Infinte kinetic energy

[Hunter Parasite]

It is common knowledge that when you hold something, such as a tennis ball, you build up kintetic energy. Well, in space lets say you attach that ball to a piece of string. And if there was gravity, you pulled down the ball, and let go. It would bounce up of course, and keep bouncing until it stops. In space, due to energy emmited from the sun, it can keep bouncing because of the continuious enegry flow.

[t00fri]

It is common knowledge that when you hold something, such as a tennis ball, you build up kintetic energy.

What you misprinted as kintetic energy is actually meant to read kinetic=motion energy. (It is from Greek: kinEtikos).

So please could you explain, where there is motion involved when you hold a Tennis ball in your (incorrect) example??

Rather...

If instead you bring your body of mass m to a speed v by riding in a car (for example), you acquired a kinetic energy 0.5*m*v^2. Notice, in this correct example there is indeed motion of a mass

Of course you mixed kinetic energy up with so-called potential energy...Think about it...

[Tanketai]

In space, due to energy emmited from the sun, it can keep bouncing because of the continuious enegry flow.

I wondered why t00fri didn't come harder on you...


The ball would keep bouncing because of the energy flow of the sun?


First of all: bouncing on what?

Well, in space lets say you attach that ball to a piece of string. And if there was gravity, you pulled down the ball, and let go. It would bounce up of course, and keep bouncing until it stops.

Keeping in mind that I really missed the point of yout post ( ), if you're talking about potential -> kinetic energy transformation (like a ball falling), I guess that the energy flow of the sun (as light and charged particles) wouldn't affect such a small object as a tennis ball.

[Malenfant]

Please keep in mind this is a forum to discuss Physics and Astronomy, not a forum to post wacky, poorly thought out, nonsensical misinterpretations about physics as if they were fact.

[t00fri]

Hi all,

in line with the content of PM's that I am getting from friends, I have to state that it is a real pity how badly the level of this discussion board deteriorated recently!


Bye Fridger

[Spaceman Spiff]

I had trouble following the initial post too, but I think it is fairly obvious it can be filed under 'physics' and this is the Physics and Astronomy forum. But, I had no idea it was common knowledge that holding a tennis ball increases one's kintectic energy!

Scientific method anyone? I think I've posted enough in Hunter Parasite's other topic From the Big Bang to the Big Rip ( http://www.celestiaproject.net/forum/viewtopic.php?t=8010 ) to give people clues.

Spiff.

[Hunter Parasite]

The point is if there was gravity in space and you built up kinetic energy through pulling the ball down on the string, and you released it, the energy would be released, and the suns various wavelengths mostly mostly radio and X-rays, the ball would be collecting the waves just as any other object in the universe would, and this energy would keep it bouncing.

[t00fri]

The point is if there was gravity in space and you built up kinetic energy through pulling the ball down on the string, and you released it, the energy would be released, and the suns various wavelengths mostly mostly radio and X-rays, the ball would be collecting the waves just as any other object in the universe would, and this energy would keep it bouncing.

Rubbish!

[Malenfant]

HP - Please stop making statements as if they are fact when you clearly don't have a clue how physics works. If you had rephrased your post so that it was a question - which people could answer - then it probably would have been better received.

Fact is, the radiation emitted by the sun has no effect on the motion of the ball what so ever (other than to warm it up, at least). If you pulled down on a ball on an elastic string in a vacuum in space then it will keep oscillating around the point at which it is attached for a long time, but AFAIK it will eventually stop because it loses energy in the stretching/heating of the elastic string. Radiation would do nothing to keep it bouncing.

[Malenfant]

in line with the content of PM's that I am getting from friends, I have to state that it is a real pity how badly the level of this discussion board deteriorated recently!

Yeah, I was under the impression this forum was to ask serious science questions about physics and specifically astronomy and talk about topical astronomical topics. Not to talk about nutty fringe ideas or inflict 'personal theories' on people.

[BrainDead]

It is common knowledge that when you hold something, such as a tennis ball, you build up kintetic[sic] energy.

Well, this could be true, could it not? If the ball were travelling
through space at 25000 mph, and you grabbed it and held on to it, I'd think
that you might build up a bit of kinetic energy mightn't you?

The point is if there was gravity in space

Where in space is there not gravity?

It would bounce up of course,

Uh... Which way is up?

Just curious...

[StarSeeker]

My two cents, please feel free to ignore it...

Not everyone is an expert on astronomy or physics, and insulting noobs doesn't really present the community in such a great light...

One can correct and teach without being rude about it... try something more like "Actually, that's not quite correct, let me try to explain it... *explanation here*."

Less bad energy that way.

[t00fri]

My two cents, please feel free to ignore it...

Not everyone is an expert on astronomy or physics, and insulting noobs doesn't really present the community in such a great light...

One can correct and teach without being rude about it... try something more like "Actually, that's not quite correct, let me try to explain it... *explanation here*."

Less bad energy that way.

Non-experts usually realize themselves that they are non-experts..

Everyone here does welcome questions or also properly phrased speculations from non-experts.

However, people with very little actual knowledge, PRETENDING the opposite, will always meet my strong opposition at least. Fortunately, it seems, I am not the only one.

The physics & astronomy board has seen an inspiring and instructive period full of interesting contributions notably also from non-experts. This has changed dramatically, recently. Such crack-pot type writing style will drive away all reasonable or knowledgable people from the board.

I cannot imagine ANY physics argument by a real expert that could make people like e.g. Hunter Parasite LISTEN ...

Bye Fridger

[Spaceman Spiff]

Yes, quite right, Starseeker, but this is by no means the worst that has happened here. This is quite mild compared to previous!

