Author Topic: SParkers GROUP PROJECT ANNOUNCEMENT  (Read 5286 times)

Offline Troubleat Mills

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SParkers GROUP PROJECT ANNOUNCEMENT
« on: April 02, 2007, 08:30:38 PM »
A project for the SParkers has been set.

For this particular project, Decimus has been allocated the position of Project Leader. He will be responsible for overseeing things, but ALL of you are responsible for your own input to achieve a final result.

I have already sent a PM to Deciums with instructions (see below), but they are posted here for everyone's perusal. A notification will appear on the wiki discussion board (with a link to this posting) and also on a couple of the in-world boards in the next few days.

I cannot over emphasise that repeatability is of great importance in any scientific experiment, so everyone should aim to perform the experiment under the same conditions. If someobody thinks their results are wrong, or they don't achieve consistent results, repeat them.

Only one set of apparatus is required. Everyone is to use the same pendulum when it is their turn to complete their part of the experiment. It is also important that nobody goes in-world and alters your apparatus between sessions, otherwise it will void all the results and you will have to start again.


Your basic instructions (as sent to Decimus) are as follows:

Firstly gather your fellow SParkers and explain what has been asked of you. It is your task to ensure that each member of your team carries out their part of the experiment and reports their findings to you.

With the help of your team, I would like you to build the apparatus in SL. It doesn't need to be hi-tech or complicated. In science, simpler methods leave less room for error and it is also easier to trouble-shoot problems if they occur.

You will need to make a list of the (virtual) apparatus you built, write up your method of completing the experiment, the results (everyones) and a conclusion.

Experiment to measure g using a simple pendulum

1. You will need to create your pendulum using either small chain links or if you are able to built it, rope. Ideally a small bob should be attached to the end, but you may like to take into account whether this will make any difference to the pendulum.

2. You will need to devise a way of measuring your pendulum. In the real world this would be done with a ruler. In SL you could possibly use the x, y, z values to calculate a length of the pendulum, but have a think about it, talk it over with your team. Measure the length L of the pendulum from the anchorage point at the top to the centre of the bob (if there is a bob).

3. Determine the time period, T, of small oscillations of the pendulum by timing 20 complete oscillations. Do this 3 times. (Do not pull the pendulum out too far before releasing it - small even swings are very important to achieve).

4. Every memeber of your team should carry out instruction 3. Collate all the results and calculate the average value for the time period.

5. Repeat this procedure for five further lengths, either shortening or lengthening the pendulum.

6. Plot a graph of T2 on the Y (vertical) axis against L on the X (horizontal) axis.

Since T2= (4Pi2/g) x L

the graph should show a straight line through the origin with a gradient equal to 4Pi2/g

Hence g = 4Pi2/gradient of the graph


Good luck!

I will be around for the session on Thursday, but not tomorrow.
Teen Second Life: Troubleat Mills   /  Second Life: (two lives, two names and two different egos!!) Callisto Carter and Maisy Mayo

Offline Decimus Schomer

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Re: SParkers GROUP PROJECT ANNOUNCEMENT
« Reply #1 on: April 02, 2007, 10:07:13 PM »
I'll go into TSL soon and just check to see how I can set up the apparatus in preparation for the session.
Anyway, we need to sort out the times for the sessions and sort out the wiki pages.

And I'm guessing that the group sessions tomorrow and on Thursday are both for this experiment?
« Last Edit: April 02, 2007, 10:08:44 PM by Decimus Schomer »

Offline mgaved

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Re: SParkers GROUP PROJECT ANNOUNCEMENT
« Reply #2 on: April 03, 2007, 08:33:02 AM »
Hi Decimus, I believe that's the case, that both today and Thursday's sessions are for this experiment.

Mark Cabaret
Teen Second Life: Mark Sparker / Second Life: Redmark Hax

Offline Marko Schomer

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Re: SParkers GROUP PROJECT ANNOUNCEMENT
« Reply #3 on: April 03, 2007, 08:43:15 AM »
I thought we'd found the value of g as 9.8 by measuring the acceleration of a falling body?

As to building the pendulum, it's impossible to make it out of any form of rope, as flexible objects cannot be made physical (and so cannot be made to be effected by gravity, or by another object which is effected by gravity) Using linked chain segments does work.

Offline Troubleat Mills

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Re: SParkers GROUP PROJECT ANNOUNCEMENT
« Reply #4 on: April 03, 2007, 10:16:20 AM »
I thought we'd found the value of g as 9.8 by measuring the acceleration of a falling body?
Was this completed as a proper experiment, or was this just a random event by one or two people?

