Search found 341 matches

by FancyHat
Mon May 04, 2015 6:18 pm UTC
Forum: Science
Topic: Deadlifter
Replies: 17
Views: 4455

Re: Deadlifter

This reminds me of an idea I had once, for transporting valuable metals back from the Moon. Make the rocket itself of out of your cargo! In this case, design the upper stages of your Big Dumb Booster with the express goal of being disassembled in space and recycled into new structures--girders, tan...
by FancyHat
Thu Apr 02, 2015 7:22 pm UTC
Forum: Science
Topic: Miscellaneous Science Questions
Replies: 2962
Views: 731452

Re: RELATIVITY QUESTIONS! (and other common queries)

If there was some speed lost/gained on the way down the leg that was parralel to the earth's rotation, it would gain/lose it on the way back cancelling it out. That is my initiial thoughts as I look at that experiment from that line of thinking. Such things were taken into account over a century ag...
by FancyHat
Thu Apr 02, 2015 6:07 pm UTC
Forum: Science
Topic: Miscellaneous Science Questions
Replies: 2962
Views: 731452

Re: RELATIVITY QUESTIONS! (and other common queries)

I guess one of the implications of my line of questioning the reference frame thing is there might be an absolute rest frame, albeit really hard to figure out where. And that you cant call a moving frame a rest frame. If this is the case, you could measure how fast your local reference frame is tra...
by FancyHat
Tue Mar 31, 2015 12:43 am UTC
Forum: Science
Topic: Extension cord question. Is Jimmy right?
Replies: 21
Views: 5924

Re: Extension cord question. Is Jimmy right?

Regarding health'n'safety:- He explains, "When we had the saw hooked just to the shorter thicker cord you could hear and see the saw cut faster. There's power loss along any cord thick or thin, so the saw slows down the longer the cord. Right?" "Of course, Jimmy." "Well clos...
by FancyHat
Mon Mar 30, 2015 8:26 am UTC
Forum: Science
Topic: Extension cord question. Is Jimmy right?
Replies: 21
Views: 5924

Re: Extension cord question. Is Jimmy right?

I just measured the capacitance of a 6 foot computer power cable at 0.23nF. If we assume that an extension cord has similar properties, a 100ft cord might have a capacitance of about 3.8nF. Perhaps it would be measurable, but probably not significant. That would give a reactance of about 700 kΩ at ...
by FancyHat
Sun Mar 29, 2015 11:29 pm UTC
Forum: Science
Topic: Extension cord question. Is Jimmy right?
Replies: 21
Views: 5924

Re: Extension cord question. Is Jimmy right?

Jimmy is wrong. Each cord has two wires in it (I'm assuming), each of which has a bit of resistance, so can be treated as a resistor, which I'll call R i . So, the circuit you get is: from one of the holes in the outlet; along one of the wires of the first cord, R 1 ; along one of the wires of the s...
by FancyHat
Sun Mar 29, 2015 7:41 am UTC
Forum: Science
Topic: Miscellaneous Science Questions
Replies: 2962
Views: 731452

Re: RELATIVITY QUESTIONS! (and other common queries)

It takes the signal 1.865 seconds to reach the front of the station since the signal is traveling at the speed of light and the station is 1.865 lightseconds long. Since the train takes 1.866 seconds to reach the front gate then the train passes through safely. I don't think you've got that right. ...
by FancyHat
Sun Mar 29, 2015 6:16 am UTC
Forum: Science
Topic: Miscellaneous Science Questions
Replies: 2962
Views: 731452

Re: RELATIVITY QUESTIONS! (and other common queries)

That sounded really right for a second. I thought that I had screwed up by not realizing that even though the signal is twice as fast that the train's front would still reach the front of the tunnel before the signal could make up the difference. And you would have been right, if you'd stuck with t...
by FancyHat
Sun Mar 29, 2015 3:42 am UTC
Forum: Mathematics
Topic: Paths between two points
Replies: 18
Views: 3504

Re: Paths between two points

Something from your original post:- ... but wouldn't longer paths have more degrees of freedom so there would be more of them? Consider two paths, one longer than the other. As long as both paths have lengths greater than zero, it is possible to put the points along one path into a one-to-one corres...
by FancyHat
Sun Mar 29, 2015 3:15 am UTC
Forum: Science
Topic: Miscellaneous Science Questions
Replies: 2962
Views: 731452

