npts2020

That's the usual method of predicting efficiency. Again, all of the suggested motors would easily handle the load but not be nearly as efficient as one rated slightly higher than that expected load. Apologies for not being clearer.

Unlike internal combustion engines, there is little difference between lower HP electric motors and higher HP ones so far as energy use is concerned. Electric motors like running at full power and higher HP will mean more weight to move from a larger motor but those differences are small and almost entirely made up by less losses from heat and friction in that stronger motor.

I never claimed otherwise, was merely agreeing that is possible those compounds could show life has existed other than on planet Earth. The second part about aliens visiting us wasn't meant to be connected to any commentary about life on Mars, just speculation about why any advanced civilization would be interested in us other than pure scientific curiosity. (I don't buy the resource argument, it is hard to imagine an out-of-the-way place like ours would be the closest or easiest way for them to get what they want)

Sure, but if it quacks like a duck... I just don't see why an alien civilization would want to have anything to do with a species like humans that appear to be knowingly headed toward self destruction.

Besides linearity, it is seemingly irreversible.

It seems to me that if there are signs of life in meteorites, it is likely to be a pretty commonplace occurrence throughout the cosmos even if that is still speculative. Whether that life somewhere could be "intelligent" is even more speculative but still probable IMO. Whether any of that life has ever traversed the universe to arrive at planet Earth through means other than the aforementioned meteorites is possible but seemingly highly improbable knowing how long it takes the fastest moving thing we know of (light) to get here and the length of life of even the longest lived higher organisms on Earth. If both of those things can be overcome, somehow, then it seems probable we have been checked out by aliens.

We may find out for sure in another 10-15 years when they finally get some samples back to Earth. Hopefully all of the funding for it won't be cut before then...

If life existed on Mars (past or present), what are the odds that it is fairly commonplace among the cosmos? If true, it seems virtually impossible to me that there aren't advanced civilizations out there somewhere, especially since there are parts of the universe far older than ours. https://www.livescience.com/space/mars/incredibly-exciting-nasa-claims-its-found-the-clearest-sign-yet-of-past-life-on-mars

I have read most of the books mentioned in this thread and agree that it mostly comes down to taste. If you are familiar with the workings of the military, I highly recommend Harry Harrison's dystopian "Bill the Galactic Hero" series, not particularly strong on science but (IMO) hilarious on the social commentary. I don't know, I found "The Ship Who Sang" to be rather thought provoking but that was many years ago. (I would tend to agree about her "dragon" books, tho, regardless of how entertainingly written they are)

Exactly. If you don't know anything about eclipses and one day it starts getting dark toward the end of it then suddenly gets bright again to seemingly extend it....

I often wondered if this wasn't just an eclipse (or partial) near sunset on a cloudy day. Would people back then even know about cause and effect of one or have a good way of measuring whether the day was a half hour longer or shorter after engaging in hard physical activity for likely many days previously.

IMO we are not really close to even sending a human to Mars, let alone sending a bunch of them to settle there. When we can't even survive in a closed environment like Biosphere here on Earth, what hope is there for doing so in a far away place with conditions so much more hostile?

Maybe true but B.A.D. also looked at 75 peer reviewed studies (mostly British) on vitamin D production during sunscreen use, including the most recent 3, to reach their conclusions. I can't believe they would ignore anything that was peer reviewed and contradicted the official line.

How do you get this ^ from this>? In general, cosmetics and body care products are relatively benign since anything that causes obvious problems is quickly restricted or taken off the market. It would be a lot easier to discuss particular ingredients because there are so many (I have several hundred chemicals just for making body oils and fragrances). Pretty sure the above is commentary about chemicals compared to each other and not whether any particular one(s) is "safe".

When Cad & AutoCad came out the licensing for using them was pretty restricted but I got to fool with them a bit at an architect friend's house. It was pretty amazing for the time but I doubt many millennials would be impressed.

This actually made me burst out laughing. How can you tell there is any difference if you don't compare them?

The first time I can remember one side actually destroying something the other side built was when Reagan took off the solar panels Carter had installed at the White House, although it probably has happened before. Since then, both have done it.

One can only hope. I am not that optimistic but we shall see. I might vote for whoever promises to raze the $200 million ballroom Mr Trump wants to add on to the White House..

Unfortunately, when combined with Presidential pardon power, those subordinates DO have criminal immunity in actual practice.

I wasn't commenting on your usage of epoch vs eon, just pointing out that it should be obvious why the earth hasn't at any time since then looked like it did during the Hadean without saying it.

It's obvious Mr Trump "listens" to the courts since he has something to say about virtually every ruling. What he won't do is follow a court order if it doesn't suit him. I guess SCOTUS could send Ketanji Brown Jackson to bust the President. 🤪

It seems to me that if a circle could actually reach r=0 it would cease being a circle, meaning that there will always be space when trying to fill any space with smaller circles regardless of their size. Once r=0 it becomes a point, as stated above, (unless one wants to redefine what a circle is) and any space will be filled by an infinite number of points...

Are you referring to the Hadean Eon, at the end of which is, when the Earth first began to solidify?

Something I find interesting is that Trump chose a guy, who thinks launching a brand new car into space is a worthwhile use of resources, to cut waste and inefficiency...