The exponential function and that the temperature of hell gets to always increase so based on the explanation of that teaching its temperature will over take everything, including heaven. A small talk about energy.

My mom has a strict new rule at family gatherings::

No religion
No politics
No love
No money
No sports

Let's just say we have had a few unhealthy debates over Easter dinner ???

Quantum mechanics.

I am in the UK and I would agree with lpdg77. I once got threatened withe sack when I said I would not bow to Prince Andrew visiting my work.

For me, in the UK, the remnants of the class system, specifically the notion of deference to a 'higher' social class. So, if for example, the Queen was visiting my place of work tomorrow I would make sure I was out on a call rather than be expected to bow, tug my forelock or do the whole 'Yes Maam' thing.

nationalism is a usual no go parenting skills mental health i think biscuits(cookies) and weather are generally safe unless you have strong views on hob nobs

National heroes, romanticized history, romantic love, "natural" parent-children bound, gender roles, ethnicity differences, ideologies in general, etc.

Anything to do with Trump. But if you mean in this website, I've found that many here flip out over anything to do with gender issues, supernatural or psychic events, ghosts, UFOs, teleportation, alternative medicines, past lives, etc.

I don't worry about it.
I say whatever I wish, and when the trolls rush out to attack me, I just go to their profiles and block them. That solves the problem and I don't have to encounter them again.

Alternatively, any potentially touchy subjects likely have a designated "group" already formed where you can discuss them in peace.

I even started a group for people who experienced or have "supernatural" abilities, such as ESP, etc.

My group: [agnostic.com]

Well there is several subjects you can talk about without potentially offending someone like for example:

You can talk about our solar system, including gravity and all black holes and different galaxies.

You can talk about people when they are in the vegetative state. Are they conscious or aware?

You can’t talk about science, history, art, Physics, math, culinary and so much more!

So much to talk about! I love it!

Patriotism. Nationalism. Who the fuck needs it? Why should I blindly declare how goddamned wonderful is the country I happened to be born into by happenstance?

Now, I fully get that being a white male raised in the USA during it's most prosperous of times was a stroke of incredible luck. No question. But, why does that obligate me to worship the land and the institutions into which I was born? Don't get me wrong, if the country were invaded, my rickety old bones would be out on the front lines; I would defend this country from invasion as vigorously as possible. But, our system, prima facie, has become perverted in the manner of capitalism we practice. Our military is used to test new weaponry; our "justice" system has become a system to oppress minorities. Our political system...I could go on, but you get the idea.

Stuff like Gluten sensitivity in non Celiac sufferers. Or anti-GMO campaigning. Or Mysticism related crap.

All the "isms" including environmentalism.