在PTE中,无论是Summarise Spoken Text 还是 Re-tell Lecture的考题大都是从真实的讲座或者演讲中截取的, 中间经常经常夹杂很多不同的环境音.很多同学都反映有时未必是听不懂,而是听不到. 鉴于此,墨尔本文波雅思PTE专门为大家总结了真实讲座的PTE练习音频,相比新闻音频来说,整体更加接近PTE考试的真题,内容方面,我们也会为大家提供考试中存在的近似题,最近我们会持续更新,敬请期待!
If space is expanding, what is it expanding into? This is a very subtle and deep question. To answer it, I want you to imagine a line of army ants, marching along in what they believe to be a perfectly straight line, tiny tiny ants. They could be marching over a lampshade, say. Now we take a step back, we see this line of ants making some crazy paths all over this lampshade, but we can only perceive that because we’re very big. The army ants are very tiny, they believe they’re going in a straight line. These straight as possible lines are called geodesics. Now it turns out it’s possible to describe the curvature of space or space time, using just these geodesics. We don’t need to hypothesise a higher dimensional space that this space, this curve space, this space time embedded in. So for example our expanding universe is just expanding, it’s not expanding into anything because we can completely describe the expansion just using measurements within our space. Now could be there is something expanding into, there’re some spectacular theories that project this and try to project this. But we don’t need to hypothesise this in the big bang theory.
