John Nowak
Graduate Poster
So because he wants to avoid subtracting when he wants to work with numbers less than one, he subtracts on all numbers less than one?
That's unnecessary, unworkable, and probably insane. I think you're right.
Kinetic energy at atmospheric reentry from lunar mission
- Thread starter wogoga
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So because he wants to avoid subtracting when he wants to work with numbers less than one, he subtracts on all numbers less than one?
That's unnecessary, unworkable, and probably insane. I think you're right.
jaydeehess
Penultimate Amazing
.000126 is not 126 X 10-3It is 1.26X10-4 or 126 X10-6
I read 3n251 as indeed 251X10-3 = 0.251
3p126 I read as 126X103=251000
But if I am simply reading it wrong , I believe I am still correct in it's not being "less complicated", and that introducing letters into numbers will just make algebra even more flummoxing to high school students.
jaydeehess
Penultimate Amazing
What?
Thats lunacy, even more unecessarily complicated than I thought it was supposed to work.
Jrrarglblarg
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The problem is, that's not why snow shelters are warmer than ambient, and your explanation differs from all other versions I've ever heard, because it's wrong. Ground temp won't contribute anything, because the frost line is 30 inches below the surface, minimum.
The correct explanation is that the interior of the snow cave can be warmed all the way up to the freezing point of water, which can be very much warmer than ambient.
Thus, steel buildings cannot be warmed to greater than the melting point of steel.
Dave Rogers
Bandaged ice that stampedes inexpensively through
Also not a real advantage. These days, using the letter e to replace "x 10^" is pretty much universal, courtesy of Excel. So, for example, 6.626e-34 is not significantly harder to type than 66n6626 - two extra characters not requiring shift or control keys - and its actual magnitude is much clearer.
Dave
jaydeehess
Penultimate Amazing
Snow shelter construction.
-pick an area at least twice the diameter of the finished shelter
-use shovel or snowshoe to mix up the snow on the ground and pile it up in the area where you want the finished shelter to be.
-Make coffee, sing take pictures,,, whatever, for at least an hour
-dig an entrance and hollow out the pile. The turning and piling will have mixed up different temp layers of snow, the outer foot solidifies.
- the interior will always be warmer than the exterior(once you have put a snow block door in place) even if there are no people in it or candles burning.
Heat has to come from somewhere and it isn't the ambient air.
Yes, the addition of people and/or candles(making sure there are air holes in the sides and top of the shelter) will warm it up to the point of the melting of water.
Slept in a few myself when I was young and invincible.
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jaydeehess
Penultimate Amazing
John Nowak
Graduate Poster
Minor glitch: I said 0.00126, not .000126.
I believe his mantissa is always a number less than 10; there's an implied decimal after the 1. Thus, 1.26 x 10-3.
John Nowak
Graduate Poster
I'm in full agreement.
JayUtah
Penultimate Amazing
The document I thought had the actual numbers in it, didn't. Let me pick through my library.
jaydeehess
Penultimate Amazing
Like I said "less" confusing????
Now we just imply where the decimal point is supposed to be, and that whole hot mess that deals with numbers smaller than zero, and have a good percentage more high school students run away from science and engineering because we not only use letters for variables but also introduce a couple into numbers themselves.
Hell, compared to this idiotic number notation, understanding the dissipation of heat in re-entry vehicles is easy-peasy.
jaydeehess
Penultimate Amazing
Let me guess though that it's a damn sight less than goes into raising the temperature of the spacecraft?
To this non-engineer one thing is quite obvious, the air below the capsule is not static, it heats up and flows away to be replaced by cooler air. A torch would be the opposite, it heats up gases that are then directed to an object, those gases may flow away but are being replaced by more, previously heated gases
JayUtah
Penultimate Amazing
Yes, there is a convective component to the model. There is also a radiant component whereby the heated atmospheric gas applies heat to the heat shield via infrared. That's part of the brilliance of the design: the gases produced in the ablation process are substantially opaque to infrared. This principle is also applied in ablative linings for rocket nozzles.
John Nowak
Graduate Poster
True enough. Look how hard it was to figure it out.
JayUtah
Penultimate Amazing
I predict that Wogoga, if he responds at all to this critique of his system, will just say you're obviously not mathematically competent and can't see the genius inherent in his invention.
jaydeehess
Penultimate Amazing
I did not mean to imply that convection was the only or even primary form of heat transfer.
However, to any layman it is the most obvious.
Have a too hot cup of coffee, blow on it. Blow more air on it faster and see the temp lower faster.
