# What... if light speed: 10m/s ???

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hi guys!!

I recently learned about Newton's laws and at a moment, the teacher told us that the Newton's first law(a body continues to maintain its state of rest or uniform motion unless acted upon by an external unbalanced force)is always true unless the studied system has a speed near, = or > to light speed; So now I wonder if light speed was 10m/s, how would the world look like and how would Newton's laws be changed?

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Well, I'm not much of a physicist, but I can tell you two things: a) in this case the ">" part is rubbish, or at least I'm pretty sure, and b) the universe would be a LOT slower. But this is an interesting question; I guess the human race wouldn't see a difference, since the electrons in our brains would be slowed down considerably, from which I deduce that so would our perception of time. But that's just a 16 year old's guess )
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then 10m in the hypothetical universe would equal 300,000,000 meters in the real universe.

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Why? Not to sound aggressive, but how does the speed of light change distance? The distance should still be the same, just the length of time it would take for one to cross it would, from the perspective of our Universe, be 30 000 000x longer (I think).

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The book "Mr. Tompkins in Wonderland" by George Gamow is about stuff like this. I'd encourage you to get it from the library, as it is a good read. I think the first chapter is exactly the situation you posed.

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A very good suggestion.

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well guys, i find very interesting the hypothesis which assumes that probably our thinking and perception of time will slow down, but what are the scientific evidence or support of this asumption?

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Well, the electrons in our brains will be limited to 10 m/s, which is about 30 000 000x slower than now. Logically, this means that our thinking will be slowed down. But just imagine; a simple calculation that would take you one second in this Universe, such as 16*2, would take you almost a year in that Universe. Relative to our Universe.

I wonder if time would actually slow down though. I can think of some reasons why it could, and some why it shouldn't. Anybody got any ideas?

Cheers,

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Why? Not to sound aggressive, but how does the speed of light change distance? The distance should still be the same, just the length of time it would take for one to cross it would, from the perspective of our Universe, be 30 000 000x longer (I think).

Because a meter is defined as how far light travels in 1⁄299,792,458 of a second.

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Forgot about that thanks for the refresher
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If light travels at 10 m/s, the world would be a lot noisier. Screw fibre-optics. Shouting is faster.

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What if it was only photons that moved at 10m/s but electrons moved at their standard speed?

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That depends on how you imagine this fictional Universe. If that Universe were to be exactly the same as ours, except for the speed of light, then that couldn't be; nothing can go faster than light. Information travels at the speed of light. If something moved faster, it'd be going backward in time. Meaning that if electrons moved at their "standard" speeds, whenever we though about something we'd essentially be traveling backwards in time

Cheers,

Gabe

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:eyebrow:this discussion is just interesting since you guys have talked about our perception of distance, sound, thinking now i ask what's about our perception of images? do you think that the speed at which we see images, colors would be slower and why?

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That depends on how you imagine this fictional Universe. If that Universe were to be exactly the same as ours, except for the speed of light, then that couldn't be; nothing can go faster than light. Information travels at the speed of light. If something moved faster, it'd be going backward in time. Meaning that if electrons moved at their "standard" speeds, whenever we though about something we'd essentially be traveling backwards in time

Cheers,

Gabe

Actually, latest theory suggests that light is an irrelevant factor in the theory of relativity.

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Well as I said earlier, I'm not a physicist, and physics isn't exactly my strong area. My posts are based on my deductions, and what little I picked up about physics in my short life time. But thanks for the link, it's an interesting read

As for the color part, color is light. So you're basically asking the same question all over again.

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I'm not sure if it is too obvious for you but perhaps I should nit-pick a bit:

The teacher told us that Newton's first law (a body continues to maintain its state of rest or uniform motion unless acted upon by an external unbalanced force) is always true unless the studied system has a speed near, = or > to light speed

If he really said that then your teacher is wrong. Bodies maintaining their states of rest or uniform motion unless there is a force acting on them is supposedly always true. What does change at velocities close to the speed of light is that Newton's prediction of the reaction of a particle on a force becomes bad/wrong.

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If the speed of light were 10 m/s and everything else the same, then as pointed out a meter would just be a bigger unit. However, if you changed one of the unitless constants, such as the fine structure constant, then there would be significant differences (notably, a similarly large change would prevent life from being possible).

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Smaller unit, the meter would be a smaller unit

Also, if light speed were slower, would that would make weird chemistry, because the electromagnetic force would be much slower as well...

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Actually it would be new meter = 29,979,245.8 old meters, or new second = 3.33564095 × 10-8 old seconds, or a combination thereof.

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