Something amazing to tell you concerning physics and motion

[Jenson71]

This blows my mind.

Okay, say you have two ball bearings. You hold one in your hand and drop it. The other you put in a gun, point it straight forward, as level as the one in your hand, and pull the trigger, sending it hundreds of yards.

Which one lands first?

The one dropped in your hand right? RIGHT!?!?

No, actually they both hit the ground at the same time.

This is because the vertical component of motion is the same for both objects. They both fall vertically the same distance at about 10 meters per second squared (gravity, actually more like 9.8).

But Jenson, Jenson! What about the horizontal component of the gun-fired ball bearing? Actually, when air resistance is small enough to ignore as it is in this case (being that the bearings are exactly alike), the horizontal and vertical components of a projectile's velocity are completely independent of one another.

And, in this experiment, the gun-fired bearing is constantly falling from the moment it is fired. Yes, it looks like it is holding up in a straight line, but, it's actually falling and it's just hard to see with our eyes. And again, it is falling at exactly the same speed as the ball bearing you released in your hand -- the speed of gravity.

Post more cool science things in this thread.

I think I will later post Aristotle vs. Galileo and gravity, for a little history spin on science.

[bdeg]

this is assuming the bags are on the bus, which was not necessarily a given..

are the bags on the bus?

[bdeg]

if not, 14.

[Slainte]

Buses have wheels not legs/10990

[Comanche]

Originally Posted by bdeg

if 0
2(busdriver)+7x7x7x7x4+7x7x7x4+7x2
2+9604+1372+14
10992
if busdriver is a female with a backpack then

10990

The riddle didn't say a bus driver was ON the bus. The bus driver was in taking a leak and wasn't on the bus.

[headsnap]

Originally Posted by orange

If you think it's a very simple question - yes there's something wrong with you. Try googling it. Baby Lee mentioned one site that has 300 PAGES of comments.

there is a depressing amount of DUMB in this world...

Mud is a better example.

If your 747 is in your said mud, will it move?

[tiptap]

Ok I will put my 2 cents in.

The bullet question represents more of a math discussion than science. All linear transformations can be described by the two independent normal basis transformations. And in this case both bullets have the same force field, g, applied in the vertical direction representing one basis and the fired bullet has an additional momentum vector along the horizontal axis representing the other independent basis. And to the degree that you align actions along different basis directions you will have independent consequences. But along the same basis they will be the same. This is straight out of vector or matrix or linear algebras. Not so much science except to note what forces or momentum is aligned with what basis.

As far as the plane question, somewhere along the discussion, the "plane don't fly" gang stated that momentum and forces where not part of the problem. That speed was the only concern. So that the speed of the jet and the treadmill canceled out leaving no airspeed for lift. And yet in order to get lift anytime, whether in this scenario or just everyday flight, you have interjected forces and momentum. You can't ignore this then with the jet engines and that system of transfer of forces and momentum and just look at speeds and then talk about flight and use forces and momentum to describe how flight would or would not take place. After all MOMENTUM is what is conserved, not speed in science, in the real world. Therefore while you can create a system in which your premise is correct, it is not part of the science and this world AT ANY SCALE. So the jet takes off in this universe.

So next are the the questions concerning Special Relativity and General Relativity involving speed of light and Black Holes respectively. I would like to point people to my discussion with patteu about Copernican vs Ptolemian representations of the solar system. I made part of my arguments concerning Einstein's theories on the GPS representing a test of Special Theory and Atomic Clocks at different gravitational fields proving the validity of General Relativity.

So for the question of what will be the speed of light emitted from some object traveling close the speed of light, the answer "that the speed will be the speed of light" is not complete. You must go on to say that the speed measured from the near light speed object as well as an earth bound observer both will see the same speed for the light. This being the case, the independent observers will not see the same distances and times that the other observers note for each other. Leading to the lack of being able to agree upon a unit of measure in distance or alignment of clocks. However both observers will agree that ds^2=d-ct^2 + dx^2 +dy^2 +dz^2 which is an analogue for pythagorean distance that includes time as a negative component of distance.

As far as the Black Hole, Baby Lee's description of both views of two observers, one outside and the falling inside observer, are actually the view and only the view of the outside observer. They would see the stretching of the falling object at the event horizon and such. The actual falling observer would not even notice he passed through the event horizon. He would feel no forces (ignoring tidal forces say by having so large of black hole that the event horizon is essentially flat). He is in free fall and as such is not subject to gravitational forces. Acceleration and gravity being the same. The stars would still twinkle above and the black hole would still be black though it would be getting bigger blocking out some stars in its direction.

That is all for now.

[Coach]

E=mc²

[EyePod]

Originally Posted by mikeyis4dcats.

how many gallons are in a 5 gallon bucket?

There are 5 gallons of AIR.

[Buck]

Holy crap this thread went on forever last night. I believe it is time for a new question.

[MagicHef]

Originally Posted by MediaCenterJunkie

Holy crap this thread went on forever last night. I believe it is time for a new question.

Okay:

A group of people with assorted eye colors live on an island. They are all perfect logicians -- if a conclusion can be logically deduced, they will do it instantly. No one knows the color of their eyes. Every night at midnight, a ferry stops at the island. Any islanders who have figured out the color of their own eyes then leave the island, and the rest stay. Everyone can see everyone else at all times and keeps a count of the number of people they see with each eye color (excluding themselves), but they cannot otherwise communicate. Everyone on the island knows all the rules in this paragraph.

On this island there are 100 blue-eyed people, 100 brown-eyed people, and the Guru (she happens to have green eyes). So any given blue-eyed person can see 100 people with brown eyes and 99 people with blue eyes (and one with green), but that does not tell him his own eye color; as far as he knows the totals could be 101 brown and 99 blue. Or 100 brown, 99 blue, and he could have red eyes.

The Guru is allowed to speak once (let's say at noon), on one day in all their endless years on the island. Standing before the islanders, she says the following:

"I can see someone who has blue eyes."

Who leaves the island, and on what night?


There are no mirrors or reflecting surfaces, nothing dumb. It is not a trick question, and the answer is logical. It doesn't depend on tricky wording or anyone lying or guessing, and it doesn't involve people doing something silly like creating a sign language or doing genetics. The Guru is not making eye contact with anyone in particular; she's simply saying "I count at least one blue-eyed person on this island who isn't me."

And lastly, the answer is not "no one leaves."

I've done my best to make the wording as precise and unambiguious as possible (after working through the explanation with many people), but if you're confused about anything, please let me know. A word of warning: The answer is not simple. This is an exercise in serious logic, not a lateral thinking riddle. There is not a quick-and-easy answer, and really understanding it takes some effort.

[Buck]

Do you already know the answer?

[MagicHef]

Originally Posted by MediaCenterJunkie

Do you already know the answer?

Yes, because I cheated. I definitely did not figure this out on my own.

[Buck]

My only guess is that someone with lets say blue eyes, sees someone counting the amount of people with blue eyes (they can tell that person is counting the people with blue eyes because they themselves can see those people have blue eyes), and they see themselves getting grouped in with that count.

Otherwise, I have no clue.

[MagicHef]

Originally Posted by MediaCenterJunkie

My only guess is that someone with lets say blue eyes, sees someone counting the amount of people with blue eyes (they can tell that person is counting the people with blue eyes because they themselves can see those people have blue eyes), and they see themselves getting grouped in with that count.

Otherwise, I have no clue.

Nope.

[Buck]

Ok, I just read the answer. There was no way I was getting that. We have some smart minds on here, but I really doubt anyone gets it.