Mathematical equations, physics buffs. - Page 3

v gate · 17-04-2011, 05:45 AM

Quote:

Originally Posted by Sezzy

I got a duck...

as far as i can tell your way ahead with the duck.
everyone knows chickens suck at flying.

Rodp · 17-04-2011, 06:31 AM

Quote:

Originally Posted by Spanrz

Ok, here's one. One of my questions that I've just thought about for a while.

Going on the speed of light stuff.

If I look with a large Telescope at a star, do I gain an advantage on seeing the light before it hits earth?

No. The telescope is gathering light just as your retina is. The light has to reach the telescope before you can resolve an image using a telescope. Depending on how it resolves light, it may take longer than viewing the object with the naked eye - but that amount of time would be so small it would be insignificant.

gtfpv · 17-04-2011, 11:58 AM

Quote:

Originally Posted by flappist

The sound comes from the point where the aircraft is at the time the sound is made so it is always coming from the aircraft.

All that happens is that if the aircraft is travelling towards you it will get to you before you hear it coming.

If it were travelling at the speed of light it would get to you before you could see it coming.

It only appears to come from behind because in the time it takes for the sound to get to you the aircraft has move from the point where the sound was made. This is not just a phenomon of supersonic travel.

Watch a V8 supercar race in real life standing back a few hundred metres from the track. Close your eyes. Listen for the cars and then open your eyes to look at them. They will not be where you are looking rather they will be further down the track.

In your original question the sound would only appear "2 hours" the behind the aircraft if you were observing it from a point that is "1 hour" from where the aircraft was when it made the sound.

That's a hard concept to grasp. but thanks . it doesn't seem to be relative to physics . because we all know something traveling faster than something else is pulling further away from it at all times . i guess in comparison of the distance the sound travels from the craft is what comes into play here .

EgoFG · 17-04-2011, 12:31 PM

Quote:

Originally Posted by In Focus

Correct. It's not (theoretically) possible for an object with mass to hit light speed. If you were to get to that speed, then you (the object) would have infinite mass. You would also, I think, be the size of the universe.

If, however, you can find a way to reduce your mass to zero (ie, have no weight whatsoever), then I think you could achieve light speed.

Glad you agree - And do you know the best polish for getting the light stains off the side of my car ? Used to be a real problem on my Chrysler by Chrysler - I had 800w coming out the front and the light used to get blown back along the sides of the car on the porous paint - It was sooo much harder than polishing the Grasshoppers and Datsuns off the chrome.

Rodp · 17-04-2011, 06:59 PM

Quote:

Originally Posted by gtfpv

That's a hard concept to grasp. but thanks . it doesn't seem to be relative to physics . because we all know something traveling faster than something else is pulling further away from it at all times . i guess in comparison of the distance the sound travels from the craft is what comes into play here .

Get 2 people to stand 100 meters apart. Quietly whisper in their direction. Measure how long it takes for that sound to reach them. Oh, didn't reach them? Sound dissipates the further it travels.

In Focus · 17-04-2011, 07:04 PM

Quote:

Originally Posted by EgoFG

Glad you agree - And do you know the best polish for getting the light stains off the side of my car ? Used to be a real problem on my Chrysler by Chrysler - I had 800w coming out the front and the light used to get blown back along the sides of the car on the porous paint - It was sooo much harder than polishing the Grasshoppers and Datsuns off the chrome.

Get a small quantum singularity and VERY carefully drag it parallel to the sides of your Chrysler. Don't get too close, or it'll suck the paint off the car, and maybe the doors as well.

ford man xf · 18-04-2011, 09:55 PM

Can anyone answer this conundrum

If you had access to a time machine would it be possible to go back in time and kill your parents or grandparents?

SEZ213 · 18-04-2011, 09:57 PM

Quote:

Originally Posted by ford man xf

Can anyone answer this conundrum

If you had access to a time machine would it be possible to go back in time and kill your parents or grandparents?

Yes, but you will potentially disappear, alah Back to the Future...

ford man xf · 18-04-2011, 10:09 PM

Quote:

Originally Posted by Sezzy

Yes, but you will potentially disappear, alah Back to the Future...

BUT.....if you went back in time before you were born, and killed your parents how on earth could you be alive to do it in the first place, let alone even concieve to do it?

