1866: "Russell's Teapot"

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Re: 1866: "Russell's Teapot"

Postby dtilque » Fri Jul 21, 2017 7:54 pm UTC

Soupspoon wrote:You're not one of those "Cher never walked on the Moon" people, are you? Sheesh...


I'm more of a "Cher never did a Moonwalk" people, myself. And no, don't show me a utube of her doing one. Utube is a known repository of fake videos. It probably has a video of Russell launching a teapot into orbit.



This made me think of an SF story that someone should write. A spaceship is launched to Mars, but its booster malfunctions and it ends up in an orbit between Earth and Mars. They still have some delta-V left, but they have to lighten their load or they can't get to Mars. One passenger named Russell has brought along a family heirloom, his great-aunt's teapot .....


Further thought: any teapot launched into space should have a transponder so that we can verify it's still there.
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Re: 1866: "Russell's Teapot"

Postby bgaskin » Fri Jul 21, 2017 8:38 pm UTC

Here's the Wikipedia definition (Russell's Teapot):
https://en.m.wikipedia.org/wiki/Russell ... prov=sfla1

Russell's teapot is an analogy, formulated by the philosopher Bertrand Russell (1872–1970), to illustrate that the philosophic burden of proof lies upon a person making unfalsifiable claims, rather than shifting the burden of disproof to others.


Russell specifically applied his analogy in the context of religion. He wrote that if he were to assert, without offering proof, that a teapot orbits the Sun somewhere in space between the Earth and Mars, he could not expect anyone to believe him solely because his assertion could not be proven wrong.

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Re: 1866: "Russell's Teapot"

Postby gmalivuk » Fri Jul 21, 2017 9:12 pm UTC

orthogon wrote:(That he postulated a teapot is so twee and so quintessentially British that I can't help picturing Russell as a kind of Alan Bennett of philosophy. An American would probably have mentally launched a "football" [handegg]; a French philosopher - I don't know - a baguette, perhaps?)

I mean, he was pretty quintessentially British with or without the teapot.
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morriswalters wrote:You can't look everywhere at once.
There is no reason in principle for this to be true.
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Re: 1866: "Russell's Teapot"

Postby SuicideJunkie » Fri Jul 21, 2017 9:51 pm UTC

Rombobjörn wrote:Of course it isn't. It's Randall's teapot.
Easily solved by simply selling the teapot once it is in place.

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Re: 1866: "Russell's Teapot"

Postby morriswalters » Sat Jul 22, 2017 1:20 am UTC

gmalivuk wrote:There is no reason in principle for this to be true.
There are some practical problems. And you have limits if the universe doesn't. And you're limited by the ability to see the teapot. The only viewpoint that can see everywhere at once is at the center of the system. The maximum view port is the the area in front of you where the teapot is visible. And those view ports need to have the teapot in sight at all times. Russell chose an elliptical orbit but we'll choose a circular one to keep it simple. So the the viewpoints exist on a Dyson Sphere who's radius is 200 feet less the the orbital radius of the teapot. Each viewpoint representing one person. This represents the number of places you need to look. That's a big number, not to mention putting them where they would need to be. But imaginable.

So if the teapot and the viewpoints move a the same speed then only one viewpoint ever sees the teapot. What is the chance that any one viewpoint will see the teapot? One divided by the number of viewpoints. Look at the idea you can see everything at once. You either see it or you don't. The odds are fifty/fifty. Or are they? Assume the condition that what one knows that all will know. Why is the probability not one divided by the number of view points?

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Re: 1866: "Russell's Teapot"

Postby gmalivuk » Sat Jul 22, 2017 1:35 am UTC

morriswalters wrote:
gmalivuk wrote:There is no reason in principle for this to be true.
There are some practical problems. And you have limits if the universe doesn't. And you're limited by the ability to see the teapot. The only viewpoint that can see everywhere at once is at the center of the system. The maximum view port is the the area in front of you where the teapot is visible. And those view ports need to have the teapot in sight at all times. Russell chose an elliptical orbit but we'll choose a circular one to keep it simple. So the the viewpoints exist on a Dyson Sphere who's radius is 200 feet less the the orbital radius of the teapot. Each viewpoint representing one person. This represents the number of places you need to look. That's a big number, not to mention putting them where they would need to be. But imaginable.

So if the teapot and the viewpoints move a the same speed then only one viewpoint ever sees the teapot. What is the chance that any one viewpoint will see the teapot? One divided by the number of viewpoints. Look at the idea you can see everything at once. You either see it or you don't. The odds are fifty/fifty. Or are they? Assume the condition that what one knows that all will know. Why is the probability not one divided by the number of view points?

Are you drunk?

I don't really follow any of that, but it doesn't seem to do anything to answer the question of whether we could eventually put enough instruments in space to know a teapot isn't there.
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Re: 1866: "Russell's Teapot"

Postby morriswalters » Sat Jul 22, 2017 4:47 am UTC

Here, I'll write using small paragraphs, I don't want to confuse you.

Basically I told you the number of telescopes you would need to see everywhere you have to look at.

You do it from the center because of the properties of a sphere. Savvy symmetry?

It is the most efficient place to search because you don't need to move.

You know, because you can look faster than you can orbit.

I used the inverse square law and the visual field of a telescope to describe how much of the area you could see. So a telescope that would let you see a teapot 200 feet away would be the same as standing 200 foot away and looking and looking at the teapot. Savvy inverse square? Optics.

