Tests of Astrology

[Tigers!]

Plutonium has a density of about 20 tonnes per cubic metre, and 150lb is 68kg, so 150lb of Pu is 68/20000 = 0.0034m³ in volume.

0.0034m³ is 3,400cm³, and 6' is 183cm, so a 6' cylinder of Pu massing 150lb has a cross sectional area of 3,400cm³/183cm = 18.58cm².

Area is pi x the square of the radius, so the radius of your cylinder is the squareroot of 18.58cm²/3.14, which is the square root of 5.92cm², which is 2.43cm, or just less than 1" (0.96").

As to your other problem, I have a problem with your problem, in that my knowledge of plutonium far outweighs my knowledge of coolwhip.

Though I did google the density of Plutonium, so when ASIO arrest me, I shall be depending on you as my alibi. I fear that ignorance of coolwhip is no defence in law.

Cool Whip is mostly air and has a density of 0.22–0.27 grams/cubic centimeter. It has 25 calories per serving, which is the ridiculous amount of 2 tablespoons. No one in history has limited one serving to 2 table spoons. This compares to 104 calories for the equivalent volume of whipped cream, but in defense of whipped cream, more calories are burned whipping the cream, than by prying the lid off a tub of cool whip.

Perhaps all of us on this thread need to get out more?

Not I.
I need to eat more. 5’11” and under 150lbs? I’m like a plutonium stick! Never been over 165, but prefer to be around 155-160. Too much activity?

I can give you up to 10lbs (4.5kg) right now.

 

[bilby]

100-kg object 1 m away, like a birthing assistant: 6.67*10^(-9) s^(-2)

Astrologer: I am surprised that a middle-aged Saggitarius would buy a Ferrari

Physicist: I expect he's having a midwife crisis.

 

[Loren Pechtel]

Plutonium has a density of about 20 tonnes per cubic metre, and 150lb is 68kg, so 150lb of Pu is 68/20000 = 0.0034m³ in volume.

0.0034m³ is 3,400cm³, and 6' is 183cm, so a 6' cylinder of Pu massing 150lb has a cross sectional area of 3,400cm³/183cm = 18.58cm².

Area is pi x the square of the radius, so the radius of your cylinder is the squareroot of 18.58cm²/3.14, which is the square root of 5.92cm², which is 2.43cm, or just less than 1" (0.96").

As to your other problem, I have a problem with your problem, in that my knowledge of plutonium far outweighs my knowledge of coolwhip.

Though I did google the density of Plutonium, so when ASIO arrest me, I shall be depending on you as my alibi. I fear that ignorance of coolwhip is no defence in law.

I think you can actually have your cylinder without it blowing up on you.

Yeah, nice long thin cylinder, plenty of surface area.

But the plain sphere critical mass is a pretty small ball. Thicker than your cylinder. And your cylinder has no meaningful neutron escape from the ends. And the more I think about it the closer to critical I think your cylinder is. The surface of a sphere goes at 4pi*r^2. The surface area of a cylinder goes at pi*r^2*h--but since we are looking at a section of a cylinder the neutrons "lost" are equal to the neutrons it will receive from that part and thus h drops out of the equation. Thus we are left with the sphere having 4x the surface area (and thus neutron loss) as the cylinder slice. Now you're making me pollute my search history even more as I didn't do the math yesterday with enough precision.... A 10kg (bare sphere critical mass for plutonium) has a radius of 4.94cm. 4.94cm/2.43cm = 2.032. If I haven't messed the modelling up the sphere has 4.13 the neutron creation and 4x the neutron loss giving a multiplication factor of .96 for the cylinder slice. 4% from critical, which I think is meaningless as I would be surprised if that 10kg figure was accurate to two digits.

The surface area of a cylinder would be (2*pi*r*h) + (2*pi*r^2). Excluding the end surfaces, it's just 2*pi*r*h, where h is the length of the cylinder section under consideration.

