# timo

Senior Members

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2

1. ## Teleporation with infinite mass

Quite the contrary. If the universe has infinite mass then you only need a tiny fraction of the universe mass for your infinite-mass project.
2. ## Relativity for [one of the] Dummies

The main direction for understanding this in my opinion is: Forget about relativity in this context. It is a statement that stems from non-relativistic mechanics (and happens to still be true in relativity). You can actually define force as a change of momentum, which for most objects relates to change of velocity. The statement "an object remains at rest" is just a special case of "an object keeps its current velocity" (for the special case of this velocity being zero). So both statements are not contradictory.
3. ## my problem with infinite divergent series

You mean when used as "obviously wrong"? I fail to see how adding up all natural numbers is supposed to a) end up in a finite result and b) in a fraction, and c) in a negative number. You have either not seen what probably is a typo or I am not getting the joke.
4. ## Simulating gravity in a space ship via rotation

Actually, I think that unless you jump very high/fast the feel should not be that different. Most importantly, you still come back to the floor (from an outside observer your jumping upwards looks like jumping up- and forwards in which case you hit the upwards-bent floor again at some point), and at a similar position as the one you started with (for an outside observer, the rotation of the circle largely compensates the displacement of the jumper).
5. ## What exactly is magnetism?

A bit in a rush, but two comments: - Saying that magnetism wasn't really understood is wrong. At least in the sense as claiming that houses were not understood is wrong: Of course there are details about houses that are not understood if you dig deep enough, but no one would seriously say we haven't understood houses. - A good way forward to understanding magnetism is to forget about virtual photons. The way to go forward is to first understand basic magnetostatics, then classical electrodynamics. Neither of those has to do with virtual photons. Virtual photons arise in a particular approach to quantum electrodynamics (namely the perturbative one). And I have yet to be demonstrated how any of this helps in understanding what one would conventionally call magnetism.

7. ## Decoupling from the Higgs field?

Strange gave/indicated a very good reason why a particle would not stop interacting with the Higgs field (the paradox that every massive particle would always interact with the Higgs field and also not do so). On the other hand, there is no reason why it actually should stop interacting with the Higgs field (and even less reasons why it would suddenly lose other properties and become its own anti-particle). So the answer to the question looks like a solid "no" to me.
8. ## Pepetual Motion Device that really works

I propose you keep your invention secret, build an engine that creates energy without the need for any kind of fuel, and get super-rich commercially exploiting your idea. Of course, given that you posted your idea here already, I also recommend to do so in a secret location in maybe some Chinese mega-town that no one in the west ever heard about (to avoid being sniped by hired hitmen of the oil companies).

10. ## Black Holes & White Holes

The process of radiating away energy is called "Hawking Radiation". It happens close to but outside of the "point of no return" (called the "event horizon"). Not inside it. You are correct that a process happening strictly within the no-return zone could not radiate off energy unless it had additional weird properties (like FTL).
11. ## Black Holes & White Holes

I'll restrict my reply to a single paragraph because it would get out of hand otherwise. Hope it still helps There is one reason for white holes I am familiar with. That is a certain mathematical extension of the original Schwarzschild solution that indeed features a white hole alongside a black hole (see https://en.wikipedia.org/wiki/Kruskal%E2%80%93Szekeres_coordinates). However, this is just a mathematical extension with no observation supporting it. Also, the physical interpretation of this extension (a negative radius squared) is a bit dubious. So while there are mathematical models in which a white hole is part of the black hole solution the step to the statement that this must (or even MUST ) manifest in physical reality does not seem appropriate to me. Black holes are often assumed to radiate off energy due to quantum effects, thereby losing mass over time. This effect, has not been experimentally verified (to my knowledge). In terms of how likely the average physicist believes this to be the case I think it resides between "black holes exist" and "white holes exist". There is no principal upper limit to the mass of a black hole. In fact, larger ones are supposed to be more stable than smaller ones even before taking into account that they probably suck in more mass.
12. ## Working with values below 1

The standard way for dealing with numbers smaller than one is not seeing a problem with doing so. I don't see the problem with the standard deviation: You square numbers to get the mean square distance, and then you take the square root of this which sort of cancels the square operation.
13. ## Python code to extract specific lines in a textfile