I made two simplifications of note.

I made the orbit circular.

I made the teapot move at a zero rate as compared to the observer. I'm lazy, so shoot me. That's one of the neater properties of a Dyson Sphere.

I'm pretty sure that the race will die off before they can find that teapot.
gmalivuk wrote:
morriswalters wrote:You can't look everywhere at once.
There is no reason in principle for this to be true.
You know this is rather amusing now that I look at it. I really have never disputed this, I simply gave you the scale. But if a Christian said precisely the same thing you would have kittens, sabre tooth kittens.
Matthew 10:29 wrote:What is the price of two sparrows--one copper coin? But not a single sparrow can fall to the ground without your Father knowing it.

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Re: 1866: "Russell's Teapot"

Postby gmalivuk » Sat Jul 22, 2017 12:03 pm UTC

I see, so you made a bunch of unjustified assumptions about detection instruments and didn't bother to mention them, and also wrote a paragraph that looked like you were disagreeing but never actually addressed my statement.

First of all, I can see a teapot with my eyes more than 200 feet away, and a telescope could do orders of magnitude better.

Also, if you know the orbital distance, then you know that anything a bit closer to or farther from the sun will move faster or slower than the teapot. It's a simple matter to figure out how long you need to watch before you can be sure nothing is orbiting there.
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Re: 1866: "Russell's Teapot"

Postby rmsgrey » Sat Jul 22, 2017 1:57 pm UTC

If you know which plane the teapot's orbiting in, you can just sweep the orbit twice (once each way) and guarantee to see any teapot that's there, whatever speed it's orbiting at.

Searching the surface of a sphere is going to be significantly more difficult, depending on what your resources are, but how difficult depends on your assumptions.

Release a Von Neumann machine into the asteroid belt, and get the eventual camera swarm to check for teapots inside Mars' orbit...

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Re: 1866: "Russell's Teapot"

Postby PinkShinyRose » Sat Jul 22, 2017 2:41 pm UTC

rmsgrey wrote:If you know which plane the teapot's orbiting in, you can just sweep the orbit twice (once each way) and guarantee to see any teapot that's there, whatever speed it's orbiting at.

Searching the surface of a sphere is going to be significantly more difficult, depending on what your resources are, but how difficult depends on your assumptions.

Release a Von Neumann machine into the asteroid belt, and get the eventual camera swarm to check for teapots inside Mars' orbit...

Also, even if you don't know the exact orbit (but would for some reason know the distance), wouldn't the mere fact that it's orbiting make it unnecessary to search the entire sphere simultaneously? Shouldn't searching half a hemisphere twice suffice?

EDIT: nevermind, you'd need to search continuously. Better search a hemisphere twice.
Last edited by PinkShinyRose on Sat Jul 22, 2017 2:50 pm UTC, edited 1 time in total.

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Re: 1866: "Russell's Teapot"

Postby gmalivuk » Sat Jul 22, 2017 2:49 pm UTC

The phrase "between Earth and Mars" suggests the plane. A hundred or so orbiting radar stations would be enough to eventually find any teapots orbiting there.
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Re: 1866: "Russell's Teapot"

Postby orthogon » Sat Jul 22, 2017 2:51 pm UTC

morriswalters wrote:I made the teapot move at a zero rate as compared to the observer. I'm lazy, so shoot me.

I'm going to have to shoot you. By doing this, you threw away a whole dimension. To find my keys, I don't need to rig up an array of cameras all over my flat and have them all take a simultaneous photo. I can travel from room to room making use of the time axis to look in one place after another. (As my wife will tell you, I won't actually find them without her help, but the principle stands nonetheless).
xtifr wrote:... and orthogon merely sounds undecided.

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Re: 1866: "Russell's Teapot"

Postby gmalivuk » Sat Jul 22, 2017 3:21 pm UTC

Yeah, if the thing you're looking for (teapot or keys) could move under its own power, you would need multiple detectors to make sure it's not simply avoiding the limited detection range of a single one, but if it moves predictably (a subset of which is staying in one place), a single moving detector (that can move as needed) could eventually find anything that might be there.

If you suppose the thing is in a particular circular orbit exactly 200 million km from the Sun, and your shitty cameras can only detect a teapot in a 100m region, you'd need two million of them to find it if they are stationary relative to it. If you're allowed to launch cameras that aren't stationary relative to each other, you can make do with just two (one in each direction).
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Re: 1866: "Russell's Teapot"

Postby orthogon » Sat Jul 22, 2017 3:35 pm UTC

gmalivuk wrote:Yeah, if the thing you're looking for (teapot or keys) could move under its own power ...

They can, damn it! I swear they can!
xtifr wrote:... and orthogon merely sounds undecided.

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Re: 1866: "Russell's Teapot"

Postby gmalivuk » Sat Jul 22, 2017 7:23 pm UTC

The Wikipedia article on radar astronomy says a good radar can detect a 1km object most of an AU away, meaning it could detect a 10cm object at a million kilometers.
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Re: 1866: "Russell's Teapot"

Postby morriswalters » Sat Jul 22, 2017 7:49 pm UTC

gmalivuk wrote:I see, so you made a bunch of unjustified assumptions about detection instruments and didn't bother to mention them, and also wrote a paragraph that looked like you were disagreeing but never actually addressed my statement. I don't argue with theists so I answered the question I assumed you meant to ask.

