MigL

The equivalence principle is certainly valid but I wouldn't say that "we don't feel gravity, only pressure on a surface". More appropriate would be pressure on a 'volume' ( if that makes any sense ). In a positive G maneuver, in an agile aircraft, your blood is forced away from your head, resulting in black-outs, unless compensated for by a G-suit or a reclining seat. You don't just feel the Gs pushing you down, every individual part of you feels that force ( or acceleration ).

Both of your questions have the same answer. As Swansont has mentioned, gravity isn't strong at all, in fact, it is extremely weak. So weak, in fact that you can counteract the gravitational 'pull' of the whole planet on an apple with one hand.

Ukranian 'know-how' and engineering don't take a back seat to anyone. I will speak to what I'm familiar with... The Antonov design bureau has designed/built most of the transport aircraft used by the former USSR, until the recent re-alignment with the West threw away that arrangement. One could argue that if the West had wanted to boost Ukranian autonomy/economy, Europe would have chosen a derivative ( with European engines ) of the excellent An-70 transport aircraft, instead of sinking billions into the Airbus A-400 mess. It could have been operational 10-15 yrs earlier. Similarily ivchenko-Progress has developed , and continues to develop, aircraft engines of all sizes and power ranges. To understand how important this is, consider the problems China has faced in trying to develop indigenous engines for their military aircraft. The Ukraine could, if it wasn't for lack of available funding, have an aeronautical industry comparable to, at least, the UK or France

Darn ! Your avatar gives it away !

Whether intrinsic or extrinsic, Euclidian, or 'flat' geometry fails when curvature is involved. In Euclidian geometry a triangle's angles always add up to 180 deg, and Pythagoras can be used to measure distances. In any 'curved' geometry this does not hold. A triangle's angles add to more than 180 deg on a positively curved surface such as a sphere. And less than 180 deg on a negatively curved surface like the inner part of a doughnut ( torus ). Reminds me of a joke/riddle... A hunter sets off from his camp due South. After travelling 50 mi he turns due West. After travelling 50 mi he shoots a bear. Then he turns North and, after travelling 50 mi is back at his camp. What color is the bear ?

Here's an example... Consider a computer monitor on which you're playing Pac-Man. As you move your Pac-Man towards the right side of the screen, it re-appears on the left hand side. All on a 2dimensional space. This is because every point on the right hand side of the map has a one-to-one correspondence, or identifies, with every point on the left hand side, This is an example of INTRINSIC curvature, Topologically, it is certainly curvature, but it doesn't require an embedding dimension. It is not EXTRINSIC, which it would be if the Pac-Man was physically required to go behind the screen and move to the opposite side. This 'depth' would be an embedding dimension.

I tried to help him extract his foot with a little grace... But he's not helping himself with the attitude.

Russia ( or rather V. Putin ) wants the Ukraine back, if not totally then at least under its influence. Western Europe is reluctant to lend support to the Ukraine because they depend on Russian gas ( and other economic ties ). Ukraine is between a rock and a hard place.

Just to be fair to Velocity_Boy, he did a more than fair job of explaining things. What Swansont mentioned is true, matter is matter and energy is energy, and neither are forces. However... We postulate dark matter. None has been identified yet. All we have are observations of modified galactic rotation in response to a ( gravitational ?? ) force. What this force is due to, dark matter or not, is yet to be determined. We postulate dark energy, and associate it with the Cosmological Constant. Yet we have not been able to derive this from first principles and get a meaningful result ( 120 orders of magnitude too high ??? ). All we observe is distant galaxies moving away at accelerating rates, and speculate that it is vacuum pressure which provides this force. In other words neither matter nor energy, directly cause a test mass to change its motion. Forces do that. That being said, matter and energy DO give rise to forces by their very presence, and so indirectly, cause changes in motion. ( or sometimes directly, as in collisions )

Sitting at the bar is no good. I always end up having a 'liquid' lunch.

Trump's advantage is that he's a 'media' personality. He 'sells' the news. Is it any wonder he gets a disproportionate amount of exposure ? If the election was based solely on the amount of media exposure, the Democrats would have to run Kim Kardashian to win. ( the clown car would need a wider seat for that a*s )

SOCs like Raspberry Pi make this much simpler today than it was in the early days of 8 bit uprocessors.