I wasn't modelling the whole cylinder. I was modelling a slice from the middle of the cylinder. There should be basically zero net neutron flow through either end of the slice. And if I didn't mess up the math the critical point is within the accuracy of the data.

 

[Loren Pechtel]

Perhaps all of us on this thread need to get out more?

Not I.
I need to eat more. 5’11” and under 150lbs? I’m like a plutonium stick! Never been over 165, but prefer to be around 155-160. Too much activity?

The decades have robbed me of an inch, I used to be 5'11" and a bit, I always rounded it to 6' although I'm not sure if that was actually the proper rounding. And this morning I was 154 pounds. If I go below 150 I get too skinny.

 

[lostone]

A heavenly body wiped out the dinosaurs - is that enough proof of astrology?

 

[lpetrich]

That's a VERY coarse-grained effect. Astrological claims are MUCH more fine-grained than that.

There are some significant celestial influences on the Earth, and by far the strongest is the light that the Earth receives from the Sun. I will now calculate our planet's surface temperature without the Sun's light.

 Earth's internal heat budget - Our planet's heat emission is about 47 +- 2 terawatts.

Averaged out over our planet's surface, this gives us 0.093 watts/m^2, about 0.03% of what our planet receives from the Sun.

Using the Stefan-Boltzmann law and assuming perfect emission, this gives a temperature of around 36 K -- *very* cold.

Doing that calculation for incoming sunlight gives 278 K or 5 C -- the Earth is a little warmer than that because of its greenhouse effect, about 10 degrees, giving 15 C.

 

[bilby]

Plutonium has a density of about 20 tonnes per cubic metre, and 150lb is 68kg, so 150lb of Pu is 68/20000 = 0.0034m³ in volume.

0.0034m³ is 3,400cm³, and 6' is 183cm, so a 6' cylinder of Pu massing 150lb has a cross sectional area of 3,400cm³/183cm = 18.58cm².

Area is pi x the square of the radius, so the radius of your cylinder is the squareroot of 18.58cm²/3.14, which is the square root of 5.92cm², which is 2.43cm, or just less than 1" (0.96").

As to your other problem, I have a problem with your problem, in that my knowledge of plutonium far outweighs my knowledge of coolwhip.

Though I did google the density of Plutonium, so when ASIO arrest me, I shall be depending on you as my alibi. I fear that ignorance of coolwhip is no defence in law.

I think you can actually have your cylinder without it blowing up on you.

Yeah, nice long thin cylinder, plenty of surface area.

But the plain sphere critical mass is a pretty small ball. Thicker than your cylinder. And your cylinder has no meaningful neutron escape from the ends. And the more I think about it the closer to critical I think your cylinder is. The surface of a sphere goes at 4pi*r^2. The surface area of a cylinder goes at pi*r^2*h--but since we are looking at a section of a cylinder the neutrons "lost" are equal to the neutrons it will receive from that part and thus h drops out of the equation. Thus we are left with the sphere having 4x the surface area (and thus neutron loss) as the cylinder slice. Now you're making me pollute my search history even more as I didn't do the math yesterday with enough precision.... A 10kg (bare sphere critical mass for plutonium) has a radius of 4.94cm. 4.94cm/2.43cm = 2.032. If I haven't messed the modelling up the sphere has 4.13 the neutron creation and 4x the neutron loss giving a multiplication factor of .96 for the cylinder slice. 4% from critical, which I think is meaningless as I would be surprised if that 10kg figure was accurate to two digits.

The surface area of a cylinder would be (2*pi*r*h) + (2*pi*r^2). Excluding the end surfaces, it's just 2*pi*r*h, where h is the length of the cylinder section under consideration.

I wasn't modelling the whole cylinder. I was modelling a slice from the middle of the cylinder. There should be basically zero net neutron flow through either end of the slice. And if I didn't mess up the math the critical point is within the accuracy of the data.

I didn't suggest that you were, and I agree; You can disregard the surface area of the ends when considering a section from the middle.