... or even use the much simpler "grep". However, that assumes Jo27 is on a linux (or mac) system. And not only is that not certain. In fact, if someone asks for a Python script to do trivial text processing I would assume a Windows user.
14. ## Electric Rates in Germany

Actually, the 25 years may not be such a bad value, and I think they are common in professional literature - even among supporters of renewables. Rough estimates I know are 20 years for wind turbines and 30 years for PV. What is more dubious is the implicit assumption that people calculating energy costs are not aware of typical lifetimes of power plants, and that you need to correct some of the numbers calculated by people who make their living by doing such calculations by a factor of two because you think you know better - possibly without even having read the publications the numbers originated from. EDIT: Thinking of it: How would one even calculate levelized costs without taking into account lifetimes or lifetime-generation of the power plants?
15. ## Found It! Countdown From August 2008, "100 Months"

There is nothing wrong with this. The many replies show that there is a great interest in this way of approaching issues.
16. ## Is it misleading to say "IN the universe"

I am not sure I agree with your statements about language that for "in" to have a meaning you must have an opposing "out" - or even that there was a definition requiring it. "Not in" may be more suitable opposite, and even that may require mental parentheses that are mathematically common but create strange language. Take the sentence "last year I have been in Portugal and Australia", for example (fun fact: that sentence being true necessarily requires that "last year I have been out of Portugal and out of Australia" is also true ). Nitpicking about language aside, I agree with the statement that "in the universe" is often redundant (maybe not if you want to make a distinction between hypothetical things and actually-existing things). It may indeed be a good idea to avoid it when sensibly possible. Altogether. That is, your example would simply become "it is the largest known star". My experience also confirms your suspicion that "in the observable universe" can be a sensible thing to say: I wrote this (or just "the observable universe") quite a few times in the last years because that was required for the statement to be true. Also note that language or conversation in a wider sense is not necessarily about transporting factual information. Arguably, most of human communication is not about exchange of facts, both in oral communication and in writing (-> novels). It may not be bad if this familiar "story-telling style" also appears in scientific texts, especially at lower levels. As an extreme example: Math books written for mathematicians can be extremely efficient and careful about their choice of language. But it takes a university degree in mathematics to understand this kind of writing.
17. ## The Official JOKES SECTION :)

Kind of my favourite joke at the moment, mostly because my work reminds me of it so often. Hope I did not actually have it from this thread: A mathematician, a physicist and an engineer are given a small red rubber ball and the task to determine its volume. - The mathematician measures the circumference and then calculates radius and volume using the relations of a sphere. - The physicists dumps the ball into a measuring container with water and measures the amount of water that is displaced. - The engineer goes looking for the industry norm for "small red rubber balls".
18. ## Higgs Boson

No offense meant, and the comment is more a general one than about this particular question: But I think one should not get over-excited about occasionally guessing the answer to a yes/no question correctly. EDIT: @Sorcerer's post below (don't want to derail the thread with a separate response): I somehow had the urge to make the statement above, since I too often wonder about people wanting themselves or some phenomena to be taken seriously for having the accuracy of a random number generator. You are indeed correct that it does not exactly match to the statement you were trying to make.
19. ## radioactive decay and dark mater

First question that comes to my mind is whether you expect energy and momentum to be conserved. Currently, that is in our description of radioactive decay we have today, this is the case. If there were unknown particles involved, you would expect energy and momentum not to be conserved for the known particles, since the unknown particle may have a different energy or momentum before and after collision (hence causing the knowns to have different energy/momentum before and after the process, if total energy and momentum are conserved). As far as I know, conservation of energy and momentum holds for all known particle processes. In fact, particle physicists are pretty deperately looking for processes where conservation of energy or momentum of the known particles does not hold. They are hoping to label the missing energy/momentum as a sign of dark matter. To no avail so far, despite huge effort such as the LHC experiment, which particle physicists proudly call the biggest scientific experiment in the history of mankind.
20. ## Electric Rates in Germany

