Random Thought Thread

TRfromMT said:
Then that event is over, and our second choice is constrained to the same box. You know the gold boxes had one of two options for the second coin. The second gold-coin-containing box is not part of the population.
Click to expand...
I don't understand how that gets you to the specific answer 1/2. Either way, you are considering the chance you chose from the all gold box versus the half gold box. You're saying they're equally likely given you chose a gold coin. I'm saying they're not.
 
It took me a minute to understand it, but here's why the 2/3 answer is correct:

You've pulled a gold coin, so you can eliminate the all silver box. There are a total of 3 gold coins. Let's call them G1, G2, and G3.

Since the problem says you are definitely pulling out a gold coin, there's an equal chance it could be G1, G2, or G3 and it HAS to be from one of the boxes with a gold coin in it.

Once you've pulled out that coin, whichever one it is, there are only 3 other coins left, two gold and one silver.

People who are stating the probability is 50/50 are thinking, "Hey, I've pulled a gold coin, so either this box is the one with two gold or the one with one gold, so it's 50/50."

I think what most people are ignoring is that you also have to include the chance during the initial draw that you got EITHER of the gold coins from the box with both gold coins, effectively increasing the chance that the other one is gold. In other words, by saying that you DEFINITELY pulled a gold coin, there's an increased chance of the box you selected from being the one with two gold coins in it.
 
Synov said:
I don't understand how that gets you to the specific answer 1/2. Either way, you are considering the chance you chose from the all gold box versus the half gold box. You're saying they're equally likely given you chose a gold coin. I'm saying they're not.
Click to expand...
I got interrupted by a colleague at work and posted my comment before completing it. Have a quick look back.

The problem becomes clear when you consider many (more than 2) gold-coin-containing boxes. Your odds go up.
 
Nathan the Machinist said:
It's a demonstrable fact that can be (and is) shown experimentally.

The Monty Hall paradox

Some things are counterintuitive

For example, if you're riding on a perfectly smooth train at a thousand miles an hour, the track is perfect and there's no wind, a perfectly smooth train. There is no way experimentally that you could know that you were moving. Even though you might think, moving at a thousand miles an hour, it would be obvious. It isn't.

But that's a different theoretical situation isn't it. My bad...
Click to expand...
The Earth revolving around the Sun and the Sun revolving around the Earth are equally valid physically.
 
An easier way to think about is:

If I'm definitely pulling a gold coin, is it more likely that I'm going to get one from a box with two gold coins in it or a box with one?

Clearly the answer is the box with two, so you have to consider this fact later on when thinking about the odds of the next selection.
 
You're much more likely to pull a gold coin from a box with two gold coins in it than a box with one gold coin in it. So, if you've pulled a gold coin, chances are it was from the box it had two of them in it.


Should this be an activity for the Sunday after the Outlaw cut?
 
Nathan the Machinist said:
You're much more likely to pull a gold coin from a box with two gold coins in it than a box with one gold coin in it. So, if you've pulled a gold coin, chances are it was from the box it had two of them in it.


Should this be an activity for the Sunday after the Outlaw cut?
Click to expand...
Except that they're Shivs. Some with silver fasteners and some with gold. Presented blade first...


And for that sphere thing, if you have a magical material that can pass through itself, why would folds be an issue? Just for nerds to nerd-out I guess.
 
Nathan the Machinist said:
...
Click to expand...

Nathan the Machinist said:
Some things are counterintuitive

For example, if you're riding on a perfectly smooth train at a thousand miles an hour, the track is perfect and there's no wind, a perfectly smooth train. There is no way experimentally that you could know that you were moving. Even though you might think, moving at a thousand miles an hour, it would be obvious. It isn't.

But that's a different theoretical situation isn't it. My bad...
Click to expand...
My physics brain is trying to tell me that you might actually be able to tell that you were moving if this was all happening on a planet rather than an infinite plane. You could in theory detect a reduction in the apparent acceleration due to gravity because of centripetal force induced by the angular velocity (implied by the linear velocity of 1000 mph). I think. Maybe. But you would have to know what that value was in a state where you weren't moving with respect to the planet's surface.
 
Nathan the Machinist said:
It's a demonstrable fact that can be (and is) shown experimentally.

The Monty Hall paradox

Some things are counterintuitive

For example, if you're riding on a perfectly smooth train at a thousand miles an hour, the track is perfect and there's no wind, a perfectly smooth train. There is no way experimentally that you could know that you were moving. Even though you might think, moving at a thousand miles an hour, it would be obvious. It isn't.

But that's a different theoretical situation isn't it. My bad...
Click to expand...
Ummm...look out the window? 😁
 
fnordmorph said:
My physics brain is trying to tell me that you might actually be able to tell that you were moving if this was all happening on a planet rather than an infinite plane. You could in theory detect a reduction in the apparent acceleration due to gravity because of centripetal force induced by the angular velocity (implied by the linear velocity of 1000 mph). I think. Maybe. But you would have to know what that value was in a state where you weren't moving with respect to the planet's surface.
Click to expand...

Yeah, I think you're right about that.

Although some people think the earth velocity should sling us off into space. That would be escape velocity. The velocity of the Earth at the equator if I remember right is somewhere around a thousand miles an hour. If it were 10 times that, you would actually be noticeably lighter on your toes. If it were 20 times that, you would be very light on your toes, and if it were 30 times that, then you would actually get flung off the Earth, with the escape velocity being something around 25,000 mph. I think this is why launchpads are placed close to the equator and launches launch the direction they do, so they get that little bit of boost from the Earth's rotation. It ain't much, but it ain't nothing either.

This is also why launches don't go straight up, they get up a ways and then they turn at an angle. No good going out into space, you'll just fall right back to Earth, you have to achieve and maintain orbital velocity.
 
The idea of the space elevator says that a satellite physically locked to the Earth with a tether but at a distance beyond a geostationary orbit remains in place with a taunt tether capable of holding weight. Materials science isn't ready for this problem yet, but if it were ever achieved, you could simply climb into space without a launch.
 
Nathan the Machinist said:
The idea of the space elevator says that a satellite physically locked to the Earth with a tether but at a distance beyond a geostationary orbit remains in place with a taunt tether capable of holding weight. Materials science isn't ready for this problem yet, but if it were ever achieved, you could simply climb into space without a launch.
Click to expand...
Jason Hough, The Darwin Elevator (Dire Earth cycle, etc.) Space elevators and zombies. Epic.
 
I figure, a potential weapon could be put on the opposite side of the Moon and lunch space rocks from the Moon in the opposite direction of its rotation at the exact same speed as its rotation and these rocks would fall to Earth and could be aimed at an adversary as a weaponized meteorite that would be difficult to defend against or attack.

Thinking about the feasibility of a solar powered railgun operating in low gravity and low air resistance. It might actually be cheap and easy to operate too.
 
So there's my conspiracy theory. Maybe that's why people are trying to get back to the moon so fast. And China is doing stuff on the other side of the moon that can't be seen from Earth.

Probably not

But maybe?
 
You must log in or register to reply here.
Back
Top