MigL

Geodesics determine trajectories. ( for massive and massless particles ) Unless other forces are in play.

Not sure what you are after with this ? I know it is impossible to have a global Cauchy surface to describe all of space-time, but local surfaces are allowed. A Cauchy surface is a submanifold of the Lorentzian manifold defined by GR, and is usually interpreted as a time-slice of the 4Dimensional manifold, and is 'local' because it is defined by causal boundries and structures. I don't know what any of this means, and unless you explain it better, it reads as word salad. In GR, the geometry is the field. Each point of he field has associated infnformaion describing the deviation from flat, at that point. These deviations define the local 'curvaure', and geodesics, we call gravity. So, no, in GR graviy is not a force.

Not blaming anybody. He obviously has issues he needs to work through. Thank you though,for being so understanding.

I've heard of this on DSLR camera lenses that are stored in dark, humid conditions. If you can get at it ... Mild H2O2 ( 3-6 % )would kill the fungus. Mild acid ( vinegar ? ) will prevent its growth.

If you click on the hyperlinks embedded in the partial quotes I provided from the two Wiki articles, it will take you to a further description. For example, in the quote from the Big Bang article the embedded hyperlink "universe expanded" will take you to another aricle describing how the intrinsic, metric expansion of the universe differs from an explosion originating at a central point. I think we on this forum, sometimes forget that we are not here just to boost our egos. We are here to learn, and pass on what knowledge we have, or gain, onto others.

A toke might help to calm him down; and so would respecting his opinions, and not pushing him to the edge ( like last time ). But we're talking about depression, here. For mild depression, I always found choccolate to work wonders. Then a good workout, to burn the calories, helps even further.

I'm sorry if we have failed you in your quest to understand photons and the Big Bang Theory. perhaps, read through these two articles, and ask questions ( don't make assertions ) about the things you don't fully understand. Photon - Wikipedia "A photon (from Ancient Greek φῶς, φωτός (phôs, phōtós) 'light') is an elementary particle that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force. Photons are massless,[a] so they always move at the speed of light in vacuum, 299792458 m/s (or about 186,282 mi/s). The photon belongs to the class of bosons." and Big Bang - Wikipedia "The Big Bang theory is the prevailing cosmological model explaining the existence of the observable universe from the earliest known periods through its subsequent large-scale evolution.[1][2][3] The model describes how the universe expanded from an initial state of high density and temperature,[4] and offers a comprehensive explanation for a broad range of observed phenomena, including the abundance of light elements, the cosmic microwave background (CMB) radiation, and large-scale structure." Lets take this opportunity to both learn from our mistakes.

"Are human babies the loudest in animal kingdom?" No, it only seems that way when you're trying to get them to stop. ( my nephew has a newborn baby girl, Sadie )

I agree!!! You contradicted your own previous statement. The full sentence was "The universe does not expand, nor can its contents shrink, linearly." IOW observations show that it expands, or contracts ( as you claim ), differently at different scales, ie not linearly. The fact that you have reading comprehension issues does not mean I'm contradicting myself. Approximately 100 MegaParsecs ( +/- 50 ), and depending on the distribution of its component galaxies. That is, at best, a pseudoframe. GR does not allow for a universal, or 'special', frame. I attempted nothing, merely trying to identify/clarify the mechanism by which you think this universal contraction could happen. You have, so far, offered up no such mechanism, so there is nothing to consider. Just rubbish.

Either. "ASATs were generally given low priority until 1982, when information about a successful USSR program became widely known in the west. A "crash program" followed, which developed into the Vought ASM-135 ASAT, based on the AGM-69 SRAM with an Altair upper stage. The system was carried on a modified F-15 Eagle that carried the missile directly under the central line of the plane. The F-15's guidance system was modified for the mission and provided new directional cuing through the pilot's head-up display, and allowed for mid-course updates via a data link. The first launch of the new anti-satellite missile took place in January 1984. The first, and only, successful interception was on 13 September 1985. The F-15 took off from Edwards Air Force Base, climbed to 11613 m (38100 ft)[8] and vertically launched the missile at the Solwind P78-1, a US gamma ray spectroscopy satellite orbiting at 555 km (345 mi), which was launched in 1979.[9] The last piece of debris from the destruction of Solwind P78-1, catalogued as COSPAR 1979-017GX, SATCAT 16564, deorbited 9 May 2004. Although successful, the program was cancelled in 1988. On 21 February 2008, the US Navy destroyed the malfunctioning US spy satellite USA-193 using a ship-fired RIM-161 Standard Missile 3 about 247 km (153 mi) above the Pacific Ocean. That test produced 174 pieces of orbital debris large enough to detect that were cataloged by the US military.[10] While most of the debris re-entered the Earth's atmosphere within a few months, a few pieces lasted slightly longer because they were thrown into higher orbits. The final piece of detectable USA-193 debris re-entered on 28 October 2009." From Anti-satellite weapon - Wikipedia

