Problems with two DVDs that are always watched.

[Mudcat]

I few weeks ago, I finally broke to the kids demands and bought the Incredibles and Cars on DVD. There appears to be a problem on both disks. Early in each movie, they just stop, like they are going a one frame per minute. It is never consistent, but always in the beginning only.

It happens on all my DVD players:
Pioneers
Sony
JVC
and two portables that were cheap.

Any hints? Is it the disks or software/hardware?

 

[GlocksRock]

It seems very odd that it's happening with more than one disc, and on all of your players. Have you tried cleaning the laser lens on your players?

 

[Buckeye_Nut]

If it's happening on all of those DVD players, then it must be disc related. I've purchased hundreds & hundreds of DVDs over the years and never once bought a defective disc.

And you've got two defective discs at the same time??

Woahhhh.......they must be either be filthy or scratched............

Clean the discs..... I've even had success with 'buffing out' scratches by wiping from the center-outward.

 

[mpompey]

I've bought hundreds of discs and I've had defective and misformatted discs before. One that immediately comes to mind was the DVD series of Space: Above and Beyond. All of the disc 2's were defective and Fox would send replacements.

Buckeye has been incredibly fortunate.

 

[j_garcia]

I'd say it is a disc problem as well, return them to the store you bought them at, stating they are defective and get new copies. I have bought hundreds of discs too and have had a few bad ones.

 

[mtrycrafts]

... I've purchased hundreds & hundreds of DVDs over the years and never once bought a defective disc.

And you've got two defective discs at the same time??
.

Yep, that is allowed statistically speaking

 

[Buckeye_Nut]

Yep, that is allowed statistically speaking

LOL....


Two at once....woah...... those are extremely long odds!!

 

[mtrycrafts]

LOL....


Two at once....woah...... those are extremely long odds!!

He drew the short straw twice. There are 2 sequences of 10 odd/even digits in the 1st 1000 decimal digits in pi. What would the odds of that be?

 

[mpompey]

Wouldn't the odds be 100% since they will always be there as a component of Pi. Pi is only one specific number. Right?

 

[old_kid]

try playing them on your computer. See if it is still a problem;if so,replace the disk. If not, rip a copy,and play that on your player .

 

[mtrycrafts]

Wouldn't the odds be 100% since they will always be there as a component of Pi. Pi is only one specific number. Right?

The decimal places in pi are considered to be random numbers, no repeated patterns, as best I know. Hence, even and odd number distributions would be random as well. What is the probability of having 10 of one in a row, like getting 10 heads or tails in a row? Then to have two such sequences in only 1000 tosses?

 

[Adam]

What is the probability of having 10 of one in a row, like getting 10 heads or tails in a row? Then to have two such sequences in only 1000 tosses?

The probability of getting ten heads (or tails) in a row is exactly the same as that of getting any other combination. Each coin flip has a 50% probability of being heads and the same for being tails. No flip is influenced by the one before or the one after.

I could be wrong, but I figure that I have a 50% chance of being correct.

 

[avaserfi]

The probability of getting ten heads (or tails) in a row is exactly the same as that of getting any other combination. Each coin flip has a 50% probability of being heads and the same for being tails. No flip is influenced by the one before or the one after.

I could be wrong, but I figure that I have a 50% chance of being correct.

That is actually incorrect. The first flip has a fifty fifty chance as does the second, but when you say what are the odds of two flips being heads in a row the first stays at 50 percent but the second will be less than fifty because the probability of two heads in a row is not the same as two separate trials. Sorry if that is a little convoluted.

Think of it as each flip is separate and has a 50/50 chance but you aren't asking about each flip alone you are asking about a series of flips.

Edit: Something that might make it a little easier to swallow. If you have 100 coins to flip there isn't a 50/50 chance of having ALL heads or ALL tales. Each flip has those odds and overall you most likely will see about a 50/50 distribution but the chance of all of them coming up heads is far from even.

 

[Adam]

That is actually incorrect. The first flip has a fifty fifty chance as does the second, but when you say what are the odds of two flips being heads in a row the first stays at 50 percent but the second will be less than fifty because the probability of two heads in a row is not the same as two separate trials. Sorry if that is a little convoluted.

Think of it as each flip is separate and has a 50/50 chance but you aren't asking about each flip alone you are asking about a series of flips.

Ahhh, but I didn't say that the probability of getting two heads in a row was 50%...I said that it was the same as any other combination. The probability of getting two heads is the same as getting heads/tails, tails/heads, or tails/tails. All four combinations are equally likely.

