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Computer Org
Skeptic Friend
392 Posts |
 Posted - 07/25/2003 : 09:57:47 [Permalink]
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quote:
Originally posted by Computer Org
quote:
Originally posted by Dr. Mabuse
quote:
Originally posted by NubiWan
".., on average every 100,000 years." 20 million years, 60 reversals..., BUZZZZZ!!! Does not compute!
If GOD wasn't specific about numbers when He dictated the Bible, then we shoudln't be held accountable for a miscalculation every now and then... 
Uh. Err. But which of the numbers is right?- "On average every 100,000 years"? or
- "20 million years, 60 reversals"?
Ah, well: I answer my own question (for NubiWan) by using jmcginn's original link to NASA ( Ye Olde Link ).
To quote from NASA's page:quote:
"Simple (Ho, ho!) formulae derived from the electrodynamical equations of such a system yield a polarity reversal time that depends on the conductivity and rotation of the body. For the Sun, these factors lead to a short 11-22 year reversal time, for the Earth you get reversal times in the 100,000 year range. During the last 20 million years the fossil record shows 60 reversals, and that the period between reversals seems to be slowly decreasing and getting shorter. But, looking at the Sun again, we know that for some systems, these reversals can abruptly stop for many cycles. This happened during the Maunder and Sporier Sunspot Minima in the 1600s. We don't know if the Earth is like this or not." 
(chuckles, emphasis, and smiley added)
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Do thou amend thy face, and I'll amend my life. --Falstaff |
| Edited by - Computer Org on 07/25/2003 10:10:45 |
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Darwin Storm
Skeptic Friend
87 Posts |
Posted - 07/25/2003 : 10:33:37 [Permalink]
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quote:
Originally posted by Phobos
Good point, Sanity.
Perhaps a more interesting question from a mystic (one that I have not heard from them) would be the coincidence of the moon's apparent size as compared to the sun (essentially identical) such that total eclipses are possible. Given that the moon's orbit is changing, at one time in the past and at some point in the future, total eclipses will not be possible. Someone may conclude we live in a special time.
It just plain coincidence. If our species lasts more than 100,000 years, our descendents will never see an eclipse ( I think that is the right time frame, it is guite small).
In the not to distant past (about the same time frame backwards), eclipses were total and completely blocked the sun and corona. |
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Dave W.
Info Junkie
USA
26022 Posts |
Posted - 07/25/2003 : 22:59:45 [Permalink]
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Okay, let's do the math:
The full image is 2,777 pixels high. Approximately 43 pixels on the top and bottom of the image are wasted on the blackness of space, leaving us with a Moon image that is 2,691 pixels tall. The polar diameter of the Moon is 3,472 kilometers, or 2,152.64 miles, or 11,365,939.2 feet, so the entire image is about 4,224 feet-per-pixel. "Beta in the Leibnitz Range," at 36,000 feet, would be about 8.52 pixels tall.
Since the biggest "lumpiness" I think I can measure on the edge of the Moon in that big image is just 2 or 3 pixels, that represents just 8 or 12 thousand feet - relatively small for a body without erosional processes.
So, it's probably not just compression artifacts that I'm seeing, it's the actual lumpiness of the Moon. That is very, very cool.
Oh, and since the Earth's polar diameter is 12713.6 km, we'd need a photo at least 9,854 pixels tall to get the same amount of lumpiness as in this Moon photo. Whole-Earth pictures with better than one-mile resolution aren't all that common.
Phobos wrote:quote:
Perhaps a more interesting question from a mystic (one that I have not heard from them) would be the coincidence of the moon's apparent size as compared to the sun (essentially identical) such that total eclipses are possible.
Carl Sagan, in his book Broca's Brain, talks about some character (can't recall his name) who claimed to be a "Messenger of God." This guy said (according to Sagan, per my memory - my copy of the book is packed away):
1) The Sun and the Moon both take up approxiamtely half a degree of angular space when viewed from Earth.
