Need some commonly accepted untruths/misconceptions

[rockyct]

Since we're going into physics stuff: a cat is either dead or alive.

 

[Malak]

things with mass cannot move at the speed of light.

Why not?

 

[Cogman]

Why not?

Theory of relativity.

 

[yh125d]

things with mass cannot move at the speed of light.

I may be entirely wrong here but I think I'm correct in saying that this is false because, well, LIGHT moves at the speed of light. And since light carries energy, it must also have a mass




(only 3 years of physics, may be missing something so dont flame me bro)

 

[sandorski]

Columbus Proved the Earth was round and everyone at the time thought he was crazy because they all thought the World was flat

 

[Fenixgoon]

I may be entirely wrong here but I think I'm correct in saying that this is false because, well, LIGHT moves at the speed of light. And since light carries energy, it must also have a mass




(only 3 years of physics, may be missing something so dont flame me bro)

photons have momentum, but do not have mass in the sense that all elementary particles do (neutron, electron, proton, quarks, etc.)

but yes, they do have some energetic mass given by E/c^2

 

[Malak]

Theory of relativity.

I don't believe it.

 

[DrawninwarD]

Irrelevant, assuming there's no air.
velocity = acceleration * time

Since acceleration is the same for all bodies in the same gravitational field, you could drop a bullet made of magnesium, one made of aerogel (lightest solid known), and a bullet made of ultradensium. They'd all impact at the same speed.
(See also: Hammer vs feather.)

Now, tack in air resistance, and the lighter object (well, less weight per unit surface area) will experience much more of the effects of wind resistance, and thus will have a lower terminal velocity.




Why? Dropping it just means it takes longer to reach final velocity.
Now, shoot someone at point-blank, the bullet may well be traveling faster than its terminal velocity in air.

But if you drop a bullet, and assuming it remains stable during flight, and also assuming that air resistance is magically negligible, its final velocity will simply depend on how long it's been falling.
You'd probably get better results with some sort of apparatus that would give the bullet a decent spin before it's dropped, giving it some of the wonderful lovin' of gyroscopic stability.

Yeah, terrific assumption there. Let's just eliminate air resistance, meaning let's just eliminate air from the equation. Why don't we also assume that the human actually has no skull and just an exposed brain. Then the bullet will kill him for sure.

 

[fleabag]

Well, PURE H2O does not, but you have to make that stuff, it doesnt occur naturally. And its very expensive, and the average person doesnt have it in their home.

How about this....It's a misconception that pure H2O does NOT conduct water! Pure water does in fact conduct water and that's due to the covalent bonds that are formed between the other molecules.

 

[Jeff7]

Yeah, terrific assumption there. Let's just eliminate air resistance, meaning let's just eliminate air from the equation. Why don't we also assume that the human actually has no skull and just an exposed brain. Then the bullet will kill him for sure.

Physics is just so much easier without air though.

 

[fleabag]

Physics is just so much easier without air though.

Fluid dynamics....just gets me all teary-eyed...

 

[PhoKingGuy]

How about this....It's a misconception that pure H2O does NOT conduct water! Pure water does in fact conduct water and that's due to the covalent bonds that are formed between the other molecules.

It does, but at levels so low its basically nonexistant. We used pure H2O as a buffer/stable medium/volumizer for a lot of things in molecular biology. I think its something like this:

Pure H2O is something like 0.055 µS/cm conductivity while normal tap water is 50ish µS/cm, basically as you increase the electrolyte/ion concentration, the conductivity goes up

 

[Kev]

People think that Americans invented the internet, but the general public (of morons) doesn't realize it was Cern labs

http://en.wikipedia.org/wiki/CERN <-- Read computer science section

fail

World Wide Web != Internet

 

[grrl]

Johannes Gutenberg didn't invent the printing press. The Chinese did hundreds of years before.

Actually the Chinese were with with wood type, the Koreans were first with metal type but used Chinese characters.

 

[angminas]

How about this....It's a misconception that pure H2O does NOT conduct water! Pure water does in fact conduct water and that's due to the covalent bonds that are formed between the other molecules.

Is this a typo or a joke I don't get?

