MigL

Again, this is not 'energy' becoming matter. Both mass and energy are properties, and can be associated with particles. Massless particles ( say photons ) don't have inertial mass, but they do have energy ( momentum >> kinetic energy ). They can convert to an electron/positron pair where some of that energy is converted to inertial mass (accoding to conservation laws ). Both, the initial photons ( massless and very energetic ) and final fermions ( massive but not so energetic) generate the equivalent gravitational field.

Energy does gravitate, and in that way it is certainly equivalent to mass. In the earliest moments of the universe, everything would have consisted of fields. Fields which have an energy density, and therefore an equivalent 'mass'. These scalar, vector and tensor fields underwent dissociation as energy density dropped, and it wasn't until the electroweak field dissociated into EM and weak fields that some of the previously massless field particles gained the ability to interact with the scalar Higgs field to acquire the associated property of what is now called inertial ( or rest ) mass. Electrons, neutrinos, quarks and W/Z particles, previously massless, now had mass, and they comprise what we generally call 'matter'

The FAA certification was 'rushed' because Boeing made the convincing argument that the 737 MAX had the same handling qualities as the 737 NG. So it did not need full re-certification. They could have called the plane a 797, certified it without the MCAS software ( as there is nothing inherently dangerous about its 'raw' hanling behavior ), but certification would have taken about 2-3 yrs. They chose, instead, to simulate the already certified handling qualities of the previous model, and got it to market a lot quicker. It didn't work out too well.

This is what happens when you eat fried/spicy foods before going to sleep.

I wish you hadn't posted the OP and simply sent the message to our minds.

A 'stall' isn't necessarily about speed; you can always give a plane more throttle to regain speed ( unless you are touching down ). So airspeed is not that serious a problem. On the other hand, a wing that exceeds a certain angle of incidence, experiences delamination of the airflow over the top of the wing. The resulting loss of lift causes the plane to 'drop like a rock' unless it can be levelled out. Unfortunately at such high angles the tailplane loses control authority to force the nose back down, and you crash. MCAS was designed to prevent such a departure before it got serious. It turns out it was a little too aggressive.

Theoretical physics ( best minds ) does seem to concentrate on subjects which are much removed from experimental physics and our ability to verify the theories. The scales and energies which must be probed to validate SString/M theories, or LQG, won't be achievable until we can build colliders on a galactic scale. Does that mean we should stop theorizing and allow experiment to 'catch-up' ? I don't think so.

The changes made to the MAX to accommodate the more economical higher bypass engines, necessitated different engine-to-wing mounts ( because of their larger diameter ), placing them higher and farther forward. The altered CoG/ CoL characteristics made the plane very slightly unstable in pitch, such that excessive nose-up angle would diverge and stall the wing. Now this is nothing new, just about every military fighter plane since the 80s has been unstable in pitch as it makes them extremely maneuverable. But since all new planes ( even airliners ) are fly-by-wire, it is easy enough for computer software to control a humanly unflyable plane. The computer software does the job that a human would not be able to do. A Eurofighter Typhoon is so unstable, trying to fly it manually has been described as "sitting on the hood of a car doing 100 mph, holding a bike backwards, by the handlebars, and trying to keep it going straight". The 737 MAX is nowhere close to this and is easily controlled by the pilot. But since this is a commercial airliner and extra precautions have to be built in, to control the pitch-up moment on the 737 MAX, Boeing added MCAS ( Maneuvering Characteristics Augmentation System ), which receives information from two Angle-of-Attack ( attitude ) sensors, and if they deviate too far in pitch, the MCAS software forces the nose down. The problem in the two crashes ( shortly after take off, with nose high pitch ) was that one of the two sensors wasn't working and with no pilot notification, the MCAS could not be over-ridden by pilot control, and it re-applied continuously, eventually crashing the plane into the ground. The 'fix', all in software, is to compare the two attitude sensors and if one isn't working notify the pilot. Make the input from MCAS weak enough so that it can easily be overridden by the pilot. And apply MCAS control only once, as that should be enough to get the pilots attention to a possible problem. The Boeing 737 MAX series are good planes, and maybe suffered from Boeing trying to make them idiot proof by putting too many roadblocks on the pilot flying the plane. I understand Boeing is considering re-naming them to get rid of stigma associated with the plane ( as demonstrated by Mistermack ), but I'm not sure if it'll work. They may have to introduce a replacement for it.

