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photon emission (split from length contraction)


Deepak Kapur

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@ swansont

 

Plank time has to come in every activity because every activity has to 'start' in time. So, it means every activity has to start from zero time and then has to move forward in time...

 

In other wor͚7jr튇(~ۍ

5:[čq@BDj81"Hr;vܐHnaZ]契G?Gz

@ swansont

 

Plank time has to come in every activity because every activity has to 'start' in time. So, it means every activity has to start from zero time and then has to move forward in time...

 

In other words, every activity has to encounter the time period that is not defined because it is below plank time and then move forward in time...reach plank time....and move forward in time.

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Plank time has to come in every activity because every activity has to 'start' in time. So, it means every activity has to start from zero time and then has to move forward in time...

 

In other wor͚7jr튇(~ۍ

5:[čq@BDj81"Hr;vܐHnaZ]契G?Gz

 

I can put the kettle on at 3pm (your "start" or "zero" time). After a while it boils. I could measure the time it takes it fortnights, days, minutes, seconds, picoseconds, or Planck times. What is special about the last of those? It is just a (very small) unit of time.

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Are we able to describe what happens when the photon goes inside the atom?

 

It gets absorbed. Beyond that, AFAIK there's no way to test any model details. Our investigation tools are the photons.

@ swansont

 

Plank time has to come in every activity because every activity has to 'start' in time. So, it means every activity has to start from zero time and then has to move forward in time...

 

In other wor͚7jr튇(~ۍ

5:[čq@BDj81"Hr;vܐHnaZ]契G?Gz

@ swansont

 

Plank time has to come in every activity because every activity has to 'start' in time. So, it means every activity has to start from zero time and then has to move forward in time...

 

In other words, every activity has to encounter the time period that is not defined because it is below plank time and then move forward in time...reach plank time....and move forward in time.

 

The times we are discussing are much larger than the Planck time, so I don't see what the problem is.

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@ swansont

 

imo, the problem is that when we talk of photon emission/absorption , the time involved can be even small than the plank time.....we cannot be sure of the time intervals in such cases...

 

moreover, when BPT is unknown and every activity has to encounter it, it means that every thing/activity passes from the unknown/supernatural to natural in a way that is unknown to us...

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@ swansont

 

imo, the problem is that when we talk of photon emission/absorption , the time involved can be even small than the plank time.....we cannot be sure of the time intervals in such cases...

 

moreover, when BPT is unknown and every activity has to encounter it, it means that every thing/activity passes from the unknown/supernatural to natural in a way that is unknown to us...

 

I defy you to provide an atomic transition with a lifetime anywhere close to the Planck time. I'll even spot you 14 orders of magnitude. Find me an atomic transition that's got a lifetime shorter than 10^-30 seconds.

 

I doubt you'll find anything that even comes close to 10^-20. At 10^-17 seconds, that's a transition width of around 100 eV. I don't see how you could have a width wider than the excitation energy. The hydrogen 2P transition (10.2 eV) lifetime is around a nanosecond, which corresponds to a transition width of around a GHz. Lifetimes for dipole transitions vary as 1/(transition energy)^3 so if you could muster a 100eV transition, you'd get closer to the goal.

 

Happy hunting.

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@ swansont

 

Whenever a photon is to be emitted or two electrons come together or an electron comes near the nucleus etc. etc., a change takes place...calculations are done and it is said absorption/emission/repulsion/attraction has taken place....

 

This is rudimentary technology, imo

 

Once things improve, events even below plank time will be well in reach....

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It gets absorbed. Beyond that, AFAIK there's no way to test any model details. Our investigation tools are the photons.

 

I don't think you understand what is being said, he mentioned the photon is our investigation tool. In other words we use the electromagnetic spectrum to investigate particles.

 

particle physics can determine a particles mass, spin and momentum. However much of the information we get on a particle is usually measured by its deflections and impacts. Most of the particles were discovered by shooting particles at a small region and watching for path interference patterns. Most detection mechanisms rely on the fact that when high-energy charged particles pass through matter they ionize atoms along their path. The "Wilson cloud chamber" is an early example of a particle detector

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

 

the planck length is considered the shortest theoretical length the same holds true for the planck time. keep in mind we cannot come close to measuring anything near this scale. Without going into details here is a statement that covers the theory,

 

"The greater the energy of photons, the shorter their wavelength and the more accurate the measurement. If the photon has enough energy to measure objects the size of the Planck length, it would collapse into a black hole and the measurement would be impossible. Thus, the Planck length sets the fundamental limits on the accuracy of length measurement."

