# All Activity

1. Past hour
2. ## Could Fictitious forces accelerate and change the CoM through internal mass transfer?

Just a note, "Fictitious" is not a synonym for "magic".

4. ## Could Fictitious forces accelerate and change the CoM through internal mass transfer?

Fig.1.Isolated System and Internal Fictitious Force $\Delta \omega \neq 0 \Rightarrow \sum{F}_\mathrm{int} = {F}_\mathrm{Fictitious} \neq const. (varying)$ $\sum{F}_\mathrm{int} = \frac{m_\mathrm{T} \cdot ({u}^{\prime}_{\mathrm{cm}}- {u}_\mathrm{{cm}})}{\Delta t} \neq 0$ $\frac{\Delta {p}}{\Delta t} = \frac{m \cdot ({u}^{\prime} - {u})}{\Delta t} = \frac{m_\mathrm{T} \cdot ({u}^{\prime}_{\mathrm{cm}}- {u}_\mathrm{{cm}})}{\Delta t}$ ${u}^{\prime} \neq {u} \Rightarrow {u}^{\prime}_{\mathrm{cm}} \neq {u}_{\mathrm{cm}} \Rightarrow {a} \neq 0.$ Fig.2.Isolated System and Internal Collinear forces (Action-Reaction pair) $\sum{F}_\mathrm{int} = \left( {F}_\mathrm{A} + {F}_\mathrm{R} \right) = 0 \text{ (collinear)}$ $\frac{\Delta {p}}{\Delta t} = \sum{F}_\mathrm{int} = \frac{m \cdot ({u}^{\prime} - {u})}{\Delta t} = 0$ $\frac{m \cdot ({u}^{\prime} - {u})}{\Delta t} = \frac{m_\mathrm{T} \cdot ({u}^{\prime}_{\mathrm{cm}}- {u}_\mathrm{{cm}})}{\Delta t}$ ${u}^{\prime} = {u} \Rightarrow {u}^{\prime}_{\mathrm{cm}} = {u}_{\mathrm{cm}} \Rightarrow {a} = 0.$ Could someone help me on these questions: a) In Fig.1. is what is shown a Fictitious force? b) IF (a) is true, is there any force opposing it?
5. ## Do ticks somehow choose a preferred host

It’s probably better to view them as opportunistic. Host availability and predictability matter more than just about anything else. They’re also generalists when it comes to global populations, but specialists when it comes to local or regional populations. They’ll bite just about anything, but are better at biting certain things based on their local environment. It seems they’re pretty sensitive to temperature and humidity, and likely respond to chemical signals and similar hormone related outputs bodies generate. I cannot comment on its validity or modernity, but this overview seems comprehensive: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3790072/
6. ## michel123456's relativity thread (from Time dilation dependence on direction)

My “syndrome” was misreading the circumstance of the example (the “length” was, indeed moving) The physics was not wrong The distance to planet X is not contracted. There is no motion between earth and X; they exist independent of a rocket and its motion. The earth sees 1 LY. There is no motion between earth and X, thus there is no length contraction of this distance.
7. Today
8. ## Can you be a scientist and still believe in religion?

I recognize no truth, but degrees of certainty.
9. ## Which subshell does the 30th electron belong to?

Nothing will be filled, because copper and zinc individually elements. Copper has stabil configuration 3d10 4s1 and zinc has 3d10 4s2
10. ## what does "scientist" mean,exactly?

ya yes. but sometimes people or more correctly folks may be bigoted (i.e. incorrect). this presumably in somewhere may be extended to wide range of people,which is really significant count of people. For instance, here in turkey,I am sure that many people believe or act as you have to have a relevant and expected title (e.g. associate professor ), education and most seriously and very interestingly : regular salary and work. (in other words "an approved academic job at any university" the last one to me is very interesting and I think that this can be accepted as a type of bigotion. because that is incorrect. First, under that that one complies the official rules (i.e. regulations), and deals with any contexts and spends sufficient effort and has expected knowledge,then this should be enough. But in many times this does not happen. I agree to charonY if she/he implies/shows the regulations, but surely, pofession is a bit different. I know several languages, but , there are many professors who do not know even one foreign language or who are not qualified on this issue, which is directly affecting the quality of any academic research.
11. ## Which subshell does the 30th electron belong to?

Yes, i know chenbeier. Electrons are not actually distinguishable; but it was the question i had to answer; Do you think it is basically wrong?
12. ## Which subshell does the 30th electron belong to?

Electrons are not different, so it doesn't matter if the d Orbitale will filled or the s Orbital.
13. ## Which subshell does the 30th electron belong to?

Thank you both for your replies. But I'm still a little confused; Both of you mentioned that a '4s electron' moves to 3d subshell. So, it isn't a S electron any longer, or is it?! I don't have a problem with the movement of that electron, I can't realize what exactly happens after that; let's say the 29th electron goes to 3d, so we have 3d⁹ but it isn't stable so one 4s electron moves to the 3d subshell and makes it 3d¹⁰4s¹. But how about the 30th electron?! I can only imagine 2 possible ways: 1) Because the 3d is already filled (3d¹⁰4s¹), the 30th electron goes to 4s to fill it. 2) that 4s electron which had moved to 3d to fill it, will return to the 4s and the 30th electron goes to 3d. I think the 1st one is more logical, but the second one is the only way to convince Zn belongs to d block (according to my book). Which one is correct? Or if none of them, where exactly does the 30th electron go?!
14. ## what does "scientist" mean,exactly?

