# Driving a car with a speed of light?

**URL:** <https://boards.straightdope.com/t/driving-a-car-with-a-speed-of-light/187191>\
**Category:** Factual Questions\
**Created:** [July 9, 2003, 7:44am UTC](https://boards.straightdope.com/t/driving-a-car-with-a-speed-of-light/187191 "2003-07-09T07:44:23Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![Aristotle85](https://avatars.discourse-cdn.com/v4/letter/a/3ab097/32.png) [@Aristotle85](https://boards.straightdope.com/u/Aristotle85)\
**Post date:** [July 9, 2003, 7:44am UTC](https://boards.straightdope.com/t/driving-a-car-with-a-speed-of-light/187191/1 "2003-07-09T07:44:23Z")

</div>

Can somebody answer this question? If you are driving a car at the speed of light with the head light on, what will happened to the car? Is it the car will go through time like the film “Back to the Future”? And what will happened to the head light and the car itself? Is it the car and the head light will visible on our eyes? Or it will vanish? Whoever want to answer this question, can you please stress on the head light and the car…

---

<div class="post-metadata">

**Author:** ![Tarantula](https://avatars.discourse-cdn.com/v4/letter/t/e274bd/32.png) [@Tarantula](https://boards.straightdope.com/u/Tarantula)\
**Post date:** [July 9, 2003, 7:49am UTC](https://boards.straightdope.com/t/driving-a-car-with-a-speed-of-light/187191/2 "2003-07-09T07:49:26Z")

</div>

The good man has already addressed this cosmic issue -

Cf. [http://www.straightdope.com/classics/a3\_143.html](http://www.straightdope.com/classics/a3_143.html)

enjoy…

---

<div class="post-metadata">

**Author:** ![prefect](https://avatars.discourse-cdn.com/v4/letter/p/3be4f8/32.png) [@prefect](https://boards.straightdope.com/u/prefect)\
**Post date:** [July 9, 2003, 1:05pm UTC](https://boards.straightdope.com/t/driving-a-car-with-a-speed-of-light/187191/3 "2003-07-09T13:05:00Z")

</div>

This may be kind of a “me too” post, but…

Cecil mentions “Space and Time in Special Relativity” by N. David Mermin (1968) as a good book for learning more on the subject. He’s absolutely right – I took an intro to relativity course in college, and this was one of our textbooks.

The book’s not simple reading, but it’s got enough diagrams and examples that anyone should be able to get it on close reading. It’s not easy to understand what’s going on, but when you really _get_ it, really _understand_ what’s happening, you get this spectacular feeling in your brain. Maybe it’s enlightenment. Must be what Cecil feels like all the time. 🙂

---

<div class="post-metadata">

**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\
**Post date:** [July 9, 2003, 5:33pm UTC](https://boards.straightdope.com/t/driving-a-car-with-a-speed-of-light/187191/4 "2003-07-09T17:33:10Z")

</div>

You will notice that Cecil doesn’t actually answer the question. He talks about a car going .99 C.

That’s because the actual question has no meaning. Nothing with mass can move at the speed of light. There is not even any good theoretical way to answer the question.

And just to stomp this into the ground. Nothing goes through time. Particles that travel at the speed of light have time stop for them. We just see their interaction when they come to a stop, another reason why talking about what would happen _while_ moving at the speed of light has no meaning.