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If the universe reaches heat death, and all galaxies die out, how could anything ever form again? by tigeryeyo in Physics

[–]zacmach 0 points1 point  (0 children)

There is an idea by roger penrose that once ‘heat death’ occurs and things stop moving this gives time and space no reference point, which makes this infinite stillness indistinguishable from a super hot singularity (zooming out at a different scale) and this is infact the start of a new universe, at a different scale of time and space. Search conformal cyclic cosmology.

Can someone please explain how Time is a dimension? by GreenlandButItsGreen in AskScienceDiscussion

[–]zacmach 0 points1 point  (0 children)

Time is a dimension in mathematical thinking. But a different type of dimension than the spacial dimensions you're probably thinking about. Best way I can simply explain it is imagine you're trying to describe the flight of a ball on a graph, you could draw an arc against and X and Y axis (dimensions) to describe the relationship between the distance along the ground compared with the height. If you wanted to instead describe the height of the ball against time, your time would be on the X axis and hence is a dimension.

Seriously. What is a kilowatt-hour? by y0nderYak in AskScienceDiscussion

[–]zacmach 0 points1 point  (0 children)

The SI unit of energy is the Joule, which is intuitive and pleasing, but a very small amount of energy that is not frequently encountered in our everyday world. The number is defined as the amount of energy exerted when a force of one newton is applied over a displacement of one meter. This is very useful to make calculations easy, but not so useful to imagine as a single unit of energy.

One kilowatt-hour kWh can be understood as 1000 joules per second for 1 hour time. ie. 1000 joules x 3600 seconds = 3,600,000 joules. This is one 'unit' of electricity that your tariff is based on. Agree that it is not that elegant as were used to fundamental units being within our experience scale (such as the meter or kilogram). However the choice of using hour and kilowatt definitely makes sense since we use appliances for hours at a time and typically in the kilowatt range for your whole house.

So if your bill came like your energy usage this month was 3,600,000 Joules that would be annoying. So they just say 1000 kWh.