Search found 441 matches

by Goemon
Tue May 10, 2016 12:23 am UTC
Forum: Science
Topic: Alkaline Food
Replies: 26
Views: 7766

Alkaline Food

A friend was telling me about his troubles with excessive stomach acid (potentially leading to heartburn, acid reflux, etc) so I was thinking that people with that sort of difficulty should try to eat alkaline foods to help counteract the acid. So I did a quick search, and ... there aren't any. At l...
by Goemon
Mon May 09, 2016 12:33 am UTC
Forum: Science
Topic: Phoenix Energy
Replies: 4
Views: 2081

Phoenix Energy

http://www.al.com/news/index.ssf/2016/05/phoenix_energy_wants_to_buy_be.html http://www.freeenergynews.com/Directory/Induction/PENV/PENV_Rev-4_Induction-Energy_Re-Heat_Stm-Waste-Ht-Energy-Recov-Electric-Pwr-Plant_11-1-2015.pdf Ok, am I missing something here? It looks like this company is in the ru...
by Goemon
Wed May 04, 2016 3:57 am UTC
Forum: Science
Topic: Does potential energy have mass?
Replies: 78
Views: 15832

Re: Does potential energy have mass?

- The objects fall towards each other - each gaining kinetic energy and hence mass. - As they do so, the pairing loses potential energy, and hence mass. An accurate description from a Newtonian point of view. But as Doogly noted earlier, from a General Relativity point of view, there's no such thin...
by Goemon
Thu Apr 07, 2016 2:35 am UTC
Forum: Science
Topic: Recyclable Pudding
Replies: 3
Views: 2072

Recyclable Pudding

For no particular reason, I was wondering if it's possible to make "rechargeable" food. Suppose you have a supply of inert pudding-like substance that you suffuse with some digestible energy source, e.g. simple sugars. Eat the pudding. The digestive tract extracts the sugars and the inert ...
by Goemon
Tue Apr 05, 2016 1:58 am UTC
Forum: Science
Topic: Does potential energy have mass?
Replies: 78
Views: 15832

Re: Does potential energy have mass?

"Gravity" lives on the left side. You don't count Newtonian style gravitational potential energy on the right side, because that sort of thing is already on the left side. Then puzzle me this (from farther up this thread): Let's take a spherical volume of space 1 light second across. Our ...
by Goemon
Sat Feb 13, 2016 8:10 pm UTC
Forum: Mathematics
Topic: INT Function
Replies: 13
Views: 3263

Re: INT Function

Yep, modulo is more or less the same function we're looking for. What about checking whether sin(πx) is zero? Actually, I kind of like that. It might not actually provide a solution any faster - don't think you can calculate sin exactly in finite steps - but at least hints that there is something to...
by Goemon
Sat Feb 13, 2016 8:01 pm UTC
Forum: Science
Topic: LIGO Gravity Waves: Questions and Answers
Replies: 49
Views: 9179

Re: LIGO Gravity Waves: Questions and Answers

If you have two neutrons 1km apart, then a passing gravitational wave will physically change the distance between them: the actual measured distance will oscillate, becoming momentarily and alternately slightly less than 1km and slightly more than 1km. If you have a physical ruler stuffed in between...
by Goemon
Wed Feb 10, 2016 3:11 am UTC
Forum: Mathematics
Topic: INT Function
Replies: 13
Views: 3263

Re: INT Function

So basically, the only way to tell if a number x is an integer is by saying "is it equal to zero? No? Well then, is it equal to 1? No? How about 2? How about three?" And just continue until either you hit upon a "yes" or you get to a number that's larger than x. (Reverse for x<0)...
by Goemon
Wed Feb 10, 2016 3:04 am UTC
Forum: Mathematics
Topic: Trying to divide a spherical shell into equal-volume "wedges
Replies: 4
Views: 3930

Re: Trying to divide a spherical shell into equal-volume "we

Your pattern of "number of slices in each shell" is actually kind of interesting because you (not coincidentally) get the same pattern in two dimensions if you do this (you can demonstrate to yourself with a collection of pennies or similar coins, or examine a hexagonal game board): Start ...
by Goemon
Thu Feb 04, 2016 4:16 am UTC
Forum: Mathematics
Topic: INT Function
Replies: 13
Views: 3263

INT Function

I'm thinking of a real number x. Is there a procedure/program that given x as an input, can perform a finite series of arithmetic operations (addition, subtraction, multiplication, division) and simple comparison operations ( =, <, >) on x to determine whether or not x is an integer? After thinking ...
by Goemon
Thu Feb 04, 2016 4:07 am UTC
Forum: Mathematics
Topic: Infinite balls
Replies: 6
Views: 2573