Re: RELATIVITY QUESTIONS! (and other common queries)

The way your rewrote the question solves the problem, but I wrote it the original way in order to create the paradox not to resolve one. I was seeking to show that length contraction and relativity of simultaneity are also effects that need to be taken into account. The paradox only occurs if you h...
by FancyHat
Sun Mar 29, 2015 1:17 am UTC
Forum: Science
Topic: Miscellaneous Science Questions
Replies: 2962
Views: 731452

Re: RELATIVITY QUESTIONS! (and other common queries)

I've been confused by a thought problem. Have you also taken length contraction and relativity of simultaneity into account? In the train's rest frame, the platform is length-contracted. As a result, it only takes 26 minutes to pass past the train's clock. Now put clocks at the ends of the platform...
by FancyHat
Sat Mar 28, 2015 7:10 am UTC
Forum: Mathematics
Topic: Paths between two points
Replies: 18
Views: 3504

Re: Paths between two points

Could you clarify something? Is X a set of paths that all have the same length p , where 1≤ p ≤3? Or is X the set of all paths with lengths in the range [1, 3]? And the same for q and Y . I get the impression it's the latter, that X and Y each have paths of various lengths within the ranges [1, 3] f...
by FancyHat
Wed Mar 25, 2015 8:35 pm UTC
Forum: Fictional Science
Topic: Fission Stars
Replies: 26
Views: 9118

Re: Fission Stars

If it's a sufficiently huge (in terms of volume) and rarefied star, could induced fission be limited by the outer parts of the star simply being too rarefied to be critical? The more rarefied it is, the more neutrons will decay before inducing further fissions. Could that provide a (fuzzy) boundary ...
by FancyHat
Mon Mar 23, 2015 5:45 pm UTC
Forum: Fictional Science
Topic: Fission Stars
Replies: 26
Views: 9118

Re: Fission Stars

I'm reminded of the demon core , and the accidents with it. Did the demon core qualify as a fission star during those accidents? That article led me to articles on prompt criticality and delayed neutrons . Prompt neutrons are those emitted pretty much immediately when a nucleus fissions, while delay...
by FancyHat
Sat Mar 21, 2015 5:32 pm UTC
Forum: Science
Topic: Deadlifter
Replies: 17
Views: 4455

Re: Deadlifter

There are also hybrid rockets , which, like many liquid rockets, have separate fuels and oxidizers, except one's liquid and the other's solid (usually the fuel). They can be relatively simple, like a big dumb booster, or more complex, more like a liquid rocket with turbopumps. Solid rockets can be e...
by FancyHat
Tue Mar 17, 2015 11:42 pm UTC
Forum: Mathematics
Topic: Happy Super Pi Day, Everyone!
Replies: 37
Views: 7738

Re: Happy Super Pi Day, Everyone!

By the revolution logic, I propose to celebrate tau every day at Solar noon –others may celebrate pi at noon and midnight. But the earth rotates nearly 361° in 24 hours. It only takes about 23 hours 56 minutes to rotate 2𝜋 radians. This is because, in the time it takes to rotate 2𝜋 radians, the ear...
by FancyHat
Mon Mar 16, 2015 4:59 pm UTC
Forum: Fictional Science
Topic: Maximum efficiency when doing work over a distance
Replies: 57
Views: 20115

Re: Maximum efficiency when doing work over a distance

I favor Elasto's description of space bending, This preserves Newton's laws but without introducing the need of other objects. In this model, the amount of "extra" work needed to be done is the work needed to do the space-bending. That sounds a bit like building a space elevator in order ...
by FancyHat
Mon Mar 16, 2015 4:48 pm UTC
Forum: Fictional Science
Topic: Fission Stars
Replies: 26
Views: 9118

Re: Fission Stars

How viable might a thorium cycle fission star be?
by FancyHat
Sat Mar 14, 2015 4:50 pm UTC
Forum: Fictional Science
Topic: Maximum efficiency when doing work over a distance
Replies: 57
Views: 20115

Re: Maximum efficiency when doing work over a distance

Another, different illustration:- telekinesis-2.png This time, the telekinetic doesn't feel an equal and opposite reaction force. Instead, the telekinetic sends some mass-energy in a suitable form to the remote object. This is like elasto 's rocket device, and requires good aim as Yakk observed. Whe...
by FancyHat
Sat Mar 14, 2015 12:37 am UTC
Forum: Fictional Science
Topic: Maximum efficiency when doing work over a distance
Replies: 57
Views: 20115