First of all, I can see a teapot with my eyes more than 200 feet away, and a telescope could do orders of magnitude better. At the relative scales involved small differences aren't really meaningful. Make the field of view a disk represented by a disc equal in diameter to the earth and it would give you 550 million places to look.

Also, if you know the orbital distance, then you know that anything a bit closer to or farther from the sun will move faster or slower than the teapot. It's a simple matter to figure out how long you need to watch before you can be sure nothing is orbiting there.How many elliptical orbits are possible between Earth and Mars?


You suck all the fun out life.

Here would be my experimental setup. We are at one AU+. We have one observer with a blindfold. Assume the object is stationary but that you don't know where. This represents the initial condition not knowing the location of the teapot. Understand that by realizing that finding the object, represents one moment in time. Its location will matter but not its motion. Also think about what that means when the two bodies move with respect to each other in multiple multiple orbits about a single axis. The odds of him seeing the teapot are 1 divided by all the places it could be.

So the odds of orthogon finding his keys are 1 divided by the number of unique places he has to look. His strategy should be to stand in the center of the room and locate all those unique places by rotating his view through all the relevant axis. Think of this unique area as all the things he can see without moving his eyes. His search is complicated by there being places he can't see. He needs to look under the sofa cushions. What he can be glad of, is that his floor plan has less square footage then the target space. Obviously his wife is smarter than him.

The length of the search, is the number of unique places to look divided by the time it takes to search them. The most efficient search in this case is the search that lets you look in as many of those unique places as you can, in the shortest period of time.

Telescopes in the center of the search space is as good as it gets, because the telescope only needs to rotate about its three axis. Apparent movement lets you shift your viewpoint faster than you can move through space.

I also treated space as free of obstructions.

I think that covers it, even that silly remark about radar. Currently my Troll'o meter is pegged. So fuck it anyway. Thanks I guess.

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Re: 1866: "Russell's Teapot"

Postby rmsgrey » Sat Jul 22, 2017 9:46 pm UTC

gmalivuk wrote:The Wikipedia article on radar astronomy says a good radar can detect a 1km object most of an AU away, meaning it could detect a 10cm object at a million kilometers.

Diffraction. You'd need to be using a shorter wavelength than most radar does...

morriswalters wrote:Telescopes in the center of the search space is as good as it gets, because the telescope only needs to rotate about its three axis. Apparent movement lets you shift your viewpoint faster than you can move through space.


Depends how long it takes to resolve a given volume at a given range. If it takes longer for your sun-based telescope to analyse a target volume than it does for a mobile device to move through it, then the speed of shifting aim is wasted.

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Re: 1866: "Russell's Teapot"

Postby gmalivuk » Sat Jul 22, 2017 11:57 pm UTC

morriswalters wrote:
gmalivuk wrote:I see, so you made a bunch of unjustified assumptions about detection instruments and didn't bother to mention them, and also wrote a paragraph that looked like you were disagreeing but never actually addressed my statement.
I don't argue with theists so I answered the question I assumed you meant to ask.
Why did you assume I meant a totally different question than what I actually said?

First of all, I can see a teapot with my eyes more than 200 feet away, and a telescope could do orders of magnitude better.
At the relative scales involved small differences aren't really meaningful. Make the field of view a disk represented by a disc equal in diameter to the earth and it would give you 550 million places to look.
All 550 million of which would be swept through by detectors in their own orbits.

Also, if you know the orbital distance, then you know that anything a bit closer to or farther from the sun will move faster or slower than the teapot. It's a simple matter to figure out how long you need to watch before you can be sure nothing is orbiting there.
How many elliptical orbits are possible between Earth and Mars?
Are you back to talking about elliptical orbits? Why'd you change your mind?

You suck all the fun out life.
Sorry you don't find science fun. Seems like maybe this is the wrong place for you if that's the case though.

Here would be my experimental setup. We are at one AU+. We have one observer with a blindfold. Assume the object is stationary but that you don't know where. This represents the initial condition not knowing the location of the teapot. Understand that by realizing that finding the object, represents one moment in time. Its location will matter but not its motion. Also think about what that means when the two bodies move with respect to each other in multiple multiple orbits about a single axis. The odds of him seeing the teapot are 1 divided by all the places it could be.

So the odds of orthogon finding his keys are 1 divided by the number of unique places he has to look. His strategy should be to stand in the center of the room and locate all those unique places by rotating his view through all the relevant axis. Think of this unique area as all the things he can see without moving his eyes. His search is complicated by there being places he can't see. He needs to look under the sofa cushions. What he can be glad of, is that his floor plan has less square footage then the target space. Obviously his wife is smarter than him.

The length of the search, is the number of unique places to look divided by the time it takes to search them. The most efficient search in this case is the search that lets you look in as many of those unique places as you can, in the shortest period of time.

Telescopes in the center of the search space is as good as it gets, because the telescope only needs to rotate about its three axis. Apparent movement lets you shift your viewpoint faster than you can move through space.

I also treated space as free of obstructions.

I think that covers it, even that silly remark about radar. Currently my Troll'o meter is pegged. So fuck it anyway. Thanks I guess.
How was the radar comment silly?

