Okay, folks, I just did a little science experiment in Minecraft, and I want some help. Today, we are going to find out the universal constant for the acceleration due to gravity in the Minecraft world.

If you've ever taken a physics class, you'll know that the equation for a freefalling object looks something like this:
Y=Vt+1/2at^2

Where X is the change in height, V is the initial velocity of the object, t is the time it takes for the object to go that distance, and a is - in this case - the force of gravity.

Now, if the object doesn't start with an initial velocity (V=0), then Vt will cancel out, and we'll be looking at something like this:
Y=1/2at^2

If you find a tall structure in the game above water, we can do a fun little experiment together to find out the constant for how fast gravity is Minecraft.

What you'll need to continue:
A calculator (most likely)
A stop watch
Minecraft
A structure above the water that lines up with the edge of the water. Water must be at least 3 deep, or you will die on impact.

First, find out how tall your structure is. The easiest way is get next to it with a stack of gravel, and start piling them underneath yourself while you're jumping. The structure's height will be however many gravel blocks you put down. Remember that each block is equal to 1 meter tall. Once you figure this out, this value will be the Y value in our experiment.

Next, go to the top of that structure, and walk off it into the water, at the same time starting your stop watch. When you hit the water, stop the watch. This value will be t in our experiment.

It is very important that you do not jump, just walk off the edge. Jumping will give you an initial velocity, and change the height that you're falling from. This will make the experiment void and we'll be unable to determine the end results.

Next, plug in your numbers and begin the math.

My structure I jumped off was 43.5 meters tall (it was built with half steps, which are each .5 meters tall), and I timed my friend falling off the edge and into the water. He fell for exactly 2.09 seconds.

So, my experiment looks like this:
Y=1/2at^2
43.5 meters = 1/2(a)(2.09)^2
We're trying to solve for a, so, we multiply both sides by 2, then divide both sides by t^2, and it should look like this:
2(43.5)/2.09^2=a
2(Y)/t^2=a
then it's just a matter of solving, and I came up with the result of 19.92 meters/second^2

The force of gravity on earth is 9.80m/s^2, which means that if I'm correct, the force of gravity in the Minecraft world is nearly twice that number! Crazy stuff.

You can help, too! I want to know what the force of gravity is in your world! Let's see if we can come up with a universal constant for the force of gravity in minecraft!

Try two or three attempts, too. Then use the average of your results for your final number (add all results together and divide by the total number of results). If other people try this, I will use their numbers to average with my numbers, too, and we'll get a rough idea of how fast Gravity is. The more people who do this, and the more times each of us do this, the less chance any errors - like hitting the stop watch at the wrong time - will actually make the number erroneous. So, do this multiple times, record your numbers in here so we can all see it, so we can double check each other's math (I feel like such a nerd, haha).

I'll keep updating this part of the post with what the average acceleration of gravity is:
My trials:
Y=43.5m
t=2.09, 1.81, 2.09, 2.16, 1.95, 1.81, 1.74,

a=19.92 m/s^2, 26.56m/s^2, 19.92, 18.65, 22.88, 26.56, 28.74
Average a = 23.31 m/s^2

Unless Notch programmed them into the game, no. Also, I don't know how to factor those in, haha. We're just assuming that we're dropping a free falling object with no air resistance, and it's starting velocity is 0, so it's only being affected by gravity.

But, I like that you're asking these questions! Makes me feel like less of a nerd doing this if other people can get behind the idea, too :biggrin.gif:

viewtopic.php?f=35&t=100206
There IS air resistance, so you can't simply use xf = .5at^2+vt+xi. You'll, instead, end up with some second order differential equation. I don't know how I figured it out.

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My Youtube channel.
Contains Pachebel's Canon made with noteblocks, a working Rubik's cube made with pistons, and the ultimate TNT cannon.

This was more just for grins and giggles anyway. I think there's still some merit to this, though. I don't think players have air resistance, only objects like TNT, arrows, eggs, etc.

Huh, so I was way off, then, huh? You're getting a number about 3 times what I had.

Very cool, though. I'm really glad that other people are nerdy enough to care about the physics in this game. Even though some of the physics, like the fact that bows shoot with the same speed and trajectory underwater as they do in air, is completely mind bogglingly strange, it's good to know that some of it is sound and actually makes sense.

You, sir, are getting my first usage of the "I approve" icon.

Consider this your Nobel Prize (Notch Prize?) in Minecraft Physics:

Im digging this post back up. I did my own experiments as well. I found that the acceleration due to gravity for a player is 22 m/s/s, pretty close to the OP's 19.92. I did my free fall from 100 blocks(meters) up, so I believe it makes 22m/s/s just slightly more accurate, although I can't quote it down to the hundreth's place.

