how did they measure it?

[zhi_yi]

hi there, i am confused with one thing, i wonder how did our great physicians find and proove their law's, for example, the speed of light in the space is 3.10^8, how did they measure it? the weight of an electron, the bolztmann constant, how did they measure it? is it absolutely true?

 

[Nigel Goodwin]

hi there, i am confused with one thing, i wonder how did our great physicians find and proove their law's, for example, the speed of light in the space is 3.10^8, how did they measure it? the weight of an electron, the bolztmann constant, how did they measure it? is it absolutely true?

Almost all science is just 'guesses', which they then 'prove' in exceedingly clever ways - often, later on, a different theory becomes more popular (usually when a flaw is found in the previous theory).

For example, for a great many years everyone 'knew' the earth was flat, now they 'know' it's round.

So nothing is really 'absolutely' true, it's just the currently accepted theory, based on observations and measurements - which may change in the future.

 

[Someone Electro]

I kon wiv sean it wen they ware trying to find out if time goes slower wen somting goes relay fast.What they did was acseletare an litium ion to near light spead(They used they same magnetic techic as an atom smasher)Then they obesrved the color of the light coming from it.And the color changes from green to orange.

They also tryed to test this by putting a atomic clock on an jet airpaine and ride it round the world and an same clock runing wen still.And the clock that wnt around the world in a jet was a bit slower.

 

[JimB]

Your value for the speed of light is a bit off, also you don't mention the units. I have assumed you mean metres per second, I may be wrong.

To find out how the speed of light was measured, look here:
https://scienceworld.wolfram.com/physics/SpeedofLight.html
Look at "Fizeau disc" and "Michelson and Morely experiment", there is lots of information.

JimB

 

[zhi_yi]

okay, thank you all, how about the weight of electron, how did they measure it? and how about boltzmann constant??

thank you very much

 

[Joel Rainville]

I kon wiv sean it

What?!? :shock:

 

[Someone Electro]

Typo that shod be "I know ive seen it"

 

[audioguru]

Typo that shod be "I know ive seen it"

Typo again. "Shod" is a horse that has had horse-shoes nailed on.
The English word is supposed to be "should".

 

[roboticmisinfo]

somting goes relay fast.What they did was acseletare

Somting? Are you Jamaican?
Relay? We all know what a relay is, and I don't think it has anything to do with what you were talking about. i think you meant "really"?
Acseletare? I used to play a game called "Solitaire". Is that what you mean? I'm pretty sure relays can't play solitaire. (You would have some pretty complexed relay logic for that!)

Some others nobody has pointed out yet.....

"Cod" Is a marine fish. The word you are looking for is "could"
"Wod" - This is not a word. It can be used as an abbreviation for "Weapons Of Destruction" or "War On Drugs" but I think the word you want is "would."

I could go on all day, but you get the picture (or is it "pihcer"? :lol: )
So you can see why some people might get confused. I think a lot of your mistakes are just laziness! (pressing keys in the wrong order, then not checking afterwards!!)

Oooh I must be in a bad mood today. Sorry.

Mike

 

[roboticmisinfo]

Sorry I'm being a bit "hypercritical" as someone has just pointed out. Maybe we should learn to speak Slovenian and we'd probably be more sympathetic.

I'm still waking/sobering up!

Mike

 

[audioguru]

Wod is wood! :lol:

 

[Glyph]

Electron mass is measured by the measuring the curvature radius of the electron path in a magnetic field of a known strength with the electron containing a known amount of kinetic energy (and thus a known speed). The greater the deflection, the lower the mass of the electron. The math is rather involved so i won't get into it.


Are these measurements "absolutely right"?

That's a far weirder question than it might first seem. "Absolutley right" implies this can't change or be refined... ever. Somethings might for most purposes be "absolutely right" like 1+1=2. Is it really? i can't prove to you that the mass of the electron is correct, anymore than i can prove to you 1+1=2. If you don't believe me, or think i'm wrong, then it doesn't matter what i say.

But for the purposes of doing experiments, making machines and building nuclear bombs, these measurements are "right" in that if used properly, they will allow you to arrive at the proper conclusion. Are our measurements of nuclear properties "absolutely right"? I can't really say, but 80000 dead japanese people can attest that nuclear science is "right enough".

Sometimes we purposely simplify numbers just to make calculations easier. The speed of light is exactly 299,792.458 km/s but for the purposes of doing high-school math, or even most types of univeristy math, its simpler just to use 300,000km/s. Clearly this is not "Absolutely right" but it is "right enough" for most purposes.

"Proving" something is true is impossible, because there will always be people that don't believe you. They will ask for proof that is too hard to give or completely deny proof that you do give them. I've had people argue with me that Einstein is completely wrong. Even though nuclear technology is staring at them in the face they completely deny that nuclear technology actually works the way Einstein says it does.

If its bothering you whether something is "Absolutely right" or whether its proven then don't worry. This has been bothering people since the day we learned to count. And the nature of the universe will probably keep bothering people for millenia to come.