ...
Fri Sep 30, 2011 7:56 pm UTC
Forum: Science
Topic: Jack Horner wants to make dinosaurs out of chickens
Replies: 35
Views: 6264

### Re: Jack Horner wants to make dinosaurs out of chickens

EDIT: I just perused this particular article, and I wager mfb hasn't. There is an image of a bird skull with toothbuds. As it says in the article: “Development has the capacity to remake a lot of things,” Harris says. “But what you lose are some of the last bits, like enamel and dentine, that are s...
Wed Sep 28, 2011 7:32 am UTC
Topic: Is knowledge justified true belief?
Replies: 136
Views: 50667

### Re: Is knowledge justified true belief?

Meh, the thread was kinda over from the beginning. But then, if we needed a point to talk about things, we'd never get anywhere
Mon Sep 26, 2011 1:42 am UTC
Forum: Science
Topic: stationary hovering
Replies: 12
Views: 2035

### Re: stationary hovering

I've done a 3d testbed using jbullet, using a basic pid work, but i want understand if i can find out the physic formula, for hovering and maybe for "brake" To rotate you can just "move" force from some rotors to others. Think of it like hovering being the "zero point,"...
Sun Sep 25, 2011 1:42 am UTC
Forum: Fictional Science
Topic: Portals that don't allow you to create energy
Replies: 22
Views: 6974

### Re: Portals that don't allow you to create energy

So I had an idea for a miniseries that I might (but probably won't) write one day. Basically the invention of a portal technology allows man to travel to distant worlds by sending these portals on rockets at .25c (well, nanobots that land on a planet and build the portal to launch into space). Now,...
Sun Sep 25, 2011 12:17 am UTC
Forum: Science
Topic: How Does A Bike Work?
Replies: 20
Views: 4469

### Re: How Does A Bike Work?

Wheels of finite width and curvature help a bike stay up too. When the bike tilts, the inside goes farther than the outside, so it helps turn the bike into the tilt and keep it upright.
Sat Sep 24, 2011 5:52 pm UTC
Forum: Books
Topic: xkcd's favourite 100 books - vote now!
Replies: 226
Views: 176547

### Re: xkcd's favourite 100 books - vote now!

Intentionally ones not yet on the list:

Kingdoms of the Wall - Robert Silverberg
The Mote in God's Eye - Larry Niven and Jerry Pournelle
Earthsea trilogy - Ursula Le Guin
The Time Traveller's Wife - Audrey Niffenegger
Fri Sep 23, 2011 3:11 pm UTC
Forum: Science
Topic: Time Without Change
Replies: 69
Views: 8218

### Re: Time Without Change

Can we have co-ordinate space, too? Can you show me a point in the universe with an absolute x-y-z co-ordinate, one by which the universe moves around as it remains fixed? Yeah, sure. I hereby define myself to be 0,0,0 in my coordinate system! Because you're suggesting an absolute time Nope. I here...
Thu Sep 22, 2011 10:48 pm UTC
Forum: Science
Topic: Time Without Change
Replies: 69
Views: 8218

### Re: Time Without Change

I have added my reasons for being annoyed in an edit.
Thu Sep 22, 2011 10:34 pm UTC
Forum: Science
Topic: Time Without Change
Replies: 69
Views: 8218

### Re: Time Without Change

I'm saying that in a deterministic universe, saying it "could have" had an impact isn't a good way for classifying hypotheses, because, by determinism, it was never going to have an impact. Then you still seem to be saying it isn't a good hypothesis to claim that those dice didn't all com...
Thu Sep 22, 2011 9:08 pm UTC
Forum: Science
Topic: Time Without Change
Replies: 69
Views: 8218

### Re: Time Without Change

It means, at the very least, that it could have had an impact on observations made at the appropriate time. But it didn't. In a deterministic universe, it not having had an impact on our observations is equivalent to it not being possible, given that model of the universe. What? If I shake a box of...
Thu Sep 22, 2011 3:42 pm UTC
Forum: Science
Topic: Time Without Change
Replies: 69
Views: 8218

