giga/tera hertz timer? super fast spinning disc?

Projects General Guidance
1

How would I go about detecting a very small amount of time dilation

I want to accelerate something and measure the time dilation ,even if I reach 1km/s time dilation is very small but it looks just barely within reach.

I'm currently thinking a spinning disc, but the numbers are all just a bit beyond what I know how to build. For the timer I obviously want maximum resolution.

I could spin a 0.6m diameter disc at 1000hz(60,000rpm).. I suppose... in a vacuum...errrrmmm... I'm trying not to kill myself.....

I want to test a hypothesis...
cosmic inflation redshift destroys energy
cosmic inflation create new space
new space has vacuum energy

HYPOTHESIS 1: expansion red-shift of certain energies(eg photons) has space-energy conservation. space to energy / energy to space conversion is occurring, and if you factor in space as energy there is conservation.

I roughly calculated the energy numbers and they fall within reasonable range, but I cant think of a way to test it except correlating expansion rate with radiation energy traversing various regions of spacetime,

So while I'm working on that I moved on to hypothesis 2, which is much more of a long shot, because relative velocity redshift doesn't have lost energy, the energy is conserved as momentum. But I figure if one form of redshift involves space-energy conversion then perhaps so do the other types of redshift.

Hypothesis 2 : All red/blue shifting includes an energy to space conversion. While traveling at high speed if light is emitted forward it is blue shifted and converts some space into energy, emit light backwards and it creates space.

So my plan is to arrange a time dilation test by accelerating a time counter. Sandwiched it between 2 powerful LED arrays, one facing forward and one facing backwards. check if time dilation is affected when light is emitted forward and/or backwards. (try both pointing at the counter and both pointing away, always aligned so lights are pointed parallel to motion vector)

2

If you can write the mathematics for the effects you are testing, then you probably belong in a large university with a whole department of technicians who can build the experimental apparatus for you.

What is the magnitude of the effect you are looking for? How much time dilation do you expect?

Have you looked into other experiments which have demonstrated the Einsteinian time dilation? Flying clocks on airplanes and satellites? I think there was even one experiment which showed different time at the top and bottom of a tall building. (The top is further away from the center of the Earth, so gets less distortion from the mass of the Earth.)

3

Physics aside an Arduino is not fast enough by many many magnitudes to do this sort of thing.

4

Grumpy_Mike:
Physics aside an Arduino is not fast enough by many many magnitudes to do this sort of thing.

Actually that's not true. I could just runt the apparatus for days or months per sample.. the longer I run it per sample the more resolution I get.

5

With an Arduino securely attached to the spinning disk, it will go exactly as fast as the disk does.

The trick with these kinds of measurements is to use a vernier or PLL effect, so you don't need a processor as fast as the signal being measured. GPS modules don't use GHz processors even though they are working with signals that travel at the speed of light.

6

MorganS:
If you can write the mathematics for the effects you are testing, then you probably belong in a large university with a whole department of technicians who can build the experimental apparatus for you.

What is the magnitude of the effect you are looking for? How much time dilation do you expect?

Have you looked into other experiments which have demonstrated the Einsteinian time dilation? Flying clocks on airplanes and satellites? I think there was even one experiment which showed different time at the top and bottom of a tall building. (The top is further away from the center of the Earth, so gets less distortion from the mass of the Earth.)

I am a Mechatronics, software, pcb, mechanics, construction, etc.. but my physics is amateur, best I have is "studied some MIT opencourseware"

I can not model it into existing quantum or classical models via pure formula, no.

I can think of ways to empirically test, If i first discover a measurable effect then I can work from there though.

But the data way is proving that it will require massive amounts of work and time, and /i am having trouble find relevant data

the experimental way is just an order of magnitude or two outside my grasp it seems.

it looks like its possible to get samples that might be long periods ( 20 mins per sample at least I think )

7

3,600,000rpm with a 60cm diameter disk?

angular velocity:
ω = θ/t
ω = 3.6E06 * 2π/60
ω = 376,991.12 rads/s

centripetal acceleration:
r = 0.3m
α = ω^2 * r
α = 376,991.12^2 * 0.3mm
α = 42,636,691,012.7 m/s^2
α = 4,346,247,809.6g

Do you have a specific material in mind that can sustain centripetal accelerations of 4.3 million g?

8

MorganS:
With an Arduino securely attached to the spinning disk, it will go exactly as fast as the disk does.

The trick with these kinds of measurements is to use a vernier or PLL effect, so you don't need a processor as fast as the signal being measured. GPS modules don't use GHz processors even though they are working with signals that travel at the speed of light.

cool. I will read into it asap.
THANK YOU!

any idea how fast they go?

9

Blackfin:
3,600,000rpm with a 60cm diameter disk?

angular velocity:
ω = θ/t
ω = 3.6E06 * 2π/60
ω = 376,991.12 rads/s

centripetal acceleration:
r = 0.3m
α = ω^2 * r
α = 376,991.12^2 * 0.3mm
α = 42,636,691,012.7 m/s^2
α = 4,346,247,809.6g

Do you have a specific material in mind that can sustain centripetal accelerations of 4.3 million g?

hmm.. looking into that.. I have worked on 50-100hz discs before, even acrylic works around 50hz (NOT SAFE DON'T TRY)

the equation looks like frequency squared is my problem... so I guess .. cringe.. I have to make the disc bigger

luckily it looks like timer frequency gets a boost, so that will help.

10

I would go for making the disc smaller instead. g forces go up maybe, but the total force may go down due to there being far less material in that disc.

