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PlasteredDragon
2009-Aug-30, 02:40 AM
Can someone please help? I'm arguing with a YEC (yeah that's a mistake right there I know) and he's blurted out some new propaganda that I've never heard before and can't find any information on. Can someone (a) tell me what it is he's confused about and (b) give me some advice as to how to respond? Here's what he said:

Decay of gravity is an interesting tidbit. We have been measuring gravity for 300 years and it has been decaying at a constant rate year after year. No biggie, except that life can only exist within a very smal window of fluctuation in gravity. If you reverse the measurements, assuming the same constant, the earth becomes unihabitabal in only 10,000 years, give or take. Thus, life on earth couldn't possibly be millions of years old.

Incomplete
2009-Aug-30, 03:18 AM
Can someone please help? I'm arguing with a YEC (yeah that's a mistake right there I know) and he's blurted out some new propaganda that I've never heard before and can't find any information on. Can someone (a) tell me what it is he's confused about and (b) give me some advice as to how to respond? Here's what he said:

Decay of gravity is an interesting tidbit. We have been measuring gravity for 300 years and it has been decaying at a constant rate year after year. No biggie, except that life can only exist within a very smal window of fluctuation in gravity. If you reverse the measurements, assuming the same constant, the earth becomes unihabitabal in only 10,000 years, give or take. Thus, life on earth couldn't possibly be millions of years old.

a) never heard that one before
b) it's not true.

There are a few details on the wiki http://en.wikipedia.org/wiki/Gravitational_constant#History_of_measurement

Van Rijn
2009-Aug-30, 03:37 AM
Can someone please help? I'm arguing with a YEC (yeah that's a mistake right there I know) and he's blurted out some new propaganda that I've never heard before and can't find any information on. Can someone (a) tell me what it is he's confused about and (b) give me some advice as to how to respond?

Welcome to BAUT. This is new to me too, though I don't spend much time following YEC arguments. My suggestion would be, if you choose to respond, ask for references. It will probably be some YEC website, but you might at least be able to get more of the background for this notion.

Also, I find this interesting:

We have been measuring gravity for 300 years and it has been decaying at a constant rate year after year.

The margin of error is much smaller today than it would have been 300 years ago. It wouldn't surprise me if somebody is ignoring the limits of accuracy in some old measurement and is making a naive comparison to modern measurements.

Van Rijn
2009-Aug-30, 03:50 AM
Yes, looking at this a little further, I strongly suspect it is a naive comparison. From here, discussing the Cavendish experiment:

http://en.wikipedia.org/wiki/Cavendish_experiment#Did_Cavendish_determine_G.3F

After converting to SI units, Cavendish's value for the Earth's density, 5.448 g cm−3, gives

G = 6.74 × 10−11 m3 kg−1 s−2,

which is almost 1% error of the currently accepted value: 6.67259 × 10−11.

Notice the difference in the numbers. They're probably taking them as given, and ignoring error margins.

Incomplete
2009-Aug-30, 03:53 AM
Yes, looking at this a little further, I strongly suspect it is a naive comparison. From here, discussing the Cavendish experiment:

http://en.wikipedia.org/wiki/Cavendish_experiment

Notice the difference in the numbers. They're probably taking them as given, and ignoring error margins.

If that's it it's very easy to falsify. Just find some early and mid 20th century experiments. Error bars tend to fall exponentially with time; that will rule out the "constant decay" that was claimed.

astromark
2009-Aug-30, 04:41 AM
_:)Welcome 'Plastered Dragon'_ and as Incomplete has said; Its not true.
I smell a rat.
If Its got a long grey tail and looks like a large mouse. Its a rat.
I am not familiar with the abbreviation term YEC... Is it some Intelligent design bunch of woo, woo's ? But regardless,.. my advise is to not bother to attempt to tell or guide them. They can not be told. and when they are would never concede error. So turn your back and walk away... Education is the only remedy for stupidity., but you can not tell those that will not listen. Good luck & Welcome.:)mark.

