Faster than light travel

Faster than light travel

Poll: Faster than light travel

Total Members Polled: 70

Just keep accelerating, Einstein was wrong.: 23%
Convenient wormhole.: 19%
Space warp.: 36%
Short cut via another dimension.: 23%
Author
Discussion

Dr Jekyll

Original Poster:

23,820 posts

262 months

Tuesday 23rd May 2017
quotequote all
Halmyre said:
Wasn't Newton's quote a sarcastic dig at someone (Hooke?) who had claimed that Newton was riding on the efforts of others?

+1

Hooke was a bit on the small side.

ATG

20,697 posts

273 months

Tuesday 23rd May 2017
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Ayahuasca said:
Doesn't gravity travel faster than light?
Nope.
Ayahuasca said:
Or, was the gravity that we experience now created in the past and has traveled to us at light speed?
This.

"The speed of light" is a bit of a misnomer because it isn't really a property of light. It's a property of space-time. It's the speed of cause and effect, man. Pass the doobie.

ATG

20,697 posts

273 months

Tuesday 23rd May 2017
quotequote all
Halmyre said:
Wasn't Newton's quote a sarcastic dig at someone (Hooke?) who had claimed that Newton was riding on the efforts of others?
"If I have seen further it is because I am standing on the shoulder of giants" ... or something like that, in a letter to Hooke. It has been interpreted as taking the piss out of Hooke, but they weren't at each others throats, Hooke wasn't a midget, so probably more of a good story than actually true.

tight fart

2,939 posts

274 months

Tuesday 23rd May 2017
quotequote all
Can you experience G force in zero gravity?

thebraketester

14,280 posts

139 months

Tuesday 23rd May 2017
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tight fart said:
Can you experience G force in zero gravity?
Yes.

Ayahuasca

27,427 posts

280 months

Tuesday 23rd May 2017
quotequote all
tight fart said:
Can you experience G force in zero gravity?
G force has nothing to do with gravity, it is just the effect of you trying to go in a straight line, and something (like the side of your seat) trying to go somewhere else. Newton's first law of motion I believe.

HaiKarate

279 posts

135 months

Wednesday 24th May 2017
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tight fart said:
Can you experience G force in zero gravity?
Of course. Acceleration and gravity are equal forces. They are indistinguishable from one another. So you just need a rocket pack in outer space to experience GForce.

annodomini2

6,874 posts

252 months

Wednesday 24th May 2017
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HaiKarate said:
tight fart said:
Can you experience G force in zero gravity?
Of course. Acceleration and gravity are equal forces. They are indistinguishable from one another. So you just need a rocket pack in outer space to experience GForce.
Actually they are different, not in a vector math sense, but in a physical sense, acceleration from a rocket is very different to acceleration in a gravitational distortion.

In the rocket the thrust is created at the back pushing on the rocket which pushes on the body and subsequently the seat you are sitting in, whereas under Gravity the force is acting on every particle (mostly) evenly, depending on the size of the distortion.

So in the Rocket you experience G-Force, in Gravity you don't until you hit the surface of the object causing the distortion.

thebraketester

14,280 posts

139 months

Wednesday 24th May 2017
quotequote all
Buy surely if you were in space and accelerating in a straight line at 9.8m/s/s , wouldnt the "force" effect to you feel exactly the same as the gravitational force when stood on the surface of the earth?

Einion Yrth

19,575 posts

245 months

Wednesday 24th May 2017
quotequote all
annodomini2 said:
acceleration from a rocket is very different to acceleration in a gravitational distortion.
Only if relativity is very, very wrong is this true. Now relativity is certainly not the whole story, and indeed may only be, like Newton's laws, an adequate approximation, but there is no reason to believe it's that far wrong; unless of course you have the maths to demonstrate it?

RobDickinson

31,343 posts

255 months

Wednesday 24th May 2017
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thebraketester said:
Buy surely if you were in space and accelerating in a straight line at 9.8m/s/s , wouldnt the "force" effect to you feel exactly the same as the gravitational force when stood on the surface of the earth?
Yep, identical

Dr Jekyll

Original Poster:

23,820 posts

262 months

Wednesday 24th May 2017
quotequote all
RobDickinson said:
thebraketester said:
Buy surely if you were in space and accelerating in a straight line at 9.8m/s/s , wouldnt the "force" effect to you feel exactly the same as the gravitational force when stood on the surface of the earth?
Yep, identical
Subtle difference surely, in gravity you are being pulled towards the centre of mass, standing on a accelerating platform it would feel although every part of your body was being puled in exactly the same direction. Not that you would notice the difference unless your gravitational force came from a very small dense object.
The force itself would be indistinguishable I agree.

