Strange

And yet the page you link to says no such thing. So perhaps you have misunderstood something.

! Moderator Note Do not hijack other people's threads with your own ideas.

Please define what you mean by "electricity" in that context, how it is measured and what units it is measured in. (I suspect most of the problems in this thread come from your misuse of English rather than any errors in electrical theory - on either side.)

Don't use it to wash anything aluminium, though, as it can corrode it.

Soaps (and detergents, generally) have a hydrophilic (water attracting) and lipophilic (fat attracting) part. This enables them to bind to oily or fatty compounds and emulsify ("dissolve") them in water, hence removing them from skin, clothes, dishes, whatever.

I just meant “my vague memory [that bicarbonate can be produced from carbonate]” https://en.m.wikipedia.org/wiki/Sodium_bicarbonate As i said, I had no idea what the main production method is.

I don’t know which is most widely used, but Wikipedia did confirm my vague memory

Sodium carbonate is commonly known as “washing soda” and is easy to buy over the counter You could also look at making your own soap (for the tougher, oil-based marks) - this can be done with vegetable oil and sodium hydroxide (caustic soda). The latter is quite dangerous, so be careful if you try it Also worth noting that sodium bicarbonate is manufactured from sodium carbonate. So you are using (wasting?) a lot of energy to “undo” that step.

Prime number spiral? https://en.m.wikipedia.org/wiki/Ulam_spiral

By itself it wouldn't but it would slow the rate of descent, perhaps making it easier to counterbalance the force of gravity. But then the stickiness would act against the upward force, too. So, yes, it is probably a daft idea!

Why do you find this unbelievable, when you have grown up with this perfectly normal experience? It is like saying "It's unbelievable that I can breath the air around me" or "It's unbelievable that I can hear the range of sounds that my ears are specifically made to receive" or "It's unbelievable that water is wet" or any number of perfectly ordinary things.

Also, the total force on the ground will be exactly equal to the weight. And the force of the ground on the person will also be equal to that. So Newton is redeemed once again.

! Moderator Note When you come back, you can start a new thread in Speculations. That thread must provide the mathematics behind this idea. And show how that matches what we observe.

I would say you are basically correct, in this case. But there are a some other factors that can come into play. For example, friction. You might have seen that trick (wall of death?) where a motorcyclist drives around the inside of a vertical circular wall. The friction of the tyres (generated by the outward pressure caused by the rotation) stops them slipping down. So if your nephew coated the inside of the glass with, say, honey, he might be able to keep the ball in the glass. Also, I think the motorbike has to continually steer upwards slightly to counter the force of gravity. So if you nephew could learn to angle the tube as it is spun to provide a slight upward force, then that might work. The diameter of the tube will make a difference too.

! Moderator Note One more post like this and you will be banned as a spammer

This is a good read on why it would be the neutrinos that kill you: https://www.forbes.com/sites/startswithabang/2019/12/27/this-is-how-wed-all-die-instantly-if-the-sun-suddenly-went-supernova/#7e585634502c

! Moderator Note You have been told that it is the field which changes with distance so atoms do not need to "know" the distance. If you do not start engaging seriously, this thread will be closed.

! Moderator Note This is a science forum. Please try and post something that makes sense.

Here is one counterexample: https://en.wikipedia.org/wiki/Major_histocompatibility_complex_and_sexual_selection Animals (including humans) appear to prefer mates who differ in the major histocompatibility complex (and there are fairly obvious evolutionary reasons for this).

! Moderator Note The rules require you to present the topic for discussion here, not just link to a video. You could start by presenting some evidence that "humans generally like people who are most like them or those they would like to become more like"

It is important not to misinterpret this phrase (which was invented as a sort of advertising slogan for evolution by natural selection). It does not mean the survival of the most "fit", in the sense of the most healthy. It means the survival of those who have the best fit for the environment (ie. those who are able to survive and reproduce in that environment). All that human treatment for diseases has done is provide an environment where a wider range of people fit. This is not any different in principle from the invention of agriculture, or any other social or technological development. Also important to note that evolution does not have a direction, so there is no "backwards."

That's a good point. The development of agriculture would have needed more than just an observation that new plants sprout from the unwanted seeds of old plants. You need a place and time where there is enough fertility to support a large enough population. You need to have enough people that it is worth doing the extra work, but not so many that there is never a surplus to allow some seed to be planted. It took many thousands of years for the techniques and the domesticated plants to spread form the original sites of agriculture. Each new technology (writing, metals, new materials, money, new source of energy, etc) stimulates and enables further advances. We live in a world built on 10s of thousands of years of development and innovation. Absolutely. If you could transport a baby from 20,000 years ago to the modern day, there is no reason they wouldn't be able to do a PhD in astrophysics or whatever.

Why? So that we know the total mass. ! Moderator Note Do I need to move this to Speculations? Do you have an alternative theory you are proposing?

Also, remember that there are still people living pretty much the same hunter-gather lives as people thousands of years ago. And this is not just due to lack of knowledge of modern developments in science and technology. It is often is spite of it. Some such tribes have not just turned their back on outside contact but have actively rejected it. They prefer to live as they do. So, some sort of "cultural inertia" is probably a factor - our life is good enough, why would we change it with this fancy "agriculture" that you speak of. Also, it wasn't until the development of agriculture, and the consequent surpluses, that it was possible for there to be a class of people who had enough time to think, tinker, share ideas and develop new ways of doing things. That was probably the point at which the acceleration started (in both the growth of cities and the development of technology). Both agriculture and textiles (the word "tech[nology]" derives from "textile") date from about 10,000 BC. I'm sure I have read a book that said quite a lot of this, but I don't remember what. (And people nowadays would probably watch something on youtube!)

Because, although genes can have an effect on many traits, they very rarely determine those traits. Also, because a brother and sister are not genetically identical (they could differ in all 500 or more genes). Also because the environmental factors will not be the same for both of them (because of difference in sex, age, birth order, personality, etc, etc)