What is time

And this book alone would not give a lay reader enough information to render judgement. The Order of Time does, however, raise and explore big issues that are very much alive in modern physics, and are closely related to the way in which we limited beings observe and participate in the world. Article 10 NOV Research Highlight 05 NOV Article 03 NOV News Feature 10 NOV Correspondence 09 NOV University of Lethbridge.

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You have full access to this article via your institution. Download PDF. OK, everyone, time's up for this week. His goal in the third minute of time added on sealed the match.

You can also find related words, phrases, and synonyms in the topics: Relating to time. Delaying and wasting time. Scarce, inadequate and not enough. Linguistics: expressions telling people to stop doing something.

A2 [ S or U ] a particular period of time for which something has been happening , or that is needed for something:. After a time, it became clear that nobody was interested in coming to the meetings. They stayed with us for a short time.

It was some time ago that I last heard from her. I asked my boss if I could have some time off from work to go to the dentist. For a time, we all thought that Sheila and Frank would get married. B2 for a fairly long period of time:. I've been doing yoga for some time. C1 for a limited period :. Leave the ironing for the time being - I'll do it later. She often gets stomach pain when it's her time of the month.

Her mother told her she needed to eat red meat because you lose more iron at that time of the month. I cherish the memories of the time we spent together. Childhood is not always a happy time. She has a difficult time ahead of her. Being out of work for a long time is very demoralizing. Have we got time for a quick drink? You can also find related words, phrases, and synonyms in the topics: Cancelling and interrupting. Short in time.

Long periods of time. Until a particular moment. A1 [ C or S or U ] a particular point in the day , as expressed in hours and minutes or shown on a clock , or a particular point in time:. Have you got the time? Did you find out the times of the trains to Kiev? We always have dinner at the same time every day. When would be a good time for me to call you? We regret that at the present time US also at this time we are unable to supply the products you ordered.

A2 at the particular point when something was thought of or done:. It seemed like a good idea at the time. B1 If two things happen at the same time, they happen together:. We arrived at the same time. At his time of life , he ought to be taking things easy. What time would it be convenient for me to come round? By the time the meal began , the youngest children were getting tired and crotchety.

I might go to the cinema tomorrow - it depends what time I get home from work. The train was empty by the time it reached London. The exact time of the accident was 2. Points in time. You can also find related words, phrases, and synonyms in the topics: In the past. Simultaneous and consecutive. B1 [ S or U ] a particular point of the day , year , etc. Put your toys away now - it's time for bed.

It's time that I was leaving. B1 early enough:. I got home just in time - it's starting to rain. If we don't hurry up, we won't be in time to catch the train. My parents go to the house right on time. Let's meet for lunch. I'll call you ahead of time to decide exactly when and where. It's about time that the school improved its food service. It is high time for the critics to open their minds to a new approach.

I haven't told him yet , but I will when the time is right. She felt the time was right to leave. The time is ripe for invest ing in new technology. It's time we dug up those potatoes. Many politicians argued that this was no time to disarm.

The submarine dived just in time to avoid the enemy attack. Drink up! It's time to go. Borrowers are expected to return books on time. You can also find related words, phrases, and synonyms in the topics: At the right time. Before, after and already. Describing when something happened or will happen. A2 [ C ] an occasion when something happens , or the experience connected with it:.

The last time we went to Paris , it rained every day. They go swimming three or four times a week. There are times when I wish I didn't live where I do. Sometimes I enjoy my English classes , but at other times I find them really boring.

B2 sometimes, but not often:. From time to time I still think of her. C2 again and again:. Time after time she gets involved in relationships with the wrong men. I've told you time and time again - look before you cross the road. When you're at the airport , you should make sure you have your luggage with you at all times.

Only a certain number of people are allowed in the building at any one time. I'm sorry , but I'm too busy to help you now - I can only do one thing at a time.

C1 sometimes:. You can be really annoying at times, you know. Parking is not allowed here at any time. The times I've told you, ask before you borrow my clothes. The announcement came at a bad time. Don't be daft - let me pay - you paid last time. That's an excellent point. And the answer is, almost nothing happens there. There is no state the universe could be in that would just stay put for ever and ever and ever. If there were, we should settle into that state and sit there forever.

It's like a ball rolling down the hill, but there's no bottom to the hill. The ball will always be rolling both in the future and in the past. So, that center part is locally static — that little region there where there seems to be nothing happening. But, according to quantum mechanics, things can happen occasionally. Things can fluctuate into existence. There's a probability of change occurring.

So, what I'm thinking of is the universe is kind of like an atomic nucleus. It's not completely stable. It has a half-life. It will decay. If you look at it, it looks perfectly stable, there's nothing happening … there's nothing happening … and then, boom! Suddenly there's an alpha particle coming out of it, except the alpha particle is another universe. Does the arrow of time still exist there?

Carroll: It could. The weird thing about the arrow of time is that it's not to be found in the underlying laws of physics.

It's not there. So it's a feature of the universe we see, but not a feature of the laws of the individual particles. So the arrow of time is built on top of whatever local laws of physics apply. Carroll: Not really. The way it works is that the perception comes first and then the understanding comes later. So the understanding doesn't change the perception, it just helps you put that perception into a wider context.

Augustine, where he says something along the lines of, "I know what time is until you ask me for a definition about it, and then I can't give it to you. Carroll: This goes back to relativity and Einstein.

For anyone moving through spacetime, them and the clocks they bring along with them — including their biological clocks like their heart and their mental perceptions — no one ever feels time to be passing more quickly or more slowly. Or, at least, if you have accurate clocks with you, your clock always ticks one second per second. That's true if you're inside a black hole, here on Earth, in the middle of nowhere, it doesn't matter. But what Einstein tells us is that path you take through space and time can dramatically affect the time that you feel elapsing.

The arrow of time is about a direction, but it's not about a speed. The important thing is that there's a consistent direction. That everywhere through space and time, this is the past and this is the future. Fox that it's impossible for him to go back to the past and save his family?

Carroll: The simplest way out of the puzzle of time travel is to say that it can't be done. That's very likely the right answer. However, we don't know for sure. We're not absolutely proving that it can't be done. Carroll: Yeah, no. You can easily go to the future, that's not a problem. One of things I point out in the book is that if we do imagine that it was possible, hypothetically, to go into the past, all the paradoxes that tend to arise are ultimately traced to the fact that you can't define a consistent arrow of time if you can go into the past.

Because what you think of as your future is in the universe's past. So it can't be one in the same everywhere. And that's not incompatible with the laws of physics, but it's very incompatible with our everyday experience, where we can make choices that affect the future, but we cannot make choices that affect the past.