Strange

Maybe he is thinking of the myth that the atom bomb could have ignited the atmosphere. When the atom bomb was being developed, Teller did point out that a nuclear chain reaction was possible between nitrogen atoms (and there is a lot of nitrogen in the atmosphere). Bethe quickly calculated that the possibility of this happening was so low it wasn't a risk. https://blogs.scientificamerican.com/cross-check/bethe-teller-trinity-and-the-end-of-earth/

Well, length is a single spatial dimension. But the ruler does exist as a world-line in 4D space-time. No, I meant the curvature of the Earth affects the construction of large structures. Sorry if that wasn't clear.

Large ones! Some long bridges for example.

That’s OK because we use the most appropriate model for the job. Calculating the path of a thrown rock can be done by treating gravity as a force. Small buildings can be designed assuming the Earth is flat. On the other hand, some buildings need to consider the Earth’s curvature and some space missions have to take the curvature of space-time into account.

Many diseases are quite host specific. Influenza is a disease of humans. Foot and mouth infects cattle and a few other species. There are a few diseases (zoonoses) which can be transmitted from animals to humans such as rabies, Ebola, cowpox, ... Thinner than what?

That can only reduce the rate at which expansion is slowing, not speed it up. So, if the density of the universe were low enough (and there were no dark energy) then expansion could continue forever at the same rate. With a higher density it would slow down and eventually collapse again. With dark energy it looks as if it will continue to expand at an ever increasing rate. http://astronomy.swin.edu.au/cosmos/C/Critical+Density https://www.physicsoftheuniverse.com/topics_bigbang_accelerating.html

Hmmm.... Not sure. In science "facts" are usually the evidence that theories are based on (and tested against). Theories shouldn't really be accepted as facts (or true) because they are always provisional - further evidence could show them to be wrong (although this doesn't happen very often). But some theories are so well established that it is hard to see how they could ever be overturned. The quote in my signature is from Hans Rosling, pointing out that many of the ideas we have about the world around us (about, for example, the relative wealth and health of countries) is based on inaccurate stereotypes and out-of-date information.

Well, if this bit isn't homework ... In 2011 three guys (Perlmutter, Riess and Schmidt) got the Nobel Prize in physics for finding evidence that the expansion of the universe is accelerating. Previously it had been assumed that gravity would cause it to slow down and then, possibly reverse (leading to the "big bounce"). But instead they found that, starting about 4 billion years ago, the rate of expansion started increasing. This can most easily be explained by the presence of a fixed amount of energy in empty space - so, as the universe expands and there is more space then there is more of this energy. No one knows what this energy is so it is called "dark energy". The presence of this energy causes the rate of expansion to increase (which means more dark energy and faster expansion ...) http://www.bbc.com/news/science-environment-15165371

Quite the reverse. Google "dark energy" Is this really homework? (Much more interesting homework topics than when I was at school!)

Why not contact the company and ask them about the history of the product? (Why do you want a website that isn't the manufacturer?) http://tethon3d.com/about-us/story/

No. But it does form part of several models. Area54 has mentioned the "big bounce" or cyclical models. There are also "eternal inflation" models where multiple universes could be continuously created: https://en.wikipedia.org/wiki/Eternal_inflation It seems unlikely that there could ever be evidence for any of these ideas though. Not currently. Although Stephen Hawking's last paper suggests it may not be a necessary consequence of inflation.

And research has shown that people tend to have more faith in people who speak with confidence (even when they are repeatedly wrong). So, you and I might trust someone who appears thoughtful and cautious about their opinions, most people prefer definitive statements.

Fair point. Fiction probably works just as well. Huh? Ah! Things like RF resonators?

What do you mean by "hacking"? Do you mean engaging in illegal activities? In which case, I would recommend you study law. Or do you just mean programming and using computers? In which case computer science may be useful.

Yes, I have seen people screaming that "it is used industrial cleaning solutions" (er, so is water). Hmmm... it seems the policy is that unless it can be proven to be harmless it will be labelled as "possibly carcinogenic".

Very good. I don't think they exist in the real world though. Although, opera singers: http://www.discovery.com/tv-shows/mythbusters/mythbusters-database/human-voice-shatter-glass/

I will admit, I don't know your history very well. But the way (some) Americans alternately praise democracy and (laughably) claim to be the most democratic country in the world but also insist (unlike any other democtratic country) that they need weapons to defend themselves against government is .... well, bizarre. (And that wasn't the purpose of the 2nd amendment anyway. But that has been done to death in its own thread, so...) Not much difference. One set of people (the slave owners in the slave states) thought that the federal government and the governments of the other states were oppressive and wanted to remove their (non-existent) right to own slaves. If the US ever got a truly repressive government (luckily Trump is too vain and stupid to achieve it) and people tried to rise up against it then they would be crushed like any other rebellion (by the largest army on Earth).

Is there any such thing?

They didn't overthrow the "repressive government", though. Just ended up getting lots of people killed. Civil war is rarely a good idea.

That worked out well for your southern states, didn't it.

You put a few cc of washing up liquid in several litres of water; a small percentage of that is sodium laurel sulphate (which is demonised on the web for some reason). Most of the liquid left on the plate runs off or is wiped off when your dry them. I doubt it is significant. I would be more worried about the oils, food residues and bacteria in the water than soap.

Challenge accepted: Q: What does Itoero post on science forums? A: Belgian waffle.

Did you look at the doses that can cause unpleasant symptoms? I don't think that the tiny amount left on a plate is going to have much effect.

I think there are some very simple conceptual models (for SR, at least). For example you can think of movement as "swapping" part of your movement through time for movement through space. When you are stationary, you do not move through space and your time ticks at "1 second per second". When you are moving (relative to some other observer) then they will see you moving through space and, as a result, moving slightly more slowly through time. This works because the Lorentz transform is actually a rotation between the time and space directions (dimensions). This is more of a philosophical issue: what does it "mean" when we represent time and space in this way. You can view it as all events in time and space being fixed in a block and, instead of time flowing for us, there is just a line that represents our existence in space-time.