MigL

Mordred is much more qualified to answer, but there is a difference between vacuum energy , and vacuum expectation value. My ( limited ) understanding is that while the concept of the VEV is a property of the vacuum which in Quantum field theory ( QED, QCD, Higgs ) governs virtual particles and condensation of fundamental masses, vacuum energy ( zero point or false zero ) is a property of the universe, and encompasses contributions made by virtual particles. The one place where the two 'meet up' is in regards to spontaneous symmetry breaking. Physicists are not like chemists ( no offence meant ). We are much more anal, and hate plugging numbers ( constants, fundamental or otherwise ) into equations. These numbers have to have a 'reason', otherwise we ask "Why that number ?", or have to invoke the observation selection effect ( anthropic principle ). So we try to derive these such numbers from 'first principles'. The usual method for vacuum energy is treating each point in space as a harmonic oscillator, summing over all such points and renormalizing the resultant infinity, usually with a suitable cut off, or ( as Sabine mentions ) that energy is a gauge condition where only differences are measurable. I believe there has been some research into using vacuum energy as 'effective mass' of the vacuum, or a field strength that 'resists' global curvature ( in GR ), to derive G from first principles ( like I said, we are anal 😄 ).

And a more, shall we say, controversial ( as always ) interpretation of vacuum energy

Really ? Sometimes they seem very appropriate for any geopolitics.

Here is a simple to follow calculation of the expected vacuum energy, and comparison to the observationally estimated vacuum energy which results in the 124 orders of magnitude 'vacuum catastrophe'. It also provides clarification about Cosmology, universal expansion and the Cosmological Principle.

There are different kinds of nuclear weapons; strategic, in the form of ICBMs and SLBMs, and tactical battlefield weapons of much smaller ( or single warhead ) yield. But all are weapons ( of a possible much larger scale ), so you may as well ask what would happen if say, NATO gave up its weapons ? I think V Putin's armies would be at the Atlantic European coast in a year ( assuming they can get their logistics in order ). If Taiwan dismantled their defenses, and the US wasn't willing to provide military support, China would start building a land bridge to Taiwan, to make them part of the mainland. How long would Israel last as if they discarded their weapons and relied on the good will of Syria, Iran, Lebanese Hezbollah and Hamas ? Because that is what you are proposing. And arguing that you don't mean conventional weapons, just nukes, is pointless. An army ( including tanks ) of 100 000 can be wiped out by a single hi-yield battlefield nuke, if your rogue opponent chooses to disregard the 'treaty' and keep their nukes. @MSC You may have misunderstood ( must be ADD at such a young age 😄 ) It is not that we are extorting and blackmailing these rogue states like N Korea and Iran not to develop nukes, rather, they are extorting/blackmailing ( usually ) the US, and demanding economic support as a condition of not developing nukes ( which they do anyway ). The reality is, in a 'perfect' world there are no bad actors, people who covet other's possessions/property/land, or people who crave wealth/power, and that is the only place where unilateral disarmament would work. That is not the world we live in. I wonder, if your child is being bullied at school, do you tell him/her " just go ahead and give the bully your lunch money, he/she will learn from your selfless act, and become a 'good' person too". How do you think that would work out, considering we now have punitive laws against bullying?

You guys are too old to be that naive; well intentioned, but naive. You ban handguns, yet criminals still get them. You ban nuclear weapons, yet rogue states still get them. Some people just don't abide by laws, that's why we call them criminals. Is V Putin abiding by international laws ? How about N Korea and Iran ? ( even Israel, Pakistan and India; not actually criminal, simply not signing on to any nuke banning treaty ) At best, you propose a system which ensures continued extortion/blackmail to keep them from developing nuclear weapons ( all the while continuing their development ).

The genie is out of the bottle, and it's too late for wishful thinking. The states that do have such weapons have a history of being provoked to the brink, and haven't used them since 1945. Even new nuclear powers like India, Pakistan and Israel. They are an almost known quantity. It's the unknown quantities like Iran and N Korea that make the equation hard to calculate.

What can I say ? I'm a complicated person. You mention Israel dropping a nuke on Iran, yet Israel has had nuclear weapons for about 30 years. They haven't used them yet. Would you be so confident that the same would hold true if Iran had them ?

Exactly. Even nuclear deterrence doesn't work with madmen dictators. Deterrence only works when both sides have something of value to lose. V Putin is arguably the richest man in the world; do you think he is 'mad' enough to lose that? Even KJU lives in the lap of luxury in N Korea; do you think he'd want to give that up ? The only ones I fear are the religious delusional nutbars running Iran, if they get nukes. They will use them, and Israel will respond; not proportionately either

There is a vast difference between what I have the stomach to do, and what should be done. Were I suddenly transported into President Truman's body, I may not have dropped nuclear weapons; but if I had lived his life, and experienced the horrors of that war, being responsible for all the people lost in the Pacific theater ( and those yet to come ), I certainly may have. I'll give you an ounce of T-Nitro-Toluene and an ounce of radioactive Cesium, and task you with transporting both, in your car, to the next city. With a little knowledge, you can provide shielding for the radiation; that's always been the biggest fear most people have, they can't see it and they don't understand it. Most people understand TNT perfectly well yet they don't know enough to be more afraid of it. Which do you think you should be more afraid of ? The danger is in how it is used.

Proportional response is highly over-rated. Deterrence of any particular action depends on the realization that the consequences could far outweigh any benefit. If I steal $100, and my only punishment is a $100 fine, I'm no worse off than I initially was, so I may as well attempt it.

Some people just see other people's ideas as damaging, and wish to silence them. Lesson learned ... stay off social media. That's where all the idiots are to be found.

