Search found 2201 matches

by thoughtfully
Fri Sep 05, 2014 2:59 am UTC
Forum: Science
Topic: A proof that hyperspace cannot transport matter
Replies: 26
Views: 6437

Re: A proof that hyperspace cannot transport matter

Yeah, but we already broke conservation of energy. That kinda opens things up for perpetual motion devices and painfully twerking thermodynamics.
by thoughtfully
Thu Sep 04, 2014 8:23 pm UTC
Forum: Science
Topic: Fuck Dark Matter; It's a sprinkler, not a whirlpool.
Replies: 135
Views: 27686

Re: Fuck Dark Matter; It's a sprinkler, not a whirlpool.

Quizatzhaderac wrote:How an over spinning black hole could form is another question.

http://arxiv.org/abs/gr-qc/0506129
tl;dr the cosmic prudes can probably relax.
by thoughtfully
Sun Aug 31, 2014 1:29 am UTC
Forum: Coding
Topic: The "IT DOESN'T WORK!" thread
Replies: 1963
Views: 573247

Re: The "IT DOESN'T WORK!" thread

Code: Select all

#undef __cplusplus


Alas, if only making C++ go away were so easy!
by thoughtfully
Fri Aug 22, 2014 3:34 pm UTC
Forum: Science
Topic: Why is it hard to get things cold?
Replies: 15
Views: 4805

Re: Why is it hard to get things cold?

Part of the problem seems to be the distinction between making a hot reservior by toppling over a big pile (generally chemical) of potential energy, versus the lack of convenient access to cold reservoirs. But this is just a recapitulation of thermodynamics. Systems at a high potential tend to get r...
by thoughtfully
Fri Aug 22, 2014 3:25 pm UTC
Forum: Science
Topic: Definition of Structure
Replies: 10
Views: 3813

Re: Definition of Structure

I'll submit a candidate definition. Structure is low entropy. A homogeneous, isotropic cloud of gas does not have much structure.
by thoughtfully
Wed Aug 06, 2014 7:06 pm UTC
Forum: Science
Topic: Radioactive decay can be influenced?
Replies: 9
Views: 2840

Re: Radioactive decay can be influenced?

Not what is usually meant by radioactivity, but you might find this apropos:
http://en.wikipedia.org/wiki/Induced_gamma_emission
by thoughtfully
Wed Aug 06, 2014 1:14 pm UTC
Forum: Science
Topic: Radioactive decay can be influenced?
Replies: 9
Views: 2840

Re: Radioactive decay can be influenced?

Radioactivity of heavy isotopes isn't fundamental like a muon decaying into an electron. It's really quite messy inside a large nucleus. Nuclei generally do their own thing independently of what's going on around them, since they are pretty heavy and the strong force is dominant and short range, but...
by thoughtfully
Sat Aug 02, 2014 11:53 am UTC
Forum: Science
Topic: Miscellaneous Science Questions
Replies: 2962
Views: 732143

Re: RELATIVITY QUESTIONS! (and other common queries)

Naive response here, but from simply geometrical arguments, I'd say yes. The circumference of a circle gets longer when its radius increases. The area of the sheet is larger when it's distended. That part of the analogy doesn't go away when you add dimensions and remove the higher dimensional space ...
by thoughtfully
Fri Aug 01, 2014 8:09 pm UTC
Forum: Science
Topic: Speculative biology -- the affairs of dragons
Replies: 33
Views: 10741

Re: Speculative biology -- the affairs of dragons

Holy mother of It's a common practice to depict dinosaurs and the like in improbably upright postures to elicit the maximum response. Could that critter really support itself upright as shown? Would it have impressed you as much if it was shown rather more horizontally? A grizzly standing up is rat...
by thoughtfully
Fri Aug 01, 2014 3:47 am UTC
Forum: Science
Topic: "Fat" Universe Theory
Replies: 50
Views: 7930

Re: "Fat" Universe Theory

My take on math is this: math is a useful way to organize and manipulate observations (at least the helpfully quantifiable ones), and is connected to "reality" only insofar as the observations (the helpfully quantifiable ones) are, which is another philosophical debate. Personally, I find ...
by thoughtfully
Mon Jul 28, 2014 3:26 pm UTC
Forum: Science
Topic: "Fat" Universe Theory
Replies: 50
Views: 7930

