# Does the present/now exist?

1. May 17, 2013

### imageek

I was watching a video on the arrow of time, and it got me quizzing ... does the present i.e. now actually exist?

The past can be said to be something that happened at a certain time ... i.e. a second ago, a minute ago etc. The future can be said to be something that may/will/could happen and a time can be linked to that too ... "Grandma said she will ring in 30 minutes". But what about the present?

If the present is what's happening at this moment in time, how do you define, or measure, the moment? Is it what's happening this second? If it can be a second why can't it be a millisecond, or a nanosecond? Or an amount of time that is to quick for us to even realize? Which would then mean by the time we've thought about what's happening in the present it becomes the past and then there is no present.

Sorry if my terminology is incorrect, I'm not a physicist, although I do have a deep interest in physics.

2. May 17, 2013

### HallsofIvy

Why would it be necessary to define a time interval for the present? The present occurs at a specicific time ("now"). It does not have a time interval.

3. May 17, 2013

### tiny-tim

we can't observe anything else in our present until it's in the past

4. May 17, 2013

### imageek

The present is a period of time that occurs now, and as it's time - which can be measured - shouldn't it be possible to define and measure now?

Does now have no interval or is it's interval variable?

I only ask out of pure curiosity and I thought this is the best place to ask such questions. Even the definition of time includes the present, but the present differs from the past and the future which can both me measured the same.

It's as if it's a state that we're aware of, but it's only until it's passed that we're aware of it which by then it's the past.

5. May 17, 2013

### resurgance2001

I think I can see the point you are making Imageek.

It seem to be a popular conception of time that the moment of 'now' is this tiny fraction of a second that happens so briefly that we can never quite catch it. There is the past which has gone and the future forever arriving, so where is now?

The answer I have been playing with is this: 'time' is an illusion. By the same reasoning which creates our linear conception of time, the past is something which has 'gone' and so it is in fact no longer real. And, by the same token, the future which has not arrived yet is also not real. So if, neither the past or the future are real, what are we left with? We are left with the present. The present, everything that is
here - now - is real. To
my mind it follows that despite my culturally inherited belief in the idea
of time, that it does not actually exist. The only thing, which is everything, exists now, and that is all there ever will be. It does
not mean that change does not happen. Change certainly does happen. But for the moment I feel inclined to suspend the belief that the existence of change is enough to prove that time is something that is real - well at least in the typically Newtonian sense of a linear flow, which despite a hundred years of relativity, a person can still be very tied to. My understanding (albeit very limited) of relativity is that it all exists together: past, present and future. Which still seems to me to say that all there is, is what is present.

Time seems to me to be hard to get one's head around. I mean in the universe there is matter and there is energy. So what is time? If time is not substance and it is not energy, then does it really - like really exist?

6. May 17, 2013

### physwizard

what a nonsensical question.

7. May 17, 2013

### Staff: Mentor

The question has been satisfactorily answered.