Re: Maximum efficiency when doing work over a distance

In an attempt to clarify what's meant by 'telekinesis', I have produced the following illustration:- telekinesis.png This isn't supposed to completely define 'telekinesis', but it does seem to be the essential feature in the simplest terms. There is then the question: does, or should, telekinesis vi...
by FancyHat
Thu Mar 12, 2015 5:51 pm UTC
Forum: Fictional Science
Topic: Maximum efficiency when doing work over a distance
Replies: 57
Views: 20115

Re: Maximum efficiency when doing work over a distance

This is a long post, so I'll spoiler the two replies it contains. In Reply to Cradarc I'm not quite sure where the torque comes from. Wikipedia's article on torque. Wikipedia's article on angular momentum. Wikipedia's article on moment of inertia. The cricket ball is 100 m away from ...
by FancyHat
Thu Mar 12, 2015 12:03 am UTC
Forum: Science
Topic: milky way today versus what we see
Replies: 18
Views: 4104

Re: milky way today versus what we see

Whatever the spiral arms are made of, they're still affected by gravity, and therefore must orbit or they would be pulled in towards the center of the galaxy. Right? Imagine a Mexican wave of passengers on a moving train, where the train is moving as some particular speed, relative to the tracks, i...
by FancyHat
Wed Mar 11, 2015 11:38 pm UTC
Forum: Fictional Science
Topic: Maximum efficiency when doing work over a distance
Replies: 57
Views: 20115

Re: Maximum efficiency when doing work over a distance

Does acting at a distance make a difference? Yes. For example, as gmalivuk said: torque. Is there an absolute maximum efficiency limit that always applies, no matter what, because of the distance? No. Is there anything that limits the efficiency of telekinesis itself to a maximum limit that's less t...
by FancyHat
Tue Mar 10, 2015 10:08 pm UTC
Forum: Fictional Science
Topic: Maximum efficiency when doing work over a distance
Replies: 57
Views: 20115

Re: Maximum efficiency when doing work over a distance

I can argue 100% efficiency is also fictional, since it's impossible to achieve in reality. You can have a limit that can't be achieved without it failing to be a limit. For example: there's no largest real number less than one, but that doesn't stop one being the limit of 1-1/ x as x tends towards...
by FancyHat
Tue Mar 10, 2015 11:35 am UTC
Forum: Fictional Science
Topic: Maximum efficiency when doing work over a distance
Replies: 57
Views: 20115

Re: Maximum efficiency when doing work over a distance

The battery can't insert itself. That's a detail of your example, not some kind of fundamental limit. That you can come up with examples which have such details doesn't mean such things are inevitable in all cases. Also notice, by giving the battery a small nudge, you must give it some kinetic ener...
by FancyHat
Tue Mar 10, 2015 4:54 am UTC
Forum: Fictional Science
Topic: Maximum efficiency when doing work over a distance
Replies: 57
Views: 20115

Re: Maximum efficiency when doing work over a distance

True, but having the battery collide elastically with the car is not the same as having the battery powering the car directly (as in before you removed it). I didn't say it would "collide elastically with the car". Nudging it to send it to the car was just to get it to the car. Once at th...
by FancyHat
Mon Mar 09, 2015 3:08 am UTC
Forum: Science
Topic: Black holes, weak force.
Replies: 13
Views: 3203

Re: Black holes, weak force.

gmalivuk wrote:In that case, I think yes, you got it.

:D
by FancyHat
Mon Mar 09, 2015 2:58 am UTC
Forum: Fictional Science
Topic: Maximum efficiency when doing work over a distance
Replies: 57
Views: 20115

Re: Maximum efficiency when doing work over a distance

Consider a battery operated toy car. Take the batteries out and put them far away. You must then set up a system to transfer the energy stored in the batteries back to the car. Assume you have the magical ability to convert the battery's energy into any form you want without any work or loss. Is th...
by FancyHat
Sun Mar 08, 2015 11:29 pm UTC
Forum: Fictional Science
Topic: Maximum efficiency when doing work over a distance
Replies: 57
Views: 20115

Re: Maximum efficiency when doing work over a distance

I think there might be at least two issues mixed together here. One is the issue of what difference, if any, varying the distance makes. Cannonball billiards is about that. The other seems to be about converting energy, or otherwise processing it, so as to then send it from the source to the target ...
by FancyHat
Sun Mar 08, 2015 10:00 pm UTC
Forum: Science
Topic: Black holes, weak force.
Replies: 13
Views: 3203

Re: Black holes, weak force.