And I still don't understand why you want to find it as quickly as possible. Yes, obviously a faster search is going to require more equipment, but that's another thing you added to the problem yourself, without anyone else having mentioned it.

rmsgrey wrote:
gmalivuk wrote:The Wikipedia article on radar astronomy says a good radar can detect a 1km object most of an AU away, meaning it could detect a 10cm object at a million kilometers.

Diffraction. You'd need to be using a shorter wavelength than most radar does...
And?
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Re: 1866: "Russell's Teapot"

Postby morriswalters » Sun Jul 23, 2017 1:23 am UTC

rmsgrey wrote:Depends how long it takes to resolve a given volume at a given range. If it takes longer for your sun-based telescope to analyse a target volume than it does for a mobile device to move through it, then the speed of shifting aim is wasted.
I can move faster than the speed of light in apparent motion, you can't. You are limited to orbital velocity. You did cause me to reevaluate something somebody said earlier, there is a plane where all the orbits pass through. You could count on seeing the teapot on average between 3 and 6 months after you start looking on average.

@gmalivuk
Me- You can't look everywhere at once. You-There is no reason in principle for this to be true.
Make statements about godlike behavior and I will ignore them going forward.
gmalivuk wrote:All 550 million of which would be swept through by a single detector over the course of about a year.
Would you please describe that orbit?
gmalivuk wrote:Are you back to talking about elliptical orbits? Why'd you change your mind?
Mainly to confuse you. Russell talked of elliptical orbits. I used circular ones because they're easier.
gmalivuk wrote:Sorry you don't find science fun. Seems like maybe this is the wrong place for you if that's the case though.
On the contrary, its you that sucks all the fun out. Not science.
gmalivuk wrote:How was the radar comment silly?
All it does is change the resolution. You can do the same thing with a telescope. But you still live and die by the inverse scale rule, law, or whatever. Radar is active, it requires a return, it also doesn't know the difference between a teapot and a rock the same shape. Visual data has higher bandwidth, or something like that.
gmalivuk wrote:And I still don't understand why you want to find it as quickly as possible. Yes, obviously a faster search is going to require more equipment, but that's another thing you added to the problem yourself, without anyone else having mentioned it.
As I've said pretty much continuously, I did it to simplify it. Russell set the problem up as it relates to an astronomer looking through a telescope. I don't care about finding the teapot, I care about the odds of any one astronomer doing it. Which was what I gather his point was. Setting enough telescopes at the center to see every place the teapot could be gives you the odds. You can only see it the first time once. So the odds are 1 divided by the number of places it could be. This could also work at the disc I identified in the plane. You use fewer sensors but have a higher "something or another" that encompasses the time you might have to wait to make a sighting. I don't know how to express it. What I wanted was the magnitude of that number.

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Re: 1866: "Russell's Teapot"

Postby gmalivuk » Sun Jul 23, 2017 1:36 am UTC

morriswalters wrote:
Me- You can't look everywhere at once. You-There is no reason in principle for this to be true.
Make statements about godlike behavior and I will ignore them going forward.
What part of eventually having lots of detectors out in space is godlike? And is it godlike in a way qualitatively different to how our current ability to see everywhere on Earth at once would appear godlike to our own ancestors?

gmalivuk wrote:All 550 million of which would be swept through by a single detector over the course of about a year.
Would you please describe that orbit?
Sorry, I just did the math and figured out you were talking about your sphere, rather than the plane I'd mentioned (and that your next comment seemed to be about). So fine, you'd need a lot of different detectors orbiting in different planes.

And as impractical as 550 million (or whatever fraction of that we can cut it down to by allowing our detectors to move) may be, it's eleven billion times better than your original 400' diameter scenario.
gmalivuk wrote:Are you back to talking about elliptical orbits? Why'd you change your mind?
Mainly to confuse you. Russell talked of elliptical orbits. I used circular ones because they're easier.
Right, but when I'm responding to problems with your circular orbit description, switching back to elliptical orbits all of a sudden seems rather disingenuous.

gmalivuk wrote:How was the radar comment silly?
All it does is change the resolution. You can do the same thing with a telescope. But you still live and die by the inverse scale rule, law, or whatever. Radar is active, it requires a return, it also doesn't know the difference between a teapot and a rock the same shape. Visual data has higher bandwidth, or something like that.
Yeah, the inability to definitely identify it as a teapot is an issue, but as for changing the resolution, it does so by a factor of more than six thousand compared to your earth-disc version. Now we're down to less than 100,000 detectors if they aren't allowed to orbit independently.

gmalivuk wrote:And I still don't understand why you want to find it as quickly as possible. Yes, obviously a faster search is going to require more equipment, but that's another thing you added to the problem yourself, without anyone else having mentioned it.
As I've said pretty much continuously, I did it to simplify it. Russell set the problem up as it relates to an astronomer looking through a telescope. I don't care about finding the teapot, I care about the odds of any one astronomer doing it. Which was what I gather his point was. Setting enough telescopes at the center to see every place the teapot could be gives you the odds. You can only see it the first time once. So the odds are 1 divided by the number of places it could be. This could also work at the disc I identified in the plane. You use fewer sensors but have a higher "something or another" that encompasses the time you might have to wait to make a sighting. I don't know how to express it. What I wanted was the magnitude of that number.
But the discussion in this thread was never about one astronomer doing it. Your initial incredulous response, in case you've already forgotten, was to the question, "Might we eventually have enough instruments in orbit to scour the alleged region of space exhaustively and with sufficient resolution?"