Most people recognize the difference between an unprovoked action, and a re-action to it. If you walk up to me and punch me in the face, no one will fault me for breaking your arm in response. ( not implying you would; you seem a nice enough person 🙂 ) It's brutal, but it's reality; if you don't want the consequences, don't do any harm to others.

The reason you can 'picture' the 2dimensional surface of the sphere/world is because you ;ive in three dimensions. To see a volume loop back on itself, you would need to live in 4 dimensions. The volume is effectively embedded in a higher dimensional manifold. You cannot picture it, however, you can demonstrate it mathematically. Space-time is a 4dimensional manifold, however, we have no need ( nor can they have any effect ) for embedding dimensions, so we call any topological curvature intrinsic, whereas an embedded topology would be extrinsic. I think you've hit the nail on the head; failure to elevate your thinking is leading to your confusion.

I'm not very familiar with him or his work, and frankly, I've never seen any validity in tilting at windmills like Religion; you cannot disprove a belief. But after Eise's glowing review of his life/works I will try to educate myself. I probably wouldn't understand his Philosophical leanings, but I like red wine ( a little too much ) also, and have pictures of myself on a tractor.

You seem to have assumed there should be simultaneity, where relativity says there is none. Your analysis incorrectly uses a common 'now' for the two observers. Things have to be caused for them to happen, and causality moves at c . ( Dan should take the +1 back )

Not very realistic Airbrush. A ten kilometer asteroid would require a rocket two orders of magnitude larger ( at least ) to perform that sort of stunt. As TheVat explained, the farther away you can influence the asteroid's trajectory, the less force is needed to produce sufficient deflection. I'd go with small and high speed, coupled with adequate detection time ( pre-impact ).

I thought this thread was about planetary defense against large asteroids on collision course with Earth. I never worried much about it, but it might be time to have a back-up plan. After all, Bruce Willis is retired with a form of dementia, and Ben Affleck is constantly drunk and in rehab. And I don't think Steve Bushemi, Billy Bob Thornton, Owen Wilson, and Michael Clark Duncan can do it on their own; even if Liv Tyler lends a hand. ( yes, it's a reference to the movie Armageddon 😄 )

Quite a few businesses that rely on min wage employees are still having difficulty finding people to work. I know of restaurants that have since closed on Monday and Tuesday, as well as for lunch, as they need available staff for busy weekend evenings. I remember Tim Horton's coffee shops closing in the evening for lack of staff, for about a year after lockdown ended; it has since gone back to normal. Most bars stay open till 11 pm, and only on Thurs/Fri/Sat till midnight, whereas it used to be 2 am closing. Fast food places, like McD, used to be staffed by young people after school/evening/weekend, now I see a majority of older retired people who used to only do weekdays previously. While CERB is not the cause, it is making the 'change' worse. I myself remember going to local farms, when I was about 12 to 15, to pick fruit like strawberries, cherries, peaches, etc. No 'self respecting' teenager will do that now, and the Government has to subsidize foreign workers ( Mexicans, Jamaicans, etc ) to help farmers pick their fruit. Is the Government going to have to subsidize foreign workers to work in fast food restaurants and bars also ? There was once a 'stigma' associated with handouts ( welfare, panhandling, etc ), now it is expected, as witnessed by the large numbers of young panhandlers. Handouts ( like CERB should be there for people who cannot take care of themselves, for whatever reason; not for people who don't want to take care of themselves. And Ontario's min wage is $16.55 ( going to $17.20 in October ); of course that is in our 3/4 dollars. I'm starting to get the impression that 'somewhere in the Americas' is actually ( or, used to be ) in Canada, as you seem to know a lot of stuff about Canada most Americans would not. Not that that's a bad thing; arrogant Americans should know more about us 🙂 .

In this 'transmission', no energy is gained by incorporating magnets, and you would be better off using simple gears. I don't think you understand what the magnets are doing in your design. They are simply used as a force generating mechanism, as would be the teeth of gears. One big difference is that this force is limited by the strength of the magnets and the geometry of the magnet/finger system, as opposed to the the tensile strenth of hardened steel, which limits forces in a gear system. IOW, at best you have the same frictional losses in your system so you will always get less output than input, and the amount of power you can transfer is severely limited by the magnetic coupling. ( I tried to be as nice as possible and gave a serious response, without laughing )

We had a package during COVID also. Our Government paid people $2000 Can per month to stay home. Now, our economy is still struggling to recover, because small business can't find people to work, and the Government has a crap-load of debt that is still fueling inflation. But it's not like you guys don't have your problems. No doubt, if D Trump manages to get re-elected President, he'll be telling everyone how well the economy is doing under HIS Presidency.

I don't like Dimreepr's analogy, but I'll try to use it. Picture yourself living on that salt flat, which is level as far as the eye can see, and seems to go on forever. You start walking in one direction ( at a great speed ) and eventually you lose sight of the salt flat, and run into mountains and forests. Even cities and bodies of water that you have to swim across ( again at great speed ) until eventually ( after quite a while ) you come back to the same exact spot on the salt flat. But from the opposite direction. Clearly the surface of the world is finite; but there is no boundary. So where is the center of the world's surface ??? Now ( and this is a big step ) extend your thinking to 4 dimensional intrinsically curved space-time.

It is not the size that is revolutionary, rather the approach used. The American Government has chosen to reward industry for switching to low carbon emission processes. Most other country's Governments ( our PM in Canada also ) have chosen the stick approach, subjecting small industry to punishing carbon taxes, which keeps them from making the changes to low carbon processes, and the vicious cycle eventually drives them out of business. It is this far-sighted thinking that allows the American economy to perform much better than ours.

Rookie mistake. There is no such thing.

I just knew pyramids were going to be involved ... Now you've included picture salad ( not topology ), but still no meat.