 

the formulas involved and these statements are from the same page

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

 

"There is currently no proven physical significance of the Planck length; it is, however, a topic of theoretical research. Since the Planck length is so many orders of magnitude smaller than any current instrument could possibly measure, there is no way of examining it directly. According to the generalized uncertainty principle , the Planck length is, in principle, within a factor of order unity, the shortest measurable length – and no improvement in measurement instruments could change that." for the reasons above.

 

now here is planck time

 

"In physics, the Planck time (tP) is the unit of time in the system of natural units known as Planck units. It is the time required for light to travel, in a vacuum, a distance of 1 Planck length"

 

Now think about the above, we cannot measure a planck length, its a calculated value, if its true then we can never measure below that value, so we also cannot measure a smaller time scale. Can a smaller length exist? or a smaller time? certainly but we will never be able to know for sure as we will never be able to test any smaller units. The key term is the planck length is the smallest theoretical measurable unit. It is not the smallest possible unit in reality ( or at least probably not, but then we would have to find and measure a particle smaller than the planck length-good luck with that). Its a theoretical limit on measurements.

 

any model can later be proven wrong, but unless you have some testable results, this usually doesn't occur, so until we can test a smaller unit then the planck scale will remain as a limit. (its not even a case of being rudimentary technology, we don't even have the tech to test the planck length, nor are we likely to be able to any time soon)

Edited by Mordred
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@ mordred

 

u said that if a photon ( a unit of EM energy) has high enough energy to measure plank length, it would turn into a black hole...

 

Does this mean that extremely large concentration of energy also leads to a black hole?

 

imo, infinite no. of waves can be superimposed on one another without leading to a black hole...

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@ swansont

 

Whenever a photon is to be emitted or two electrons come together or an electron comes near the nucleus etc. etc., a change takes place...calculations are done and it is said absorption/emission/repulsion/attraction has taken place....

 

This is rudimentary technology, imo

 

Once things improve, events even below plank time will be well in reach....

 

Calculations are doen — that's the theoretical side of physics. When you do experiments, it involves photons. Photons go in, photons come out. Other particles can come out, too. That doesn't tell us what's going on during the interaction, only whether or not the model is giving us the correct answers. The model has to include the interaction details in order to be able to gather that information.

 

So: is there any experimental confirmation (not your opinion) that these interactions are being driven at timescales approaching the Planck time? If so, I'd like to know how they are doing their timing measurement.

@ mordred

 

u said that if a photon ( a unit of EM energy) has high enough energy to measure plank length, it would turn into a black hole...

 

Does this mean that extremely large concentration of energy also leads to a black hole?

 

imo, infinite no. of waves can be superimposed on one another without leading to a black hole...

 

Yes, you can superimpose the waves. That does not mean that energy-dependent interactions wouldn't happen.

 

I think you'd start creating particle/antiparticle pairs long before you'd reach a black hole.

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@ mordred

 

u said that if a photon ( a unit of EM energy) has high enough energy to measure plank length, it would turn into a black hole...

 

Does this mean that extremely large concentration of energy also leads to a black hole?

 

imo, infinite no. of waves can be superimposed on one another without leading to a black hole...

 

 

The calculations that are specific to the planck length theory is on the wiki page I posted, its not my idea but what the theory itself states.( or at least according to what the wiki page states is the basis of the planck length, I noticed their citations on this is not particularly good) Swansort however could also be correct in the particle creation scenario. (when I answer on forums I try to answer to according to what is the current concordance, to the best of my knowledge, though sometimes I am off lol, I never introduce personal theories-if you look through my posts you will notice I usually try to supply some form of reference to learn from,its a policy of mine lol. Not saying you thought it was my theory just an side note)

 

I'll dig around for a more professional paper for the planck length limit after work I recall reading an arxiv paper at one time on it but I am not sure if I recall keeping a copy

 

edit found the paper ( not the best I've read its a little shy of the style and detail of most arxiv articles,)

A New Basis for Interpretation of the Planck Length

http://arxiv.org/ftp/physics/papers/0610/0610127.pdf

 

but there is numerous papers dealing with the planck length including alternates for a smaller possible size

Measuring a Kaluza-Klein radius smaller than the Planck length

http://arxiv.org/ftp/arxiv/papers/0708/0708.0521.pdf

Edited by Mordred
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Does this mean that extremely large concentration of energy also leads to a black hole?

 

Mass and energy are equivalent. Put enough mass and/or energy inside its Schwarzschild radius and you get a black hole.

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@ mordred

 

i went through both the papers.....much of the math was beyond me....

 

but...one thing came to my mind that.....

 

in both the papers, 'the concept of measurement' was pressed into service to say that ' measurement beyond plank scale is not possible'....

 

In other words, the measuement above/at plank length is 'okay'..........but.........the measurement below plank length is ' not okay'.....

 

i think sth is missing here....

 

moreover......i think.....infinity cannot be contained at all...whether it's the small scale or the scale of the universe....

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