No, one astronomer with one telescope would never be able to do it in a single lifetime, but that's not what this discussion was ever about (until you apparently forgot how you entered it and made it about that, I suppose).
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Re: 1866: "Russell's Teapot"

Postby morriswalters » Sun Jul 23, 2017 6:34 am UTC

"Might we eventually have enough instruments in orbit to scour the alleged region of space exhaustively and with sufficient resolution?"
Yep, it's still silly, it was just as silly the first time I saw it. And it will be silly tomorrow as well. Make it non silly for me. Because to this point you haven't done much more than ask me if I was drunk.

gmalivuk wrote:What part of eventually having lots of detectors out in space is godlike? And is it godlike in a way qualitatively different to how our current ability to see everywhere on Earth at once would appear godlike to our own ancestors?
I wouldn't know about our ancestors. But we can't see everywhere at once. It's impossible. We can image the Earths surface but no human will ever experience all the Earth completely at one moment. And even those lucky enough to have gone to the moon, only ever saw half at one time at distances that destroyed detail. Satellites in polar orbit can see the whole world eventually, one small area at a time. But not all at once. And I'm not certain it is possible to put enough sensors in polar orbit to do it if you were inclined to try.
gmalivuk wrote:And as impractical as 550 million (or whatever fraction of that we can cut it down to by allowing our detectors to move) may be, it's eleven billion times better than your original 400' diameter scenario.
I cut it down some more, now it's a plane between Earth and Mars.
gmalivuk wrote:Right, but when I'm responding to problems with your circular orbit description, switching back to elliptical orbits all of a sudden seems rather disingenuous.
I accept that criticism.
gmalivuk wrote:Yeah, the inability to definitely identify it as a teapot is an issue, but as for changing the resolution, it does so by a factor of more than six thousand compared to your earth-disc version. Now we're down to less than 100,000 detectors if they aren't allowed to orbit independently.
FTFY. I've never said that you needed to restrict the movement of any sensors. I simply said that moving sensors make a hard problem harder.

Just to be clear. I don't care what conversation you were having. I never agreed to be limited to what you want to talk about. And I won't be. When I talk about putting enough telescopes in the center of the sun to look at the totality of the surface of a sphere at some point between Earth and Mars I find it hard to believe that you couldn't tell the point I was trying to make.

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Re: 1866: "Russell's Teapot"

Postby gmalivuk » Sun Jul 23, 2017 10:48 am UTC

I asked if you were drunk because that reply was so incoherent, not because whatever ideas you were trying to express were bad ones.

We can see all of Earth because we have multiple satellites, so no single one has to be able to see everywhere. And whether one person can "experience it" is irrelevant, because that was never the question.

Allowing detectors to move complicates the question of whether a particular setup allows us to exhaustively search for things orbiting a region, but it greatly cuts down on the number of detectors we would need in any setup.

I'm not trying to hold you to my own choice of conversation, I'm trying to hold you to the conversation *you* started. Changing topics willy-nilly and then acting like you've come up with some clever "gotcha" is bad form and the sort of thing some people might say deserves an arm amputation.
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Re: 1866: "Russell's Teapot"

Postby rmsgrey » Sun Jul 23, 2017 11:22 am UTC

morriswalters wrote:
rmsgrey wrote:Depends how long it takes to resolve a given volume at a given range. If it takes longer for your sun-based telescope to analyse a target volume than it does for a mobile device to move through it, then the speed of shifting aim is wasted.
I can move faster than the speed of light in apparent motion, you can't. You are limited to orbital velocity.


Okay, so I put two detectors in low solar orbit, and have them rotate rapidly so each of them covers their hemisphere in exactly one second. Would that find the teapot? Would that even find Mercury?

There's no question that your fixed detector can point at a new region faster than a mobile detector can move to it, but a detector closer to a given sample volume will take less time to search it.

Also, once you start getting multiple detectors, spacing them out within the search volume gets better results than stacking them in the middle - if you assume a circular orbit, then three fixed detectors in that orbit will mean that the teapot is never closer to the sun than to the nearest detector, allowing each to search their assigned third in less time than a central detector would.

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Re: 1866: "Russell's Teapot"

Postby gmalivuk » Sun Jul 23, 2017 1:48 pm UTC

It would be great if morriswalters deigned to let us know which scenario he's talking about whenever he makes claims about its efficacy.

A: There is one telescope at the center.
B: There are multiple telescopes at the center.
C: There are multiple telescopes in the region where the teapot might be.

1: The teapot is in a circular orbit of known radius and unknown inclination.
2: The teapot is in a circular orbit of unknown radius and known inclination.
3: The teapot is in an elliptical orbit of known inclination between the orbits of Earth and Mars.