The ablative process should be fairly obvious to any science minded lay person as well. It takes heat to cause something to change phase. When we boil water the temp of the water does not go up beyond that of its boiling point which is why boiling is called a low temperature cooking process. It is also why altitude affects cooking time when boiling (a matter fully understood and taught in Home Economics classes when I was a kid)
The steam produced can otoh be raised well above the temp of boiling water.
So yeah, I also see that heating a heat shield to the point that causes it to become a gas will mean that the still solid part of that shield cannot yet be above its phase change temp.
jaydeehess
Penultimate Amazing
I still don't get it,,, thought I did,,, nope apparently I don't.
otoh I recall having absolutely no trouble at all when I was 12-13 years old and being taught scientific notation.
It
Made
Sense
Hell, significant digits was harder. Maybe it's just because I am a Canuck, you know, American Light.
John Nowak
Graduate Poster
No bet; you're probably correct.
Dave Rogers
Bandaged ice that stampedes inexpensively through
John Nowak
Graduate Poster
I wouldn't be too worried about it - I'm intrigued by nomenclature, so it was fun for me to play with. But "not getting it?" I don't blame you. It's a silly notation system notably inferior to the ones in use.
John Nowak
Graduate Poster
Mainstream cult physics, without a doubt.
I got the physics reward in my high school; never was able to grasp the math behind quantum mechanics.
JayUtah
Penultimate Amazing
Yup, brainwashed by the Powers That Be.
I've literally had hoax theorists tell me the entire engineering profession has been brainwashed by folks answering to NASA, for decades now. That's why the entire mainstream engineering profession accepts Apollo as real when it "clearly" isn't.
Jrrarglblarg
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Citation, please.
jaydeehess
Penultimate Amazing
I had no trouble getting my college diploma in electronic technology. But that was in the 80s, after all its not like designing a cct requires doing math. Nah, just insert various value components until you get operation something like what you had in mind.
jaydeehess
Penultimate Amazing
Citing my personal experience. We would leave the hut, go ice fishing for hours, come back and the hut interior was warmer than exterior air.
Jrrarglblarg
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Numberless anecdote rejected.
The soil maintains a constant temperature of roughly 50 degrees F, but way below the surface. There are laws and building codes for how deep posts and pilings need to be sunk, for that reason. Fence or sign posts that are set too shallow tend to get shoved up out of the soil by the action of freezing water expanding. In the sign industry around here, 4x4 posts are set 30" deep, minimum, deeper in colder parts of the state (higher altitude). The soil below what is called "frost line" never freezes (never? Well, hardly ever), so if the posts or pilings are standing on that they won't frost heave.
The soil above frontline will be cold, and variable depending on insolation and ambient temperatures. The soil 6" down below your snow cave might even be colder than ambient, if the temps have been down for a while.
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jaydeehess
Penultimate Amazing
Frost heaving and frost line are well known in areas above 49N
Yes, and the temp of the soil between that constant temp layer and the surface is a gradient, and between there and the top of the snow is also a gradient that reaches the ambient air temp at the transition between snow and air ( at night or in deep shade).
Around here that ambient air can easily reach -30 C and snow cover easily be 3 feet. Our posts, pilings, water lines, sewer lines all need to be 6 feet down and even then we get frozen municipal water supply lines freezing if snow cover is light and temps stay too low too long. Septic fields sport frost fences to keep animals and snowmachines from packing the snow down, destroying insulative properties and freezing the field.
Nowadays it would be fairly easy to get temps involved in a snow hut at it's completion and over an unoccupied time period. Can purchase a remote digital thermometer at Canadian Tire for under $30. Maybe my daughter will give me permission to put my grandkids to work making one in the back yard in February. Unfortunately my health issues would mean it would take me a few days to pile up the snow and hollow it out. (A sure path to possible tragic failure)
Interesting but I suspect OT.
Back in my teens we would see what it took to destroy them before we left. You could get up on top and jump, hard, on it and even then only a knockout the size of your feet would punch through, often leaving you hanging by the armpits.
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Jrrarglblarg
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Your window of opportunity for this experiment will precede mine.
But I'm willing to try it here when we finally get snow. Actually, this year I expect massive snowfall, as I think that's where we are in the cycle-ish weather pattern of dry and wet winters here. I'm in the market for a new remote thermometer gizmo anyway, I guess I'll lurk Home Depot for the multi-sensor package to go on sale. One for ambient, one for the chicken coop and another dedicated to mad science would be ideal.
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jaydeehess
Penultimate Amazing
Your window of opportunity for this experiment will precede mine.
I'm in the market for a new remote thermometer gizmo anyway, I guess I'll lurk Home Depot for the multi-sensor package to go on sale. One for ambient, one for the chicken coop and another dedicated to mad science would be ideal.
Great.
I also contacted a professor at the University of Manitoba, who does a lot of work on cold weather survival.