Conundrumer, I did some experiments with my own TNT cannon (for the same purposes.) Interestingly, I found that primed TNT falls at a significantly slower rate, 7.5 m/s/s. With an 8 charge cannon, I was able to achieve a horizontal launch speed of 15 m/s. With a 4 second fuse time, that gave me a range of a little under 60m. I plan to try it with other numbers of charges in the future to see if there is a change in horizontal launch speed and, perhaps, calculate the power of a TNT charge exploding

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If you've ever taken a physics class, you'll know that the equation for a freefalling object looks something like this:

Y=Vt+1/2at^2

Where X is the change in height, V is the initial velocity of the object, t is the time it takes for the object to go that distance, and a is - in this case - the force of gravity.

Now, if the object doesn't start with an initial velocity (V=0), then Vt will cancel out, and we'll be looking at something like this:

Y=1/2at^2

If you find a tall structure in the game above water, we can do a fun little experiment together to find out the constant for how fast gravity is Minecraft.

What you'll need to continue:A calculator (most likely)

A stop watch

Minecraft

A structure above the water that lines up with the edge of the water. Water must be at least 3 deep, or

you will die on impact.First, find out how tall your structure is. The easiest way is get next to it with a stack of gravel, and start piling them underneath yourself while you're jumping. The structure's height will be however many gravel blocks you put down. Remember that each block is equal to 1 meter tall. Once you figure this out, this value will be the

Yvalue in our experiment.Next, go to the top of that structure, and walk off it into the water, at the same time starting your stop watch. When you hit the water, stop the watch. This value will be

tin our experiment.It is very important that you do not jump, just walk off the edge. Jumping will give you an initial velocity, and change the height that you're falling from. This will make the experiment void and we'll be unable to determine the end results.Next, plug in your numbers and begin the math.

My structure I jumped off was 43.5 meters tall (it was built with half steps, which are each .5 meters tall), and I timed my friend falling off the edge and into the water. He fell for exactly 2.09 seconds.

So, my experiment looks like this:

Y=1/2at^2

43.5 meters = 1/2(a)(2.09)^2

We're trying to solve for

a, so, we multiply both sides by 2, then divide both sides by t^2, and it should look like this:2(43.5)/2.09^2=a

2(Y)/t^2=a

then it's just a matter of solving, and I came up with the result of 19.92 meters/second^2

The force of gravity on earth is 9.80m/s^2, which means that if I'm correct, the force of gravity in the Minecraft world is nearly

twicethat number! Crazy stuff.You can help, too! I want to know what the force of gravity is in your world! Let's see if we can come up with a universal constant for the force of gravity in minecraft!

Try two or three attempts, too. Then use the average of your results for your final number (add all results together and divide by the total number of results). If other people try this, I will use their numbers to average with my numbers, too, and we'll get a rough idea of how fast Gravity is. The more people who do this, and the more times each of us do this, the less chance any errors - like hitting the stop watch at the wrong time - will actually make the number erroneous. So, do this multiple times, record your numbers in here so we can all see it, so we can double check each other's math (I feel like such a nerd, haha).

I'll keep updating this part of the post with what the average acceleration of gravity is:

My trials:

Y=43.5m

t=2.09, 1.81, 2.09, 2.16, 1.95, 1.81, 1.74,

a=19.92 m/s^2, 26.56m/s^2, 19.92, 18.65, 22.88, 26.56, 28.74

Average a = 23.31 m/s^2

Minecraft's Gravity: 23.31 m/s^2But, I like that you're asking these questions! Makes me feel like less of a nerd doing this if other people can get behind the idea, too :biggrin.gif:

There IS air resistance, so you can't simply use xf = .5at^2+vt+xi. You'll, instead, end up with some second order differential equation. I don't know how I figured it out.

Contains Pachebel's Canon made with noteblocks, a working Rubik's cube made with pistons, and the ultimate TNT cannon.

This was more just for grins and giggles anyway. I think there's still some merit to this, though. I don't think players have air resistance, only objects like TNT, arrows, eggs, etc.

Contains Pachebel's Canon made with noteblocks, a working Rubik's cube made with pistons, and the ultimate TNT cannon.

Very cool, though. I'm really glad that other people are nerdy enough to care about the physics in this game. Even though some of the physics, like the fact that bows shoot with the same speed and trajectory underwater as they do in air, is completely mind bogglingly strange, it's good to know that some of it is sound and actually makes sense.

You, sir, are getting my first usage of the "I approve" icon.

Consider this your Nobel Prize (Notch Prize?) in Minecraft Physics:

Contains Pachebel's Canon made with noteblocks, a working Rubik's cube made with pistons, and the ultimate TNT cannon.

http://www.minecraftforum.net/viewtopic.php?f=1&t=155932

Crates

http://www.minecraftforum.net/viewtopic.php?f=1&t=239467

Item Scrolling

http://www.minecraftforum.net/viewtopic.php?f=1&t=174539

Conundrumer, I did some experiments with my own TNT cannon (for the same purposes.) Interestingly, I found that primed TNT falls at a significantly slower rate, 7.5 m/s/s. With an 8 charge cannon, I was able to achieve a horizontal launch speed of 15 m/s. With a 4 second fuse time, that gave me a range of a little under 60m. I plan to try it with other numbers of charges in the future to see if there is a change in horizontal launch speed and, perhaps, calculate the power of a TNT charge exploding