🎉 Announcing Numerade's $26M Series A, led by IDG Capital!Read how Numerade will revolutionize STEM Learning


Numerade Educator



Foundational Ideas - Example 3

In philosophy, foundationalism is the view that certain basic beliefs are justified without reference to other beliefs. Such beliefs are said to be justified "foundationally". The general strategy of foundationalism is to break a chain of reasoning at its weakest link—to show that one need not accept any of the beliefs which are reached by a chain of reasoning, if one does not accept its starting point.


No Related Subtopics


You must be signed in to discuss.
Top Educators
Elyse G.

Cornell University

Christina K.

Rutgers, The State University of New Jersey

Liev B.

Numerade Educator

Farnaz M.

Simon Fraser University

Recommended Videos

Recommended Practical Videos

Recommended Quiz

Physics 103

Create your own quiz or take a quiz that has been automatically generated based on what you have been learning. Expose yourself to new questions and test your abilities with different levels of difficulty.

Recommended Books

Video Transcript

welcome to our third example video. Looking at relativity, this video we're going to ask their sell ourselves the question of the simultaneous clocks. This is a very common example that you'll see in many physics books, and the problem goes something like this. You have to clocks that you want to run on the same time. To do that, you have to have them next to each other, and you set them to be the same time. But then you want to be able to move one o'clock away and have it still be simultaneous with the first clock. Now that might not seem hard. You would probably just put it in your car or whatever and drive away, but in particular, if you put it something fast, moving and move it away and knowing now that there's something odd going on when we move stuff around, because either the displacement or the time, the change in time is not quite what we thought it was, were hesitant to do this. So it actually turns out to be we're going to have two clocks and we're going to agree to a Time T equals zero for the first clock and we'll take this clock and said it over here and at time T equals zero. We will have a signal come out of here so some light signal will be sent. It could be any electromagnetic radiation. It all travels at the same speed through space. So we send out our light signal and we have Our second clock is now over here in order for the two clocks to read the exact same time at the same moment. Then we have to take into account that it will take the light some time to travel this distance. In fact, it will take an amount of time equal to D oversee. Thus what we say is then, okay, At T equals zero. We have a clock that reads 12 o'clock and we send off our light when the light reaches our second clock. What we're going to set it to is we're going to set it to a time 12 o'clock, plus the oversee. That is to say, we're going to start it running somewhere like here, where it's the number of minutes here is dictated by this amount D overseas, which will be given in seconds. We'd have to convert it to minutes. But so the idea is then that if we know that light is traveling at a particular speed and we'll take a certain amount of time for it to traverse the distance between the two clocks weaken preset this clock so that by the time this clock starts, the first clock will be reading the same value at that time. That is to say, if this if the time takes five minutes to arrive, this clock will be reading 12 05 and this clock will start at 12 05 because we've accounted for the time that it took for the light to travel that distance.