It is also a matter of context. E.g. saying that one should listen to scientists when it comes to pandemic responses of course means that one should listen to folks with actual expertise in those areas. Not scientists with expertise in other areas or hobbyists.
15. ## what does "scientist" mean,exactly?

I think the difference in people's minds is one of profession. I'm a writer and a barista and a scientist and chef and a builder, but I don't get paid to do those things.
16. ## Do ticks somehow choose a preferred host

If that's true, do we know why they'd prefer one species over another? And what would make them prefer one host over another within the same species?
17. ## what does "scientist" mean,exactly?

It’s a person who’s doing science. It’s not like there’s a committee somewhere approving people to use the label or disallowing others from doing so.
18. ## Reactionless Drive and Newton's 3rd law

! Moderator Note John2020, I would suggest you go back through the thread and pay close attention. You've had three pages of objections and problems with your device that haven't been addressed adequately for the Speculations section. You need to support your ideas with evidence, and address the reasonable objections you're getting. The people involved are only trying to help, but you seem more interested in teaching something wrong than in learning something right. I hid your last post with the links to past experiments, since it was completely off-topic. If you're going to swim against the mainstream, you need to be more rigorous. Thread closed.
19. ## Do ticks somehow choose a preferred host

More broadly, since repellents like Deet and similar products actually work, it seems rather obvious that ticks can sense and smell things in their environment that serve to alter their response or path... including differences between Person1 and Person2 Ticks also often focus on specific hosts... and will differentially bite deer over dogs or humans, for example.
20. ## what does "scientist" mean,exactly?

No, but you can call yourself a scientist if you like. The definition is rather vague on what a scientist is exactly.
21. ## What are your thoughts on the Presidential Debate ?

in 2016 Trump beat Realclearpolitic's aggregated polling by 7% in WI. Fivethirtyeight gave Clinton a 83.5% chance of winning WI which was better than Clinton's overall chance of winning the White House. In MI Trump beat aggregated polling by 4% and 538 gave Clinton 79% of winning which was also greater than her overall. You are probably correct about AZ and IA. Nothing strange there. The numbers actually surprised me when I looked them up. Both finished within decimals of a percent of their polling in 2016. Which isn't to say I think every state will mirror polling. WI and MI had issues (see below). So I think MI & WI are right there with FL & GA as virtually unwinnable by anything less than robust margins.
22. ## what does "scientist" mean,exactly?

I have not wanted to enroll any master or/doctorate program but I deal with and would continue dealing with scientific contexts and research. simply,I would like to do the research on whatever I want and it seems I am a bit pragmatist (because I do not want to deal with anything that would not provide any efficacy anymore). Thus can we accept me as a scientist?
23. ## michel123456's relativity thread (from Time dilation dependence on direction)

I should have said : When length contraction is applied, Earth see the length traveled by the clock <in 45 minutes> as contracted by a factor of 0.6.
24. ## Do ticks somehow choose a preferred host

If anyone else tries this ,would they put it on Youtube?😆 Not taking the piss,just hard not to laugh.
25. ## Do ticks somehow choose a preferred host

No. It was an impromptu hike into the woods behind my house -- a nature walk. We didn't have any kind of bug repellent. However, I don't know if he was wearing deodorant or cologne. The reason we did the experiment was because I've had so many anecdotal experiences like this with ticks, I wanted a real measurement. Especially with this particular friend. We'd walk the same path through tall grass or in the woods and I'd come out with ticks on me while he'd have none. On that day, I took the opportunity to have a somewhat controlled experiment, since I had the living tick. I should point out, if anyone tries to repeat this, I'd really like to know the results.
26. ## michel123456's relativity thread (from Time dilation dependence on direction)

What's the point of working through the details of relativity, like length contraction, but not accepting the predictions of SR, and instead replacing them with your own opinions? Does the length contraction as you're describing it, actually make sense to you? Or are you hoping to show that if you replace a few details with nonsense, then all of SR can be clearly seen as nonsense? Have you convinced yourself of that? Do you expect to convince others? Do you actually believe what you're saying, do you really believe that if length contraction as predicted by SR is applied, then Earth sees the traveler having gone only 0,6 LY in the example above? Or is the above example meant to show that length contraction must be nonsense? If it's the latter... Can I convince you that addition is nonsense, by adding 3 plus 2 together and getting 9? Are you convinced? Do you think I should spend 20 years telling people that addition is nonsense because I think addition, in my opinion, gives a ridiculous answer of 9?
27. ## Can you be a scientist and still believe in religion?

A part of the issue is that folks thinking that they are in the right tend to make intellectual shortcuts. In the early 2000s I was somewhat interested in various atheist movements, in part because I was worried about rising anti-intellectualism and creationism. But apparently once enough folks gather things go quickly to a self-congratulating group of folks who cannot stop emphasizing how rational and therefore superior they are (without actually putting in the work). There were plenty of folks, including academics who did a great job in outreach and educating. But some of their followers were sketchy and did not put in the intellectual work before succumbing to insufferable smugness (the result being attitudes that are way closer to religious organizations than folks would admit) .
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