Because as far as I can tell, each of these has been the case in at least one of his posts.
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Re: 1866: "Russell's Teapot"

Postby morriswalters » Sun Jul 23, 2017 11:22 pm UTC

For anybody looking, there is a wall gibberish inside this spoiler, aimed at rmsgrey and gmalivuk. I have no idea why you might be interested, but you were warned.
Spoiler:
The longer I write the worse it gets so I'm freezing at this point, warts and all.
rmsgrey wrote:Okay, so I put two detectors in low solar orbit, and have them rotate rapidly so each of them covers their hemisphere in exactly one second. Would that find the teapot? Would that even find Mercury?
The question is answerable, I just can't give you that answer. The question you are asking is how fast can your sensor see? On a more human scale scanning radar can at least get close to doing it and it takes advantage of that principle. gmalivuk has argued something similar to this. But radar doesn't see the way we think of seeing of course.

rmsgrey wrote:Also, once you start getting multiple detectors, spacing them out within the search volume gets better results than stacking them in the middle - if you assume a circular orbit, then three fixed detectors in that orbit will mean that the teapot is never closer to the sun than to the nearest detector, allowing each to search their assigned third in less time than a central detector would.
Earth or near Earth could be the location of one of your sensor platforms, it's in your sweet spot. Take radar. It can sweep 360. Define three circles which see all the area you need to see distributed on the orbit of your choice.

This is the area we need to look in, a disc seen edge on defined with a major radius at the orbit of Mars and a minor radius at the orbit of Earth swept through an arc of 120 degrees. Draw three circles around each of the three arcs which make a complete circle. What you will see is that these three circles also touch the origin. By symmetry the spread is 120 degrees of arc on the major radius starting with the vertex on the minor radius. Draw it with a compass and a protractor if it isn't clear. What I see is that, in the area you need to see, you would have to have a range of 1 AU in one direction to get the whole arc. I personally hated geometry. It gives me headaches.

If you sweep 120 degrees with radar, it requires the antenna to be in the sun. This is locked by geometry. The inverse square law is a product of that geometry. The closer you get to what you're looking for, the more overlap you required, to see everything you need to see. And this is why it is most efficient to look from the center. There isn't any overlap needed. And by symmetry this is true in any direction you look, since a sphere is symmetric in all its axis.

In my example I took this to absurdity in terms of the numbers. At the center this represents the difference between one telescope moving to every point you need to see, or many telescopes looking at every place you need to see all at once. This will define the number of sensors you need depending on the radius to the center at that point you decide to look. Independent of the orbit of what you're looking for. Assuming the circular orbit passes between Earth and Mars.

If you eyes haven't glazed over yet consider a circle divided into 10 equal arcs. There is a circle near the axis that can be divided into 10 equivalent arcs equal in their angular measurements but different in relative magnitude. If the outer arcs represent what the viewer could see at that point, the inner arc represents the same viewpoint.

This describes geometrically how I define the problem. Assuming there is no major flaw in this reasoning the number of sensors then becomes a kind of sanity check. Do you believe we could put that number of sensors where they would need to be? Point out any defects you see, but from my standpoint this is a geometric argument.

As a general statement we only have a couple of sensors available suitable for the task insofar as I'm aware of. We can look passively or actively. The means we look visually or we look with radar at one frequency or another. Am I missing something else?



gmalivuk wrote:It would be great if morriswalters deigned to let us know which scenario he's talking about whenever he makes claims about its efficacy. Fair enough. If you got this far you should have all the information on how I set it up. I'll clarify or retract depending on what errors you might find.

A: There is one telescope at the center.
B: There are multiple telescopes at the center.
C: There are multiple telescopes in the region where the teapot might be.
I represent both A and B in my presentation as they are the endpoints. C is representative of what a person would see if the were standing in the position that they see through the telescope.
1: The teapot is in a circular orbit of known radius and unknown inclination.
2: The teapot is in a circular orbit of unknown radius and known inclination.
3: The teapot is in an elliptical orbit of known inclination between the orbits of Earth and Mars.
The circular orbits are the simple case. And I cover both. And where my argument lays. The elliptical orbit was specified by Russell. I have a vague idea of how to attack the question of how this would work for an ellipse, but it's going to stay vague, the circular orbits illustrate the point I was trying to make. If I have confused you I'm sorry.

Because as far as I can tell, each of these has been the case in at least one of his posts. Yes. The inclination is irrelevant, in the sense that the case is true for all circular orbits in the space. Three is a misstatement, or me becoming confused when I posted. That plane is circular and not elliptical. All of the circular orbits between Earth and Mars cut this plane.

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Re: 1866: "Russell's Teapot"

Postby BlueSloth » Mon Jul 24, 2017 8:37 am UTC

Something I've been wondering is whether Bertrand Russell actually owned any teapots (I'm guessing yes), and if so, where are they now? Is one of them sitting on a collector's shelf, with said collector waiting for the perfect moment to make a Russell's Teapot joke?

dtilque wrote:This made me think of an SF story that someone should write. A spaceship is launched to Mars, but its booster malfunctions and it ends up in an orbit between Earth and Mars. They still have some delta-V left, but they have to lighten their load or they can't get to Mars. One passenger named Russell has brought along a family heirloom, his great-aunt's teapot .....

Or maybe the teapot is secretly put into a stable orbit as a prank to future astronomers.

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Re: 1866: "Russell's Teapot"

Postby Keyman » Mon Jul 24, 2017 1:35 pm UTC

All you 'detectors' out there seem to be missing the part of the quote that says...
Bertrand Russell wrote:...nobody would be able to disprove my assertion provided I were careful to add that the teapot is too small to be revealed even by our most powerful telescopes.
So if you were to detect it, it would not be Russell's Teapot.
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Re: 1866: "Russell's Teapot"

Postby orthogon » Mon Jul 24, 2017 2:25 pm UTC

Keyman wrote:All you 'detectors' out there seem to be missing the part of the quote that says...
Bertrand Russell wrote:...nobody would be able to disprove my assertion provided I were careful to add that the teapot is too small to be revealed even by our most powerful telescopes.
So if you were to detect it, it would not be Russell's Teapot.