I kept the email to the point not giving hint to which take on this point I fall on. I'll pm you a copy.
Jrrarglblarg
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Awesome, I look forward to it.
See, despite the efforts of woo merchants, we can find ways to discuss actual science around here. This is much more interesting discussion and useful to the OP topic than wogoga's number system. Because it's about heat flow, heat retention and heat rejection.
See, despite the efforts of woo merchants, we can find ways to discuss actual science around here. This is much more interesting discussion and useful to the OP topic than wogoga's number system. Because it's about heat flow, heat retention and heat rejection.
Slowvehicle
Membership Drive , Co-Ordinator,, Russell's Antin
I look forward to the responses...and will (if the snow allows) build one of my own for a third data point.
Jrrarglblarg
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As you know, Bob, heat is transferred by convection, conduction, and radiation. Our sensory apparatus for measuring temperature is flawed in that it measures subjectively the skin surface temperature compared to the internal body temperature and how much heat we are dumping. When we have a fever our skin surface is hot, and we feel hot, but we also feel cold because our body is dumping heat. Most of that is convective heat flow but radiative heat flow is very important to our sense of temperature.
You are a Snickers powered meat candle illuminating the universe in the 30THz region. Have you ever been in an old house with heavy plaster walls? In cold weather the walls will never come up to room temperature, so your body heat radiates out and is absorbed by the walls. Even though the air temp will be at the comfort zone, you will always feel chilly. When the walls are warmer, they are radiating heat nearer your radiated temperature, with the net result that your body heat "reflects back" to you and you don't feel chilly. This is why radiant subfloor heating is so effective - the air temperature can be in the lower end of normal house comfort zone or below and still not feel chilly. Sorta.
So stepping into an igloo, quinzee or snow cave from outdoors, you are no longer illuminating sky, frozen trees and cold ground with your body heat, and even small air flow (convective, anyone) from wind or walking will continuously strip the thin layer of body-warmed air from your skin surface, so sitting down in still air will allow the air nearest your body to warm and stay close.
You are a Snickers powered meat candle illuminating the universe in the 30THz region. Have you ever been in an old house with heavy plaster walls? In cold weather the walls will never come up to room temperature, so your body heat radiates out and is absorbed by the walls. Even though the air temp will be at the comfort zone, you will always feel chilly. When the walls are warmer, they are radiating heat nearer your radiated temperature, with the net result that your body heat "reflects back" to you and you don't feel chilly. This is why radiant subfloor heating is so effective - the air temperature can be in the lower end of normal house comfort zone or below and still not feel chilly. Sorta.
So stepping into an igloo, quinzee or snow cave from outdoors, you are no longer illuminating sky, frozen trees and cold ground with your body heat, and even small air flow (convective, anyone) from wind or walking will continuously strip the thin layer of body-warmed air from your skin surface, so sitting down in still air will allow the air nearest your body to warm and stay close.
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jaydeehess
Penultimate Amazing
The professor got back to me saying that with no other heat source, interior and exterior temps will be the same after sitting empty.
Though it seems no one has tried it.
Is a foot of snow enough insulation to create a gradient between interior and exterior? When heat is lost from the earth as frost goes further down, is there enough flow to cause a noticeable gradient?
I did find this:
http://www.fsavalanche.org/temperature-gradient/
although in avalanche prone areas the snow pack would be very deep.
Though it seems no one has tried it.
Is a foot of snow enough insulation to create a gradient between interior and exterior? When heat is lost from the earth as frost goes further down, is there enough flow to cause a noticeable gradient?
I did find this:
http://www.fsavalanche.org/temperature-gradient/
although in avalanche prone areas the snow pack would be very deep.
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threadworm
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Thread snowdrift.
Jrrarglblarg
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The topic flaked out. It's still about heat flow.
The Hindu-Arabic numeral system is apriori simpler and more effective than the Roman numerals. Nevertheless, to the persons having grown up with Roman numerals, the new decimal system seemed more confusing than the accustomed one.
Thus, as long as you have to translate e.g. 8p2998 m/s into 299,800 km/s, or 0n25 meter into 2.5 Angstrom = 2.5 x 10^-10 meter, the new systems only represents an additional complication. Yet if you have assimilated the concept eight.po as "hundred mega" (2p1 ∙ 6p1), or as "zero point one billion" (…999n1 ∙ …009p1), or as "ten raised to the power of eight", then 8p2998 is easily recognizable as around "eight.po three = 8p3". And in a mental calculation it is easier to use the concept "eight.po two nine nine eight meter" than "two hundred ninety nine thousand eight hundred kilo-meter".