 

[ShawnD1]

Is this a typo or a joke I don't get?

Probably a joke of some kind.

http://www.myronl.com/applications/diapp.htm

Resistivity/ conductivity is the most convenient method for testing Dl water quality. Deionized pure water is a poor electrical conductor, having a resistivity of 18.2 million ohm-cm (18.2 megohm) and conductivity of 0.055 microsiemens.

Metals like copper and silver are around 1 uOhm-cm which would make copper about a trillion times more conductive than water.

 

[yh125d]

Yeah I think technically everything CAN conduct, but all the stuff we call non-conductive has millions and millions of ohms to it

 

[darkxshade]

10 lbs is considered bulk

 

[SirStev0]

10 lbs is considered bulk

"Bulk" is actually dependant on the shape/size not the weight. Anything larger than say, an alternator, is considered bulk.

 

[alrocky]

Your bride to be really is a virgin

 

[angminas]

Did anyone else notice fleabag saying that water conducts water?

 

[waggy]

that the civil war was faught over slavery and Lincoln faught to free the slaves.


that colombus discovered America.

 

[Modelworks]

So... let's go ahead and ignore the FACT that every court filing resulted in acknowledging the telephone was invented by Bell, that Bell denied ever having paid the patent clerk any money, and, of course:

Compare who Bell and Gray were at the time. Look at the people involved. Gray could have handed the judge a working telephone and Bell still would have won.

The best of Edison's and Swan's light bulbs were combined into the conventional light bulb, but Edison's design was better, and he had been working on it longer than Swan (he merely did not get the initial patent first). Hence, Thomas Edison invented the light bulb. Swan did do a lot of other cool stuff, though, if I remember correctly from science class.

Edison never invented much of anything. He was a business man first and scientist/engineer last. Copying someone else idea and changing it slightly so you can sell it better is not invention. That is mostly what Edison did his entire life, take others ideas and market them.

School textbooks aren't inaccurate on these issues, they merely don't acknowledge the failures of scientists' whose work got used only in prototypes and never in commercial versions of an actual public item -

You do realize that an invention is supposed to be credited to the inventor not the person who makes it profitable ?

I would strongly advise NOT writing a college paper based off the ramblings of people in this thread -- AND not basing all of your information off of a wikipedia page (I did so in this post because this is the internet, and the information people cited from Wiki magically did not contain any of the information Wiki had that could be used to dissolve their arguments).

So wiki is okay if it suits your purpose.
As for ramblings . I wrote several papers, one is published at the school for EE at NCSU and kept for research reference on Tesla and during the course of tons of research I learned a whole hell of a lot about the kind of man Edison was.

 

[jagec]

It does, but at levels so low its basically nonexistant. We used pure H2O as a buffer/stable medium/volumizer for a lot of things in molecular biology. I think its something like this:

Pure H2O is something like 0.055 µS/cm conductivity while normal tap water is 50ish µS/cm, basically as you increase the electrolyte/ion concentration, the conductivity goes up

Pure H2O is not a good buffer (it will go acidic due to CO2 dissolution if not buffered by Tris or others), not a good stable medium (see above, not only will it hydrolyze bonds, but generally you want to add something like EDTA (to scavenge divalent cations and inhibit any enzymes that may have gotten in) and/or NaAz (to prevent the growth of any bacteria or yeast)), and I really wouldn't cause it a "volumizer" given that pretty much all molecular biology experiments are fluid-phase anyway. It's more of a diluent to achieve the proper concentration.

For the thread:
Man really landed on the moon
Lee Harvey Oswald acted alone
9/11 was planned by Osama Bin Laden
Obama was born in Hawaii
Vaccines are safe and do not cause autism
Its conductivity or lack thereof has nothing to do with its utility for molecular biology.

 

[SparkyJJO]

For the thread:
Man really landed on the moon
Lee Harvey Oswald acted alone
9/11 was planned by Osama Bin Laden
Obama was born in Hawaii
Vaccines are safe and do not cause autism
Its conductivity or lack thereof has nothing to do with its utility for molecular biology.

This post smells of some conspiracy theories mixed in there.