swansont

Who is saying it's a pseudovector? I don't see that in your book excerpt. It's a vector, following the protocol of a cross product. The dipole can have any orientation and the result will be the same. There's no directionality relative to a coordinate system. It's a scalar. The dissipation of energy follows certain rules, and it depends on the system. The gradient of potential energy gives you the force; the gradient is where directionality comes in, not the energy itself. Knowing that e.g. the electrostatic potential energy depends on the separation tells you the gradient is radial, and the force is indeed radial.

Are you new here? Have you met SFN? Pleading ignorance of the concept of "back up what you claim" isn't going to wash. Claiming that nobody is held to this standard is ludicrous. I have already clarified this (see my earlier post); it wasn't a response to you. And there are so many details one could consider. How quickly can you accelerate? How much fuel and reaction mass would you need for just this trip. You need even more if you need to maneuver. What of the problem of things wearing out - how much raw material do you need to fix things? Is radiation a problem? Damage to the ship because it's traveling at a million mph? How do you ensure you have the diversity of life that would allow survival for that long? Pick any aspect of the travel and there's likely a rabbit hole to go down exploring the problems that have to be overcome.

This is why dimreepr needs to specify what the conditions of the thought experiment are; discussing different scenarios gets confusing.

I suspect the young folks would balk at going to war for the old folks much more than they currently do. There would be a shift in other motivations, too, since you aren't likely to get an inheritance if you are only ~30 years younger than your parents. As far as a social safety net goes, who pays for it? How would an economy sustain itself if you only worked until you are ~70 and then spent 900+ years trying to not go broke?

You have to have many reactors, too, because the containment vessel will fail owing to fast neutron embrittlement. And all the components will wear out, which makes for logistical problems. But you didn't address this, just as you don't address any other solutions you present. There's never any detail. If you've glossed over nothing, show me where you go into the details of any of the proposed solutions to show that they are viable and not just a pipe dream. Instead of just saying "generation ship" how about estimating its size and what must be carried to travel even 1 LY through space. There's probably some very interesting science and engineering to discuss, but it's never come up, because you stop at e.g. "generation ship" and go no further. I cited physics as the reason that "They can travel to different areas at will" is a bad assumption (that's the only mention of physics by me in the thread before now). If you think that being limited to some (probably small) fraction of c and relying on some future generation to be alive at the destination is getting somewhere "at will" then I guess we have different definitions of "at will"

Assuming they have similar lifespans to ours. And if they do, that the interest level in these probes continues even though there is no feedback for a long, long time. And they maintain the technology to interface with the probes (though this is not quite like needing to find a device that lets you read an 8" floppy disk, which is only ~50 year-old tech, and hoping your software can read whatever files are on it)

You haven't answered the question. If we age the same but just don't die of old age for another ~900 years, all of our young people are going to be working in the nursing homes of people who are old and can't care for themselves. They would also have to be fed, putting a strain on food supply as the population grew because people weren't dying. So yeah, we'd stagnate. Things might be different if this were the case all along, but then it wouldn't be our society, it would be the society of the people that lived for 1000 years. And this all changes if puberty didn't hit until we were ~120, our fertility were different, and we didn't start suffering the ravages of old age until we were ~600 or 700 or even later, and many other things to consider. Lots to unpack, and impossible to do so with so many variables that have not been defined.

And the death rate from being unvaccinated is even higher than that. https://www.scientificamerican.com/article/how-to-compare-covid-deaths-for-vaccinated-and-unvaccinated-people/ For the month of March, “unvaccinated people 12 years and older had 17 times the rate of COVID-associated deaths, compared to people vaccinated with a primary series and a booster dose,” And if you look at the graphs, it's almost 17x for people 65+ and boosted, and even bigger for people 50-64 and boosted So the cost of this N-antibody immunity is a markedly higher chance of dying.

Where's the part that says that immunity from having the disease is better?

That's not a link to peer-reviewed literature. You've already admitted you're not a scientist, so you have no credibility in making claims

I'm going to need supporting evidence for this. i.e. peer-reviewed literature. edit to add "A study published in August 2021 indicates that if you had COVID-19 before and are not vaccinated, your risk of getting re-infected is more than two times higher than for those who got vaccinated after having COVID-19." And other links that indicate vaxxed is better than not being vaxxed, after having the disease https://www.hopkinsmedicine.org/health/conditions-and-diseases/coronavirus/covid-natural-immunity-what-you-need-to-know

To some extent they are the same thing. We haven't been "advertising" ourselves until relatively recently, so not knowing we are here and us being ill-developed are almost the same thing. The distinction would be whether they know about us (and don't care), or don't know about us. But why would they know about us?

And if you don't have a vaccine, the virus will also mutate, as it has already done in the absence of a vaccine. Again I ask: what is the actual problem? What does "the distance between vaxxed is shorter" mean? ! Moderator Note Note: similar threads merged

It's the amount of fuel available, which might limit the population (number and geographic spread) and the energy density, which would restrict travel and scope of industrialization. Scientific advancement relies on having people free to pursue science, which would happen slower if more manual labor was still required because you didn't have the same available machinery that high-energy-density fuels make available. A solar furnace isn't going to propel a train very effectively, for example. I'm also not sure how effective metallurgy is going to be with wood vs coal fires.

You're going to have to do a better job of explaining what the problem is, because I can't believe that anyone thinks the virus wouldn't mutate in the absence of vaccines, because it did. The alpha variant (identified below as the first "highly publicized" variant, suggesting there were others) showed up in Nov 2020, and the first recipient of a vaccine (other than trials) was the following month. Beta also showed up around that same time. https://www.yalemedicine.org/news/covid-19-variants-of-concern-omicron As I understand it, "immune escape " means the virus mutates to where vaccines (or possibly acquired immunity from having the disease) no longer affords protection. So we'd be in the same boat as if there were no vaccine. But more people would be alive, not having succumbed to the disease, relative to the situation where there was no vaccine. Why is this bad? You also need to explain why "Usually dangerous variants can´t spread well but what about now when so many got the shots?" Dangerous variants can't "spread well"? What is it about shots that make the virus "spread well"?

! Moderator Note If you have no studies, it precludes being certain. You are pushing an idea without scientific backing, and that has no place here.

It doesn’t matter what their technique is if the evidence of intelligent life hasn’t had time to reach them yet.

We have generational ships? Fusion hasn’t been 20 years away for the last 60 years? How long does a fission reactor last, vs the travel time for interstellar travel? This is but one example of the details you gloss over in these discussions. “Proposed” is not solved.

Which you’d expect early in the universe, before you had stars going supernova or having neutron stars merging, and dispersing the heavier elements. You’d also have issues if they evolved early in the planet’s life, before large coal and oil deposits formed.

Why is this a matter of philosophy? What changes with respect to our aging process?

Because these are waving-of-hands with no analysis backing them up. It’s the Sidney Harris “then a miracle occurs” cartoon - you need to be more explicit in step 2. http://www.sciencecartoonsplus.com/pages/gallery.php (it’s reminiscent of the joke in our D&D group when a tough foe was encountered: “we kill them and go on”) IOW the devil’s in the details

As I recall, trying to get you to give scientific/analytical support for your conjecture about interstellar travel in the past has been like pulling teeth. I’m not interested at this time.

Please show the derivation

Please don’t respond to obvious spam. You aren’t going to shame them or reason with them. Use the “report post” function to bring it to the attention if the moderators.

I agree with Greene to some extent; the earth would not stand out. If they are more than ~100 LY away, what would make us “interesting”? It’s not communicating with an anthill so much as communicating with a rock. Why would they care about this rock?