As I said, such a section has area 2*pi*r*h, where h is the length of the cylinder section under consideration. So you did "mess up the math" - the surface area varies with the radius, not with the square of the radius; It is simply the circumference (pi*d), multiplied by the length of the section you are thinking about.

If you consider the whole cylinder, you can add the 2*pi*r^2 term, (which is pretty tiny in the case of a long, thin, cylinder anyway).

 

[bilby]

this gives a temperature of around 36 K -- *very* cold.

Absolutely.

 

[bilby]

Thus we are left with the sphere having 4x the surface area (and thus neutron loss) as the cylinder slice.

This should have been your hint that you had made a mathematical error. If you conclude that a sphere, of equal mass and density to any non-spherical arrangement of the same material, has a higher surface area than the non-sphere, then you must be in error.

A sphere has the minimum possible surface area to volume ratio. All other shapes have higher surface area.

Of course, discarding the cylinder ends means we are not considering the entire surface; But the ends of a long thin cylinder are a small fraction of its surface.

Discarding them isn't going to get you to a quarter (!) of the area of a sphere of identical volume.

Discarding the h term entirely was also a misssed opportunity for a sanity check. The surface area of a cylinder section is obviously not independent of its length. A cylinder of diameter d and length h cannot possibly have the same surface area as one of diameter d and length 2h - as long as d and h are greater than zero.

 

[Loren Pechtel]

That's a VERY coarse-grained effect. Astrological claims are MUCH more fine-grained than that.

There are some significant celestial influences on the Earth, and by far the strongest is the light that the Earth receives from the Sun. I will now calculate our planet's surface temperature without the Sun's light.

 Earth's internal heat budget - Our planet's heat emission is about 47 +- 2 terawatts.

Averaged out over our planet's surface, this gives us 0.093 watts/m^2, about 0.03% of what our planet receives from the Sun.

Using the Stefan-Boltzmann law and assuming perfect emission, this gives a temperature of around 36 K -- *very* cold.

Doing that calculation for incoming sunlight gives 278 K or 5 C -- the Earth is a little warmer than that because of its greenhouse effect, about 10 degrees, giving 15 C.

Huh?? I thought the greenhouse effect was bigger than that, that we would be below zero without it.

 

[Loren Pechtel]

Plutonium has a density of about 20 tonnes per cubic metre, and 150lb is 68kg, so 150lb of Pu is 68/20000 = 0.0034m³ in volume.

0.0034m³ is 3,400cm³, and 6' is 183cm, so a 6' cylinder of Pu massing 150lb has a cross sectional area of 3,400cm³/183cm = 18.58cm².

Area is pi x the square of the radius, so the radius of your cylinder is the squareroot of 18.58cm²/3.14, which is the square root of 5.92cm², which is 2.43cm, or just less than 1" (0.96").

As to your other problem, I have a problem with your problem, in that my knowledge of plutonium far outweighs my knowledge of coolwhip.

Though I did google the density of Plutonium, so when ASIO arrest me, I shall be depending on you as my alibi. I fear that ignorance of coolwhip is no defence in law.

I think you can actually have your cylinder without it blowing up on you.

Yeah, nice long thin cylinder, plenty of surface area.

But the plain sphere critical mass is a pretty small ball. Thicker than your cylinder. And your cylinder has no meaningful neutron escape from the ends. And the more I think about it the closer to critical I think your cylinder is. The surface of a sphere goes at 4pi*r^2. The surface area of a cylinder goes at pi*r^2*h--but since we are looking at a section of a cylinder the neutrons "lost" are equal to the neutrons it will receive from that part and thus h drops out of the equation. Thus we are left with the sphere having 4x the surface area (and thus neutron loss) as the cylinder slice. Now you're making me pollute my search history even more as I didn't do the math yesterday with enough precision.... A 10kg (bare sphere critical mass for plutonium) has a radius of 4.94cm. 4.94cm/2.43cm = 2.032. If I haven't messed the modelling up the sphere has 4.13 the neutron creation and 4x the neutron loss giving a multiplication factor of .96 for the cylinder slice. 4% from critical, which I think is meaningless as I would be surprised if that 10kg figure was accurate to two digits.