### Re: Time Without Change

It means, at the very least, that it could have had an impact on observations made at the appropriate time. But it didn't. In a deterministic universe, it not having had an impact on our observations is equivalent to it not being possible, given that model of the universe. That is to say, the hypot...
Thu Sep 22, 2011 1:15 pm UTC
Forum: Science
Topic: Time Without Change
Replies: 69
Views: 8218

### Re: Time Without Change

Would you say it's unlikely that this ever so slightly unfair coin I tossed 100 times between 1800 and 1874 came up heads every time? And yet, that is the single most likely sequence of tosses possible, out of all 2 100 of the mutually exclusive scenarios. Sure, it's the most likely single outcome ...
Thu Sep 22, 2011 2:36 am UTC
Forum: Science
Topic: Time Without Change
Replies: 69
Views: 8218

### Re: Time Without Change

But you're not talking about a Russell's teapot scenario here, since that's actually a testable hypothesis that can potentially make a difference to our observations. You're talking about a truly untestable claim. Okay, then - how about a teapot having orbited the sun between earth and mars for a d...
Wed Sep 21, 2011 11:41 pm UTC
Forum: Science
Topic: Time Without Change
Replies: 69
Views: 8218

### Re: Time Without Change

"what if our perceptions aren't coming from reality, but are instead generated by an evil demon?" is a totally valid question, it's just that reality is more probable than evil demons by Occam's razor. What? Since when has Occam's razor said anything about probability? If I say that by Oc...
Wed Sep 21, 2011 5:32 pm UTC
Forum: Science
Topic: Time Without Change
Replies: 69
Views: 8218

### Re: Time Without Change

The whole point of Boltzmann brains is that their raw probabilities of creating an insanely unlikely fluctuation nevertheless totally dwarf the probability of having a universe as it seems to be. If you start with a maximum-entropy universe and look for some numbers (is there a brain that looks lik...
Wed Sep 21, 2011 2:42 pm UTC
Forum: Science
Topic: Time Without Change
Replies: 69
Views: 8218

### Re: Time Without Change

Maybe our demon has a much simpler universe but a very creative mind. To specify our observations within the scope of a "creative mind" still requires all the information of our observations, at the very least. For that one all you need is randomly fluctuating stuff lying around long enou...
Wed Sep 21, 2011 12:04 pm UTC
Forum: Science
Topic: Time Without Change
Replies: 69
Views: 8218

### Re: Time Without Change

Argency wrote:or was that not the question?

It's roughly analogous to the question Good explanation.
Tue Sep 20, 2011 10:50 am UTC
Forum: Science
Topic: Time Without Change
Replies: 69
Views: 8218

### Re: Time Without Change

"what if our perceptions aren't coming from reality, but are instead generated by an evil demon?" is a totally valid question, it's just that reality is more probable than evil demons by Occam's razor. Oh yeah? What's your measure? And never mind the Boltzmann brains. My measure's about 6...
Mon Sep 19, 2011 8:00 pm UTC
Forum: Science
Topic: Time Without Change
Replies: 69
Views: 8218

### Re: Time Without Change

I think there are still different levels being discussed. If by "memory" what is meant is something much broader than consciousness, more like "how physics moves particles around", the point holds. That's the brain-in-a-vat level of discussion which this thread has been wading i...
Mon Sep 19, 2011 9:20 am UTC
Forum: Science
Topic: Time Without Change
Replies: 69
Views: 8218

### Re: Time Without Change

You can't have an observed time without some coordinate "t" chugging away in the background, which already has the perfectly serviceable name of "coordinate time" or just "time." Dunno what's so bad about primitive notions. Maybe they're too understandable?
Sun Sep 18, 2011 9:10 am UTC
Forum: Science
Topic: Wavelength in finite potential well
Replies: 7
Views: 5406

### Re: Wavelength in finite potential well

never mind me -- was unhelpful.