Well, some dismiss Hunter Parasite as speaking 'quack'. I'd guess HP's not speaking quack, but speaking something different: 'I-read this-and-I-want-to-tell-you-about-it!' Trouble is twofold. First, there's the green type. There was a guide to recognising 'quackery' in New Scientist many years ago, and one criterion was: writes in green biro. So, apart from browser visibility, there are other reasons not to format text in any other colour than 'default'! Second, I think HP might have misphrased something he saw and what he's writing has gone slightly beyond our familiarity. Hence our strange reactions.

Anyway HP, what's this bouncing ball got to do with infinite kinetic energy? Surely you mean it's got conserved kinetic energy? Also, doesn't the Sun emit most of it's radiation in visible light? Black body radiation of a 5,800K peaks at green light (but the Sun never writes in green )

Spiff.

[BrainDead]

One can correct and teach without being rude about it...

Uh, sorry...

Was I being rude? I certainly didn't mean to be. In fact, I thought I was
interjecting a variety of levity here to liven up an otherwise, boring and
ridiculous conversation.

Jeez... Ya just can't win nowadays can you.

Sorry again. Now I suppose I am being rude...

[Spaceman Spiff]

No, not you, Bob! I'd bet it was Fridger's heckling with a big, red 'Rubbish!' wot done it. I thought you were actually the most appeasing to HP there!

Just to point out: the article about Celestia in Linux Magazine (Celestia article in Linux Magazine) ( http://www.celestiaproject.net/forum/viewtopic.php?t=7728 ) hit the newstands about Aug. I think HP joined upon reading that. We seem to have gathered a few new enthusiasts at that time, and I'm sure several are computer oriented. They might be computer competent, but still might misunderstand science reports.

Spiff.

[BrainDead]

No, not you, Bob! I'd bet it was Fridger's heckling with a big, red 'Rubbish!' wot done it.

Well, just so's you know about it... I'm one of the private posters
Doctor Schrempp mentioned earlier. I had asked the good doctor why he
even bothered to reply to this drivel at all. Obviously, I am NOT a scientist,
however, I do expect to learn something about science and physics
in this forum. If you ask me, the Good Doctor Schrempp was being extremely
polite with his single statement.

Thanks

[Hunter Parasite]

HP - Please stop making statements as if they are fact when you clearly don't have a clue how physics works. If you had rephrased your post so that it was a question - which people could answer - then it probably would have been better received.

Fact is, the radiation emitted by the sun has no effect on the motion of the ball what so ever (other than to warm it up, at least). If you pulled down on a ball on an elastic string in a vacuum in space then it will keep oscillating around the point at which it is attached for a long time, but AFAIK it will eventually stop because it loses energy in the stretching/heating of the elastic string. Radiation would do nothing to keep it bouncing.

First of, this is not a theorie. It has been proven, im not sure who did it, but its fact. Second of all, it is not heat radiation that the ball absorbs. I believe its nuclear radiation but im not sure.

[t00fri]

First of, this is not a theorie. It has been proven, im not sure who did it, but its fact. Second of all, it is not heat radiation that the ball absorbs. I believe its nuclear radiation but im not sure.

Just take the word from a very experienced theoretical physicist that your claim is NONSENSE! God knows from what unreliable source you picked this up...It just CANNOT work.

It is true that one form of energy can convert IN PRINCIPLE into another one. But this works only in a very restricted manner and usually the conversion efficiency is very small.

1. Kinetic energy converts quite well into heat energy, as we know from extensively using the break in our cars to "annihilate" our excessive kinetic energy: the break tends to get very hot easily due to friction!
2. Electrical energy also tends to convert well into heat, as we know from overloading electrical circuits with too much current...
3. The converse conversions often do NOT happen for entropy reasons:
   
   As a reminder: the classical example of that tile falling down from a roof. The tile and the environment around where it crashed on the ground will heat up: Some fraction of the tile's kinetic energy is converted into heat, some other fraction might be used to break it into pieces. But even if we later heat up this fallen-down tile very much, it will NEVER jump back onto that roof where it came from . It even should be plausible for people without specialized knowledge. Heating up the tile is an undirected form of energy transfer. From where should this "poor hot tile" know in which direction it has to jump, i.e. where the roof is ...
   
   This fact has to to with the entropy S that is different in the two directions. The second law of Thermodynamics states that in all natural processes the entropy S of the world always increases, and thus whereas with the first law there is no time, and the past, present, and future are indistinguishable, the second law, with its one-way flow, introduces the basis for telling the difference. In short many such conversions are irreversible due to the requirement ?”S > 0.
   
4. Other forms of energy might convert but usually with VERY small efficiency. So are we still waiting to observe evidence from gravitational waves released in the universe from Supernova explosions, for example. The basic instruments for tagging gravitational waves are specialized highly sensitive resonator vessels that absorb, convert and highly amplify the incoming gravitational energy into some kind of noticable signal...
   
5. A tennis ball can under NO circumstance absorb nuclear or electromagnetic energy to the extent that it might be used (converted) to increase the duration of the ball's mechanical oszillations!

Just in case my presented arguments made you think a bit, let me add the following advice:

In scientific discussion it is considered extremely bad practice to make statements in a style that pretends understanding and authority, while in reality the presented arguments have just been (rather blindly) picked up from some unrecoverable source...

All of us would be happy to discuss (and possible correct ) your ideas, if presented in a more acceptable fashion...Just like in case of our young friend WildMoon, my suspicion is that you are substantially younger than 20 years, say...right?


Bye Fridger

[Hunter Parasite]

would it matter if im under twenty years old? Age does not judge intelligence. of course, i am a stupid idiot who just wishes to be at least half as smart as the people around me