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Author Topic: Could sightless beings determine the speed of light?  (Read 2055 times)

Offline bcs4

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I hate to post too many questions in a day.  Here's one that many, if not most of you have considered in some form or another..

Could a race of sightless (but with the remaining 4 senses) beings of similar intelligence to humans determine the speed of light?

I can't imagine how they could.  It would seem the fastest wave that they could study would be sound.

If that's true, is that the reason that we only seem to be able to find waves (other than sound) and massless particles at around the speed of light and (as far as I know) nothing faster than matter that can be seen by using those same light speed waves and particles? 

Would we find slower or faster waves if we had a sense that naturally detected them?  Is it likely that we will if we lack that additional sense?



 

Offline JP

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Re: Could sightless beings determine the speed of light?
« Reply #1 on: 14/04/2014 14:59:50 »
Yes, the speed of "light" is also the speed of all other electromagnetic waves in vacuum, including: radio waves, microwaves, X-rays, gamma rays.  We can't see any of these, but we can determine their speed.
 

Offline bcs4

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Re: Could sightless beings determine the speed of light?
« Reply #2 on: 14/04/2014 15:47:50 »
If sightless, how might one detect the speed of any of those waves since the basis for the determination was the study of light?
« Last Edit: 14/04/2014 16:14:32 by bcs4 »
 

Offline David Cooper

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Re: Could sightless beings determine the speed of light?
« Reply #3 on: 14/04/2014 17:27:32 »
A sightless intelligent species would have a much more difficult time trying to do science, but it isn't clear that they wouldn't be able to get to the point where they can work out that light exists and calculate its speed. It's likely that they would be able to detect heat, so they'd start to investigate how they can feel heat without touching the hot thing that's throwing it at them. That's infrared light, and it could lead them on into detecting what they might call "cold heat" - the light that we can see but they can't see or feel.
 

Offline bcs4

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Re: Could sightless beings determine the speed of light?
« Reply #4 on: 14/04/2014 18:43:03 »
I don't know how they would differentiate "cold heat" from room temperature in a dark room.  Further, I don't see (sorry) how they could differentiate heat from a nearby source compared to that of a distant source without an additional stimuli like smoke, or the sound of a fire crackling.  Lacking the additional stimuli sometimes accompanying a "nearby" source of heat it would seem impossible to determine the distance to the source, thus no ability to calculate speed.
 

Offline JP

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Re: Could sightless beings determine the speed of light?
« Reply #5 on: 14/04/2014 21:16:53 »
If sightless, how might one detect the speed of any of those waves since the basis for the determination was the study of light?

One way would be to build devices to turn light into things we can "see" or "feel" like heat, as David notes.

But in fact you don't need to measure the speed of light to figure out "the speed of light."  As a constant, it is the speed of electromagnetic waves.  We can measure properties of electric and magnetic fields in a lab by just playing around with various circuits.  From there it is fairly straightforward to figure out that electromagnetism travels as waves at a constant speed: the "speed of light."  If we didn't have sight, we'd probably call it the speed of radio or the speed of x-rays or something like that.
 

Offline CliffordK

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Re: Could sightless beings determine the speed of light?
« Reply #6 on: 14/04/2014 21:28:36 »
All EM waves travel at the speed of light.  So, an "intelligent" species likely would have developed radio and wireless communication, and may choose to further investigate the properties of those waves.

Certainly communication delays between Earth and the Voyager probes, or even the martian rovers would pose a problem.  However, the species may identify the sun, but may have difficulties identifying other planets or stars, so there may be less deep space exploration.
 

Offline David Cooper

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Re: Could sightless beings determine the speed of light?
« Reply #7 on: 14/04/2014 22:03:44 »
I don't know how they would differentiate "cold heat" from room temperature in a dark room.

I'm imagining sightless scientists exploring the infrared light they can feel, making detectors for it and measureing its frequency, then discovering frequencies outside of the range they can feel, leading to the discovery of "cold heat" - what to us is visible light but to them is both unseen and cold. They could over time use it to make lasers to write to optical data storage devices, all without being able to see the light, just as we can't see the magnetism we use to store data to hard drives.

Quote
Further, I don't see (sorry) how they could differentiate heat from a nearby source compared to that of a distant source without an additional stimuli like smoke, or the sound of a fire crackling.  Lacking the additional stimuli sometimes accompanying a "nearby" source of heat it would seem impossible to determine the distance to the source, thus no ability to calculate speed.

How about walking nearer to a fire and feeling the heat go up. An exciting discovery is made that the heat can be blocked with a simple, thin barrier, at which point some clever individual asks the key question: how quickly is it blocked? How long does it take for the heat to radiate from the fire to us? What is the speed of radiated heat?

It's all open for them to discover. The real difficulty is how they'll make progress if they can't see, but maybe they would have echo-location capabilities instead and still be able to advance at a fair pace. Key developments like writing would likely be delayed though because they won't be able to see patterns on flat things, but they may still be able to develop something like Braille - it's just more awkward and less likely to happen.
« Last Edit: 14/04/2014 22:05:16 by David Cooper »
 

Offline alan hess

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Re: Could sightless beings determine the speed of light?
« Reply #8 on: 14/04/2014 23:16:55 »
It's not much different from man. We can't see radiation, yet we experiment with it. Most likely a sightless race would live on a dark world, so when he sunlight that hits them, they would feel it.
 

Offline bcs4

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Re: Could sightless beings determine the speed of light?
« Reply #9 on: 14/04/2014 23:34:05 »
David,

My question here is now moot because you have perfectly answered my multi-speed Photon question.  Again, many thanks.  I look forward to many sleepful nights.

However, your confidence in the blind beings is misplaced.  ((self-assured buffoon face representing me) again, not comfortable with emoticons)
 

Offline David Cooper

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Re: Could sightless beings determine the speed of light?
« Reply #10 on: 15/04/2014 18:58:53 »
I don't have huge confidence in blind beings achieving all that, but it would not be impossible for them to do so - just a lot harder than it was for us.
 

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Re: Could sightless beings determine the speed of light?
« Reply #10 on: 15/04/2014 18:58:53 »

 

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