JohnF

I'm afraid I can't agree with that. But where time is slowed down, when travelling at high velocity for example, does the stick get shorter, longer or stay the same size? And this should be from the point of view of the observer who is experiencing time running slower.

Triangulation is a good way to measure distance without events. The unit you use to seperate the two observing positions can just be a big stick. You could then work out how many 'big sticks' away the distance was.

You exist in the present. You go back in time to become your Fathers Grandfather. You still exist. Your Father is born because you impregnated his Grandmother. You still exist. You go forward in time to just before your Father impregnates your mother; with you. You still exist. You have done nothing to threaten your existence. Now the tricky part Assuming that so far everything is OK, you have free will; and perhaps a loaded gun. You kill your Father. Now what happens? Where in the chain of events does the break now occur? EDIT: Perhaps all that is required to create the paradox is having the means and the intent. It's ironic that the Mens Rea will be required to prosecute you for murder but it will also stop you committing the act.

What if you went further back in time to become your Fathers Grandfather? Your Father is only born because you impregnated his Grandmother. You now go forward in time and kill your Father. You are not born so you don't go back in time to become your Fathers Grandfather. Your Father is not born; you haven't actually killed him but he is not alive. You are still not born; no Father

Does anyone know of a way of measuring time without counting events? It just seems that time is nothing more than events being counted. Is this enough for it to be considered a dimension. If some sort of external force was applied to the planet that slowed all events down then although we would be unaware of a change an external observer would. Would that external observer think time has slowed down or just everything on the planet has slowed down?

Well that's given me something to think about. I assume entropy was considered.

Sorry, I misunderstood what you were posting about. It looked like you had singled out my comment that if the time traveller was made from something outside of this Universe he would be able to kill his father. I was rather flummoxed at the thought of trying to find a thread that dealt with that particular element, but I did have a try I assume then that your comment of False Requirement was directed to my comment and the rest was directed at the thread.

That would be a lot of searching and reading to do just to post a response, not a new thread. If you happen to know which thread the particular discussion you are referring to is in then please post a link so that I can read it.

And how is that supposed to be an explanation then?

But if you tried to go back in time wouldn't all the energy and matter that you were made of have to be back where it was at that point in time? In fact all the enrgy and matter in the entire Universe would be back where it was. This would mean that the only bit of you that existed would be in your mother to be, whilst your father wouldn't have made the other bit of you yet. I suppose you could wait until he created the sperm that was to be you then get in to his blood stream and kill him from within. But if you could go back in time then you must be made from something outside of this Universe so you could kill your father.

Thanks for that response. So if it would kill some of the viruses would you be able to keep using such a machine to flush out your whole system? I'm thinking that if 'cleaner' blood went back in the virus concentration would be diluted giving your own immune system less to do. This machine I was connected to didn't store the blood then return it; it was a continuous cycle of blood going in to the machine, platelets being separated and blood going back in the other arm. A dialysis machine would be another type that could be modified to give your blood a fever outside of your body. Are there other components to the blood that might be damaged as well as the virus?

Well; OK then. I'll put my baseball bat away

Are you stalking me? Since I know nothing about such things it seemed a reasonable question. I observe that when I have flu I get a fever and then I get better. So from where I stand getting over heated is either just a sympton of the virus or a reaction to help in getting rid of the virus; hence the question. Even if there is more going on and getting hot is just one of the factors involved in killing the virus then it's still reasonable to ask if such a treatment might help.

I used to donate platelets which were taken using a machine that took blood from one arm, passed it through a centrifuge, then returned it to the other arm. One day during this procedure I wondered if it would be possible to heat the blood whilst it was in the machine, then cool it back down before it was returned to me. I was thinking this might be like having a fever and help kill off any virus I had. I never did get to ask the question so I'm asking it here. Would it be possible to have a useful fever like that and would it help in anyway?

Perhaps it's an effect. I don't really like the idea that it is something we travel in or through. It's more like something that we witness.

But in an expanding universe all objects are moving so there is never the opportunity for two objects to occupy the same space.

I would need to use time to explain that. It's just whether it's a dimension or not that bothers me.

Hello ajb, Can you think of an example where only two changes occur, one of them being time? This might help me understand better.

Have you not used time to move them to different co-ordinates? If they are both the same distance from the door at the same time then they will collide. But if they are the same distance from the door at different times they will not collide. This is the same as saying they are at different distances from the door at the same time so they will not collide. Please be patient with me as I only thought about this a couple of hours ago. I ended up posting here because I couldn't get my head around questioning time without using time.

I'm not trying to get out of the maths. What I'm trying to do is decide if time is a real thing, not just a concept. Space exists but the units we use to measure it are just abstract. So what I am asking is does the dimension of time exist or is the measurement of time just an abstract to allow us to more easily understand space, which has caused us to conclude that the dimension of time is real. Is it really impossible to describe force or accelleration without time? All time is doing in the equation is providing a relative position in space between two events.

You're right, but could velocity be described as the product of force applied to mass? You could then describe two objects at rest in space and give their co-ordinates. Now apply force to each object so that the objects move in a direction that will cause them to impact. These two events, original location and collision, can be described without the need for time.

That's an interesting example insane_alien but you are using time to 'prove' time. What I would like you to do is prove time without reference to it. In your example you refer to the two objects having to be in the same time co-ordinates. But if there is no such thing as time then they only need to have velocity, trajectory and spatial co-ordinates that would cause them to collide. By introducing a time co-ordinate have you not changed the spatial co-ordinates without changing the trajectory or velocity?

But is it really a dimension or has the dimension of time been invented?

Can anyone can tell me if time is necessary. It's certainly convenient but all it seems to be is just that; convenient. Has it got any purpose other than to make it easier to measure the difference between events without having to directly refer to spatial co-ordinates, velocity, acceleration and change? I am wondering if it is just an abstract created by humans to help us understand reality; but in reality time does not exist.