Tenshu
2009-Aug-30, 05:08 AM
is this another question about the magnetic poles "shifting"?

Van Rijn
2009-Aug-30, 08:37 AM
is this another question about the magnetic poles "shifting"?

No, it's about a YEC (Young Earth Creationist) claim. They believe that the Earth/Universe were created only a few thousand years ago, though this is not supported by the evidence.

cjameshuff
2009-Aug-30, 04:39 PM
Can someone please help? I'm arguing with a YEC (yeah that's a mistake right there I know) and he's blurted out some new propaganda that I've never heard before and can't find any information on. Can someone (a) tell me what it is he's confused about and (b) give me some advice as to how to respond? Here's what he said:

Decay of gravity is an interesting tidbit. We have been measuring gravity for 300 years and it has been decaying at a constant rate year after year. No biggie, except that life can only exist within a very smal window of fluctuation in gravity. If you reverse the measurements, assuming the same constant, the earth becomes unihabitabal in only 10,000 years, give or take. Thus, life on earth couldn't possibly be millions of years old.

As others mentioned, they're probably taking past inaccurate measurements as being exact.

The laser retroreflectors left on the moon by the Apollo mission have allowed recent measurements that are extremely sensitive to changes in G, and those measurements eliminate changes larger than 1.1e-12/year. At worst, assuming constant "decay", 13 billion years ago it was within 1.5% of its current value. A mere 10000 years ago, it could not have been different by more than 0.0000011%.

See page 5:
http://ilrs.gsfc.nasa.gov/docs/williams_lw13.pdf

Cougar
2009-Aug-31, 11:05 PM
...A mere 10000 years ago, it could not have been different by more than 0.0000011%.

Not only that, but Tony Rothman (Harvard GR prof.) has investigated this problem for at least one choice of variable-G theory and found that at three minutes after the Big Bang, G must have been essentially what it is now.

WayneFrancis
2009-Sep-01, 12:53 AM
This is a common YEC tactic. Though they often reuse completely discredited claims over and over they are not adverse to M.S.U. It plays into their camp.

It only takes them a few seconds to make the claim and often takes a lengthy explanation to discredit but that goes over the heads of the gullible sheep in their flock or the naive fence sitters.

Not saying this person made it up. He or she probably heard it from someone else and like most of what they believe they take it on faith. Not saying faith is bad but there is a difference in having faith on a spiritual topic and faith on a scientific topic. I don't have "faith" in any scientific detail. If there is a scientific claim then there should be data to support it and as much as possible I want to know that supporting data.

There are plenty of former YECers out there but sadly, from my experience, the ones that go out and make these kind of claims are generally not the ones that will bat an eye and concede that they where wrong even when shown. They'll just jump to the next point over and over and very often come back to this one even though they have been shown it was an out right lie.

I have a similar issue with many activists. They'll spit out sound bite after sound bite but not understand what they are even saying. The sound bite might be completely true but when you hear it from someone that obviously has no clue about what they are saying it looses its impact.

Jeff Root
2009-Sep-01, 03:34 AM
I think many people don't understand measurement error, and discount it
as unimportant. To them, any error is the same as a mistake. Somebody
goofed.

I further suspect that whenever you measure anything near the low end
of the range that you can detect, the tendency will be to get a value
which is too high. So the value of G should be expected to decrease
as measurements become more precise.

-- Jeff, in Minneapolis

SkyZesus
2009-Sep-03, 03:11 PM
No, it's about a YEC (Young Earth Creationist) claim. They believe that the Earth/Universe were created only a few thousand years ago, though this is not supported by the evidence.

YEC is completely insane to think that. Not only is there no evidence to prove it, but there is a lot of evidence to DISprove it.

GuyHill
2009-Sep-03, 06:15 PM
YEC is completely insane

You sure got that one right. See http://www.talkorigins.org/indexcc/list.html for an extensive list of their ludicrous claims.

to think that. Not only is there no evidence to prove it, but there is a lot of evidence to DISprove it.