Others' ideas offend you, Dim ? It would be so much better if everyone in the world thought as you do. Intolerance takes many forms; you just displayed one by your characterization of others'ideas. And JC's claim was that the statement was pseudoscientific. It wouldn't fly in a scientific paper ( scientific studies of Covid vaccines list all side effects and anomalies ). But it may be valid as a news article. Been fun chatting; gotta go to work ...

Next time you submit a paper for review, CharonY, and your conclusion sums up a study saying "There were no changes", then you add the following line "But there may be some changes, and we don't know the extent of these changes due to time constraints.", don't be surprised if it doesn't get published 😄 .

JC is claiming that the 'absolute' statement, that there will be no difference what soever once you stop taking puberty blockers, is negated by the next statement that says there very well may be, and we don't know the extent. That falsifies the first statement, so it is not true, and definitely not scientific. He is not saying it is pseudoscientific, your link is.

Adding to Markus' point, if you consider space-time geometry as the 'field' in GR, then the analogy would be the effect on the EM field that you get when moving charges around ( minus the self interaction ). The field, space-time geometry, changes with changes in the energy-momentum distribution. But it doesn't work at all. Your example has a discernible center. The Big Bang does not; it is happening everywhere.

I was thinking about breaking them up before they re-enter the atmosphere, as the recent Chinese booster did. As long as they stay in orbit they pose little danger, as their position is fairly predictable, but when a large mass re-enters the atmosphere and can't burn up, whether it will fall on your head is pretty much a lottery.

Yeah, I was thinking along the same lines. Does this possibly make neutrinos a dark matter candidate again ?

Most of this low orbit space debris will eventually come down in uncontrolled trajectories. Quite a few have already; most break up and are small enough to burn up on re-entry, others, like the recent Chinese one pose quite a danger if they come down over inhabited landmasses. These anti-satellite weapons could be helpful in breaking satellites up into smaller pieces, so that they pose little or no danger. Although major players, like the US, China, and Russia are reluctant to use them for fear of giving away capability information.

even if we disregard the physical ramifications of the procedure, such as putting off bone desity increases until later in life when it is most difficult, what about the mental distress. A pre-pubescent boy is put on puberty blockers because his parents and doctor think he may better 'fit in' and be happier as a girl, and want to give him time to explore that possibility. All well and good. Then he gets to high school, where he is the smallest ( height, shoulder width ) boy, with a high pitched voice and no facial hair. His life is made miserable by his schoolmates, who pick on him, bully him and call him names. He finally tries to hurt himself, or even commits suicide. Yet that is seen as intolerance for trans kids, even though had he not been given puberty blockers, he would have been a star atlete, dated cheerleaders, and been one of the ones picking on small, underdeveloped schoolmates ( 😵 ). Why is it we refuse to aknowledge reality, and feel we can modify nature according to our whims and ( sometimes misguided ) wants ? But I guess, that question can be asked of Global Warming deniers also. Are you sure there's nothing further to discuss ? By the way, I'm attempting to be humorous by comparing you to Global Warming deniers. Bill Maher does a much better job with the humor, and if you haven't watched the clip I posted, do so. It won't convince you, but it is hilarious.