2) There are 360 degrees in a circle, so half a degree is 1/720th of a circle.
3) 720 equals 6 factorial, or 6x5x4x3x2x1.
4) Therefore, God exists.
This "logic," of course, is unassailable.
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- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too. |
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Sanity
New Member
19 Posts |
Posted - 07/26/2003 : 14:05:09 [Permalink]
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quote:
Originally posted by Phobos
Someone may conclude we live in a special time.
quote:
Originally posted by Darwin Storm
It's just plain coincidence.
To some people, coincidences are never plain. They always must mean something or have special significance (usually in a way related to the person). Hence Phobos's observation that sooner or later, someone will make that claim - provided, of course, they happen to pay enough attention to science to find out that eclipses will go away in the future.
The ancient observation that everything must have as its ultimate cause a sentient goal is still with us. This is the conclusion our brains will come up with through its method of matching information, unless that brain possesses sufficient information about science, critical thinking, and probabilities. The last two aren't taught in schools. The first is barely taught. According to a Gallup Poll, as late as 1999, 18% of US adults thought the Sun revolves around the Earth. 3% weren't sure which revolved around which.
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hippy4christ
Skeptic Friend
193 Posts |
Posted - 07/26/2003 : 14:38:56 [Permalink]
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Hi guys,
On another note, is there any answer as to why water expands when it freezes, while everything else still contracts? Are there any other natural substances that expand when frozen? |
Faith is believing what you are told, whether it's by a priest or a scientist. A person's scientific beliefs are ones based on personal observation and experimentation.
Lists of Logical Fallacies |
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Fireballn
Skeptic Friend
Canada
179 Posts |
Posted - 07/26/2003 : 16:46:22 [Permalink]
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| Bismuth, a metal expands when cooled. |
If i were the supreme being, I wouldn't have messed around with butterflies and daffodils. I would have started with lasers 8 o'clock day one!
-Time Bandits- |
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Fireballn
Skeptic Friend
Canada
179 Posts |
Posted - 07/26/2003 : 16:47:29 [Permalink]
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| Where are you going with this Hippy? |
If i were the supreme being, I wouldn't have messed around with butterflies and daffodils. I would have started with lasers 8 o'clock day one!
-Time Bandits- |
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Darwin Storm
Skeptic Friend
87 Posts |
Posted - 07/26/2003 : 18:33:50 [Permalink]
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quote:
Originally posted by hippy4christ
Hi guys,
On another note, is there any answer as to why water expands when it freezes, while everything else still contracts? Are there any other natural substances that expand when frozen?
Generally, as substances transition to solid form, they arrange in tightly packed forms. Liqued is generally more mobile, and is generally less dense since the molecules are not locked into a rigid form, but are bouncing, sliding, and moving around each other.
Water, being a very small molecule, and having several interesting characterisics, beheves slightly differently. Its optimum desity is actually 4 degrees celcius. Even in liqued form, it is less dense at temperatures above and below this temperature. As water transits to crystal form (ie solid), its molecular geometry and arrangment form a stable lattice that is more spaced than liqued form. (This is partially due to its polar nature). I haven't taken alot of chemistry, so you could probably get a more precise answer, but the reasons are well understood. |
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Trish
SFN Addict
USA
2102 Posts |
Posted - 07/28/2003 : 19:11:19 [Permalink]
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Actually, geologists almost consider ice as a mineral since it does form a lattice. Hydrogen is negatively charged and oxygen is positively charged. Because of the structure, the little mickey mouse looking thing, when water freezes it likes to line up oxygen to 2 hydrogen to oxygen to 2 hydrogen. sorta like this:
* *
.0
* *
.0
* *
.0
Where the * are hydrogen and 0 are oxygen. ignore the . because it's just making the diagram work. |
...no one has ever found a 4.5 billion year old stone artifact (at the right geological stratum) with the words "Made by God."
No Sense of Obligation by Matt Young
"Say what you will about the sweet miracle of unquestioning faith. I consider the capacity for it terrifying and vile!"