Re: "Fat" Universe Theory

Right, and the difference is that if the space itself is expanding, everything can move away from everything else, homogeneously and isotropically. I personally think that the universe isn't physical, and is just an illusion generated by math. We're pure math. Nothing but math. xD Ok, I can see how...
by thoughtfully
Mon Jul 21, 2014 10:23 pm UTC
Forum: Science
Topic: Why is cosmological inflation necessary?
Replies: 15
Views: 4122

Re: Why is cosmological inflation necessary?

The monopole thing is basically just that we haven't found any although our current particle physics theories strongly suggest that they should be formed in the early universe in large amounts. What? Not in any verified theories, but stuff like monopoles (and other topological defects), baryon nonc...
by thoughtfully
Mon Jul 21, 2014 7:08 pm UTC
Forum: Science
Topic: How do gravitational waves form?
Replies: 11
Views: 2795

Re: How do gravitational waves form?

The most intuition-friendly hint on gravitational waves I've seen is that a cylinder spinning along its axis does not emit them, but one spinning end-over-end (fixed rotational axis, passing through center) does. It isn't exhaustive, but maybe it's a start.
by thoughtfully
Tue Jul 08, 2014 6:26 pm UTC
Forum: Science
Topic: The limitations of the scientific method
Replies: 6
Views: 2564

Re: The limitations of the scientific method

Science is about studying and understanding the natural world. The key idea is that all science begins and ends with data. Something observable. In this physical sciences, these are concrete measurements, in the social sciences, it's a little fuzzier. Human behavior and their prejudices and thinking...
by thoughtfully
Sat Jul 05, 2014 8:15 pm UTC
Forum: Science
Topic: "Things I Won't Work With" (Derek Lowe's Chemistry Blog)
Replies: 60
Views: 52600

Re: "Things I Won't Work With" (Derek Lowe's Chemistry Blog)

Oh yes. The number of ways chemists have discovered to kill or maim themselves is truly mind-blowing, sometimes literally. Turning nitroglycerine into a practical product is how Alfred Nobel made his fortune, after all. Mostly for mining and demolition, but I'm sure he had military customers as well...
by thoughtfully
Wed Jun 18, 2014 4:04 pm UTC
Forum: Science
Topic: Toffo Talks about Trains
Replies: 128
Views: 19318

Re: Energy of transition in accelerating transportation

Another way to look at this is to use the Equivalence Principle. You and the train are accelerating, and this is equalent to an increase (and change in direction, since it isn't inline with existing gravity) of your weight. It's like pulling yourself up a ladder (or climbing stairs, whatever) while ...
by thoughtfully
Wed Jun 04, 2014 5:29 pm UTC
Forum: Science
Topic: two black holes and path 'through' 'event horizons'?
Replies: 24
Views: 5603

Re: two black holes and path 'through' 'event horizons'?

There was a paper that used Loop Quantum Gravity that suggested that when a naked singularity is forming, space develops a large negative pressure that causes it to dissipate. I never can seem to find it again when I go looking. I'm pretty sure it was on arXiv.
by thoughtfully
Sat May 24, 2014 1:11 pm UTC
Forum: Science
Topic: how does dna code the structural components of an organism
Replies: 4
Views: 1358

Re: how does dna code the structural components of an organi

A useful mental exercise is to consider a colony of unspecialized single-celled critters, and how they might get started with that multicellular thing.
by thoughtfully
Fri May 23, 2014 1:12 pm UTC
Forum: Science
Topic: Highest purity water and materials
Replies: 15
Views: 4485

Re: Highest purity water and materials

Bacteria are huge. They can be removed with a sieve, that's how viruses were discovered. Maybe you meant viruses.
by thoughtfully
Sat May 17, 2014 12:23 am UTC
Forum: Science
Topic: A new way to produce hydroelectricity
Replies: 38
Views: 9493

Re: A new way to produce hydroelectricity

No references or bibliography, and the thing is its own blog, not something an existing blogger wrote. Smells pretty funny.