My32Doors · 18-04-2011, 10:14 PM

I can see the moon

ford man xf · 18-04-2011, 10:27 PM

Quote:

Originally Posted by onetonfun

I can see the moon

Apparently you can see the moon from the great wall of China

SEZ213 · 18-04-2011, 10:29 PM

Quote:

Originally Posted by ford man xf

BUT.....if you went back in time before you were born, and killed your parents how on earth could you be alive to do it in the first place, let alone even concieve to do it?

Hrmmm...well, if there's a time-space continium, and the stars are aligned in the right position...you could only do it once...

grandpa_spec_F6 · 18-04-2011, 10:32 PM

My input:

Discuss

ford man xf · 18-04-2011, 10:36 PM

Quote:

Originally Posted by Sezzy

Hrmmm...well, if there's a time-space continium, and the stars are aligned in the right position...you could only do it once...

What law would stop you doing it anytime though? Obviously its a hypothetical question and we can never go back in time, but what if, what weird consequences would happen.

SEZ213 · 18-04-2011, 10:47 PM

Quote:

Originally Posted by ford man xf

What law would stop you doing it anytime though? Obviously its a hypothetical question and we can never go back in time, but what if, what weird consequences would happen.

Technically you could go back in time and possibly become your own grandfather, if you believe Futurama (although there is a possibility you would have a 'missing link'.

As far as laws go, it depends which movie you base it on - Time cop, Terminator, BTF, etc.

The general concensus is that if time travel were possible, the people from the future would be coming back to tell us we're doing the wrong thing.

My partner is trying to explain this to me (his interpretation)...and he's confusing the crap outta me...so I'm going to stop now (as confusion at this hour is not hard)...

GT69 · 18-04-2011, 10:55 PM

What I was saying Sez (who didn't understand what I was trying to say) At the point at which a time machine is constructed is the point that time is no longer linear, it will be the 'start' marker, You wont be able to go back further and un-invent the machine. All that is and ever will be will happen in an instant.

I don't believe time travel is possible but; Oranges.....think about it.

SEZ213 · 18-04-2011, 10:59 PM

Quote:

Originally Posted by GT69

What I was saying Sez (who didn't understand what I was trying to say) At the point at which a time machine is constructed is the point that time is no longer linear, it will be the 'start' marker, You wont be able to go back further and un-invent the machine. All that is and ever will be will happen in an instant.

I don't believe time travel is possible but; Oranges.....think about it.

***whispers*** - I understood, I just tuned out...happens quite regularly under this roof, remember?

bafel · 18-04-2011, 11:04 PM

Quote:

Originally Posted by Sezzy

The general concensus is that if time travel were possible, the people from the future would be coming back to tell us we're doing the wrong thing.

Basically, we wont invent it , people that are in the future will, then bam one day it will just appear out of nowhere, probably a phone box, with a guy called Rufus inside it.

Iggypoppin' · 18-04-2011, 11:07 PM

Time travel as we see it in the movies is impossible. Think about it. How would you go backwards to something that has already occured? Or to something that has not even happened yet. How can you go to the future? It is a non occurence. The past has happened, so you can't go there.
However, time is a wierd thing. You can, in theory, travel in such a way that you will age very little and others will age faster. Can anyone explain why? I already know, who else does?

flappist · 18-04-2011, 11:16 PM

Quote:

Originally Posted by Iggypoppin'

Time travel as we see it in the movies is impossible. Think about it. How would you go backwards to something that has already occured? Or to something that has not even happened yet. How can you go to the future? It is a non occurence. The past has happened, so you can't go there.
However, time is a wierd thing. You can, in theory, travel in such a way that you will age very little and others will age faster. Can anyone explain why? I already know, who else does?

Can you explain the operation of a mobile phone in Latin?

Or would Romans think such things were impossible......

ford man xf · 18-04-2011, 11:20 PM

Quote:

Originally Posted by Iggypoppin'

Time travel as we see it in the movies is impossible. Think about it. How would you go backwards to something that has already occured? Or to something that has not even happened yet. How can you go to the future? It is a non occurence. The past has happened, so you can't go there.
However, time is a wierd thing. You can, in theory, travel in such a way that you will age very little and others will age faster. Can anyone explain why? I already know, who else does?