Infinite balls

What's this puzzle/conundrum/paradox called? Procedure: for each iteration k, Alice throws balls numbered 2k and 2k+1 into a room. Bob then removes ball k. i.e, Step 0: Alice Adds balls 0, 1; Bob removes ball 0; room contains ball 1 Step 1: Alice adds 2, 3; Bob removes 1; room contains 2, 3 Step 2: ...
by Goemon
Fri Nov 27, 2015 5:21 pm UTC
Forum: Mathematics
Topic: Record High/Low
Replies: 3
Views: 1780

Record High/Low

We frequently see news noting that today's temperature is a record high (or low). Seems like we see that quite a lot. So I got to wondering... how often should such events occur? For a given location, there are more than 700 record high/low temperatures that might be broken each year - a high and a ...
by Goemon
Sun Apr 19, 2015 2:27 am UTC
Forum: Science
Topic: Earth's trajectory if the sun disappeared...?
Replies: 48
Views: 10738

Re: Earth's trajectory if the sun disappeared...?

eSOANEM wrote: It then takes on the order of a third of a picosecond for the potential to reach 0.


How did you calculate that?
by Goemon
Fri Mar 20, 2015 3:09 am UTC
Forum: Science
Topic: Deadlifter
Replies: 17
Views: 4379

Deadlifter

Got to wondering... how cheaply could you make rockets intended to lift dead weight? That is, suppose you want to haul a LOT of dead weight such as water, fuel, girders, concrete or whatever up to low Earth orbit, and you don't really care all that much if an individual rocket fails/explodes/crashes...
by Goemon
Fri Mar 20, 2015 2:57 am UTC
Forum: Science
Topic: Sea level rising Question
Replies: 11
Views: 2682

Re: Sea level rising Question

That's a global variation of a foot and a half, meaning it could be a bit over 5' in some places and a bit under 7' in others, so I don't see why there would have to be more going on than that to justify the wording choice. I didn't quite follow that... seems to me that if the average global variat...
by Goemon
Fri Feb 06, 2015 6:57 am UTC
Forum: Science
Topic: How long can we (human society) survive global warming?
Replies: 67
Views: 13245

Re: How long can we (human society) survive global warming?

There is no objective reason for calling technological progress "fast" or "slow." Not only is there no objective way to measure that,... Poppycock. 1. Seventy years ago antibiotics were our primary tool for fighting bacterial infections. In 2015 . . . they still are. But the las...
by Goemon
Thu Dec 11, 2014 3:57 am UTC
Forum: Science
Topic: Miscellaneous Science Questions
Replies: 2958
Views: 720793

Re: RELATIVITY QUESTIONS! (and other common queries)

So, when we put an object in our hypothetical railgun of infinite length and give it some truly absurd velocity... since we have absurd mass + small volume we have a black hole. Suppose we put YOU in the railgun. When your velocity becomes absurd and you measure the size and mass of the Earth, you ...
by Goemon
Sat Dec 06, 2014 7:02 pm UTC
Forum: Science
Topic: Charge Distribution in Fluid
Replies: 7
Views: 2826

Re: Charge Distribution in Fluid

Assuming a "perfect" insulating mechanism that prevents charge from moving between solution and plates, and that the ions are otherwise free to move throughout the solution (ie, conduct), then i think the end result would be equivalent to a pair of 1m x 1m parallel plate capacitors in seri...
by Goemon
Tue Nov 25, 2014 6:01 am UTC
Forum: Science
Topic: Smart Dinosaurs
Replies: 10
Views: 3587

Smart Dinosaurs

We (humans) generally tend to think that intelligence is some kind of evolutionary trump card. So I'm kinda curious why it is that dinosaurs and their kin dominated planet Earth for a couple of hundred million years, but it seems like none of them ever got past the "brain the size of a pea"...
by Goemon
Fri Nov 14, 2014 6:44 am UTC
Forum: Science
Topic: G-force
Replies: 16
Views: 4130

Re: G-force

suppose you have a 1mL thin-walled vacuum cavity attached with a piece of string to a 1mL ball of something twice as dense as water... Hmmm... if our "spherical cow" model a human body is a skeleton with a multitude of individual 1ml blobs of tissue hanging from it by tiny rubber bands, t...
by Goemon
Sat Nov 08, 2014 4:03 pm UTC
Forum: Science
Topic: G-force
Replies: 16
Views: 4130

Re: G-force

I wonder what kind of acceleration would be necessary in your described regime (accelerating all atoms individually) to distort electron orbitals within atoms, to the point of causing damage. Its probably very high, if it is possible at all. Does happen in nature , though not due to acceleration in...
by Goemon
Mon Oct 20, 2014 4:12 am UTC
Forum: Science
Topic: Skunk Works reveals compact fusion reactor?
Replies: 47
Views: 8883

Re: Skunk Works reveals compact fusion reactor?

