Strange

It's true that many popular science articles (and even textbooks) don't always make it clear that what they are saying is a metaphor or an analogy. In the case of pressure and voltage, the analogy is quite close. A lot of basic electrical principles are analogous to similar hydraulic ones: there is a an article here that summarises some of them: https://www.hydraulicspneumatics.com/technologies/article/21884389/hydraulicelectric-analogies-part-1 You can build "circuits" with components representing wire, resistors, capacitors, switches, etc. that use fluid flow. (I don;t know how / if you can build the equivalent of an inductor, through). There are a similar set of analogies in the design of acoustic systems, such as loudspeaker cabinets. You end up using familiar equations but where electriical values are replaced by the length or diameter of a tube , the stiffness of the walls etc.

! Moderator Note Moved to Computer Science (the Speculations forum is for people to present speculative scientific theories). But maybe Philosophy would be better; we can see how it goes. Existing now? No. Nowhere near. I think we are a long way away from anything close to string AI. If it is even possible. I have seen arguments on both sides but, generally, the "not possible" arguments seem to boil down "because we are special". The arguments that it is possible are not completely convincing, but at least they seem to be logical arguments based on facts.

+1 for confirming what I thought. And, of course, you would have also got +1 if you had explained that I was wrong!

The effects of CO2 on infra-red absorption have been intensively studied (theoretically, experimentally, and quantitatively) for well over 100 years.

Well then, I suppose what I really meant was: I don't see why the position of the motor changes the difference in acceleration of the two observers. (The point I made on Jan 28 still stands.) I may be wrong, but I think there is only a difference in the clock rate while they are accelerating. If the spaceship stops accelerating then their clocks will tick at the same rate (but they will have accumulated a time difference). But if they now decelerate back to their initial (zero) speed then the situation will reverse and their clocks will be synchronised again.

No, it is in an infinite sequence. There is no last value. Values approach 1, in the limit, but never get there. You can calculate the Nth digit of Pi (without having to calculate all the previous digits) but you can't calculate the second to last. Because there is no last.

Surely this is true of any infinite sequence?

This is relevant: https://www.sciencealert.com/earth-s-core-is-2-5-years-younger-than-its-crust-thanks-to-the-curvature-of-space-time

Great demonstration of why correlation is not causality:

I don't see why the position of the motor is relevant to relativity of simultaneity.

If so (and I don't know if that is correct or not) this is because they will disagree about exactly when the accelerations starts and stops (relativity of simultaneity).

Neither of them have a design. Both evolved for a function. There are a limited number of ways to fulfil that function and so it is not surprising that completely different organisms have come up with similar solutions. Presumably because they evolved to meet similar requirements - strong jaws for hunting and eating prey, eyes set forward (for hunting, again), etc. It doesn't really matter what creationists say as they are either ignorant or dishonest. Or, in some cases, both. You don't classify organisms by looking at just one or two traits.

I have absolutely no idea what you are trying to say,. Sorry.

This is pretty common. The eye, for example has evolved multiple times and can be very similar in species that are very distantly related (humans and octopuses, for example). This is exactly what you would expect from evolution. This is, presumably, what is known as a "straw man" argument. Claim the theory says something that it doesn't and then show that your false version of the theory is wrong. No.

Photons are neither particles not waves (so they are not "two things at one time"). They have some characteristics of both of these everyday concepts (as well as other characteristics which are less intuitive) and so the terms are used, informally, to describe their behaviour.

Reliable inertia control: they have artificial gravity and no apparent effects when they accelerate but then they get thrown about by explosions

This: https://www.nasa.gov/mission_pages/LRO/news/lro-farside.html (Probably not actually during an eclipse, but I'm not sure why that would be relevant?) But why settle for a satellite, when we can land there: https://www.sciencealert.com/feast-your-eyes-on-these-stunning-new-pictures-of-the-far-side-of-the-moon

It is in the Daily Mail. I am not even going to bother reading it. You might as well use The Simpsons or Spongebob Squarepants as a news source.

! Moderator Note Moved to Trash

As you said, earlier: "When t ≠ d the object is not observable. Not directly observable." So the future consists of events for which t < d; i.e. the light (or other signal) has not reached us yet.

I think you need to look up the word "logically" in a dictionary. And remember that this is a science forum.

! Moderator Note Moved to The Lounge (not sure if this is the best place but it isn't Science News)

After a few posts, Luke Barber has been banned as a spammer.

The colour of a hot material depends on the temperature. In the case of aluminium, the melting point is sufficiently low that it could be barely glowing and would appear silver, like the metal. But if it is hotter, it will appear red, orange and eventually white. Iron has a much higher melting point so, when molten, it will always be reddish at least. I would imagine that the static material would cool more slowly because when it is flowing it comes into contact with more cool surfaces and cool air, plus it is being "stirred" by the motion so that heat will be dissipated from inside the volume of liquid more quickly.

Not an effect I am aware of. Nor can I imagine a mechanism where the level of water vapour would affect molten metal. If there were a mist of water droplets in the air then I can imagine that coming into contact with a hot surface might have some small effect. They are bizarre and oddly specific. What are they based on? If the oxygen was depleted, then the burning would stop.