Then there's all the classic confusion between power and energy units.
by thoughtfully
Thu May 15, 2014 3:35 am UTC
Forum: What If?
Topic: What-If 0096: "$2 Undecillion Lawsuit"
Replies: 65
Views: 20506

Re: What-If 0096: "$2 Undecillion Lawsuit"

I'm a little disappointed that Randall didn't get compounding interest involved in some way, especially since exponential growth figures into several other What Ifs. All you'd need to do is invest a few bucks in China, and wait umm.. Trying to mind my sig figs, can't be bothered to go look it up...
by thoughtfully
Sun May 11, 2014 4:09 pm UTC
Forum: Science
Topic: Was Pluto Ever a Planet?
Replies: 8
Views: 2233

Re: Was Pluto Ever a Planet?

It was historical context more than anything. The hunt was on for a "Planet X" when Pluto was discovered. That Pluto was an overgrown comet with delusions of grandeur was not discovered until later. It turns out that the motivation for the hunt was based on imprecise data, anyway. http://e...
by thoughtfully
Sat May 10, 2014 4:19 pm UTC
Forum: Science
Topic: Plants - you learn something new every day (well I do).
Replies: 15
Views: 2916

Re: Plants - you learn something new every day (well I do).

Now that, I'm relieved to say, I knew. I think it was the basis of the notion that you should remove plants from hospital wards at night... I've never heard this; my hunch is it has more to do with allergens/microbes. The amount of oxygen a handful of plants generate over the course of a night in a...
by thoughtfully
Sat May 10, 2014 10:30 am UTC
Forum: Science
Topic: Plants - you learn something new every day (well I do).
Replies: 15
Views: 2916

Re: Plants - you learn something new every day (well I do).

Something else that's generally overlooked is that plants do consume O 2 when they metabolize those carbohydrates for energy. Aerobic respiration, same as the rest of us eukaryotes (modulo some freaky fungi). Their cellular processes need ATP, and can't run directly on sunlight any more than ours can.
by thoughtfully
Thu May 08, 2014 9:39 pm UTC
Forum: Science
Topic: Help Feynman's Dad
Replies: 32
Views: 6460

Re: Help Feynman's Dad

The "before" and "after" approach seems to be best to me. Trying to interpret complicated formalisms that most of us without a graduate degree don't fully understand anyway is just awkward and confusing. It may be a little unstaisfying to Feynman's dad, but sometimes we have to a...
by thoughtfully
Mon May 05, 2014 2:07 pm UTC
Forum: Science
Topic: Orbital coilgun accelerator
Replies: 38
Views: 5979

Re: Orbital coilgun accelerator

It seems to me that balance is going to matter a lot. If the mass of ferromagnetic material is not centered fairly well on the center of mass, erratic trajectories could result. And how much of the ferromagnetic mass has to be mechanically bonded to the superstructure? Coil guns are great for accele...
by thoughtfully
Sun Apr 27, 2014 9:25 am UTC
Forum: Science
Topic: Clarification on event horizons of black holes
Replies: 32
Views: 5289

Re: Clarification on event horizons of black holes

Inside an event horizon, space and time are rotated such that instead of all paths leading to the future, all paths leads to the singularity.
by thoughtfully
Fri Apr 25, 2014 10:02 pm UTC
Forum: Science
Topic: Clarification on event horizons of black holes
Replies: 32
Views: 5289

Re: Clarification on event horizons of black holes

Any signal sent from the vicinity of an event horizon (outsde, of course) is going to be redshifted, and the degree of shiftiness approaches infinity as the source approaches the horizon. Infinite wavelength equals no signal, and it becomes practically undetectable rather sooner, depending on the re...
by thoughtfully
Thu Apr 24, 2014 3:58 am UTC
Forum: Science
Topic: Relativistic rod passing over a gap.
Replies: 19
Views: 3490

Re: Relativistic rod passing over a gap.

