swansont

All lasers eventually diverge; most can be described by gaussian profiles, so they have a minimum spot size (“waist”) at some distance from the laser. Making the beam fat actually improves the divergence issues. The laser used for the moon ranging measurement diverged to be ~2 km across by the time it got to the moon (the atmosphere’s changing density played a part in this); the beam started out several meters wide https://tmurphy.physics.ucsd.edu/apollo/basics.html We use the telescope as a gigantic (3.5 meter wide) laser pointer and also as a signal receiver. Staying close to 10 cm over 1 km would seem to be possible with good optics+optomechanics and the right laser (for example, laser diodes, such as ones found in laser pointers, have horrible inherent divergence issues)

I’m not sure how to find the list of people following me.

Laser implies a certain source (stimulated emission). There may be issues of coherence of the light and beam quality with beams, but I’ve used 50mm beams without any issues. Still able to do laser cooling and trapping. We expanded the beams using lenses. I can’t see your embedded image Vision impairment is an intensity issue, which is made worse by having a collimated beam The eye is most sensitive in the green (555 nm), ~5x more sensitive in green than red (~650 nm). this shifts a little toward shorter wavelengths if your eye is dark-adjusted https://www.ncbi.nlm.nih.gov/books/NBK11513/figure/ch24psych1.F10/ The effective range is going to depend on the beam’s divergence. If it’s 10 cm at the target, a few mW should be visible.

JohnSSM has been suspended to see if he can get rid of the chip on his shoulder. Stirring the pot because you’re bored isn’t an acceptable exercise

! Moderator Note I already addressed this: you referred to it as “my theory” and admitted it was only supported by a few people. This isn’t a negotiation of whether you must follow the rules. Since you only seem to be here to stir the pot, I guess there’s nothing more to discuss.

It’s not a speculation. The OP asks a question, rather than asserting a position. No reason to move it, unlike your hijack to whine about the mods.

! Moderator Note Irrelevant. I’m not engaging on points of fact or knowledge. I’m pointing out the rules. Given your length of tenure here, you should be familiar with them ! Moderator Note It can’t be common knowledge if you need to study it in advanced courses at a university. But if it is taught as such, supporting it should be a trivial task, and you shouldn’t claim ownership of the theory. ! Moderator Note Of course they can be argued, and your position seems to mean they are easily supported, and challenges rebutted. So support/rebut them.

! Moderator Note This is an unacceptable position to take. We expect arguments to be made in good faith, and declaring you will not answer questions does not comply

! Moderator Note Not in the areas of science with which I am familiar. Mainstream topics are taught in universities and many people write textbooks explaining the subject. They publish in respected journals. It’s generally not hard finding supporting literature. Non-mainstream ideas are the ones that are brought up in discussion boards, because there’s little traction for them. Sometimes there are multiple proponents of the idea, but sometimes not. This sounds like the latter, thus it belongs in speculations, per the rules of SFN.

! Moderator Note You refer to it as “my theory” so I have to wonder which claim is misrepresentation. Is it your theory, or not? If it’s not, you shouldn’t say it is, and it should be easy to support your claims with citations.

! Moderator Note Since we can’t seem to follow the rules, we’re done here Don’t bring this topic up again

! Moderator Note Was there something you wanted to discuss? Just advertising a link is not permitted; it has been removed.

! Moderator Note A couple of things: When you present a theory of your own, you own the burden of proof. It is incumbent upon you, not others, to ensure it is complete and well-supported. It not inherently rude to be asked to clarify or support a claim. "I don't own/haven't read that cite" is not a rebuttal of a claim ! Moderator Note As far as I can see (within limits of the search function of the site), a member pointed out you were being snide ("taking a snide swipe") while discussing the clarity (or lack thereof) in your writing. I don't see where you were warned never to be snide, even without the caveat that the only real "warnings" come from staff members, whether they are modnotes or official ones issued through the forum software. While revisionist history is potentially a problem, it is also the case that an attitude that "my writing is clear and I will brook no disagreement to this" is not an attitude that will be accepted. It's not consistent with cvonversing in good faith. A member commenting on your style is merely suggestion that you may want to polish things up a bit, just as you have made similar comments to others. Any suggestion that others must conform to your standard but you are under no obligation to conform to theirs is probably not going to serve you well, but is not, in most cases, a rules violation in and of itself. (Though it is potentially a gateway to such) Please return to the discussion of the topic at hand