From a logical point of view, it seems more reasonable to move from the general to the specific, e.g. starting with country, continuing with town, street, apartment, and ending with name of addressee. (It is true that postal address is written the other way round, but it is normally read from bottom to top by the postal service.) Thus in principle, we should even start with the unit. Order of magnitude is meaningless without unit. And significant digits are meaningless without order of magnitude and unit. (One must not confuse the absence of a unit with the default unit piece.)
From the psychological point of view, it is less demanding to understand "meter eight.po three eight four" than "three-point-eight-four times ten-raised-to-the-power-of-eight meter". After "meter" we know that we deal with distance in space, after "meter eight.po three" we may recognize a distance close to a light-second. The rest simply adds less and less important accuracy.
The principle is more straightforward: In order to get a negative exponent, we simply apply the standard subtraction rule, i.e. we regularly subtract from zero:
…01000 minus …00001 equals …00999
…00100 minus …00001 equals …00099
…00010 minus …00001 equals …00009
…00001 minus …00001 equals …00000
…00000 minus …00001 equals …99999
pi = …000p314159… ≈ 0p31416 = p31416 ≈ p314
1/pi = …999n318309… ≈ 9n31831 = n31831 ≈ n318
…00100 minus …00001 equals …00099
…00010 minus …00001 equals …00009
…00001 minus …00001 equals …00000
…00000 minus …00001 equals …99999
pi = …000p314159… ≈ 0p31416 = p31416 ≈ p314
1/pi = …999n318309… ≈ 9n31831 = n31831 ≈ n318
Let us also reexamine "83n375 ∙ 90n2 = 73n75" (3.75 x 10^-17 ∙ 2 x 10^-10 = 7.5 x 10^-27) of my previous post. 83n means an exponent of …99983 (i.e. 17 below zero). 90n means an exponent of …99990 (i.e. 10 below …00000). In this system multiplication of numbers always results in direct addition of exponents. So we get "…99983 + …99990 = …99973" resp. "83n ∙ 90n = 73n".
I always get confused when I have to multiply or divide numbers in scientific notation with negative exponents. In the system proposed here, multiplication always results in addition, and division in subtraction of an exponent. And computer science demonstrates every day that implementing negative numbers by regular subtraction from zero works fine.
If you have learned the elementary charge as 1.602 x 10^-19 Coulomb, then creating the exponent by regular subtraction from zero as in 81n1602 Coulomb obviously seems more complicated. Yet after having grasped the principle of regular subtraction from zero, you can logically derive the meaning of 81n16 C. In case of 160 Zepto-Coulomb or 0.16 Atto-Coulomb however, the meaning is much less straightforward.
What is the electric charge of the electrons of one mole of hydrogen (with total weight of 1 gram = 7n1 kg). One mole of hydrogen contains 23p6022 ≈ twenty.three.po six electrons with each an elementary charge of 81n1602 C ≈ eighty.one.ne one six Coulomb. As 23p6 = 23p1 ∙ 0p6 and 81n16 = 81n1 ∙ 0p16 we get 23p1 ∙ 81n1 ∙ 0p6 ∙ 0p16 = 4p1 ∙ 0p96 = 4p96 ≈ 5p1 Coulomb = 100 kiloC.
How much energy corresponds to 1 kg according to E = mc2? E ≈ 1 kg ∙ 8p3 m/s ∙ 8p3 m/s = 16p9 kg m2/s2 = sixteen.po nine Joule.
When you do similar calculations with Apollo units such as slugs for mass (see #196) and miles for distance, then such simple mathematical relations become quite opaque.
Such reading would destroy the main advantage of the number system, which is easy recognizability of orders of magnitude. The most important information is next to the po-ne-indicator: 3p126. In case of 23p6022.1408, the last digit "8" is the least important part. For comparison: 6.022,140,8 x 10^23.
The decisive point: 66n = six.six.ne or sixty.six.ne is a schematically created concept in the same way as 'ten' = one.po, 'hundred' = two.po, and 'nano' = one.ne. And "six.six.ne six six two six" is also shorter and simpler than "six point six two six exponent minus thirty four".
All my examples and calculations of this thread are correct; at least nobody has brought forward evidence that they are wrong. The only relevant error I am aware of is post #1, corrected already in my next post. The most important post is probably #196, after which the thread degenerated more and more.
Cheers, Wolfgang
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threadworm
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Except nobody has grown up with them because they are more complex than Arabic numerals, which is why no-one uses them.
[...snip...]
No they aren't, and yes they have.
JayUtah
Penultimate Amazing
No they aren't. But your problem doesn't lie so much in arithmetical error as it does in conceptual incompetence. How you think heat shields work is not how they actually work. You can express your wrong model as arithmetically as you want, but it doesn't make it any more correct.
Wow. Just, wow.