It allows you to define the concept of a thermometer. You have three objects, one of them could be a thermometer.

从热的物体流向冷的物体,由此我们可以定义温度，我们还可以用它来定义温度计：

麻省理工公开课 - 热力学与动力学课程节选

The cells would be basically little reactors for generating lots of virus so you could make lots of virus to study.

这些细胞会变成增殖反应堆,从而产生大量病毒,由此可以得到大量供研究的病毒

耶鲁公开课 - 生物医学工程探索课程节选

Great. So now we have this ideal gas thermometer, and out of this ideal gas thermometer, also comes out the ideal gas law.

好，现在我们有了理想气体温度计,由此还可以引出理想气体定律，我们可以得到这条，插值出的直线的斜率。

麻省理工公开课 - 热力学与动力学课程节选

And from there, I go to... saying well, what can we do in terms of global poverty?

由此，我想到，我们可以为全球的贫困问题做些什么呢？

普林斯顿公开课 - 人性课程节选

Since I can imagine the mind without the body, it follows that they're separate.

由于我可以独立于身体而想象心灵,才由此推出,二者是独立的

耶鲁公开课 - 死亡课程节选

So always amazing to us how we go into the problem, our eye or mind can see one class of solutions, but the math will tell you sometimes there are new solutions and you've got to respect it and understand and interpret the unwanted solutions, and this is a simple example where you can follow what the meaning of the second solution is.

解决问题的方式总能让人惊喜不已,我们的眼睛或思想可以看见一类解,但数学有时会告诉你还有新的解,你不能忽视它,而是解释这些不期而至的解,这只是一个简单的例子,由此你可以理解第二个解的意义

耶鲁公开课 - 基础物理课程节选

Then, also emphasizing in the case of smallpox, how even after the scientific discovery was made, it took many, many decades for people to be able to produce the vaccine in large enough quantities and distribute it, so that you could think about making an impact on global prevalence of the disease.

同时重点就天花疫苗的发展展开了讨论,而即便当科学发现了天花病毒,仍然过了许多年,人类才能够,大规模生产并使用天花疫苗,由此你们可以了解到,在全球范围内,疫苗给天花以致命一击

耶鲁公开课 - 生物医学工程探索课程节选