Just thinking today...

Kinda like you do when you sit on the pooper except that's not where I was.
Anyway, I was thinking what if we were able to measure the age of a photon of
light, sorta like how we can carbon date some tangible objects. What effect
could that have on the many photons that we receive in our telescopes? We
could do some might fancy dating of events and thus timings in the universe.

Just a thought.

Glenn

Glenn Woodell wrote:

Kinda like you do when you sit on the pooper except that's not where I was.
Anyway, I was thinking what if we were able to measure the age of a photon of
light, sorta like how we can carbon date some tangible objects. What effect
could that have on the many photons that we receive in our telescopes? We
could do some might fancy dating of events and thus timings in the universe.

The main problem with that idea is that photons don't age; from the
moment it's emitted, even in a distant galaxy, to its arrival at a
detector essentially no time elapses from the photon's point of view.
That's one of the effects of travelling at c.

--
Odysseus

"Odysseus" wrote in message
...
Glenn Woodell wrote:

Kinda like you do when you sit on the pooper except that's not where I
was.
Anyway, I was thinking what if we were able to measure the age of a
photon of
light, sorta like how we can carbon date some tangible objects. What
effect
could that have on the many photons that we receive in our telescopes?
We
could do some might fancy dating of events and thus timings in the
universe.

The main problem with that idea is that photons don't age; from the
moment it's emitted, even in a distant galaxy, to its arrival at a
detector essentially no time elapses from the photon's point of view.
That's one of the effects of travelling at c.

True. But we can take advantage of the fact that, in an
expanding universe, photons will be red-shifted with distance
traveled. The greater the travel time, the greater the
red-shift. If we know the expansion rate, we can date the
photons generated by known processes (such as particular
atomic transitions).

In message , Greg Neill
writes
"Odysseus" wrote in message
...

The main problem with that idea is that photons don't age; from the
moment it's emitted, even in a distant galaxy, to its arrival at a
detector essentially no time elapses from the photon's point of view.
That's one of the effects of travelling at c.

True. But we can take advantage of the fact that, in an
expanding universe, photons will be red-shifted with distance
traveled. The greater the travel time, the greater the
red-shift. If we know the expansion rate, we can date the
photons generated by known processes (such as particular
atomic transitions).

Isn't it the other way round? We know the properties of photons produced
by a given process (absorption or emission line) and use that, plus the
distance, to measure the expansion rate. It's the rate that is unknown.
Then we check using measurements that don't depend on the properties of
individual photons.
--
Save the Hubble Space Telescope!
Remove spam and invalid from address to reply.

"Jonathan Silverlight" wrote
in message ...
In message , Greg Neill
writes
"Odysseus" wrote in message
...

The main problem with that idea is that photons don't age; from the
moment it's emitted, even in a distant galaxy, to its arrival at a
detector essentially no time elapses from the photon's point of view.
That's one of the effects of travelling at c.

True. But we can take advantage of the fact that, in an
expanding universe, photons will be red-shifted with distance
traveled. The greater the travel time, the greater the
red-shift. If we know the expansion rate, we can date the
photons generated by known processes (such as particular
atomic transitions).

Isn't it the other way round? We know the properties of photons produced
by a given process (absorption or emission line) and use that, plus the
distance, to measure the expansion rate. It's the rate that is unknown.
Then we check using measurements that don't depend on the properties of
individual photons.

Yes, the Cosmic Distance Ladder is an interlinked thing
with overlapping methods used for cross checks.

Once you've got a working model with an expansion rate,
the red-shift can act as a clock as well as ruler.

On Mon, 02 Feb 2004 09:45:22 -0500, Greg Neill wrote:

"Odysseus" wrote in message
...
Glenn Woodell wrote:

Kinda like you do when you sit on the pooper except that's not where I
was.
Anyway, I was thinking what if we were able to measure the age of a
photon of
light, sorta like how we can carbon date some tangible objects. What
effect
could that have on the many photons that we receive in our telescopes?
We
could do some might fancy dating of events and thus timings in the
universe.

The main problem with that idea is that photons don't age; from the
moment it's emitted, even in a distant galaxy, to its arrival at a
detector essentially no time elapses from the photon's point of view.
That's one of the effects of travelling at c.

True. But we can take advantage of the fact that, in an expanding
universe, photons will be red-shifted with distance traveled. The greater
the travel time, the greater the red-shift. If we know the expansion
rate, we can date the photons generated by known processes (such as
particular atomic transitions).

??? Confused here!

According to what I read: Red-shift is related to the Doppler principle,
which means that red-shift is a measure of speed rather than distance.

I know there's a relationship between them (speed/distance; due mainly to
the (so far) observed fact that the further away something is, the faster it
is going away) but, that still doesn't/shouldn't change the fact that what
is being measured is speed.

If I'm wrong here, why?

Hi Odysseus Its been theorized that what be think of as a single
photon is a quanta of one million photons,and half of them virtual. This
theory goes well with the two slit experiment,and photons able to kick
electrons around. Fits well with fields. Fits well with my "Spin is in
Theory" Fits well with the question "What is Waving"? Well Odysseus if
6 trillion photons can fit on a pin head having them go in one million
packets(quanta) does answer hard questions. Bert

"Dat's Me" wrote in message
news
On Mon, 02 Feb 2004 09:45:22 -0500, Greg Neill wrote:

According to what I read: Red-shift is related to the Doppler principle,
which means that red-shift is a measure of speed rather than distance.

I know there's a relationship between them (speed/distance; due mainly to
the (so far) observed fact that the further away something is, the faster it
is going away) but, that still doesn't/shouldn't change the fact that what
is being measured is speed.

If I'm wrong here, why?

You're not wrong. Speed and distance are directly
related at large scales. Distance and time are
related by the speed of light.

On Tue, 03 Feb 2004 18:01:51 -0500, Greg Neill wrote:

"Dat's Me" wrote in message
news


If I'm wrong here, why?

You're not wrong. Speed and distance are directly related at large
scales. Distance and time are related by the speed of light.

Der on me, after re-reading the post I replied to _more_ carefully, I
realise my confusion was due to the fact that I didn't read your message
carefully enough. Sorry.

"Dat's Me" wrote in message
news
On Tue, 03 Feb 2004 18:01:51 -0500, Greg Neill wrote:

"Dat's Me" wrote in message
news


If I'm wrong here, why?

You're not wrong. Speed and distance are directly related at large
scales. Distance and time are related by the speed of light.

Der on me, after re-reading the post I replied to _more_ carefully, I
realise my confusion was due to the fact that I didn't read your message
carefully enough. Sorry.

No problem!