Facts Definition and 119 Threads

TL;DR Summary: The thread: Can Any Country Achieve Net Zero Without Nuclear? Reference: https://www.physicsforums.com/forums/nuclear-engineering.106/ As new OP and ignorant of current nuclear technology's science and politics, the discussion in the Australia nuclear power thread was...

In the thread https://www.physicsforums.com/threads/post-selection-pre-existing-correlations-or-action-at-a-distance.1049354/, @PeterDonis claims that a certain mathematical derivation from the basic axioms of QM is an interpretation-dependent proposition. I'm referring to post #54 here and this...

To me, they all look incorrect. Oh hang on. Ultrasonic waves. I misread that. It's no 6 then.

Hi, it's been a while since I have posted, hope you all are doing good. Just recently someone on the net mentioned to me the claim that soy and tofu really is bad for men's penises, sex organs, labido as well as sex drive has been debunked. Iv'e seen articals on the net saying it does or it...

A good article on bear encounters and what to do when they occur: https://www.cnn.com/travel/article/bear-encounters-prevent-attacks-wellness/

Hi again all. I asked these questions because I want to balance out all my mbti functions making them all 100% in all areas of the mind/brain or as best as each function will get if that's possible as part of my brain exercise regimen. How can I do this? Where can I go to get tested to see my...

Hi again. I was wondering, does eating candy, Ice cream and junk food shorten ones life span? If yes then how much does it need to be to be able to do that to the human body? What effects does it have on the human body? can it give you diabetes and other body conditions like that? How much of...

Hi again all. Is mbti myers brigs reliable? Is it a science at all or is it all phycology? has it passed peer review? is there any evidence to show its lagit? what are the facts about mbti myers brigs test/s?

Hi, there. I couldn't find much information about this on the net so I came here to ask if anyone here knows as I thought it would be the right forum or maybe I just wasn't looking hard enough. Please not that I don't mean skills but rather what actually works that improves brain functions like...

Hi! If you are interested in exoplanets, you might want to know these little known facts about exoplanets. Source: In our stellar neighborhood there might be around 130 potentially (p.) habitable exoplanets, 10 of them being Earth-like. The closest p. Earth-like planet is called Tau Ceti e...

Hi again, I want to know, what are the effects that stress has on the human body when it comes to work or a job? The reason I am asking this is because I plan to have a job in the future that gives me good stress and to avoid working at a job that gives me bad stress. I base this on some website...

Hi! I would like to share with you guys some facts you might not know about antimatter: 1º - Recent studies suggest that an antimatter spacecraft could achieve up to 70% the speed of light, reaching Proxima b in just about 6 years. 2º - The maximum time that antimatter has been stored is...

Hi there, I would like to know all the ways or what I can do that actually works when it comes to slowing down or stopping the aging process for human males in both the brain and the body. I am one of those people that want to stay as youthfull as possible and to live as long as I can so...

Can anyone post here quotes from academically validated physicists that state outrageous facts? I realize that Bohr said that if one isn't shocked by QM one doesn't understand it. But I am looking for something more specific. For example a quote about superposition , entanglement etc. The idea...

Problem: If ##H = \langle x \rangle## and ##|H| = n##, then ##x^n=1## and ##1,x,x^2,\dots, x^{n-1}## are all the distinct elements of ##H##. This is just a proposition in my book with a proof following it. What I don't get is the very beginning of the proof: "Let ##|x| = n##. The elements...

A reference article to other articles on science facts that were discovered this year 2017. Some were theorized and finally proven, others were discovered totally by chance. Which ones most impressed you? http://www.sciencealert.com/23-science-facts-we-didn-t-know-at-the-start-of-2017

Christmas Facts 1. Jesus was not born on December 25. In fact, the Bible does not give the actual date of Christ's birth. 2. There is nothing in the Bible about presents under a tree. 3. Christmas Eve is not the holiest day of the year. 4. Santa Clause never existed. 5. I see no...

Take for example the following cases: It is a fact that Sam is sad That Sam is sad is a fact That 2+2=4 is a fact. What's the purpose of placing 'it is a fact' or 'is a fact' to those sentences? It would seem that Sam is sad is the same as the fact that Sam is sad. Otherwise, is just adding...

What is the difference between the fact that grass is green and the green grass?

Warning! Laymen reasoning ahead :) I've long heard that in science nothing is proven. That proof is a mathematical term. So what exactly do you call a certifiably known fact? An example is that the Earth is round or at least that the Earth is not flat. What do you call that? Can we not say it's...

Hi, Hopefully I am not asking to simple questions, but I am just confused from all internet information, and could need some help to shed light on a few things related to gravity, just to make it an undoubtfull fact to work with. When I am correct, gravity is a consequence ? What I have read...

My understanding of the distribution curves is very basic but I do have a couple of somewhat generic questions. I looked up a number of definitions but have had a hard time finding these specific answers: - Is there an agreed on minimum number of samples that one needs to take to deem a result...

Is there a better way than guess and check?

Homework Statement Let ##A## and ##B## be ##n \times n## matrices 1) Suppose ##A^2 = 0##. Prove that ##A## is not invertible. 2) Suppose ##AB=0##. Could ##A## be invertible. 3) If ##AB## is invertible, then ##A## and ##B## are invertible Homework EquationsThe Attempt at a Solution 1) Suppose...