Sounds like most of the physics of fusion is well understood, but there are too many engineering problems standing in the way of using it as a practical power source. So who knows - maybe the Skunk Works can makes some progress where teams of the world's best physicists get stuck, given that they ar...
by Goemon
Mon Oct 06, 2014 4:44 am UTC
Forum: Science
Topic: Just a Second
Replies: 1
Views: 1813

Just a Second

My car just turned over 186,282 miles, which for those of you in more civilized portions of the world translates to 299,792 km. It took ten years of commuting for me to travel the distance that light covers in a single second. If driven continuously (instead of an hour or so per day), it would take ...
by Goemon
Wed Sep 24, 2014 1:43 am UTC
Forum: Science
Topic: Black Hole Thought Experiment
Replies: 15
Views: 4974

Re: Black Hole Thought Experiment

Let's say you make a black hole where all the needed mass is in the shell... Just FYI, this really isn't possible. If we somehow move all the matter in the Earth into a thin shell at the surface, then as you note, spacetime in the hollow interior is basically flat. But we do have a small engineerin...
by Goemon
Thu Sep 18, 2014 4:44 am UTC
Forum: Science
Topic: Miscellaneous Science Questions
Replies: 2958
Views: 720793

Re: RELATIVITY QUESTIONS! (and other common queries)

If I'm holding a dumbbell or baton whose (massive) ends are also the ends of a powerful magnet, and you're standing some distance away with a magnetic compass and an accelerometer, what happens when I spin the dumbbell? Assuming your instruments are in the plane of the dumbbell's rotation, then your...
by Goemon
Sat Sep 06, 2014 4:42 am UTC
Forum: Science
Topic: A proof that hyperspace cannot transport matter
Replies: 26
Views: 6298

Re: A proof that hyperspace cannot transport matter

No, no! Then you'll use it to break thermodynamics! Don't throw rocks at thermodynamics - it's not nice! Well, as thoughtfully says, if you're going to break the law, why be so fussy about which particular law gets shattered? Actually I was looking at it like this: if you're at the lower portal loo...
by Goemon
Fri Sep 05, 2014 12:17 am UTC
Forum: Science
Topic: A proof that hyperspace cannot transport matter
Replies: 26
Views: 6298

Re: A proof that hyperspace cannot transport matter

Meh - rock that comes out the top is colder than the rock that went in at the bottom.
by Goemon
Sat Aug 23, 2014 4:33 am UTC
Forum: Science
Topic: Why is it hard to get things cold?
Replies: 15
Views: 4705

Re: Why is it hard to get things cold?

Here's a simple method for converting heat to work: Say you have a sealed piston full of air, and it requires 300 joules of work for you to fully compress the piston. Once it's compressed, you could get some work out of the piston by making it push on something as it expands when you release it, but...
by Goemon
Sat Aug 09, 2014 4:52 pm UTC
Forum: Science
Topic: "Gravitational" time dilation on an accelerating spaceship
Replies: 20
Views: 6360

Re: "Gravitational" time dilation on an accelerating spacesh

Yes, I actually think the authors are wrong. It could be me that's wrong of course, but I think I can make a pretty good case :) Really long ass post though, so I've broken it down into sections: Constructing a spherically symmetric space with surfaces that are intrinsically flat: The metric ds^2 = ...
by Goemon
Fri Aug 08, 2014 12:14 am UTC
Forum: Science
Topic: "Gravitational" time dilation on an accelerating spaceship
Replies: 20
Views: 6360

Re: "Gravitational" time dilation on an accelerating spacesh

There's a paper about an infinite plane in general relativity at http://arxiv.org/abs/0708.2906, Well, that paper doesn't seem to apply all that relevantly, since the two metrics discussed are not planar solutions, they're point solutions with spherical symmetry. Or technically, with thin spherical...
by Goemon
Tue Jul 15, 2014 4:16 am UTC
Forum: Science
Topic: Containing a nuclear explosion.
Replies: 4
Views: 3971

Re: Containing a nuclear explosion.