I thought I was the only one who remembered Hollerith punch cards... ( but I guess some of you guys are older than my 55 yrs ) A user interface is typically the method used to control the computer. It progressed from switches, to holes in punch cards to a command line. The one most people are familiar with is the GRAPHICAL user interface, which was tacked on to ( shell ) CLIs in the early 80s, and originated at Xerox Palo Alto( windows and mouse ). Early adopters were Apple, with their Macintosh, and early MSDOS Windows ( 3 and 3.11 became widespread in 1990, but really took off with Win95 ). All other early adopters such as GEM ( used on Atari ST ) were sued by Apple for intellectual infringement even though Apple had pilfered the GUI from Xerox. Apple even sued Microsoft, but they settled. Other popular, early adopters were AmigaOS, one of the first able to multitask, and Symbian, which ran on Acorn RISC Machines ( ARM processor, much evolved, found in your mobile phone ). And there were others, but memory fails me, who didn't survive the Apple onslaught. All of these eventually discarded their old CLI kernel, and current Win10, OSX, iOS and Android have the GUI as an integral part of the OS. LINUX and its various open source implementations, is the only OS to still feature a shell based GUI.

Forget about the Republicans, at this point they are a joke. Ten oz is right, they may have to scrap the lot of them and parachute someone else in. They'll still lose ( badly ), but may save face. A lot of democrats ( and people in general ) remember Bill's tenure in the White House, as good times ( people tend to forget the problems ). No Americans were getting killed overseas ( shot down, but rescued, over Kosovo ), people had employment, government deficits were trending down, etc. All these people are now 20 yrs older. Is it any wonder that older demographics favor a return of the 'Clinton years' ? II like a lot of B Sanders policies ( he could be a Canadian Conservative ) and would personally vote for him ( if I could ), but I don't think he has a chance. Hillary is known to be more to the right, and that may help her work with some Republicans. And if she were to choose Sanders as a running mate, that may soften her image to Democrats and progressives. Hopefully she can be a 'bridge' to co-operation. That being said, Canadian elections and campaigns usually last 2-3 months. American ones, because of the nomination process, last up to 2 years ! So there's still time for 'strange things' to happen.

My first reaction was ... Why are we using different 'conventions' to describe properties ? And wondered why the alternate convention, i.e. the concept of 'rest energy' or 'invariant energy', not used in physics. But as you guys explained, and once you think about it, any measured mass is simply the sum of rest or invariant mass and kinetic energy. We could, I suppose, simply say that 'mass-energy' has two components, we call the invariant component mass, and the variable one K energy.

So, just to be clear, both mass and energy are properties of a system and inexorably linked. Yet one is frame dependent and the other is not. Is this because of what we choose to define as 'mass' ? ( welcome back elfmotat )

If you do get sent away for 25 yrs, my advice is to either join the boxing team, or learn how to dance. And no, you won't be leading.

Interesting proposal. That we perceive the expansion as space-time as the flow of time into the future. But I gotta ask... If the universe would, at some point, slow down and start collapsing ( cyclic universe ), would we perceive time as going backwards ?

If I could vote in the American election, B. Sanders would probably get my vote. But I could certainly live with H. Clinton as president. ( sorry Hillary, hope wins out, although the election is still 8 months away ) Of the mainstream Republicans none are worthy of a vote ( the last one I liked was J McCain ). And if you guys elect D Trump, I personally will never visit ( 15 min away ) the US again.

Well, I'm sorry, but I was treating the light, high ( as in pay ) side as the advantaged side of the scale. Not the heavy, low side as you are. I didn't realize there was a standard convention. A scale doesn't work for me as it implies one side has to have something taken away to give to the other side. I would rather see both sides rise, or gain, to the same level. I don't know exactly what you understand, nor what kind of game you're playing. Please explain. ( or are you making assumptions about my character and motivations, again )

All other criticism of Overtone aside, iNow, he does mention... !- Reliable and universal background checks 2- Trigger locks for privately owned guns 3- Legal standards for responsible ownership $- Legal standards for responsible carry He also mentions ( I don't have the stats myself ) that 85% of NRA members are in favour of these provisions. Isn't this enough common ground to at least begin a serious discourse ? Oh, and I had addressed my post to John Cuthber. Sorry for the confusion.

This isn't really about weight scales, though, is it ?

What do you mean ? Connery was the best looking James Bond, EVER !

I knew it was a muddled analogy. ( not my fault, you introduced it ) Advantages and disadvantages between two groups are not pivotal. Men are not paid MORE because employers can pay women LESS. Women are paid less than the 'standard' wage. Pushing down on the higher ( advantaged ) side of the scale disadvantages both sides. Pushing up on the lower ( disadvantaged ) side eliminates the disadvantage. ( I know, the fulcrum of the scale confuses things )

I believe Overtone listed four approaches in the post previous to yours where you asked him to list 'a few'. Posts #1017 ( his ) and #1018 ( yours ). If you don't bother reading his posts, John, how can you have a meaningful discussion ?