The pendulum experiment is for the purposes of practicing a proper scientific experiment as a group, with method, results and conclusion to be posted on the wiki discussion page.

We will be putting in further discussions and topics for you soon. Topic suggestion by Davee: Observing Climate TRUTHS from space. We could put on a lecture and answer questions about NPL's TRUTHS satellite (see Schome Wiki and http://knowledgecast.wordpress.com/2007/01/18/virtualtruths/) that will improve our understanding of global warming. We might have a debate afterwards on global warming and what it might mean for us all in the future.
Teen Second Life: Troubleat Mills   /  Second Life: (two lives, two names and two different egos!!) Callisto Carter and Maisy Mayo

Offline Decimus Schomer

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Re: SParkers GROUP PROJECT ANNOUNCEMENT
« Reply #5 on: April 03, 2007, 10:17:28 AM »
Mark - okay then.
Marko - I have an idea for how to make a pendulum with a 'rope' (quoted because it's actually a long, solid box)

Offline Marko Schomer

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Re: SParkers GROUP PROJECT ANNOUNCEMENT
« Reply #6 on: April 03, 2007, 10:30:42 AM »
Was this completed as a proper experiment, or was this just a random event by one or two people?

The pendulum experiment is for the purposes of practicing a proper scientific experiment as a group, with method, results and conclusion to be posted on the wiki discussion page.

The experiment was carried out by using a flight feather to check acceleration. Also, the figure of 9.8 m/s/s acceleration due to gravity is that which the various wikis on scripting state. However, it wasn't really done very scientifically, so a group experiment might be a good idea (and we have a figure we can check its accuracy with   :) )

Marko - I have an idea for how to make a pendulum with a 'rope' (quoted because it's actually a long, solid box)

Ah, yes. A stiff line would work just as well as a flexible rope.

Offline Decimus Schomer

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Re: SParkers GROUP PROJECT ANNOUNCEMENT
« Reply #7 on: April 03, 2007, 11:12:24 AM »
Marko - I have an idea for how to make a pendulum with a 'rope' (quoted because it's actually a long, solid box)
Ah, yes. A stiff line would work just as well as a flexible rope.
We'll have to make two rings, one static, the other hanging from it like a chain, with the pole and the bob attached; the problem is, we will probably want to make them exactly the right size such that they can't move...

Also, when are the sessions? Because the wiki doesn't have anything about it on them...
« Last Edit: April 03, 2007, 12:52:16 PM by Decimus Schomer »

Offline Marko Schomer

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Re: SParkers GROUP PROJECT ANNOUNCEMENT
« Reply #8 on: April 03, 2007, 01:15:20 PM »
We'll have to make two rings, one static, the other hanging from it like a chain, with the pole and the bob attached; the problem is, we will probably want to make them exactly the right size such that they can't move...

It will be extremely difficult to get them the right size. Since all objects exert an absolute repulsive force up to about 0.01 away from their surface, a distance of 0.02 should be sufficient. However, in my construction of levers this has not proved to be the case. Objects can be made physical if they are just outside that area, but there is a great degree of friction, which makes greatly restricts movement. There is also quite an odd problem, in that in certain conditions (I don't know which, but they seem to involve a force being placed on the object, thus forcing it through the area where there is he repulsive force) the object which includes the axle flies completely out of its housing and far away. The larger the force on the object, the further they seem to fly away. Unfortunately, this means that somewhere on the island there is a large trebuchet arm which I was unable to find...

Offline Explo Schomer

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Re: SParkers GROUP PROJECT ANNOUNCEMENT
« Reply #9 on: April 03, 2007, 05:03:39 PM »
all objects exert an absolute repulsive force up to about 0.01 away from their surface,

To correct Marko, the Schome Strange Force lasts 0.05 with the _isolation gap_ being 0.1. As I was the one to give Marko the wrong information, sorry.

As well as this I've had the same problems with the arm flying across the island, though sometimes mine just fell through the holding block. This only happened with small hollow sizes, with medium hollow sizes the pendulum only came out when swinging. With smaller masses there appears to be no problem and I think it is that with a small hollow the pendulum intersects the holding block just slightly (due to the twitching of physical objects). Intersecting the holding block while going through it seems to be the reason why the pendulum is flung so far, with the SSF exerting an extremely large force (some of the pendulums I made actually left the island).

Despite this I've managed to build an absolutely massive pendulum at 100,42,100, next to the large black moon. It seems to work okay, with very little energy loss.
« Last Edit: April 05, 2007, 03:03:23 PM by Explo Schomer »
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