Things you always wanted to know the answer to [Vol. 3]
Discussion
ukaskew said:
How are these big concrete blocks held in place?
I walk directly underneath those blocks on a 23m tower crane every day at the moment to get to my office. My non-engineering brain is uncomfortable with the fact that there is nothing beneath them holding them in place.
On the plus side, if they did let go, I wouldn't feel a thing. Has it ever happened?
They are shaped like a capital T so the top is wider than the base, although from most viewing angles that is hard to see as you are looking up at themI walk directly underneath those blocks on a 23m tower crane every day at the moment to get to my office. My non-engineering brain is uncomfortable with the fact that there is nothing beneath them holding them in place.
On the plus side, if they did let go, I wouldn't feel a thing. Has it ever happened?
Funkycoldribena said:
ukaskew said:
How are these big concrete blocks held in place?
I walk directly underneath those blocks on a 23m tower crane every day at the moment to get to my office. My non-engineering brain is uncomfortable with the fact that there is nothing beneath them holding them in place.
On the plus side, if they did let go, I wouldn't feel a thing. Has it ever happened?
Cable ties.I walk directly underneath those blocks on a 23m tower crane every day at the moment to get to my office. My non-engineering brain is uncomfortable with the fact that there is nothing beneath them holding them in place.
On the plus side, if they did let go, I wouldn't feel a thing. Has it ever happened?
The universal attachment tool.
schmunk said:
SpeckledJim said:
Walking to the front of a 747 doing 500mph (so doing 503mph) is the same effort as walking to the front of a stationary 747 (so doing 3mph).
Only when you're on the inside.tribalsurfer said:
schmunk said:
SpeckledJim said:
Walking to the front of a 747 doing 500mph (so doing 503mph) is the same effort as walking to the front of a stationary 747 (so doing 3mph).
Only when you're on the inside.tribalsurfer said:
schmunk said:
SpeckledJim said:
Walking to the front of a 747 doing 500mph (so doing 503mph) is the same effort as walking to the front of a stationary 747 (so doing 3mph).
Only when you're on the inside.But it wouldn't be of any consequence to you or anyone else as you're only doing 3mph through the 'stationary' air inside the plane, so you won't tell any difference.
Having a chat inside Concorde at Mach 2 is the same experience as having a chat inside Concorde when it's sitting at the gate, because the air in the plane is 'still' relative to the occupants, in both cases.
Shakermaker said:
Only relative to the surface of the earth. But then the earth already spins at a rate much faster than the speed of sound and travels through the universe even faster than that, so its a moot point. You personally are only travelling at 3mph relative to your surroundings.
If the aeroplane is doing 99% of light speed, and I run through it at 99% of light speed, and an observer on the ground with very sharp eyes looks through the windows of the plane - will they see me running at 198% of light speed (i.e. they'll see me running before I actually run?) a said:
If the aeroplane is doing 99% of light speed, and I run through it at 99% of light speed, and an observer on the ground with very sharp eyes looks through the windows of the plane - will they see me running at 198% of light speed (i.e. they'll see me running before I actually run?)
I have no idea - you're into the realm of theoretical physics now a said:
Shakermaker said:
Only relative to the surface of the earth. But then the earth already spins at a rate much faster than the speed of sound and travels through the universe even faster than that, so its a moot point. You personally are only travelling at 3mph relative to your surroundings.
If the aeroplane is doing 99% of light speed, and I run through it at 99% of light speed, and an observer on the ground with very sharp eyes looks through the windows of the plane - will they see me running at 198% of light speed (i.e. they'll see me running before I actually run?)Ayahuasca said:
You have two spacecraft traveling one behind the other at a distance of say a mile.
They are both traveling at the speed of light.
If the second spacecraft flicks on a headlight pointed at the first spacecraft, does the light reach the first spacecraft?
Are they on a treadmill?They are both traveling at the speed of light.
If the second spacecraft flicks on a headlight pointed at the first spacecraft, does the light reach the first spacecraft?
Ayahuasca said:
You have two spacecraft traveling one behind the other at a distance of say a mile.
They are both traveling at the speed of light.
If the second spacecraft flicks on a headlight pointed at the first spacecraft, does the light reach the first spacecraft?
My understanding is that they can't travel at the speed of light, but 99.99999% is theoretically possible.They are both traveling at the speed of light.
If the second spacecraft flicks on a headlight pointed at the first spacecraft, does the light reach the first spacecraft?
And yes, if you're in the rear spacecraft, you will see the headlights lighting up the rear of the front spacecraft. The light from the headlights will travel at the speed of light relative to the headlight unit.
What I don't understand is what happens if there's a signpost at the side of the "road" - will the headlights light up the signpost? From the signpost's perspective the light is travelling at nearly double the speed of light... which isn't possible?
a said:
What I don't understand is what happens if there's a signpost at the side of the "road" - will the headlights light up the signpost? From the signpost's perspective the light is travelling at nearly double the speed of light... which isn't possible?
Why double when the light is coming from a single spaceship travelling at near light speed ?Ayahuasca said:
You have two spacecraft traveling one behind the other at a distance of say a mile.
They are both traveling at the speed of light.
If the second spacecraft flicks on a headlight pointed at the first spacecraft, does the light reach the first spacecraft?
A problematic hypothetical because nothing with mass can travel at light speed!They are both traveling at the speed of light.
If the second spacecraft flicks on a headlight pointed at the first spacecraft, does the light reach the first spacecraft?
Remember you have length contraction so your "mile" wont be a mile at all, it will be something Im not smart enough to calculate.
Oh and time dilation which means at light speed, time stops. So the idea of anything temporal happening doesnt make sense either.
Ayahuasca said:
GroundEffect said:
A problematic hypothetical because nothing with mass can travel at light speed!
Only if you believe Einstein.And pretty sure I heard the other day that they had discovered a particle that seems to travel faster than light.
Special relativity has been shown to be correct thousands, if not millions of times!
I like the second point of your post - just casually throwing out statements for our current model of the universe being wrong
I'd like a link if you have one - guessing it is Neutrino related?
GroundEffect said:
Well isn't your whole question based on his relativity...?
Special relativity has been shown to be correct thousands, if not millions of times!
I like the second point of your post - just casually throwing out statements for our current model of the universe being wrong
I'd like a link if you have one - guessing it is Neutrino related?
I think I heard it on Radio 4 when I was half asleep... so it could have said anything really Special relativity has been shown to be correct thousands, if not millions of times!
I like the second point of your post - just casually throwing out statements for our current model of the universe being wrong
I'd like a link if you have one - guessing it is Neutrino related?
Anyway, please can we assume for the purposes of my question that a) the speed of light is constant and b) the spacecraft both travel at the speed of light.
1) At speed of light time does not pass, therefore you cannot communicate with another ship as there's no time for the light to travel between the two ships
2) IF however both were at 0.99999c they would communicate between each other with no issue as the relative speeds are zero
2 is true because of relativity - just like a laser between earth and the moon is measured purely in the relative distance and speed, not any absolute speed compared to some fixed point in space or in the galaxy
2) IF however both were at 0.99999c they would communicate between each other with no issue as the relative speeds are zero
2 is true because of relativity - just like a laser between earth and the moon is measured purely in the relative distance and speed, not any absolute speed compared to some fixed point in space or in the galaxy
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