The probability of the second flip being heads is still 50%, though. It is not in any way affected by the previous flip.

 

[avaserfi]

That example is valid for two coins but once you add more than that my given example above comes into play. Say we have 5 coins the odds of having all heads then a tails are not the same as having two heads a tails then another two heads.

Looking at each coin flips separately gives them the same odds but that is not the case here as we are saying order matters which changes the calculations that need to be made.

 

[Adam]

That example is valid for two coins but once you add more than that my given example above comes into play. Say we have 5 coins the odds of having all heads then a tails are not the same as having two heads a tails then another two heads.

Actually, the odds are exactly the same. Now, it is true that the odds of having all heads (or all tails) for five coins flips are not the same as the odds of having a combination of heads and tails. That is because there is only one scenario that leads to all heads (and another that leads to all tails), and there are multiple scenarios that lead to a combination of the two. However, the odds of having any specific combination of heads and tails is exactly the same.

Let's take three flips just to make it easier on me. Here are the possible combinations (H = heads, T = tails):

HHH
HHT
HTH
HTT
THH
THT
TTH
TTT

The probability of getting any one of those combinations for three coin flips is the same as for any other combination, but you can see that only two of the eight cases lead to having the same result (heads or tails) for every flip.

 

[avaserfi]

I think we are actually looking at the problem from different perspectives and that is what is confusing us. I am specifically talking about the situation where we are looking for one exact outcome thus order matters. You are looking at it from the larger picture. So you are right all different combinations are equal but if you are looking for a specific combination, what I am talking about, then it is less likely due to the other possibilities being erroneous. So in your scenario each flip is separate in mine they cannot be since we are only looking for one outcome.

 

[Adam]

I think we are actually looking at the problem from different perspectives and that is what is confusing us. I am specifically talking about the situation where we are looking for one exact outcome thus order matters. You are looking at it from the larger picture. So you are right all different combinations are equal but if you are looking for a specific combination, what I am talking about, then it is less likely due to the other possibilities being erroneous. So in your scenario each flip is separate in mine they cannot be since we are only looking for one outcome.

avaserfi, we certainly might be looking at this differently. However, at the moment my perception (which has been wrong many times) is that you think that some specific combinations are more likely than others. That's not the case, and that doesn't agree with how many of us think. I know, because it took me a while to understand this back when I was learning this stuff.

You are completely correct in that one specific outcome is not as likely to occur as it is to not occur (provided that more than two outcomes are possible). Like in my three-coin-flip example, the probability of getting all heads is 12.5% whereas the probability of not getting all heads is 87.5%.

My two points are these, though:
1. The probability of getting all heads is exactly the same as getting any other specific combination (such as heads-tails-heads)...they are all 12.5%.

2. The probability of getting heads on any coin toss is always...always...50%, regardless of what has happened before or what you are looking to happen in the future. The probability of getting all heads over the span of 1000 coin tosses does not in any way affect the 50% probability of any given toss coming up heads.

Are we on the same page? Probably, but like you said, we're just saying things differently.

 

[avaserfi]

Agreed! I think its just different ways of thinking and explaining ourselves. There is a reason after all I don't want to be a teacher .

Mudcat: Minus all our babbling about this situation I would recommend exchanging the discs and seeing what happens especially if you aren't having this problem with other discs in the same player. Let us know how it turns out.

 

[mtrycrafts]

Actually, the odds are exactly the same. Now, it is true that the odds of having all heads (or all tails) for five coins flips are not the same as the odds of having a combination of heads and tails. That is because there is only one scenario that leads to all heads (and another that leads to all tails), and there are multiple scenarios that lead to a combination of the two. However, the odds of having any specific combination of heads and tails is exactly the same.

Let's take three flips just to make it easier on me. Here are the possible combinations (H = heads, T = tails):

HHH
HHT
HTH
HTT
THH
THT
TTH
TTT

The probability of getting any one of those combinations for three coin flips is the same as for any other combination, but you can see that only two of the eight cases lead to having the same result (heads or tails) for every flip.

Any one of those sequences in a row has a .125 probability if I remember my statistics properly.

With a fair coin, a million flips will have about an equal number of heads and tails in the end, that is a 50% outcome. What is the probability of getting a predetermined sequence of heads and tails?, It isn't 50% and certainly not 100%. Same with my pi example. Why is there any sequence of 10 even/odd numbers in 1000 random digits?

Yep, checking an older stat book shows what I just posted, any one of those sequency of H,T has a .125 probability.