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John VanSickle wrote:
> Darren New wrote:
>> John VanSickle wrote:
>
>>> Many things claimed by the non-religious worldview (such as the age
>>> of the earth) demand that things like the speed of light and the
>>> decay rate of radioactive isotopes have always had the values we
>>> measure them to have today.
>>
>> No they don't. They're measured in different ways and they agree.
>
> Although if the values for these constants are in fact the result of
> more fundamental properties of space and matter, then any shift in one
> could only happen with a corresponding shift in the others (for
> instance, the electric constant, the magnetic constant, and the speed of
> light, are all interrelated), and our benchmark is moving.
But that means it didn't change. If everything gets shorter, including your
measuring sticks, then nothing changed. That's exactly how relativity works.
In any case, I'm talking about entirely independent measurements. The
progress of the seasons is measured against the radioactivity of carbon-14
which is measured against the tides caused by the moon which is measured
against the rate of mutations in different species, etc etc etc.
It's how people know the moon has been slowing down and moving away, for
example.
> It's a fair assumption to state that if miracles were happening in the
> world, science would be rather hobbled in its progress. If a Supreme
> Being wanted science to progress at the fastest possible rate, He would
> refrain from causing miracles.
Assuming the supreme being wanted scientific progress, which would seem to
be in variance to numerous major religions. :-)
--
Darren New, San Diego CA, USA (PST)
Yes, we're traveling together,
but to different destinations.
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andrel wrote:
>> How about the fact that the stars of the universe are all red-shifted
>> the farther they get from *us*? Or the fact that we seem to be the
>> only creatures in the entire *universe* that broadcast radio signals?
>
> For the latter see the Drake equation.
I'm familiar with it. What about it?
>> People don't say "the red shift shows everything is moving away from
>> us" or "humans happen to live where time passes fastest in the
>> universe." They say "the red shift shows everything is moving away
>> from everything else."
>
> We say that because we believe in Lorentz invariance.
Yep. That doesn't mean things are moving away from us. We can't measure
whether they're moving away from us. All we can measure is the red shift.
The assumption is that the red shift is caused by relative motion, and not
the geometry of the universe.
--
Darren New, San Diego CA, USA (PST)
Yes, we're traveling together,
but to different destinations.
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scott wrote:
>> How about the fact that the stars of the universe are all red-shifted
>> the farther they get from *us*?
>
> Once you have the information about the surrounding stars, isn't it
> quite trivial to show that from the point of view of *any* star, all
> other stars are red-shifted more the further away they are?
Only if you assume they're red-shifted *because* they're moving apart.
You're assuming that if you're in a distant galaxy and look back towards
ours, ours too will be red-shifted, rather than blue-shifted. If, on the
other hand, we were in the middle of the universe and time just happened to
run fastest here, then we would be blue-shifted compared to other galaxies.
> Why the assumption that any intelligent lifeform would be broadcasting
> radio signals for any significant time in its existence? To me that
> seems silly. Earth has been broadcasting radio for 100 years out of 4.5
> billion, maybe we will continue to do so for another 10000 years until
> we find something better? Those timescales are tiny compared to the
> variation in ages of other stars.
There's lots of discussion about what we should have found, including von
Neumann probes and such. I think there are a lot of good arguments that (for
example) given what we've accomplished in the last 100 years, someone who
evolved intelligence only one billion years ago should already have
colonized the galaxy. The big numbers work both ways.
> Also, really can you detect the radio signals from Earth more than a few
> light years away? Isn't the signal going to be incredibly tiny and
> virtually impossible to detect? And that's just a few light years, what
> about the other planets billions of light years away?
That's the argument, yes. It's certainly not conclusive. We can tell what
planets have atmospheres and water from here, only 100 years after steam power.
--
Darren New, San Diego CA, USA (PST)
Yes, we're traveling together,
but to different destinations.
