They do if one event causes the other: that is the very definition of causality. You are confusing causally connected events from ones which are not causally connected. In your example the two tunnel gates close simultaneously in one frame which means they cannot be causally linked i.e. the fact that one gate shuts does not cause the second gate to shut, some third event caused them to shut (e.g. someone pressing a button). This is easy to see because if I block one of the gates from shutting it will not affect the other gate.

However if we take the gate shutting and the train then hitting it ANY observer in ANY inertial frame will agree that the gate shut first and then the train hit it. If the train were travelling faster than c then I would be able to find a frame where the train hit the gate first and THEN the gate closed. If I then stopped the gate from closing (which I could do in that frame) you have a major paradox.

Finnish subjects finished as subjects in 1918. Now they will finish subjects in Finnish schools and subject Finnish students to topics subject to subjects being finished.

Well actually, just to make you feel better, the OP clearly does not know the fundamental principles of special relativity because not going faster than light is not actually one of them. There are two "fundamental principles" of special relativity called "the postulates of Special Relativity" and these are:

1. The laws of physics are the same in all inertial frames.
2. The speed of light is the same in all inertial frames,

The limit on not going faster than light comes from adding a requirement for causality i.e. that if event A causes event B then everyone in all inertial frames had better agree that A occurs before B. Note that this is not 'see A before B' it actually affects the time-ordering of events so that you would be able to stop A from happening after seeing B occur.

If you can transmit information faster than light then this is exactly the same as being able to transmit information backwards in time under relativity. Apart from the issue with paradoxes, you can be very sure is not possible because you don't see us physicists winning lotteries or making a mint on the stock exchange.

In so much as cancer is a fatal genetic disease I have no problem with that. However I see no way that you can possibly make someone immune to cancer. One of the causes of cancer is damage to DNA caused by e.g. radiation. Altering the arrangement of genes in no way prevents things like radiation damage.

Yes I absolutely would. This technique changes your inherited DNA and, if applied to enough people then we will end up with a single, genetically identical immune system protecting us all. You only have to look at agriculture to see what a disaster mono-cultures can be and yet you are proposing this for the human race? Our immune systems may not be perfect but the diversity is one of its strengths.

That said if you research this area without applying it to humans then I've no problem. With enough understanding - and safeguards (like ensuring variety) - it could be possible. But because the changes are inheritable it should initially be restricted to those unlikely to reproduce so if there are problems they will not be permanent ones that we have to deal with for generations.

I've no problem with the facial recognition and/or iris scanning - we already have these at UK entry points and they work well. I'm less happy about fingerprints though. You leave fingerprints everywhere and so they are easy to get hold of and potentially copy. Plus I would worry about my fingerprints ending up in a database which is searched by police. This raises the risk of either false matches or incidental matches if you happen to have been in a location where a crime is later committed.

True but fatal, genetic diseases are a good reason not to ban use of the technique so that research on using it to cure them can proceed. However I would support strong regulation to limit it to cases where there is severe disability or greatly shortened life span. Indeed I would go as far as to say than an outright ban in these cases is unethical because of the potential to cure these diseases.

There may be risks for the first to undergo any treatments developed but this has to be set against the risk of certain death in some cases. We allow this to happen - with proper controls in place - for new drugs, why should this treatment be different?

I think it depends on the Linux knowledge of the user and the time they have available to play with the system. As a postdoc and starting faculty member I used to have a Dell and it was blazingly fast but required a huge amount of tweaking to get power management and shutdown working (and ultimately these never really worked well at all).

If you look around a typical meeting at CERN the overwhelming majority of us now have macs. These are not as cheap as a Dell but they are a lot better at taking a few knocks (which happens if you are always carrying it around) and they just work without all the tweaking and configuring which Linux needs (and which I no longer have time for). The downside is that open source software we use in physics is not always easily portable to a mac although with the increasing number of mac users this is improving a lot plus you can always run a Linux VM on the laptop if you need to and I've used this to debug code.

Ultimately it depends on the user. Those with less knowledge of how to configure linux or with less time to do it should probably look at a mac. However if you have the time and know-how Linux on a Dell will be cheaper and possibly faster performance-wise.

Actually they reinvented the wheel not just in the generic sense but also in the specific sense that someone else has already built a 64 node Raspberry Pi cluster...and instead of some custom designed case theirs used a home build lego case which was definitely cooler. Of course this should not be too surprising. It was made by GCHQ after all so they probably got the idea from reading this guy's email!

If you do it correctly you are re-using some questions out of a very large pool of questions. If some student wants to memorize every question ever asked then let them go for it - they will end up learning the material even if they think they are some how gaming the system. You can also alter some of the details e.g. numbers in a question without really changing the difficulty.

