Starship Asterisk*

I think this one is fair -- cropped only. Sorry it's not exciting

What are the rules? I pick form APODs, and can crop. Nothing else? In general, you can pick as much or as little of an APOD as you like, drawing your material from (1) the image on the APOD main page for a given date, (2) the full version of the image that is usually available by clicking on the (s...

congrats alter-ego! your turn now. choose a crop for #37. Is that how it's done? What are the rules? I pick form APODs, and can crop. Nothing else? I may be slow compared to what you all are used to; I check this forum a couple times a day. I'm happy to play, but I don't want to frustrate you with ...

http://antwrp.gsfc.nasa.gov/apod/ap971005.html

Worlds of a Distant Sun: 47 Ursae Majoris b

What do you mean, "In a few days I will post what I believe to be the correct answer."? Has this experiment been done or not? I would love to hear the _real_ answer because I swear I have wondered about this kind of experiment but never heard of it being done. Single-photon interference e...

Henning, For whatever it's worth, you description is exactly what I was struggling to put together. I've been extremely bothered why/how timing, per se, could change an observed outcome. Yes, I've assumed all along that the problem, as stated with a pre-existing, pre-timing interference pattern was ...

...but I don't yet get how event timing can be better than ~λ/c (Implied by Kim?), which is also the arrival timing difference between the slits. The event timing accuracy is a property of the pulse and detector timers; it doesn't depend on the photon wavelength. Our timers don't suddenly get crapp...

I'd still like to know if there can be intrinsic timing uncertainty imposed by the Uncertainty Principle. Why isn't it showing up in this problem? Energy and time are mutually unascertaintable measurables equivalent to position and momentum being mutually unascertainable measurables. (Just look at ...

I'd still like to know if there can be intrinsic timing uncertainty imposed by the Uncertainty Principle. There is. Time and energy are one of the standard examples of pairs of quantities that the uncertainty principle applies to. Why isn't it showing up in this problem? Why do you think it isn't? ...

2. Photon arrival times at the EXACT same screen location WILL NOT be identical. - This is the new idea and helps all the puzzle pieces fit together better. This is where I hypothesize the Uncertainty Principle applies. The fact that a collection of point-source photons arrive at the screen showing...

Hi Wavefunction, Very interesting. This seems like a good homework or test problem for a QM class. I have some questions, but I already getting feedback. This was a good problem! I'd still like to know if there can be intrinsic timing uncertainty imposed by the Uncertainty Principle. Why isn't it sh...

- Measuring the precise time a photon takes to travel is not equivalent to measuring which slit it went through. In principle, a photon could take a path that is not a straight line from the source to the target, travelling at the speed of light and taking the corresponding time to do so, though an...

I'm not sure from the reading of the question just how the video screen is timed with respect to the light signals? Are they simultaneously opened with the/each signal? Is this a "photon entanglement" setup? I believe you should consider this problem a "thought experiment" where...

Wow. Well, in the extreme, the knowledge of travel times should degrade or eliminate the interference pattern when all those images are added. But what happens if a voltage spike suddenly damages the database -- after the data is collected but before anyone combines all those images -- so that we n...

Greetings, Remember that a photon exhibits both particle and wave properties. This really becomes simply a two point wave addition problem. Presuming continuous random timing of the photons, they will ultimately create a standard diffraction interference pattern. Hi, I might be missing something, b...

Something has been bugging me from the start. :roll: It has to do with the premise that accurately timing the photons can tell all about which slit a photon goes through. In fact, I was initially on board with this concept and assumed it could work. I thought that the idea was as solid as the simpl...

Had the sun just set? I've seen that effect many times. The very low, or just set, sun illuminates the underside of the clouds as red as the setting sun. This light then floods the region from all directions. I've also seen a total black sky (thick cloud layer not bottom-side lit) with sunlight beam...

It does sound like we are in agreement. I guess it comes down to the ambiguity of the statement, "The time of release of single source photons is also recorded precisely." That's right. What does "precisely" really imply? I take it the following way: I think of measurement "...

It does sound like we are in agreement. I guess it comes down to the ambiguity of the statement, "The time of release of single source photons is also recorded precisely." That's right. What does "precisely" really imply? I take it the following way: I think of measurement "...

However, in this problem, the source is not being changed. We are only adding the ability to measure photon timings of this source (which before the timing equipment we could see an interference pattern), so the energy / bandwidth uncertainties remain unchanged. OK. But how do you time the departur...

...I think that the energy-time uncertainty relation implies that if you time the departure of the photon very precisely you must produce some uncertainty in the energy/frequency of the photon (for example femtosecond laser pulses have a rather wide frequency spread). This means an uncertainty in t...

ryan wrote: Yeah, ok, so i guess I missed why the timing was mentioned...please forgive my mean tone and my lack of knowledge of the most recent developments in slit expts.

Hi ryan - I sensed no mean tone, no worries.

Ok, am i missing something? It appears as if it is stated that all of the frames would be added together, in which case, there would be no difference between this experiment and a photographic plate. Good question, I'm actually not sure. If your saying that precise single-photon timing makes no dif...

Even if the photon passes through only one slit (e.g. experiments done with single photons at a time), it still produces an interference pattern as we can consider it to be interfering with virtual photons. Actually the interference pattern is only explained if the photon does in fact go through bo...

Robert - Just to clarify, I assume there is no "sharp-eyed" lens on the camera. True? I.e. the slits are not resolved?