Yeah, I realised that I may have led people to think I was attacking Russell's argument itself, and was going to mention it when morriswalters first said it was "silly, it was just as silly the first time I saw it". I should perhaps have pointed out that of course it's silly. At least half of what I post is kind of silly, although treating silly questions seriously is a large part of what we do on here, isn't it? It is the forum for a geeky webcomic, after all. Anyway, the whole thing got sidetracked so comprehensively that I didn't get around to it.

For the avoidance of doubt, I wasn't in any way suggesting that doing this would in any way invalidate Russell's argument; it would simply mean that the example needed to be twerked, by specifying a smaller object and/or a larger volume of space. I was interested in what might be possible, or how many orders of magnitude away from being possible it would be, and I'm happy to consider easier problems, like, say, a Fiat Panda in a circular orbit, which we have in fact touched on to some extent. And perhaps the goal of finding (or, to be more exact, not finding) the teapot is important enough to spend all of our launch capacity on it, and build massively more, and maybe it's acceptable that the exhaustive search take a thousand years, or even ten thousand.
xtifr wrote:... and orthogon merely sounds undecided.

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Re: 1866: "Russell's Teapot"

Postby Keyman » Mon Jul 24, 2017 2:53 pm UTC

orthogon wrote:
Keyman wrote:All you 'detectors' out there seem to be missing the part of the quote that says...
Bertrand Russell wrote:...nobody would be able to disprove my assertion provided I were careful to add that the teapot is too small to be revealed even by our most powerful telescopes.
So if you were to detect it, it would not be Russell's Teapot.

Yeah, I realised that I may have led people to think I was attacking Russell's argument itself, and was going to mention it when morriswalters first said it was "silly, it was just as silly the first time I saw it". I should perhaps have pointed out that of course it's silly. At least half of what I post is kind of silly, although treating silly questions seriously is a large part of what we do on here, isn't it? It is the forum for a geeky webcomic, after all. Anyway, the whole thing got sidetracked so comprehensively that I didn't get around to it.

For the avoidance of doubt, I wasn't in any way suggesting that doing this would in any way invalidate Russell's argument; it would simply mean that the example needed to be twerked, by specifying a smaller object and/or a larger volume of space. I was interested in what might be possible, or how many orders of magnitude away from being possible it would be, and I'm happy to consider easier problems, like, say, a Fiat Panda in a circular orbit, which we have in fact touched on to some extent. And perhaps the goal of finding (or, to be more exact, not finding) the teapot is important enough to spend all of our launch capacity on it, and build massively more, and maybe it's acceptable that the exhaustive search take a thousand years, or even ten thousand.
If this would the result, then I withdraw any and every objection to the search!
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Re: 1866: "Russell's Teapot"

Postby gmalivuk » Mon Jul 24, 2017 3:17 pm UTC

Keyman wrote:All you 'detectors' out there seem to be missing the part of the quote that says...
Bertrand Russell wrote:...nobody would be able to disprove my assertion provided I were careful to add that the teapot is too small to be revealed even by our most powerful telescopes.
So if you were to detect it from Earth using the most powerful telescopes, it would not be Russell's Teapot.
Fix'd.

For the record, a white teapot in sunlight about 10m away has an apparent magnitude of about -15 (calculated by considering the apparent size and magnitude of the Moon, and the fact that a truly white object reflects about 8x more light than the Moon). It would have a magnitude of +31.5 if it were 10^9.3 times farther away, or about 20 million km.

Hubble saw objects that dim with a couple million seconds of exposure. Hence the point about how long it would take for a central telescope to actually be able to see what you're looking for. At one millionth as much exposure time, Hubble would have needed something to be a million times brighter, or a thousand times closer, to see it.

In other words, Hubble would have a hard time seeing a teapot in geosynchronous Earth orbit. But sure, the number of detectors is the "silly" part.
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Re: 1866: "Russell's Teapot"

Postby Keyman » Mon Jul 24, 2017 4:20 pm UTC

gmalivuk wrote:
Keyman wrote:All you 'detectors' out there seem to be missing the part of the quote that says...
Bertrand Russell wrote:...nobody would be able to disprove my assertion provided I were careful to add that the teapot is too small to be revealed even by our most powerful telescopes.
So if you were to detect it from Earth using the most powerful telescopes, it would not be Russell's Teapot.
Fix'd.

For the record, a white teapot in sunlight about 10m away has an apparent magnitude of about -15 (calculated by considering the apparent size and magnitude of the Moon, and the fact that a truly white object reflects about 8x more light than the Moon). It would have a magnitude of +31.5 if it were 10^9.3 times farther away, or about 20 million km.

Hubble saw objects that dim with a couple million seconds of exposure. Hence the point about how long it would take for a central telescope to actually be able to see what you're looking for. At one millionth as much exposure time, Hubble would have needed something to be a million times brighter, or a thousand times closer, to see it.

In other words, Hubble would have a hard time seeing a teapot in geosynchronous Earth orbit. But sure, the number of detectors is the "silly" part.