A lot of this depends on your definition of 'matter'. Standard matter, like your desktop, while solid and of physical extension, is actually made up of fields, and the quantum mechanical exitations of said fields, otherwise known as quantum particles, which are, at best, probability distribution 'clouds', ccording to our best theories QED/QCD. These 'clouds' don't have a definite size, as Heisenberg's Uncertainty does not allow exact, and may, in fact be dimensionless, in which case your 'matter' is simply fields with nothing of physcal extent. You may state the conservation law as conservation of mass/energy, since those two properties are conserved in one way or another, but there is no conservation of matter, as any reaction which liberates energy ( chemical, nuclear ) will get rid of some ( miniscule ) matter, but its mass is preserved/conserved as energy of the system. Photons have no rest mass because they can never be at rest; they can only travel at c . Their energy is a property of their frequency ( classical wave nature ) and because of mass-energy equivalence we can asign a momentum to such a wave. The quantum mechanical momentum of a photon, while equivalent, is arrived at differently. Don't mix up quantum mechanical models with classical wave models.

Absolutely right. So why are doctors recommending puberty blockers and gender reassignment much mor often in LA than in Cincinnati ? About a century ago, in Canada, politicians, doctors, and the Clergy did what they thought was best for indigenous kids. They took them from their family and Tribe, and put them in Residential schools. The thinking was that they would integrate better with society. That was social engineering, and it failed miserably. Now we are doing the same with the gender of our kids. I sure hope this version of social engineering works out bettter. So should I ignore my concerns, and problems I see with society,because of others' unscrupulous use ? Sould Swansont not have gotten a degree in Physics because unscrupulous people may use any knowledge gained through his research, to build more efficient atomic weapons ?

Do you have any evidence to support that it does as if you had not taken the blockers ? You made that claim originally, I just questioned it. You require the evidence, and without such, I am allowed to question it.

Pro-choice and pro-life are not incompatible. My interpretation of pro-choice is simply that everyone has the right to choose what is best for themselves, or their morals/ethics. If you are for, or against, abortion, that is your choice to make for yourself, not to impose on others. But can we get back to Alito's draft proposal, and how it will affect state laws in the US ? I'm not sure, maybe JC or Peterkin have a clearer understanding of Canadian abortion laws, but it is my understanding that we have no 'concrete' laws either, just a 'gentleman's agreement' between our political parties that the issue of abortion will not be brought up. So far, it seems to have worked, but maybe we need some legislation, or a Charter 'amendment' to fix things in place before we also get into the situation the US finds itself in.

Please insert the words 'think they' between 'they' and 'are'. Who exactly is this 'freedom crowd' ? And since you include the knowledgeable, accepting and reasonable crowd at SFN, what legislation are we trying to introduce ? An 8 year old will want ice cream for breakfast, lunch and dinner; will a 'responsible' parent say"My child's feelings will be hurt if I don't give him/her ice cream for breakfast, lunch and dinner, every day, because that 8 year old knows what is best for him/her.",. Is that what you did when raising your kids ? Somehow I doubt it. Or maybe we actually ARE concerned about the effect it will have on female professional sports. Why are youu always willing to misconstrue others' opinions when they clash with yours. Is what is typed not good enough that you need to interpret according to your own biases ? Another example ... Sometimes life is unfair. Sometimes people lose an eye, have no depth perception, and can't play baseball worth a sh*t anymore. Sometimes they have a car accident and become paralized, and can't play any sports. Sometimes reality sucks, is offensive, and keeps you from doing the things you want to do. But to say those are attempts to 'whip up tribalism', blame these unfortunate people for all sorts of things, and send them to the gas ovens ( like the Jews ), is again misconstruing my posts, and way 'over the top' sensationalist. And of course these puberty blockers are 100 % reversible ? Or does the very fact that puberty is delayed contribute to an irreversible development of the child, making them that much more confused about their gender as they approach adulthood ? I think places like Texas are wrong to bring in banning legislation; this is a decision to be made by doctor and parent as to what is best for the child. But see the Bill Maher video clip I posted earlier; why are more kids ( and parents and doctors ) more likely to have children undergo these therapies in California as opposed to Ohio ? Is it something in the water ? Or is it 'trendy' in certain 'liberal' areas ? ( at the same time keeping in mind that it is much more acceptable, and less stigmatized in some areas than in others ) That used to be called 'confusion' about what you are. Now the condition has a fancy, trendy, name.

Sure. Lets base kids physical and mental health on an emotional response, instead of a rational one.

Mass-energy equivalence. Google that after you google Noether's Theorem.