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On 30-3-2010 18:11, Darren New wrote:
> andrel wrote:
>>> How about the fact that the stars of the universe are all red-shifted
>>> the farther they get from *us*? Or the fact that we seem to be the
>>> only creatures in the entire *universe* that broadcast radio signals?
>>
>> For the latter see the Drake equation.
>
> I'm familiar with it. What about it?
All we know that there are no radio signals broadcasted from a place
exactly the right time ago to be just reaching us now, send towards us,
and in a format that we recognize. Which is quite a long way away from a
conclusion that no signals are send at all.
>>> People don't say "the red shift shows everything is moving away from
>>> us" or "humans happen to live where time passes fastest in the
>>> universe." They say "the red shift shows everything is moving away
>>> from everything else."
>>
>> We say that because we believe in Lorentz invariance.
>
> Yep. That doesn't mean things are moving away from us. We can't measure
> whether they're moving away from us. All we can measure is the red
> shift. The assumption is that the red shift is caused by relative
> motion, and not the geometry of the universe.
I don't understand that last sentence, but that may be my physics
background.
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andrel wrote:
> On 30-3-2010 18:11, Darren New wrote:
>> andrel wrote:
>>>> How about the fact that the stars of the universe are all
>>>> red-shifted the farther they get from *us*? Or the fact that we
>>>> seem to be the only creatures in the entire *universe* that
>>>> broadcast radio signals?
>>>
>>> For the latter see the Drake equation.
>>
>> I'm familiar with it. What about it?
>
> All we know that there are no radio signals broadcasted from a place
> exactly the right time ago to be just reaching us now, send towards us,
> and in a format that we recognize. Which is quite a long way away from a
> conclusion that no signals are send at all.
Yes. Hence the "seems to". Anyway, you understand my point even if you
disagree. :-)
>> Yep. That doesn't mean things are moving away from us. We can't
>> measure whether they're moving away from us. All we can measure is the
>> red shift. The assumption is that the red shift is caused by relative
>> motion, and not the geometry of the universe.
>
> I don't understand that last sentence, but that may be my physics
> background.
We assume that the distant galaxies are red-shifted *because* they are
moving away from us. We don't assume that the Milky Way has the lowest speed
of light in the universe, or that time runs slower the farther you get from
humanity, or that the gravitational constant is slowly increasing the
farther you get from humanity. *If* you assume that all other places in the
universe will see the same thing when they look around, *then* all the
galaxies must be moving away from each other. *If* you assume we're in a
unique and privileged place in the universe, there are all kinds of things
that could be causing it.
--
Darren New, San Diego CA, USA (PST)
Yes, we're traveling together,
but to different destinations.
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On 30-3-2010 20:15, Darren New wrote:
> andrel wrote:
>> On 30-3-2010 18:11, Darren New wrote:
>>> andrel wrote:
>>>>> How about the fact that the stars of the universe are all
>>>>> red-shifted the farther they get from *us*? Or the fact that we
>>>>> seem to be the only creatures in the entire *universe* that
>>>>> broadcast radio signals?
>>>>
>>>> For the latter see the Drake equation.
>>>
>>> I'm familiar with it. What about it?
>>
>> All we know that there are no radio signals broadcasted from a place
>> exactly the right time ago to be just reaching us now, send towards
>> us, and in a format that we recognize. Which is quite a long way away
>> from a conclusion that no signals are send at all.
>
> Yes. Hence the "seems to". Anyway, you understand my point even if you
> disagree. :-)
yes
>>> Yep. That doesn't mean things are moving away from us. We can't
>>> measure whether they're moving away from us. All we can measure is
>>> the red shift. The assumption is that the red shift is caused by
>>> relative motion, and not the geometry of the universe.
>>
>> I don't understand that last sentence, but that may be my physics
>> background.
>
>
> We assume that the distant galaxies are red-shifted *because* they are
> moving away from us. We don't assume that the Milky Way has the lowest
> speed of light in the universe, or that time runs slower the farther you
> get from humanity, or that the gravitational constant is slowly
> increasing the farther you get from humanity. *If* you assume that all
> other places in the universe will see the same thing when they look
> around, *then* all the galaxies must be moving away from each other.