Is it to do with travelling at the speed of light? I think it's to do with someone travelling at the speed of light experiences very little ageing, whilst everyone else would age normal?

Iggypoppin' · 18-04-2011, 11:20 PM

Sorry flap you have truly lost me?

LXL15 · 19-04-2011, 12:52 AM

Quote:

Originally Posted by Iggypoppin'

Time travel as we see it in the movies is impossible. Think about it. How would you go backwards to something that has already occured? Or to something that has not even happened yet. How can you go to the future? It is a non occurence. The past has happened, so you can't go there.
However, time is a wierd thing. You can, in theory, travel in such a way that you will age very little and others will age faster. Can anyone explain why? I already know, who else does?

I do

also I think I remember reading an article about some sort of quantum experiment that basically suggested (in fact the author said it) that if we were to travel back in time things would always occur so that the present we travelled from would remain unchanged. Sort of like those movies where someone tries to avoid a future described to them but everything they do leads to the future happening as described.

Ps someone quoted me

I feel important and included now...

Rodp · 19-04-2011, 07:05 AM

Quote:

Originally Posted by Sezzy

The general concensus is that if time travel were possible, the people from the future would be coming back to tell us we're doing the wrong thing.

?!?! The general consensus of whom?

Look at it two ways;

If a time travel machine existed - how could it travel back into a time where it didn't exist?

If a time travel machine can travel back into time where it didn't exist - then a time travel machine now exists.

EgoFG · 19-04-2011, 08:59 AM

Quote:

Originally Posted by Rodp

?!?! The general consensus of whom?

Look at it two ways;

If a time travel machine existed - how could it travel back into a time where it didn't exist?

If a time travel machine can travel back into time where it didn't exist - then a time travel machine now exists.

I have it - it will only go forward though - at about 24hrs per day

Road Games · 19-04-2011, 09:04 AM

Quote:

Originally Posted by Iggypoppin'

I said I'd start one!

general maths problems, equations, formulae, discussion on maths education methods, etc.
Physics equations, space time theories, Einstein etc. There's got to be some people interested and educated in this stuff. Graphs and other instruments encouraged to be posted!

Jesmol · 19-04-2011, 09:14 AM

Quote:

Originally Posted by Swordsman88

Case in point. A medium loaded B767-300 has a takeoff speed (v2) of 150knots (roughly), so call it 172 mph. So if you pull the conveyor belt along at 172mph but apply thrust for takeoff than the 767 will take off...but the wheel speed is 2 x 172mph....Problem. Maximum tyre speed for a 767 is perhaps 190mph. Certainly i dont' know of any airliner tyre with greater than 210mph before it pops.

So in that test you'd pop all your tyres pretty quick and then assuming the rims dug into your mystical converyor belt than the takeoff would most likely never happen. These sorts of things just play on your perceptions...look at it critically and it all comes out in the wash...

Now there's a flaw in this logic. The scale argument cant be restricted to just the tyres. Sure there's an issue with maximum tyre speed, but there's an even bigger issue with building a conveyor that could hold a 767 and run at 172mph, therefore you could even do the experiment

Scott · 19-04-2011, 10:48 AM

If time travel were possible, it would mean that the lives we know and live are predetermined. It would also mean that if Climate Change were a big issue in the future, our future selves would have come back to fix it.

So, are the people spruiking Climate Change here from the future to try and help us save the planet, or are those opposed to the idea of it here to try and save us from giving control of the world to a crazy few?

My head won't expand far enough to fathom anything more than looking back in time, and even that is monumentally difficult to comprehend in a meaningful way.

AndrewR_AUII · 19-04-2011, 10:52 AM

Quote:

Originally Posted by Scott

So, are the people spruiking Climate Change here from the future to try and help us save the planet, or are those opposed to the idea of it here to try and save us from giving control of the world to a crazy few?

I think they are actually an alien race of read headed amazonian women...

flappist · 19-04-2011, 11:46 AM

Quote:

Originally Posted by Iggypoppin'

Sorry flap you have truly lost me?

Just because we think something is impossible and can demonstrate totally unassailable proof to support our position does not make it true.

All it means is that we cannot understand how it could be true.

This has two possible outcomes.

1) It is not true.
2) It is true but we do not understand it (yet).

A closed mind will never discover anything new........