The surface area of a cylinder would be (2*pi*r*h) + (2*pi*r^2). Excluding the end surfaces, it's just 2*pi*r*h, where h is the length of the cylinder section under consideration.

I wasn't modelling the whole cylinder. I was modelling a slice from the middle of the cylinder. There should be basically zero net neutron flow through either end of the slice. And if I didn't mess up the math the critical point is within the accuracy of the data.

I didn't suggest that you were, and I agree; You can disregard the surface area of the ends when considering a section from the middle.

As I said, such a section has area 2*pi*r*h, where h is the length of the cylinder section under consideration. So you did "mess up the math" - the surface area varies with the radius, not with the square of the radius; It is simply the circumference (pi*d), multiplied by the length of the section you are thinking about.

If you consider the whole cylinder, you can add the 2*pi*r^2 term, (which is pretty tiny in the case of a long, thin, cylinder anyway).

You're right. I failed to pull out an r when going from area to surface area.

 

[Loren Pechtel]

Thus we are left with the sphere having 4x the surface area (and thus neutron loss) as the cylinder slice.

This should have been your hint that you had made a mathematical error. If you conclude that a sphere, of equal mass and density to any non-spherical arrangement of the same material, has a higher surface area than the non-sphere, then you must be in error.

A sphere has the minimum possible surface area to volume ratio. All other shapes have higher surface area.

Of course, discarding the cylinder ends means we are not considering the entire surface; But the ends of a long thin cylinder are a small fraction of its surface.

Discarding them isn't going to get you to a quarter (!) of the area of a sphere of identical volume.

Discarding the h term entirely was also a misssed opportunity for a sanity check. The surface area of a cylinder section is obviously not independent of its length. A cylinder of diameter d and length h cannot possibly have the same surface area as one of diameter d and length 2h - as long as d and h are greater than zero.

No, I was right to pull out the h as both surface area and neutron emission go linear with h. Where I messed up is area of the ends goes at r^2 but area of the sides goes at r. So we have a quarter of the material losing half as many neutrons, multiplication factor is ~.5.

I was not concluding the sphere had a higher surface area, I never compared them. I was comparing the sphere to a cylinder whose ends were at practical infinity and thus disregarded.

 

[bilby]

I was not concluding the sphere had a higher surface area, I never compared them.

I know. I was suggesting that you should have, as doing so would have immediately alerted you to a problem with your math.

 

[thebeave]

Let's get back to the subject at hand, astrology...not how fat everyone here is. An increasingly weighty subject for me!

This has always been one of my favorite astrology debunking videos. It comes courtesy of the late great James Randi:



Unfortunately, its rather old so the video quality is not great.

 

[Swammerdami]

Magnetism and tides are two "forces" which follow an inverse-cube law. Any others? What about straight inverse?

The average American adult male is ~200lbs, or 91kg, and 5'9" or 175cm.

May I hijack the thread to tell what I think is an amusing anecdote about an average American body measurement?

First know that I enjoy looking at voluptuous women! (I mean "voluptuous" in its traditional meaning: Google now thinks it means "fat."
And know that I ogle such voluptuous creatures when they're on the screen. My social skills are VERY poor, but I know just enough to not drool in public!)

Anyway two decades I was in one room playing on my laptop while Miss Universe played on the TV in the other room. (It seemed more important to critique some misguided message-board poster than to ogle the nubile Miss Universe finalists!)

But while I was pounding on the keyboard, I heard the announcer announce one of the contestants' figure. She had 39 inch hips!!! This overwhelmed my imagination and I raced into the other room hoping to catch a glimpse. (Alas, I was too late.) Even Marilyn Monroe's hips were only 34 inches. This must have been before my heart attack: After that warning I wouldn't trust my heart not to race too fast contemplating the supreme allure of Thirty-NINE inch hips!!! (Quick poll question for men: Which would you find sexier, 36-25-38 or 38-25-36?)