How do you get a minor to agree to this? Their signature carries no weight and it would be a violation of academic integrity and ethics to penalize an exam mark for an action which could not possible affect the mark. The need for restrictions like this are the result of sloppy and lazy exam writing: I've written and administered many exams myself and never needed to do this. Nor when I was a school kid myself was their any such restriction placed on me after taking an exam: even ones which were administered across the country: everyone took the exam at the same time everywhere.

Then that's a copyright argument and you go after that in the courts with lawyers. You do not have the teachers monitor conversations during lunch or monitor discussion sites for any mention of the test. Instead you look for someone posting a copy of the test and then have your lawyer contact them.

Which is pretty much the same state of affairs with English and American although there are quite a few words which are completely different: lift vs. elevator, car bonnet vs. car hood, courgette vs. zucchini, aubergine vs. egg plant, car boot vs. car trunk etc. and more confusing an English word can have a different meaning in American and vice versa often to embarrassing effect e.g. rubber, pants, suspenders, chips, fanny etc.

This is why it is helpful to give the two 'languages' different names: they may be mutually intelligible (for the most part) but it can be helpful to know whether the language is English or American so that words like 'chips' with different meanings can be correctly interpreted. Calling it 'English English' and 'American English' is just redundant and it typically gets shortened to just English and then you are left guessing based on spellings or context what is meant.

Actually the entire quote is:

""The problem with defending the purity of the English language is that English is about as pure as a cribhouse whore. We don’t just borrow words; on occasion, English has pursued other languages down alleyways to beat them unconscious and rifle their pockets for new vocabulary." --James D. Nicoll"

Interesting link but wow - good thing I was not on her thesis committee because with a claim like that she would fail (either than or they are reporting it wrongly).

The total solar radiation at the Earth, outside the atmosphere, is 1.36 kW/m^2. Multiply that by the area given and the number of hours in a year and you get 762,470 TWh. However this would be the power for a solar satellite always pointing at the sun - so not even in orbit around the earth but say at one of the Lagrange points.

However things are not so simple because the panels on the ground rotate with the Earth. This means that for half the time they get no power and for the daylight period their angle is only optimal at midday. Note that even tracking panels will not help here because they would have to be spaced out so that their shadows did not meet another panel and so you would have less power collected at midday. The day-night cycle reduces the total power to 381,235 TWh and the angle of the sun throughout the day - I'll assume an RMS average here - drops it further to 269,573 TWh.

Now this assumes that the station in on the equator. If it actually was in West Virginia the power would drop further to 209,498 TWh due to the latitude (39 degrees) of the land. Now we need to look at the solar cell efficiency. The best that has ever been achieved in a lab is 46% so this leaves a total energy generating capacity of 96,369 TWh.

Unfortunately in 2008 world energy consumption was 143,851 TWh. Hence there is absolutely no way whatsoever that a solar plant of 25,000 square miles can supply the energy needs of the world. Even if it was located on the equator, there were never any cloudy days, we could mass produce solar cells which have only ever been available in a lab AND world energy needs have not increased since 2008 we still could not power the world from such an area! If the thesis in question makes those claims as reported it is just plain wrong.

It also appears that the question was posted after the test was taken. In this case there is no security issue because the exam has already been administered. If they are not giving the same exam at the same time everywhere - or at least with enough of an overlap that nobody leaves before the exam starts anywhere else - then the problem is their own broken security model. It's not academic cheating if someone who has completed the exam discusses the questions in public and since they are minors they can't even sign a contract to enforce legal penalties.

I completely agree...but isn't this what you are also doing too? Wanting to kill someone while showing zero remorse about doing so? If you are going to argue for the death penalty a far better argument is to say that it removes any possibility that the person can ever re-offend and thus protects society. The problem is that, as practiced in the US, this is very hard to argue. Those convicted are held in prison for a decade or longer and even then there are a shockingly high percentage whose convictions are quashed when carefully examined.

If you want to argue for the death penalty then you need to restrict it to cases where the evidence is overwhelming and you need to make it rapid. Even then mistakes will be made which is why I have so much trouble with the concept. About the only time I would think that it is justified is when you have someone whom you cannot safely imprison e.g. the IRA terrorists in the 1980/90s who used their contacts with the terror organization to threaten guards' families unless they got special treatment while in prison: something which almost lead to their escape. In these cases I would argue that the need to protect society from extremely dangerous criminals might make it justifiable but I'd still have concerns.

Except that you don't always! You use the American date format most of the time except when referring to "the fourth of July" then, or all the times, you always use the English format.