RobDickinson

31,343 posts

255 months

Wednesday 24th May 2017
quotequote all
Dr Jekyll said:
Subtle difference surely, in gravity you are being pulled towards the centre of mass, standing on a accelerating platform it would feel although every part of your body was being puled in exactly the same direction. Not that you would notice the difference unless your gravitational force came from a very small dense object.
The force itself would be indistinguishable I agree.
Nope no subtle difference.

When on earth you are accelerate downwards towards a point at 9.8m/s. If a Rocket accelerated at 9.8m/s you would have the same acceleration to a point below you. How far away the point is is irrelevant.

g=F/m

thebraketester

14,280 posts

139 months

Wednesday 24th May 2017
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^^ agreed. It makes no difference

RizzoTheRat

25,247 posts

193 months

Wednesday 24th May 2017
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RobDickinson said:
Dr Jekyll said:
Subtle difference surely, in gravity you are being pulled towards the centre of mass, standing on a accelerating platform it would feel although every part of your body was being puled in exactly the same direction. Not that you would notice the difference unless your gravitational force came from a very small dense object.
The force itself would be indistinguishable I agree.
Nope no subtle difference.

When on earth you are accelerate downwards towards a point at 9.8m/s. If a Rocket accelerated at 9.8m/s you would have the same acceleration to a point below you. How far away the point is is irrelevant.

g=F/m
I'm with Dr Jekyll on that. If you were standing on a basket ball with the same mass as the earth (or something generating the same gravity anyway, as I can't remember what effect distance form centre of mass makes) you're going to be pulled towards the centre of the ball, so your shoulders aren't being pulled parallel. On a rocket all the forces are going to be parallel.

RobDickinson

31,343 posts

255 months

Wednesday 24th May 2017
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if the gravity point is tiny and literally at your feet then yes it might be different. Likewise if you are near a very strong gravity source ( black hole etc the difference in height between your feet and head would mean they experience different gravity.

But a rocket doesnt produce gravity.

It produces thrust and acceleration, which would mean the floor (as a whole) would be pushing upwards at 9.8m/s. Identical to standing on earth. (apart from the noise/vibration or whatever )

caelite

4,280 posts

113 months

Thursday 25th May 2017
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The goofyness occurs when you try to use centrifugal forces in place of gravity, as is the basis for many sci-fi spaceships. This will create a feeling similar to gravity when you are stationary, however when moving through a rotating mass the effects of the centrifuge will be extremely disorientating unless the centre of rotation is a good mile or so away.

colin_p

4,503 posts

213 months

Thursday 25th May 2017
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Dumbing it down.

Isn't Alpha Centuri, the nearest star other than our sun, three light years away? So it would take three years to get there if you could achieve light speed?

To make instellar travel viable then speeds many hundreds of times faster than light speed would have to be achieved to make it viable? But then what would would happen with the time dilation effects.

I also wonder if any alien civilisations are picking up any of our radio waves which in theory would have travelled out to a radius of maybe 70-80 light years since we started broadcasting. With some of the crap on the TV any aliens would think we are a proper bunch of nutters.

Sadly I think we are stuck here on Earth and at best within our solar system.

annodomini2

6,874 posts

252 months

Thursday 25th May 2017
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colin_p said:
Dumbing it down.

Isn't Alpha Centuri, the nearest star other than our sun, three light years away? So it would take three years to get there if you could achieve light speed?

To make instellar travel viable then speeds many hundreds of times faster than light speed would have to be achieved to make it viable? But then what would would happen with the time dilation effects.

I also wonder if any alien civilisations are picking up any of our radio waves which in theory would have travelled out to a radius of maybe 70-80 light years since we started broadcasting. With some of the crap on the TV any aliens would think we are a proper bunch of nutters.

Sadly I think we are stuck here on Earth and at best within our solar system.
4.2 ly

If you could exceed the speed of light time starts going backwards the effect exponentially increasing the faster you go.

Interstellar travel for humans will require a revolution in technology, so it may happen maybe not. We may not have the answer in our lifetime.

Einion Yrth

19,575 posts

245 months

Thursday 25th May 2017
quotequote all
caelite said:
The goofyness occurs when you try to use centrifugal forces in place of gravity, as is the basis for many sci-fi spaceships. This will create a feeling similar to gravity when you are stationary, however when moving through a rotating mass the effects of the centrifuge will be extremely disorientating unless the centre of rotation is a good mile or so away.
I suspect that one could get used to it, and it would definitely be better that the physiological effects of prolonged microgravity; a return to "normal" gravity would be, I suspect, somewhat nauseating however.