Here cometh the punchline: Google once presented me with the figure measurements of the AVERAGE American woman. I don't remember all three numbers, but the hip size was well over 40 inches.

 

[Loren Pechtel]

But while I was pounding on the keyboard, I heard the announcer announce one of the contestants' figure. She had 39 inch hips!!! This overwhelmed my imagination and I raced into the other room hoping to catch a glimpse. (Alas, I was too late.) Even Marilyn Monroe's hips were only 34 inches. This must have been before my heart attack: After that warning I wouldn't trust my heart not to race too fast contemplating the supreme allure of Thirty-NINE inch hips!!! (Quick poll question for men: Which would you find sexier, 36-25-38 or 38-25-36?)

Here cometh the punchline: Google once presented me with the figure measurements of the AVERAGE American woman. I don't remember all three numbers, but the hip size was well over 40 inches.

39 inch hips on a beauty pageant contestant is very different that 39 inch hips on a blimp.

And I'm one for moderation--it's quite possible to have too much of a good thing. Your 38-25-36 sounds like too much. And big hips have never held much attraction for me.

 

[Bomb#20]

Magnetism and tides are two "forces" which follow an inverse-cube law. Any others? What about straight inverse?

I expect energy delivered by water waves would follow an inverse law, since they spread in two dimensions instead of three.

My social skills are VERY poor...

Anyway two decades I was in one room playing on my laptop

Those phenomena are not necessarily unrelated.

 

[Swammerdami]

But while I was pounding on the keyboard, I heard the announcer announce one of the contestants' figure. She had 39 inch hips!!! This overwhelmed my imagination and I raced into the other room hoping to catch a glimpse....

Here cometh the punchline: Google once presented me with the figure measurements of the AVERAGE American woman. I don't remember all three numbers, but the hip size was well over 40 inches.

39 inch hips on a beauty pageant contestant is very different that 39 inch hips on a blimp.

If you have to explain the punchline to a trivial joke, then it was a really bad joke. Sorry.

- - - - - - - - - - -

But I do have a sincere question. NO, I do not ask why nobody laughed at my "joke." Few at IIDB have a discernable sense of whimsy, and anyway my attempts at humor fail more often than not.

What I DO want to know is: Was my little joke offensive? Did it seem misogynistic, politically incorrect, or otherwise in very poor taste?

(Perhaps my old age is a culprit. "Locker rooms" in the 1970's were full of talk that would be highly "unwoke" today.)

So: Was my little joke offensive? or just too silly and boring to merit any reaction?

 

[Loren Pechtel]

But while I was pounding on the keyboard, I heard the announcer announce one of the contestants' figure. She had 39 inch hips!!! This overwhelmed my imagination and I raced into the other room hoping to catch a glimpse....

Here cometh the punchline: Google once presented me with the figure measurements of the AVERAGE American woman. I don't remember all three numbers, but the hip size was well over 40 inches.

39 inch hips on a beauty pageant contestant is very different that 39 inch hips on a blimp.

If you have to explain the punchline to a trivial joke, then it was a really bad joke. Sorry.

- - - - - - - - - - -

But I do have a sincere question. NO, I do not ask why nobody laughed at my "joke." Few at IIDB have a discernable sense of whimsy, and anyway my attempts at humor fail more often than not.

What I DO want to know is: Was my little joke offensive? Did it seem misogynistic, politically incorrect, or otherwise in very poor taste?

(Perhaps my old age is a culprit. "Locker rooms" in the 1970's were full of talk that would be highly "unwoke" today.)

So: Was my little joke offensive? or just too silly and boring to merit any reaction?

I realized it was a joke. But you got me trying to picture what 39" would look like on someone who wasn't a blimp. (I actually think I wouldn't like it--I definitely think there can be too much of a good thing and it's all too common with bolt-on tits.)

And while I realize it might offend the woke I'm not on the warpath looking for sin, I'm not going to get offended.