Mother Night by Kurt Vonnegut, Jr.
They (Women Marines) don't have a nickname, and they don't need one. They get their basic training in a Marine atmosphere, at a Marine Post. They inherit the traditions of the Marines. They are Marines.
LtGen Thomas Holcomb, USMC
Commandant of the Marine Corps, 1943
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| Edited by - Trish on 07/28/2003 19:12:38 |
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ddlewis86
New Member
USA
1 Post |
Posted - 07/30/2003 : 09:42:57 [Permalink]
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quote:
Originally posted by hippy4christ
On another note, does anyone know how fast a magnetic field decays? Another argument I've heard used is that if the earth were 14 billion years old, its magnetic field would have decayed by now. I have no knowledge of this, but does anyone else?
Hippy
I didn't think the magnetic force decays inasmuch as it reverses it's polarization. ????? |
Romans 8:10
But if Christ is in you, your body is dead because of sin, yet your spirit is alive because of righteousness.
Romans 8:16
The Spirit himself testifies with our spirit that we are God's children.
 
Robert Jastrow (self-proclaimed agnostic):
"For the scientist who has lived by his faith in the power of reason, the story ends like a bad dream. He has scaled the mountains of ignorance; he is about to conquer the highest peak; as he pulls himself over the final rock, he is greeted by a band of theologians who have been sitting there for centuries."
John O'Keefe (astronomer at NASA):
"We are, by astronomical standards, a pampered, cosseted, cherished group of creatures.. .. If the Universe had not been made with the most exacting precision we could never have come into existence. It is my view that these circumstances indicate the universe was created for man to live in."
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jmcginn
Skeptic Friend
343 Posts |
Posted - 08/04/2003 : 09:27:22 [Permalink]
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quote:
Originally posted by Computer Org
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Computer Org
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Dr. Mabuse
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">Originally posted by NubiWan
".., on average every 100,000 years." 20 million years, 60 reversals..., BUZZZZZ!!! Does not compute!
If GOD wasn't specific about numbers when He dictated the Bible, then we shoudln't be held accountable for a miscalculation every now and then... [/quote]Uh. Err. But which of the numbers is right?- "On average every 100,000 years"? or
- "20 million years, 60 reversals"?
[/quote]Ah, well: I answer my own question (for NubiWan) by using jmcginn's original link to NASA ( Ye Olde Link ).
To quote from NASA's page:<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">"Simple (Ho, ho!) formulae derived from the electrodynamical equations of such a system yield a polarity reversal time that depends on the conductivity and rotation of the body. For the Sun, these factors lead to a short 11-22 year reversal time, for the Earth you get reversal times in the 100,000 year range. During the last 20 million years the fossil record shows 60 reversals, and that the period between reversals seems to be slowly decreasing and getting shorter. But, looking at the Sun again, we know that for some systems, these reversals can abruptly stop for many cycles. This happened during the Maunder and Sporier Sunspot Minima in the 1600s. We don't know if the Earth is like this or not."
(chuckles, emphasis, and smiley added)[/quote]
[/quote]
Doh! Sorry about the really bad math :> Was getting ready to leave for vacation and division became really really hard :> |
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jmcginn
Skeptic Friend
343 Posts |
Posted - 08/04/2003 : 09:29:31 [Permalink]
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quote:
Originally posted by ddlewis86
quote:
Originally posted by hippy4christ
On another note, does anyone know how fast a magnetic field decays? Another argument I've heard used is that if the earth were 14 billion years old, its magnetic field would have decayed by now. I have no knowledge of this, but does anyone else?
Hippy
I didn't think the magnetic force decays inasmuch as it reverses it's polarization. ?????
Yes in this case "decay" is a terrible term. Yes the location of the poles and the magnetic force does fluctuate including reversals. Decaly implies that eventually it will drop down to zero which may only happen when our core solidifies??? Maybe someone better versed in physics could answer that one. |
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