Not really. Was it this bit?:- This means I only see the black hole asymptotically approach formation, and never see it formed. I've just realised that can make it sound like I objectively observe the black hole to never form in finite time, where the black hole is objectively asymptotically approa...
by FancyHat
Sun Mar 08, 2015 7:32 pm UTC
Forum: Science
Topic: Black holes, weak force.
Replies: 13
Views: 3203

Re: Black holes, weak force.

Gravitational and electric flux "escape" the event horizon just fine. Why? because all that flux is coming from just outside the horizon. After the black hole has "settled", the charge and mass is distributed evenly around the horizon, the shell theorem applies and we can treat ...
by FancyHat
Sun Mar 08, 2015 3:54 pm UTC
Forum: Fictional Science
Topic: Maximum efficiency when doing work over a distance
Replies: 57
Views: 20115

Re: Maximum efficiency when doing work over a distance

Energy technically isn't lost, but you end up having to expend more energy than you would have if you directly fired the target cannonball to get the same result. Well, your question was about doing work over a distance, so I set up an illustrative scenario where the distance could be varied withou...
by FancyHat
Sun Mar 08, 2015 3:46 am UTC
Forum: Fictional Science
Topic: Maximum efficiency when doing work over a distance
Replies: 57
Views: 20115

Re: Maximum efficiency when doing work over a distance

Ignoring gravity, just to keep things simple, there's no need for energy to actually be lost in transit. Consider the following scenario, somewhere in space. A cannon fires a cannonball, giving it some amount of kinetic energy and momentum. The cannonball travels through empty space some distance. N...
by FancyHat
Sun Mar 08, 2015 1:27 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1492: "Dress color"
Replies: 362
Views: 62444

Re: 1492: "Dress color"

Angua wrote:someone do me a favour and find Klear's sketch of the colours they said they see. Phone and forum not a great combo.

This post?
by FancyHat
Sat Mar 07, 2015 9:55 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1492: "Dress color"
Replies: 362
Views: 62444

Re: 1492: "Dress color"

ucim wrote:So, it's either deliberate, or unlikely.

You must be awfully suspicious of all those claimed lottery 'winners' who, against the odds, all 'won'!

Also: Occam's razor.
by FancyHat
Sat Mar 07, 2015 1:33 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1492: "Dress color"
Replies: 362
Views: 62444

Re: 1492: "Dress color"

Don't 169 us here. No 169 intended. 169 is about deliberately 'clever', 'tricky' wording. Reading it back, perhaps the tone of my post wasn't so great, though. (And yeah, it's great to question purported "authority" and people who think a single patent makes them an expert, but *you* are ...
by FancyHat
Fri Mar 06, 2015 4:52 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1492: "Dress color"
Replies: 362
Views: 62444

Re: 1492: "Dress color"

When I remember perceiving the dress to be white and gold, and when I remember perceiving it to be blue and black, my memories really do seem to be different. I can remember the two perceptions side-by-side, and they're different. Also, I'm currently perceiving the dress, when I look at the photo, t...
by FancyHat
Thu Mar 05, 2015 7:40 pm UTC
Forum: Mathematics
Topic: Fictional but natural Time Lord mathematical system
Replies: 11
Views: 3588

Re: Fictional but natural Time Lord mathematical system

Regarding "fictional" mathematics, I don't really see how it's fictional, since it's still just as much mathematics as, well, non-fictional mathematics. Mathematics is mathematics. Anyway, something I thought I'd just mention: hexagons! The Time Lords seem to have something for hexagons, w...
by FancyHat
Tue Mar 03, 2015 3:37 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1492: "Dress color"
Replies: 362
Views: 62444

Re: 1492: "Dress color"

A quick response, as I've got stuff to do. Here's one more bit of circumstantial evidence for the image being manipulated. Check out the selfies on the home page of woman who started the fracas: Okay, there's the avatar kind of photo, and another used decoratively as part of the background. Given th...

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