Not sure if that matters for the point you are trying to make. But since you explicitly asked, and since Germany originally was on-topic: That is not how it works in Saxony. From having talked to an Austrian farmer I know it's also not how it works in Austria. Not sure about Texas and Ontario. In Germany, installation of renewable generation is not subsidized (installing measures for improving energy efficiency are, which is a key aspect for renewable scenarios but usually not the topic of discussions like this). Instead, the generated electricity is paid for by a fixed amount depending on technology, time of installation, and a few other parameters. And as mentioned before, these subsidies are not paid by the taxpayers but by the electricity consumers (who of course often tend to be taxpayers, too), and directly appear as part of the electricity bill. The rates you get for PV generation are written down in a law called "EEG" (Erneuerbare Energien Gesetz: Law on renewable energies). The rate the house-owner pays for drawing power depends on the contract with their electricity provider. The price difference can be anything, since both the subsidies written down in the EEG and the electricity prices the provider charges are subject to change: EEG subsidy decreases, electricity prices increase. Parity was around 2012. Before that it was a better bargain to feed in everything and buy for cheaper price (as the Austrian farmer did), now there is an increasing push towards using as much of your PV generation yourself as possible. Explicit numbers can be seen in figure 5 of this link: http://www.ise.fraunhofer.de/de/veroeffentlichungen/veroeffentlichungen-pdf-dateien/studien-und-konzeptpapiere/aktuelle-fakten-zur-photovoltaik-in-deutschland.pdf. Blue line is private PV generation, red line is mean electricity costs for private households (sorry for the source being in German, but I did not want to look for an English one and Fraunhofer ISE is a very reputable source). As a side-note since Moore's law was mentioned before: Figure 4 shows a kind of Moore's law. Shown are the mean installation costs of PV panels (Euro per Watt-peak) vs. the total installed power so far (Germany, I think). It kind of follows a logarithmic relation.
21. ## EM drive, German testing and confirmation

Amazing. So the guy who became famous for non-reproducible anti-gravity experiments claims that there may be something to this drive because his experiments are inconclusive so far, Then, an anonymous NASA person adds that they have no idea how it could work but it could be related to the "technology manipulating subatomic particles which constantly pop in and out of existence in empty space". And then they add the very important statement that "If true, this could certainly revolutionise space travel" (at least it was a capital "If" - and I am just beginning to enjoy the expression "could certainly"). I have no idea on the technology. But after reading the article I literally checked if The Telegraph is a satire paper (spoiler: It's not).
22. ## Linux

You do not need to partition the hard disk from a windows program. The Ubuntu installer (Ubuntu probably being the recommended Linux distribution) gives you the option to install alongside of Windows and takes care of everything for you. I have been using this a few times and never had any problems with it. Using a virtual machine still is safer, of course. But maybe a bit more work. I am using Ubuntu with Windows running as a virtual machine, and I faintly remember that I had to enable some flags in my BIOS.
23. ## Thought experiment paper

A bit in a rush now, so in short: - first question would be: why do you want to publish a paper in the first place? You don't need it for your CV to get your next post-doc position, and also it's not a cleaned-up writeup for your colleagues world-wide. Maybe another form of publication may be more suitable to get your idea out, which I assume is your intent. - the original default-answer still stands: have a look at the journals that the papers you read and cite are published in. Or have a look at papers that publish about Compton scattering experiments: https://scholar.google.de/scholar?hl=en&q=compton+scattering&btnG=&lr=.
24. ## Thought experiment paper

The mainstream response to this common flavour of questions is: Have a look at the journals that the work you are citing has been published in. Alternatively (in in my opinion even better), ask the professor you work with. Caveat: If you don't work with other scientists and only cite Einstein's general relativity paper and the paper describing the finding of the Higgs boson then the honest advice is: Don't try to publish it at all. No offense meant by that, but realistically publication of papers is meant as a way of communication within the science community. And it's not very common for non-scientists (who tend to be the ones asking on science forum rather than asking their colleagues) to publish in scientific journals - or even their publication to be well-received by the community.
25. ## Electric Rates in Germany

Since nuclear power is not really discussed in Germany the better comparison would be a toaster that emits harmful fumes but is the favorite toaster model of the mining and steel unions.
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