The wiki page on underground nuclear testing mentions a formula for estimating how deeply a bomb has to be buried to completely contain an explosion: One figure used in determining how deeply the device should be buried is the scaled depth of burial, or -burst.[25] This figure is calculated as the b...
by Goemon
Fri Jul 11, 2014 2:02 am UTC
Forum: Science
Topic: Miscellaneous Science Questions
Replies: 2958
Views: 720793

Re: RELATIVITY QUESTIONS! (and other common queries)

I was just wondering what the train would see if they looked out the window. From the point of view of someone standing at the station, the clock on the train is always ticking at a constant rate, but slower than his own. When the train gets back to the station, the clock carried by the train shows...
by Goemon
Thu Jul 10, 2014 5:11 am UTC
Forum: Science
Topic: Miscellaneous Science Questions
Replies: 2958
Views: 720793

Re: RELATIVITY QUESTIONS! (and other common queries)

The acceleration can change, e.g. from 0 to some fixed value and still maintain Born rigidity, at least in principal. All points on the ship must accelerate at the same instant, as calculated in the ship's initial rest frame. The trick is that the rate of acceleration at a given point depends on how...
by Goemon
Wed Jul 09, 2014 4:06 am UTC
Forum: Science
Topic: Miscellaneous Science Questions
Replies: 2958
Views: 720793

Re: RELATIVITY QUESTIONS! (and other common queries)

But Ehrenfest's resolution was that you can't spin up a wheel starting from a non-rotating state in this way, some parts of the object must be getting stretched or compressed in their own local rest frame. In other words, if we assume that our rapidly rotating train wheels are shaped like disks fro...
by Goemon
Mon Jul 07, 2014 11:57 pm UTC
Forum: Science
Topic: "Gravitational" time dilation on an accelerating spaceship
Replies: 20
Views: 6360

Re: "Gravitational" time dilation on an accelerating spacesh

Hmmm... seems to me that an infinite uniform massive plate would result in flat spacetime, no different than ordinary Minkowski spacetime except there's an infinite plate which appears to be accelerating steadily toward you of its own volition. So if you ignore the plate and go about your inertial b...
by Goemon
Mon Jul 07, 2014 4:55 am UTC
Forum: Science
Topic: Miscellaneous Science Questions
Replies: 2958
Views: 720793

Re: RELATIVITY QUESTIONS! (and other common queries)

First, we have the rest frame pre spin. It's not even moving, no part of it. The circumference is 2pi R. The radius is R. Now we are interested in a frame where the com of the train is at rest. Then each point on the rim is moving. The radius is still R - the spokes aren't moving parallel to the sp...
by Goemon
Mon Jul 07, 2014 3:51 am UTC
Forum: Science
Topic: "Gravitational" time dilation on an accelerating spaceship
Replies: 20
Views: 6360

Re: "Gravitational" time dilation on an accelerating spacesh

Yep, the two most notable effects of constant acceleration (Rindler coordinates) are: Clocks at rest within the accelerating system (long rigid spaceship or fleet of spaceships or whatever) tick at a rate that's proportional to their distance from the Rindler Horizon; Objects at rest within the acce...
by Goemon
Sun Jul 06, 2014 10:14 pm UTC
Forum: Science
Topic: "Gravitational" time dilation on an accelerating spaceship
Replies: 20
Views: 6360

Re: "Gravitational" time dilation on an accelerating spacesh

I used a bit simpler formula for the calculation, dtau = (1+gx)dt but also got approximately 35 seconds per 100,000 years. The rate of aging in the nose of the ship is greater than the tail in linear proportion (no tidal = second order effects for simple acceleration) and due purely to a peculiar co...
by Goemon
Thu Jun 19, 2014 4:07 am UTC
Forum: Science
Topic: I think I understand why black holes are weird
Replies: 33
Views: 6560

Re: I think I understand why black holes are weird

IIRC, in the image you embedded, distance exists in the x-y plane. The z-axis represents acceleration. Actually, in those diagrams, distance is measured along the surface. The distance from the outside world to the event horizon is in fact infinite (the distance between concentric spheres surroundi...
by Goemon
Wed May 28, 2014 12:44 am UTC
Forum: Science
Topic: Possibly illegal but ostensibly feasible money-making scheme
Replies: 17
Views: 4196

Re: Possibly illegal but ostensibly feasible money-making sc

Think you may need to take a look at the total energy storage capacity of your flywheels (not the kW power rating). This one , for example, is rated "300kW". So it can charge and discharge pretty rapidly. But it costs $86,000 and the total energy storage is only about 1kWH. So you could ea...

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