The Big Bang and the Singularity (and other fun questions!)

[Half_Man_Half_Wit]

@Exapno_Mapcase

The expanding balloon is another example. It’s beloved by people who already understand the concept. But it works badly in practice with people who don’t have any understanding of the concept in the first place. (A 2-D version of the universe? Are you kidding me?) What they envision is a balloon with an interior, rather than a two-dimensional surface only, that grows within space just as balloons normally do when you blow them up with air or helium. The explainer may wind up proving the opposite of the originally intended point.

Well, basically, you’re right. However, the problem with non-intuitive concepts is that you can’t explain them in any intuitive, immediately graspable way, without severely distorting them. So what you try to do (or, what I try to do, at any rate), is to build intuition, which is best done through exposure. You might not understand a concept the first dozen times you encounter it, but eventually, you’ll start getting a feel for how it works – that’s after all how we developed the concepts that are intuitive to us now in the first place. Some things, you don’t understand so much as you just get used to them (as von Neumann famously said about mathematics).

That’s not to say they’re incomprehensible – you can learn to grasp them as well as everyday concepts, but of course, few everyday concepts are really understood in all their details, either.

The hope is that somebody who asks about these things is genuinely interested, and will continue to expose themselves to the concepts. Of course, not everybody will keep their interest – but then, if you’re not interested in it, there’s no harm if you don’t understand it, at least when it comes to the more remote areas of physics.

@Chessic_Sense

and when you work with subatomic particles, mass effectively is weight.

In what sense? Typically, you leave gravity – and hence, weight – completely out of the picture when working on a subatomic scale, as it’s just too weak to care about.

[Exapno_Mapcase]

@DHMO

I am not so sure. See, the problem I have is that here, on the surface of the Earth, a person who has a mass of (“weighs”) 75 kilograms (165 pounds) exerts a force of 75kg * 9.81m/s[sup]2[/sup] = 735.75 Newtons on the ground. On the Moon, with 1/6 the gravity at sea level on the Earth, a 75 kilogram person exerts a force of 122.6 N (27.5 lb). In free-fall (or in orbit) a 75 kilogram person effectively “weighs” nothing, and exerts no force on his surroundings. On the surface of a world with ten times the gravith of Earth, a 75 kilogram person would exert a force of 7357.5 N, and would appear to “weigh” 1650 pounds, or more than 3/4 ton.

In other words, the mass of a 75 kilogram person is invariant in all these cases, but in order to refer to the “weight”, the gravitaional acceleration must be specified. In my comment about the “weight” of a galaxy, in its own gravitational field, it has no weight. In which gravitational reference frame must it be put for the weight of a galaxy to have any relevance? Granted, most of the time when mass is discussed it is in the context of “here on Earth, with a gravitational acceleration of 9.81m/s[sup]2[/sup] (32.2 feet/s[sup]2[/sup]).” But, why would a person intentionally use a less-precise term, when no additional information or clarity will result?

In the early stages of the space program, reporters were fond of telling their audience that the astronauts in orbit were “beyond the pull of Earth’s gravity.” As if you could get a few dozen miles from the surface and gravity no longer had any effect. To this day, I still find people who hold this view, and are incredulous when I try to explain that the astronauts are in free-fall.

The point I am trying to make is, why can’t populizers of technical material tell the public the truth, without perverting and distorting it so much that it no longer correlates with reality? One of my favorite authors, Isaac Azimov, was a master of this technique. He could take any topic and reduce it so that the common person, with no prior familiarity or math background, could understand the subject, and still be true to the science. While he is most widely known as a science-fiction author, he was a PhD professor of Biochemistry at Boston University, and wrote or edited over 500 books in his lifetime.

Every word you use that is unfamiliar as a word and as a concept has to be explained. Space is limited. Word space, that is. You have the constraints both of the number of words you are allowed total to make every point that you want to make and the limit of how far a reader will pursue a voyage through an endless list of explanations of strange concepts.

Asimov* [note spelling] had the luxury of writing 5000-word essays for an audience that went to him specially for scientific explanation. Take a look at any newspaper or magazine article today. I doubt if they go 3000 words and most are 1000 words or under. That’s an engineering problem equivalent to designing instruments for satellites. Everything has to be shaved of weight; everything that can be ditched must be.

Mass is an unfamiliar concept. Weight isn’t. If you’re talking about science on earth they are equivalent. Therefore you don’t use the word mass. I agree that beyond the pull of gravity is bad, but its wrong because the only time anybody would ever use it is to describe free-fall. So that is a different underlying situation. However, I’d also argue that it isn’t used much anymore. When I do a Google search, every one of the top hits are to people correcting that as a mistake.
*His ego also caused him to inflate his numbers. Almost 200 of the books he “edited” he did nothing more than lend his name to as a sales tool. You’d think that 300 legtimate titles would be sufficient for anyone, but Asimov wasn’t anyone.

[Chronos]

*His ego also caused him to inflate his numbers. Almost 200 of the books he “edited” he did nothing more than lend his name to as a sales tool. You’d think that 300 legtimate titles would be sufficient for anyone, but Asimov wasn’t anyone.

IIRC, he did insist on having some creative input in those cases, at least a brief editor’s introduction before each story.

[Exapno_Mapcase]

@Chronos

IIRC, he did insist on having some creative input in those cases, at least a brief editor’s introduction before each story.

Sorry, but that’s not editorial input. That’s ego input after the fact. I have nothing against ego or the use of big names to sell books. But I’ve edited anthologies and the difference between doing so and writing an intro afterward is huge. It’s the difference between raising a cow and serving a steak.