There are lots of cheap DC motors that do some 10,000-20,000 rpm - that's 166-333 Hz. The small sprockets attached to them are perfectly fine, a (much larger) CD spun up to that speed would disintegrate. Still many orders of magnitude away from the speeds you're looking at.

I don't think that approach is feasible. You're probably much better off trying to measure frequency/wavelength (colour) shifts, or phase shifts. That's how GPS works, proving it can be done cheaply.

11

wvmarle:
I would go for making the disc smaller instead. g forces go up maybe, but the total force may go down due to there being far less material in that disc.

There are lots of cheap DC motors that do some 10,000-20,000 rpm - that's 166-333 Hz. The small sprockets attached to them are perfectly fine, a (much larger) CD spun up to that speed would disintegrate. Still many orders of magnitude away from the speeds you're looking at.

I don't think that approach is feasible. You're probably much better off trying to measure frequency/wavelength (colour) shifts, or phase shifts. That's how GPS works, proving it can be done cheaply.

I could instead of a timer put a laser, and detect redshift from a spinning laser.

The problem is I cant just spin it for longer time periods to increase my resolution.

I not only want to detect time dilation, but I want to detect small variance in that value

I have looked into some spectrum analyzers,
but I haven't found anything that can do this, and the ones I'm looking at atre already very expensive.

by measuring time dilation, I can just run it for long time periods to create a near infinite resolution.
I currently hope I will only need about half hour per sample

12

vasten:
Actually that's not true. I could just runt the apparatus for days or months per sample.. the longer I run it per sample the more resolution I get.

No, it doesn’t work like that. The longer the sample the more stable the clock has to be. Again by many many orders of magnitude the Arduino does not cut it.

13

Grumpy_Mike:
No, it doesn’t work like that. The longer the sample the more stable the clock has to be. Again by many many orders of magnitude the Arduino does not cut it.

I plan to use an external oscillator and use the arduino a data collection and storage system

maybe an oscillator, rollover counter, arduino

collect samples, sum up, deliver end count when external trigger received

thank you, you bring up a good point, I will have to look into maximum stability.

Although long term averages, while not guaranteed to be accurate, are not without their value if you get many samples and average them

14

I think you are missing the point, you have two things to worry about the stability of the oscillator and the accuracy of the oscillator. Using a normal crystal even an external one will only be accurate to 10 PPM at best, even if you use a crystal oven.

These sorts of experiments are normally done with atomic clocks, and good ones at that. Averaging is not going to help you.

15

Grumpy_Mike:
I think you are missing the point, you have two things to worry about the stability of the oscillator and the accuracy of the oscillator. Using a normal crystal even an external one will only be accurate to 10 PPM at best, even if you use a crystal oven.

These sorts of experiments are normally done with atomic clocks, and good ones at that. Averaging is not going to help you.

ok.. so how do i diy build an atomic clock :wink: hehe

I am looking for relative difference between samples from the same oscillator, so I don't care about hardware deviation from labeled frequency

And as per stability, how much of the instability is environment depended or oscillating? cause those wont affect long term samples from the same device.

16

MorganS:
What is the magnitude of the effect you are looking for? How much time dilation do you expect?

I am not sure.

at 1km/s I am only getting a very tiny time dilation, and I'm guessing that in the cosmic sense the amount of photons im emitting is small, so I am not sure, but I figure detecting a 1 millionth degree deviation in the time dilation value might be a good start. but i would settle for as low as 100 to start the experiment

17

I am looking for relative difference between samples from the same oscillator,

But how do you know? Without the oscillator being stable you can’t tell the difference between environmental changes changing the frequency and the time dilation effect you are looking for.
You need a stable reference to measure against and no amount of averageing gives you this.

18

Blackfin:
3.60,0000rpm with a 60cm diameter disk?

angular velocity:
ω = θ/t
ω = 3.6E06 * 2π/60
ω = 376,991.12 rads/s

centripetal acceleration:
r = 0.3m
α = ω^2 * r
α = 376,991.12^2 * 0.3m
α = 42,636,691,012.7 m/s^2
α = 4,346,247,809.6g

Do you have a specific material in mind that can sustain centripetal accelerations of 4.3 million g?

60,000rpm with a 60cm diameter disk?

angular velocity:
ω = θ/t
ω = 6.0E04 * 2π/60
ω = 6283.18 rads/s

centripetal acceleration:
r = 0.3m
α = ω^2 * r
α = 6283.18^2 * 0.3m
α = 11843525.28 m/s^2
α = 1,207,291.05 g

Still significant.

I want to accelerate something and measure the time dilation ,even if I reach 1km/s time dilation is very small but it looks just barely within reach.

I think this is why they use space vehicles travelling at massive speeds to test these dilation theories.

While traveling at high speed if light is emitted forward it is blue shifted and converts some space into energy, emit light backwards and it creates space.

The shifts are only relative to a stationary observer, doppler shift.
To the the object emitting the light, there is no shift.
So how can you consume and create space for the observer but not for the object?

Tom... :slight_smile:

19

TomGeorge:
60,000rpm with a 60cm diameter disk?

Dude's original post was suggestive of 3.6E+06 RPM. Has since been edited...

20

Grumpy_Mike:
But how do you know? Without the oscillator being stable you can’t tell the difference between environmental changes changing the frequency and the time dilation effect you are looking for.
You need a stable reference to measure against and no amount of averageing gives you this.

I always test new hardware before i use it of course. determine its tolerance and range etc..

Yes, it matters, but I am not sure what kind of instability to expect yet. Do you have an Idea as to what sort of deviation I might expect on 10 samples of 1 hours long at 1 ghz?

I don't see this info in any datasheets, do you know some terminology I can find to check this parameter?