I see where you're going with that edit, but I don't think it fixes anything. Rather, it distorts Russell's point. He was trying to emphasize the undetectable-ness as leading to an inability to disprove it's existence and therefore ...
"if I were to go on to say that, since my assertion cannot be disproved, it is intolerable presumption on the part of human reason to doubt it, I should rightly be thought to be talking nonsense"...

and then, in a later reference draws the analogy to religion (if it weren't quite clear what he meant in the first place)...
"nobody thinks this [teapot] sufficiently likely to be taken into account in practice. I think the Christian God just as unlikely"
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Re: 1866: "Russell's Teapot"

Postby morriswalters » Mon Jul 24, 2017 4:38 pm UTC

Russell was trolling theist's with 4 pi r2. r=141.6 million miles. Give or take.

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Re: 1866: "Russell's Teapot"

Postby gmalivuk » Mon Jul 24, 2017 4:57 pm UTC

Keyman wrote:
gmalivuk wrote:
Keyman wrote:All you 'detectors' out there seem to be missing the part of the quote that says...
Bertrand Russell wrote:...nobody would be able to disprove my assertion provided I were careful to add that the teapot is too small to be revealed even by our most powerful telescopes.
So if you were to detect it from Earth using the most powerful telescopes, it would not be Russell's Teapot.
Fix'd.

For the record, a white teapot in sunlight about 10m away has an apparent magnitude of about -15 (calculated by considering the apparent size and magnitude of the Moon, and the fact that a truly white object reflects about 8x more light than the Moon). It would have a magnitude of +31.5 if it were 10^9.3 times farther away, or about 20 million km.

Hubble saw objects that dim with a couple million seconds of exposure. Hence the point about how long it would take for a central telescope to actually be able to see what you're looking for. At one millionth as much exposure time, Hubble would have needed something to be a million times brighter, or a thousand times closer, to see it.

In other words, Hubble would have a hard time seeing a teapot in geosynchronous Earth orbit. But sure, the number of detectors is the "silly" part.

I see where you're going with that edit, but I don't think it fixes anything. Rather, it distorts Russell's point. He was trying to emphasize the undetectable-ness as leading to an inability to disprove it's existence
I know what Russell's point was. And I know he was talking about an actual physical teapot. Russell himself surely wouldn't have said, of an actual interplanetary teapot discovered by one of our probes for instance, "Well you detected that one so obviously it doesn't count."

He wasn't, after all, talking about a dragon in the garage.
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Re: 1866: "Russell's Teapot"

Postby mathmannix » Mon Jul 24, 2017 7:55 pm UTC

rhomboidal wrote:Russell's teapot really raises a profound question: Will it make hot tea or iced tea?

Khan wrote:It is very cold in space.
I hear velociraptor tastes like chicken.

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Re: 1866: "Russell's Teapot"

Postby Keyman » Mon Jul 24, 2017 9:32 pm UTC

mathmannix wrote:
rhomboidal wrote:Russell's teapot really raises a profound question: Will it make hot tea or iced tea?

Khan wrote:It is very cold in space.

gmalivuk wrote:He wasn't, after all, talking about a dragon in the garage.
Maybe we can send Sagan's dragon to heat up Russell's teapot?

@gmalivuk - I was thinking of the teapot in the same vain as the dragon. I see your point. (It's been a long time since my philosophy major.) And I learned a new word...veridically (which apparently spell-check didn't know either :wink: )
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Re: 1866: "Russell's Teapot"

Postby morriswalters » Mon Jul 24, 2017 10:32 pm UTC

Keyman wrote:All you 'detectors' out there seem to be missing the part of the quote that says...
Bertrand Russell wrote:...nobody would be able to disprove my assertion provided I were careful to add that the teapot is too small to be revealed even by our most powerful telescopes.
So if you were to detect it, it would not be Russell's Teapot.
It looks like he actually diddled theists twice. And future proofed it. Make the telescope large and you make the teapot small. Chase either to the endpoints, and you find that they both end at an asymptote. If you can see the teapot you are looking at a dimensionless point. I never knew Mr Russell, but I like him, just for that.

He certainly diddled me as well. :lol:

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Re: 1866: "Russell's Teapot"

Postby gmalivuk » Tue Jul 25, 2017 2:27 pm UTC

Well, to take Hubble as an example again, a real teapot would appear as a dimensionless point anywhere beyond a few hundred kilometers, but it would still be visible far beyond that if the exposure time was long enough.
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Re: 1866: "Russell's Teapot"

Postby morriswalters » Wed Jul 26, 2017 12:48 am UTC

gmalivuk wrote:Well, to take Hubble as an example again, a real teapot would appear as a dimensionless point anywhere beyond a few hundred kilometers, but it would still be visible far beyond that if the exposure time was long enough.
Yep. Its what fascinates me about astronomy. In the midst of the conversation I looked at what was visible in sky, Betelgeuse is visible as a disk to modern telescopes. Sorry about the image size.Image

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Re: 1866: "Russell's Teapot"

Postby SuicideJunkie » Wed Jul 26, 2017 4:04 pm UTC

BlueSloth wrote:Something I've been wondering is whether Bertrand Russell actually owned any teapots (I'm guessing yes), and if so, where are they now? Is one of them sitting on a collector's shelf, with said collector waiting for the perfect moment to make a Russell's Teapot joke?

Or maybe the teapot is secretly put into a stable orbit as a prank to future astronomers.
Huh. Those boundary conditions...
His teapot sitting indoors is orbiting the sun between (some parts of the atmosphere of) Earth and Mars. No wonder it can't be found by telescopes!


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