> *If* you assume we're in a unique and privileged place in the universe,
> there are all kinds of things that could be causing it.
hence my "We say that because we believe in Lorentz invariance" as a
abbreviation of a couple of paragraphs like the one above ;)
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andrel wrote:
> hence my "We say that because we believe in Lorentz invariance" as a
> abbreviation of a couple of paragraphs like the one above ;)
Lorentz invariance would explain it if time was running slower or the speed
of light was different farther away as well.
--
Darren New, San Diego CA, USA (PST)
Yes, we're traveling together,
but to different destinations.
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On 30-3-2010 20:29, Darren New wrote:
> andrel wrote:
>> hence my "We say that because we believe in Lorentz invariance" as a
>> abbreviation of a couple of paragraphs like the one above ;)
>
> Lorentz invariance would explain it if time was running slower or the
> speed of light was different farther away as well.
>
No, differential time- and lightspeeds are incompatible with lorentz
invariance of physical laws, because they should be invariant under
translation and uniform velocity changes.
In particular Maxwell's equations are lorentz invariant and they imply a
*constant* velocity at which E and B fields propagate (generally known
as c).
It might be possible to modify Maxwell's equations to allow timevarying
lightspeed and find a new invariant that for times close to our own
reduces to Lorentz invariance, but I have not heard of anybody doing
that trick.
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On 3/28/2010 3:53 PM, Darren New wrote:
> Patrick Elliott wrote:
>> Still, its an interesting idea, and explains nicely why your desk will
>> never "jump" all into one corner of the room, for no reason.
>
> I think we already knew that. If you work out the probability that
> happens, it's exceedingly low.
>
Well, not really. The presumption is still that it *can* do so. However,
if there is a limit on what things can do that, such that a desk doesn't
simply have almost "no" chance of doing such a thing, but *absolutely no
chance*, then you have a difference situation. That is the point.
Standard QM insists its possible, just so insanely improbable that you
will never see it happen. But, if QM gets even more greatly limited, or
virtually switched off, for objects whose size and density exceeds some
specific factor... That is a whole different ball game, since it means
your QM is trapped, like air in a balloon, and no longer has the "range"
needed to cause you desk to do such a thing.
--
void main () {
If Schrödingers_cat is alive or version > 98 {
if version = "Vista" {
call slow_by_half();
call DRM_everything();
}
call functional_code();
}
else
call crash_windows();
}
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Patrick Elliott wrote:
> Well, not really. The presumption is still that it *can* do so. However,
> if there is a limit on what things can do that, such that a desk doesn't
> simply have almost "no" chance of doing such a thing, but *absolutely no
> chance*, then you have a difference situation. That is the point.
Well, sure, but I never heard of anyone postulating that.
> Standard QM insists its possible, just so insanely improbable that you
> will never see it happen. But, if QM gets even more greatly limited, or
> virtually switched off, for objects whose size and density exceeds some
> specific factor... That is a whole different ball game, since it means
> your QM is trapped, like air in a balloon, and no longer has the "range"
> needed to cause you desk to do such a thing.
QM also has probabilities that cancel out, such that there's zero
probability of something happening in a combination where either individual
event could happen. E.g., electron 1 might go to location X[*]. Electron 2
might go to location X. Electron 3 might go to location X. But there is zero
probability that all three will go to location X. Also, the likelihood that
a photon will go somewhere far away at anything other than very close to the
speed of light is zero (and not just very low), because the probabilities
actually cancel out. You don't need to postulate an upper size on QM
locality to get impossible events. And when "improbable" is "1/10^500 that
any particle in the universe will ever do that", then yeah, that's pretty
much impossible too.
[*] "location" in spacetime, i.e., an "event".
--
Darren New, San Diego CA, USA (PST)
Yes, we're traveling together,
but to different destinations.
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