Page 1 of 4

Radioactive Decay not a constant ?

Posted: Tue Nov 11, 2008 1:51 pm
by ravingdave
If true, it looks like we don't understand everything yet.


http://www.sciencenews.org/view/feature ... or_less%29



David

Posted: Tue Nov 11, 2008 2:07 pm
by Solo
Wow, that's interesting. Thanks for posting! It reminds me of the claims I heard from "young earth creationists" who needed to discredit radioisotope dating; this is much more convincing obviously. Someone was paying attention to detail.

Posted: Tue Nov 11, 2008 2:28 pm
by classicpenny
Solo wrote:It reminds me of the claims I heard from "young earth creationists" who needed to discredit radioisotope dating.
However, in this report, these are only variations in tenths of a percent. Young earth creationists would need variations by several orders of magnitude, to get the young (5000 yr old) earth they want.

Bill Flint

Posted: Tue Nov 11, 2008 3:12 pm
by Professor Science
I've often pondered over how universal the physics we've established. How is it we're positive all the observations we've made on earth would also occur elsewhere. We've flubbed up like that before with that whole air-resistance-falling thing.

Posted: Tue Nov 11, 2008 5:02 pm
by Betruger
Professor Science wrote:I've often pondered over how universal the physics we've established. How is it we're positive all the observations we've made on earth would also occur elsewhere. We've flubbed up like that before with that whole air-resistance-falling thing.
None of it's for sure. It's a continuous work in progress, an asymptotic progress towards the exact truth of the matter.
From desire ariseth the thought of some means we have seen produce the like of that which we aim at; and from the thought of that, the thought of means to that mean; and so continually, till we come to some beginning within our own power.
Our aim is precision.

Posted: Wed Nov 12, 2008 12:22 am
by Alchemist
I wonder how this would look if the Heim equations were were applied to it.

In Heim theory all of the various "universal" forces are considered to be related to multi-spacial geometry and magnetism and gravity are (greatly simplified) two sides of the same coin.

The Sun is the single largest gravitational influence in our solar system, and solar storms can cause variations in the sun's gravitational field.

So let's assume that it's not simply "the sun" affecting the rate of nuclear decay but actually "variations in the sun's gravity."

Given Heim's theory that the geometric structure of the universe is responsible for all of the universal forces and that a change in a major gravity field would also constitute a small change in the universal geometry. If Earth was at a point close to the sun or the the gravity variation was strong enough then the distortion in universal geometry would have propagated out far enough from the sun to have minor influence on the strong and weak nuclear forces of elements here on Earth. If the change caused a minuscule increase in one of the forces there would have been no effect on stable elements, but radioactive elements would have shown a decrease in radioactivity.

Sounds plausible to me.

Posted: Wed Nov 12, 2008 1:30 am
by Damon Hill
A possible test of that theory would be the decay rate of RTGs used to power planetary probes as they traveled far from the Sun. Was a measurable variation in the power decay observed? I don't recall any mention of unexpected changes from them.

Yes Cassini.

Posted: Wed Nov 12, 2008 2:12 am
by Helius
Damon Hill wrote:A possible test of that theory would be the decay rate of RTGs used to power planetary probes as they traveled far from the Sun. Was a measurable variation in the power decay observed? I don't recall any mention of unexpected changes from them.
They looked at Cassini and found no variation. Cassini, as you remember got 2 gravity boosts from Venus and one from Earth, before getting one from Jupiter, and flying out to Saturn. It might be that the Plutonium in the battery is less effected, or the whole thing is bogus.



We certainly need many more careful measurements (and zero uncareful ones). http://saturn.jpl.nasa.gov/mission/gravity-assists.cfm

Posted: Wed Nov 12, 2008 2:40 am
by Professor Science
If it's a purely spatial relationship than that would be solid proof, but if it's a spatial relationship, in addition to a velocity relationship, then something in an unpowered orbit would behave the same way all the time, wouldn't it?

Posted: Wed Nov 12, 2008 4:32 am
by drmike
It's not really about "constants" not being constant. These guys have to ensure tidal effects don't do something to their detectors before they invoke neutrino interactions.

It'd be cool if there is a nuclear or weak force interaction, especially since neutrino's oscillate. But there are simpler reasons to work with first.

As for constants not being constant - that was proposed by Dirac some 40 years ago and is a requirement of the Big Bang theory. The assumption is that things are still changing, we just can't measure it.

Posted: Wed Nov 12, 2008 4:46 am
by djolds1
Damon Hill wrote:A possible test of that theory would be the decay rate of RTGs used to power planetary probes as they traveled far from the Sun. Was a measurable variation in the power decay observed? I don't recall any mention of unexpected changes from them.
The Pioneer Anomaly?

Duane

Posted: Wed Nov 12, 2008 6:01 am
by icarus
Seems like an obvious question/experiment: has anybody measured if radioactive decay is affected by rotational acceleration?

Anybody ever put some caesium in a centrifuge and measured decay?

Posted: Wed Nov 12, 2008 2:01 pm
by drmike
The Pioneer anomaly is a ranging effect. But it could be we aren't measuring it correctly. And it could be that the tidal effects are not changing
the radioactive material, but they are changing the measuring equipment. A slight change in distance between detector and source might be in the range of .1% change in effective decay rate - the solid angle increases or decreases just enough to capture more or less decays. Kinda like 3 neutrons from a pulsed experiment telling you the total number of fusions actually occurring.

Posted: Wed Nov 12, 2008 3:18 pm
by Torulf2
The measuring equipment may stay on a table or on something how change length from temperature. The outdoor temperature change during the year and the indoor temperature may not be constant.

Posted: Wed Nov 12, 2008 3:50 pm
by Aero
There exists detailed information on the Pioneer Anomaly on Wikipedia for those who would like a refresher. It unfortunately does not seem to describe the ranging system used for pioneer. As I recall it used range "ping" and Doppler. I don't remember if it was one way, or echo Doppler but I think echo. And didn't the Pioneer 10 and 11 probes carry Cesium clocks?

From Wikipedia -

The effect is seen in radio Doppler and ranging data, yielding information on the velocity and distance of the spacecraft. When all known forces acting on the spacecraft are taken into consideration, a very small but unexplained force remains. It appears to cause a constant sunward acceleration of (8.74 ± 1.33) × 10−10 m/s2 for both spacecraft. If the positions of the spacecraft are predicted one year in advance based on measured velocity and known forces (mostly gravity), they are actually found to be some 400 km closer to the sun at the end of the year. The magnitude of the Pioneer effect is numerically quite close to the product of the speed of light and the Hubble constant, but the significance of this, if any, is unknown. ....

Read a lot more, here.

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