I'd have to think about this. The acceleration is there, but we are also in freefal. about the sun owing to our orbit. (Need caffeine to make brain work) edit: A confounding factor is the change in the mass distribution of the earth owing to the tides. g gets bigger or smaller because of the moon or sun, but the water moves around if you're near the coast, and all that water moving depresses the crust a small amount. The net effect is the body being overhead reduces g, but the nearby mass increases it, reducing the net effect As it's a tidal effect, the impact of the sun is smaller. As you would be getting closer to the limit of the pendulum clock's stability, the difficulty in measurement is bigger than the simple difference in the magnitude of the effect; the net variation is (IIRC) a few milliseconds per day, and the limit of the best pendulum clocks are a little under a millisecond, so the sun's effect is closer to being lost in the noise (S/N of 5 is markedly easier to measure than a S/N of less than 2)

The lesson here is that all of physics is approximation. There's always more to it when you dive deeper into any topic.

I think you'll find having proficiency in math will help a lot with being able to work chemistry problems. Good luck!

! Moderator Note 1. without reading the link, I can say that they do not give good evidence 2. You must present evidence here, not just give links (see rule 2.7) 3. Advertising your other threads is also against the rules

I like to point out that the effect of the moon's pull on pendulum clocks has been measured. Small effect, of course, but it's there.

We are discussing physics, but I mean the laws of science are mathematical relations, or can be presented as such. I don't think anyone would be so confused as to think we're talking about the legal system.

I though "beauty" was abandoned long ago in favor of "bottom" (along with "truth" as an alternative to "top")

! Moderator Note You can present an idea and defend it, but what you can't do is assert something and call everyone idiots who show flaws in your idea. I think you have mistaken us for the "Credulous of Crackpottery" discussion forum. That's not us. We require models and evidence for non-mainstream proposals. Since you have decided not to engage in a constructive manner, you've declared you're done, I will close this. Don't bring it up again, in any form.

It's based on the math analysis of data. You do a bunch of measurements where you change one variable (e.g. temperature) and then measure the effect on the one you measure, e.g. pressure. In this example, you know V is fixed, because you're using a rigid apparatus. You look at the graph. You can fit a curve/line to the data (studiot gave the equation you would use for fitting a straight line)

You've simplified it to the point that it's wrong. And what "frills" are there? Spin is conserved. If you have two particles stemming from a spin-0 state, one will be spin-up, the other spin-down. Making up some story about ping-pong seems far more convoluted. I had given a spin example, and you responded with a polarization diagram, as if you did not know the difference. It happens without intervention by us, so, sure. I don't see where I've said anything that would lead you to such a conclusion. Efficiency of entanglement in spontaneous parametric downconversion is low, but photons are easy to make https://en.wikipedia.org/wiki/Spontaneous_parametric_down-conversion"The conversion efficiency of SPDC is typically very low, with the highest efficiency obtained on the order of 4 pairs per 10^6 incoming photons for PPLN in waveguides" and then you can only have entangled photons if they come from the overlap region of the two cones. So, it's not particularly easy, from a numbers standpoint. Fortunately you're going to have of order 10^15 photons per mW of visible photons. Entanglement is not necessarily nonlocal. https://en.wikipedia.org/wiki/Quantum_nonlocality#Entanglement_and_nonlocality Saying "We don't know" is preferable to making stuff up. But we know this is wrong, since the ping-pong ball has to travel at infinite speed. Your example is unphysical. It assumes information is traveling, and you have no basis for that assumption.

There are the laws of thermodynamics Laws, of course, are mathematical relations. The laws give guidance on the behavior of energy, temperature (which is related to energy) and entropy. There are other laws within thermodynamics which give relationships of these and additional variables that we encounter in thermodynamics, such as pressure and volume.

You're creating a false dichotomy. ""If thermodynamics is not an original force of the universe" means it could be, or not be an original force. But you're saying if it isn't, then it's still a force, created by the four forces. Either way, the statement is declaring that it's a force. And it's not. Let's simplify: If Bob did not kill Alice, then Bob killed Charlie" Same format, just with substitutions. The statement is saying Bob killed somebody. Could be Alice, could be Charlie.