Uhmm, I wonder... The gluon is a massless particle, which because of its properties, acts, in some ways like a massive particle. Its 'residual' interaction results in the short range force that used to be called ( before QCD ) the strong nuclear, and binds protons and neutrons to the confines of the nucleus. Could this 'apparent' force again be the result of 'residual' interactions ? I haven't read the paper, and frankly I don't know whether I could make heads or tails out of it. ( and I don't wanna learn a 'new' standard model )

Wheeuww ! Wasn't sure where you were going with that Koti. Hope your kids and grandkids have an un-spoilt Earth to enjoy. I also hope you have the means/employment to make sure they have that chance. If governments want people on board, they have to present alternatives. Not just say "Go without. Its for the benefit of all". Instead of subsidizing oil companies and giving car manufacturers billions of our dollars, make charging E-vehicles as easily as gasoline, so that people who don't live in big cities can switch, and travel across a country like Canada Make standards for ALL new homes for metal roofs and solar panels ( and incentives for retrofit ) Invest heavily in nuclear ( like France ) and fusion research. Don't allow the buying of carbon credits or tax carbon. That just allows the rich to keep polluting while the rest suffer ( for the benefit of all ). Incidentally, melting tundra does release greenhouse gases back into the atmosphere, but it also allows for the new growth of plant covering. I don't know if one a counteractor to the other, but there is some carbon re-capture.

I'm in for the tweed jackets and scotch ( single malt Lagavulin please ), but can we make it Cuban cigars instead of pipes. Oh, and you win an argument ( or convince someone to your point-of-view ), by reason and evidence, not by clobbering them over the head with demerit points. Just sayin'.

I don't like to make fun of anyone's health issues, but do you think the stress of the Hearings is getting to the President ? Apparently he was rushed to the Hospital for a possible heart condition/monitoring. Yes, life IS rough for old white men, Zap. Not so much the 'white' part, but the 'old' part is really starting to annoy me.

Thanks JC. And +1; that's the nicest thing anyone has said about me in a while. I don't know much about H Biden, but wasn't he appointed to the board of AMTRAK by G W Bush ? He is a layer and a lobbyist. And while lobbyists trade political favors, that is a problem with the system that needs to be addressed. For all we know Hunter himself, may be very capable

I would have to advise President Trump not to 'throw rocks when he lives in a glass house', JC. Claiming that H Biden's position was undeserved ,and due to nepotism, as his father is VP, is hypocritical. How many members of his family ( D Trump's ) are 'working' for the US government ? ( I wouldn't doubt the little kids are drawing substantial salaries ) Without any previous government experience ? But I guess that's OK; The President himself has no previous government experience.

I don't think any Americans reading the news or watching the hearings are checking the definitions of bribery and extortion to see if they fit the President's actions. I think most know that what he did was wrong, even Republicans. His base and the a*s-kissers will no doubt stick with him. But all these revelations, angry spiteful tweets, and his refusals to release information have to be damaging him some. And if these hearings were next summer or it keeps fresh in people's minds for a year, we may get a one term President.

Live and learn, Dagl1. That's why I'm here. I also like those PBS videos.

I have one laptop with a broken touchscreen. It is almost impossible to navigate the mouse without spurious 'clicks' opening all sorts of windows. I usually put it in the freezer for a while, which renders the touchscreen insensitive, then I navigate to the Device Manager and disable the Human Interface device. This makes the laptop fully useable using the trackpad and buttons. Until the next major Windows update, which re-enables it ! Is it just me, or does anybody else wanna strangle Bill Gates ?

I don't have a problem with it. A postal worker might. But I don't think he would give a rat's a*s about the Pony Express rider.

In General Relativity 'faster' than light travel, whether by a 'wormhole' or a 'warp' drive enables a phenomenon called Closed Timelike Loops, which are essentially a time machine. One of the more famous physicist to have worked on these phenomena is Kip Thorne. As Endy mentions above, while the theory of GR allows this, there are many problems such as breaking causality and circumventing the 2nd law of Thermodynamics.

Well I could send you a letter in reply, through the postal system, but that would probably take about a week to get to you. I much prefer the 'automated' reply system offered by computers/internet/forum software. Don't you ?

Original elements created shortly after the Big Bang event, were Hydrogen and Helium nuclei in a ratio of approx. 3 to 1. A few percent were heavier elements like Lithium and traces of Beryllium. Heavier elements up to Iron ( AW 26 ) are the result of fusion burning in stars; and that is what INow refers to as star stuff. Any elements heavier than Iron that you may have in your body, need energy to form, instead of releasing it. They are formed when stars reach the end of their active life and explode ( Nova ), thereby spreading their star stuff to gas/dust clouds from which second generation Solar Systems ( such as ours ) form. That is where the atoms in your body come from. Kind of makes you feel humble, doesn't it ?

Only time I've noticed something similar is shortly after a Windows update. It seems all other installed utilities set to auto-update, are trying to update their respective installations or virus updates.

Naked singularities are not possible; they must have an event horizon. Oh wait, singularities themselves are extremely improbable

Thank you for educating me, guys. I stand corrected, and next time will further research before jumping to conclusions.

Apparently while we were sleeping, Ohio has passed a bill that students can't be penalized for mathematically or scientifically incorrect answers for reasons based on their beliefs. ( my religion teaches the Trinity; three goes into one evenly !!! ) https://local12.com/news/local/ohio-house-passes-bill-allowing-student-answers-to-be-scientifically-wrong-due-to-religion Can't offend their vulnerable sensitivities with facts and evidence now, can we ? When you combine this with right-wing hate groups, anti-vaxxers, and your politics, the once great America is spiralling the toilet bowl. Please come back to sanity; the world needs you