Hello, I'd like to know which book or papers I'd read to understand, possibly without too rigorous mathematics knowledge, how do photons like X-rays or gamma ones reflect off surfaces and attenuate through solids or generally speaking, facts about how do they interact with the real world. So...

I have been trying unsuccessfully to find a way to view Facebook my way. What I mean is to view the pictures and prose posted by my friends, but no ads, not their likes, not their shares, no suggestions. I'm like sergeant Joe Friday on Drag net - "Just the facts sir, nothing but the facts."...

Hello people! , I got to do a school project and i chose to find information about galaxies and stars...i found interesting because i never studied about them..and i thought it was time to learn some things..at first i was about to choose the topic about black holes but i thought it would be too...

Stephen Colbert gave some airtime Monday to a story that is pretty interesting. The Supreme Court is doing a very poor job of checking references. Justices often take Amicus Briefs written by lobbyist as fact, cite blog posts, and all sorts of nonsense. The following link is the actual paper...

I am trying to find the density, scale radius and normal radius of the milky way's halo. But these things are pretty hard to find. I want to find them so I can input them into the NFW profile:

Fantastic infographic! http://lightsinthedark.files.wordpress.com/2013/04/50-facts-about-earth3.jpg

So I've done a little research on EMP and I know how they disable electronics, but I don't quite understand the aftermath. If planet 'A' gets hit with a MASSIVE pulse, or several less massive pulses, would flora and fauna be directly affected? All the electronics present on 'A' would...

Although scientists once thought that radioactivity violated the law of conservation of energy, then new understanding of nuclear decay helped demonstrate that the law was fact. So why do we continue to call the Conservation of Energy a law, and not a fact. Why not a principle? Is there a...

Good article about Quark stars: http://www.nanowerk.com/news2/space/newsid=31543.php of course, the title instantly makes me think, "Piccard would not approve!" :biggrin:

Hi there Am to teach a lesson on stars and galaxies to my year 7 class on Monday... Want to brush up on a few things... so would be grateful for answers to these questions: 1.Is the current thinking that the universe is infinite or finite? (I thought the consensus was that it was...

I'm volunteering at an elementary school for the next couple of weeks to teach the kids cool stuff about science and I think it would be great if I had a "Daily Awesome Universe" fact. I think having a funny/cool facts for the kids to see when they come in would interest them. I have a few, but...

Ten Anatomical FactsIt takes about seven seconds for food to pass from the mouth to the stomach. Women blink twice as often as men. The average adult has about five liters of blood. The brain uses 20% of the oxygen. It takes about twelve hours to digest food. The length of a man's "member"...

Hi, so I just wanted some opinions on string theory, superstring theory, or M theory. Any of them would be fine probably, but M theory is the one I'm really curious about (since it's the latest and greatest, according to some of the books I've read). So the only opinions on M theory that I've...

Spin is the art of presenting facts in such a way as to make yourself look good. The best spin, IMO, utilizes accurate facts (to avoid being shown a liar), but utilizes cherry-picking and carefully worded descriptions to paint a picture much more favorable than another view might present. In...

Top 3 facts that would blow the facebook generation away? Hi guys, i come on here and read every thread and try to undertand some of it. most of it blows my mind! so how about a top 3 facts that'l blow the public away. tx for your time if you participate i am in awe tx

I've read in many places that if, in a Young's double slit experiment, you can determine by whatever method through which slit your photon goes through (enhancing the "particle" behavior of light), then the interference pattern dissapears. For this reason Zeilinger says that entangled photons...

Homework Statement I am studying for my final and just want some clarification on mirror facts. Homework Equations The Attempt at a Solution Convex: focal length = negative and concave is opposite positive Diverginging = - image dist converging just the opposite or positive if...

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I have 2 close friends who believe we've never been to the moon. I've tried explaining to them why the flag moved, why there is no need to go back, etc, and it falls on deaf ears. This morning i saw this video by NASA [...

Homework Statement I would want to know how free fall, acceleration and friction works ? I mean it like there is a greater friction when an object is heavier or an object is possible to have zero velocity but nonzero accelaration. I need those kinds of things to study :D Homework...

Hi, Suppose I have this matrix A: Why is the matrix exponential like so: when A is not simple (eigenvalues not distinct)? Thanks.

Hello everybody, I am a high school student from Vietnam. I have been self-studying Physics for two years and I definitely want to study Theoretical Physics at university. However, most of my friends told me not to do Theoretical Physics. The reasons for this are: My view on Physics as a high...

I am currently taking Biology 2 and learning about Micro organisms like bacteria and fungi. However, I find both listening to my professor lecturing and reading the material draining and only slightly interesting. Its like learning another language where nothing seems to hold much significance...

How hard is it to get a PhD in Physics? Does it matter which University I do it at? How long does it take? Do I get paid? Is it harder depending on Universities? I want to do one at Cambridge, is that really difficult to do? Thanks! :)

Hello all. I go to a state school and would like to know how much of the actual cost has been paid for by the state taxpayers. Is there a way to find this out without tracing tons of government documents?

I am doing a project on Andromeda, just doing a big write up about it, and draw some pictures of it by hand and so on. Anyone have some facts on it that may not be so well known, and maybe some interesting facts about it that the average stargazer might not know that I can write about. ...