In the rest frame of the object, sound travels as you'd expect; there's no motion. The usual velocity addition formulas will apply to other observers moving at some significant fraction of the speed of light.
by thoughtfully
Mon Apr 21, 2014 10:08 pm UTC
Forum: Science
Topic: Global Thermodynamics
Replies: 20
Views: 3284

Re: Global Thermodynamics

I think saying "weather is driven by energy flux from solar radiation" is a gross oversimplification of the system to the point of being wrong. I think it's been pointed out, but it bears repeating. The energy for weather comes from the Sun, but the cause of weather is the temperature dif...
by thoughtfully
Mon Apr 21, 2014 12:21 pm UTC
Forum: Science
Topic: Optical telescope arrays
Replies: 3
Views: 1275

Re: Optical telescope arrays

EDIT: Oops, I'm not sure how the extra post got here. Sorry!
by thoughtfully
Mon Apr 21, 2014 12:13 pm UTC
Forum: Science
Topic: Optical telescope arrays
Replies: 3
Views: 1275

Re: Optical telescope arrays

The basic answer is wavelength. Radio telescopes work with wavelengths millimeters to tens of meters long, while visible light has a wavelength of 100s of nanometers. With inteferometric arrays, the resolution does depend on the baseline. The light-gathering ability is simply the sum of each of the ...
by thoughtfully
Mon Apr 21, 2014 4:27 am UTC
Forum: Science
Topic: Global Thermodynamics
Replies: 20
Views: 3284

Re: Global Thermodynamics

It might be at 100 degrees for most intents and puposes, but it starts cooling as soon as you remove the heat. To the point regarding weather. Having more heat around increases the severity of storms, that's pretty well established. A system in equilibrium with its environment can still have interna...
by thoughtfully
Sun Apr 20, 2014 12:26 am UTC
Forum: Science
Topic: VOC's in the home, need help
Replies: 3
Views: 1660

Re: VOC's in the home, need help

It's "outgassing", and it's real. It's where "new car smell" comes from. It can be a real problem in applications that require very hard vacuums. It could affect your lung problems, but I'd take caution to not get carried away. Instruments have gotten so sensitive that things are...
by thoughtfully
Fri Apr 18, 2014 4:38 pm UTC
Forum: Science
Topic: Return of the LHC
Replies: 7
Views: 2190

Re: Return of the LHC

Depends on what you mean by exotic. In a sense, anything beyond protons/neutrons/electrons is exotic. It sure isn't the "exotic matter" one hears about in connection with wormholes, that has negative energy.
by thoughtfully
Thu Apr 17, 2014 10:21 pm UTC
Forum: Science
Topic: Return of the LHC
Replies: 7
Views: 2190

Re: Return of the LHC

This news is about a week old, but pretty neat if you missed it. Looks like a tetraquark, c/c-bar/d/u-bar being the most likely combination. http://www.quantumdiaries.org/2014/04/09/major-harvest-of-four-leaf-clover/ As is de rigeur for pop science, it doesn't live up to the hype. No thoroughly vett...
by thoughtfully
Wed Apr 16, 2014 11:46 am UTC
Forum: Science
Topic: Global Thermodynamics
Replies: 20
Views: 3284

Re: Global Thermodynamics

* The sun's average energy output hasn't varied significantly in the last several centuries nor is it expected to vary in the near future. Yes and no. The amount of energy the sun emits increases slowly as it ages. I can't find the details but I believe it is around a percent per 1000 years. This d...
by thoughtfully
Wed Apr 16, 2014 4:07 am UTC
Forum: Science
Topic: 1 in 4 Americans Apparently Unaware the Earth Orbits the Sun
Replies: 46
Views: 8770

Re: 1 in 4 Americans Apparently Unaware the Earth Orbits the

That said, there are two things that precision errors mean: the inability of the fractional portion of a binary number to accurately be converted to the fractional portion of the decimal number, I don't really think this one counts. It's a conversion error, and not fundemental. It's an artifact of ...
by thoughtfully
Tue Apr 15, 2014 7:37 pm UTC
Forum: Science
Topic: 1 in 4 Americans Apparently Unaware the Earth Orbits the Sun
Replies: 46
Views: 8770

Re: 1 in 4 Americans Apparently Unaware the Earth Orbits the

The cooking rice question is a little obtuse. As the question points out explicitly in each answer choice, the boiling point of water is lower. The knowledge you are tested on is that the boiling point puts a ceiling on the temperature of the water the rice is immersed in. The other bit of implicit ...

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