Relativity is Relatively Misunderstood

[heydaralon]

Luckily I only rely on it to make sure I break 10k steps a day.
Time travel is just an added perk.

Why not just run two miles? You should be able to maintain a daily run of around 1-2 miles without breaking down, and that's far better for you than steps.

Two reasons -
2 miles is only about 5.6k steps
My standard run is 3 miles in 25 mins

When I ran in high school (recreationally not for competition) I would go around this block that was about 3.2 miles. My personal best was 27 minutes. I was never much of a runner, but that is quite an impressive time DB, especially considering you are probably quite far from high school age. I usually do elliptical machines for cardio now in a futile attempt to save my joints, as I've always had flat feet. Impact stuff really messes me up, and my mom has had both of her knees replaced, so I'm in conserve mode. I do walk a few miles at night twice or three times a week while listening to a podcast. My metabolism has slowed down a bit, so I gotta get that cardio in somewhere.

[Speaker to Animals]

25 minutes is about average. That's where I come in on three miles, and I don't consider myself a fast runner at all. Nor was I talking about the time you can complete a run. I am saying: steps don't mean shit. What matters is the time during which your heart rate is elevated into aerobic range. Optimal running/walking for most people seems to be alternating between running and walking to keep the heart rate just above aerobic but not much higher. Aim for a set time in that aerobic range. If you follow a running training plan, then do this on your off days. You won't get splints as long as you avoid running fast and you only run until your heart rate goes back up and then switch back to brisk walking. If you do not train, then do this every day for an hour.

This focus on steps is WAY overrated.

[heydaralon]

25 minutes is about average. That's where I come in on three miles, and I don't consider myself a fast runner at all. Nor was I talking about the time you can complete a run. I am saying: steps don't mean shit. What matters is the time during which your heart rate is elevated into aerobic range. Optimal running/walking for most people seems to be alternating between running and walking to keep the heart rate just above aerobic but not much higher. Aim for a set time in that aerobic range. If you follow a running training plan, then do this on your off days. You won't get splints as long as you avoid running fast and you only run until your heart rate goes back up and then switch back to brisk walking. If you do not train, then do this every day for an hour.

This focus on steps is WAY overrated.

What are your thoughts on Crossfit? It seems to be adored and maligned equally. Many people swear by it, and many people detest it. I don't know what causes Crossfit to bring that out of people.

[Speaker to Animals]

25 minutes is about average. That's where I come in on three miles, and I don't consider myself a fast runner at all. Nor was I talking about the time you can complete a run. I am saying: steps don't mean shit. What matters is the time during which your heart rate is elevated into aerobic range. Optimal running/walking for most people seems to be alternating between running and walking to keep the heart rate just above aerobic but not much higher. Aim for a set time in that aerobic range. If you follow a running training plan, then do this on your off days. You won't get splints as long as you avoid running fast and you only run until your heart rate goes back up and then switch back to brisk walking. If you do not train, then do this every day for an hour.

This focus on steps is WAY overrated.

What are your thoughts on Crossfit? It seems to be adored and maligned equally. Many people swear by it, and many people detest it. I don't know what causes Crossfit to bring that out of people.

What can I add to the concept of "high intensity oly lifting" that would convince people how bad an idea this is?

[Martin Hash]

The problem with your question, Martin, is that it presumes constant speed, which means no relativistic time dilation.


To capture relativistic effects, you need constant acceleration. So assuming this ship was accelerating at 1 g the whole trip (flipping over at the midway point to accelerate away from Alpha Centauri in order to arrive at that system in order to reach a parking orbit)..


Alpha Centauri: 4.37 light years from Sol system.

δTearth = γ·δTship

γ = 1 / √ 1 - v2/c2
v - velocity of the star ship
c - speed of light in vacuum = 299,792,458 [meters/second]

http://convertalot.com/relativistic_sta ... lator.html


Time passed on Earth: 6.002906337443892 years.
Time passed on spaceship: 3.583014607222012 years.


It takes 4.37 light years for the light to reach Alpha Centauri, so the year on Earth when he observed late 2017 would be 2022. He left 6 years earlier from Earth's perspective (though only 3.5 years ago from his perspective). So he left Earth in 2011.


Because Alpha Centauri is so close, this is the only way this scenario is really possible. You have to accelerate up to 100% C and then again to match the relative velocity of Alpha Centauri system. Just maintaining a constant 1 g acceleration would get you to about 95% C at one point, and then you'd need to flip over and start accelerating down retrograde anyway.

It's the acceleration that causes time dilation, not a constant speed no matter how fast.

Assume the astronauts had the entire season of "Lost" on video and all 3 locations began playing it simultaneously: Earth, Alpha Centauri, astronaut. According to the numbers above; Earthmen & Alpha Centaurians would have finished but the astronaut would only be in season 4.

If the astronaut was broadcasting "Lost," reception on Earth would start out okay but then get slower & slower, eventually losing 2 seasons; and when the signal finally got to Alpha Centauri, it would also have to play slower and slower. Yet if "Lost" was broadcast from Earth, it would play at the same speed the whole time.

Apparently, acceleration is a Special Pleading to explain the time travel because if the astronaut was already traveling at lightspeed when he passed Earth, and kept going right on by Alpha Centauri, all the while broadcasting "Lost," Alpha Centaurians could watch without a slowdown.

[SuburbanFarmer]

Acceleration has nothing to do with time dilation. It’s about relative speed.

[Martin Hash]

Acceleration has nothing to do with time dilation. It’s about relative speed.

It's bullshit. ("Special Pleading" is a debate term that is an instant loser because it means you have to make an exception for the position you're taking.)

[SuburbanFarmer]

The problem with your question, Martin, is that it presumes constant speed, which means no relativistic time dilation.


To capture relativistic effects, you need constant acceleration. So assuming this ship was accelerating at 1 g the whole trip (flipping over at the midway point to accelerate away from Alpha Centauri in order to arrive at that system in order to reach a parking orbit)..


Alpha Centauri: 4.37 light years from Sol system.

δTearth = γ·δTship

γ = 1 / √ 1 - v2/c2
v - velocity of the star ship
c - speed of light in vacuum = 299,792,458 [meters/second]

http://convertalot.com/relativistic_sta ... lator.html


Time passed on Earth: 6.002906337443892 years.
Time passed on spaceship: 3.583014607222012 years.


It takes 4.37 light years for the light to reach Alpha Centauri, so the year on Earth when he observed late 2017 would be 2022. He left 6 years earlier from Earth's perspective (though only 3.5 years ago from his perspective). So he left Earth in 2011.


Because Alpha Centauri is so close, this is the only way this scenario is really possible. You have to accelerate up to 100% C and then again to match the relative velocity of Alpha Centauri system. Just maintaining a constant 1 g acceleration would get you to about 95% C at one point, and then you'd need to flip over and start accelerating down retrograde anyway.

It's the acceleration that causes time dilation, not a constant speed no matter how fast.

Assume the astronauts had the entire season of "Lost" on video and all 3 locations began playing it simultaneously: Earth, Alpha Centauri, astronaut. According to the numbers above; Earthmen & Alpha Centaurians would have finished but the astronaut would only be in season 4.

If the astronaut was broadcasting "Lost," reception on Earth would start out okay but then get slower & slower, eventually losing 2 seasons; and when the signal finally got to Alpha Centauri, it would also have to play slower and slower. Yet if "Lost" was broadcast from Earth, it would play at the same speed the whole time.

Apparently, acceleration is a Special Pleading to explain the time travel because if the astronaut was already traveling at lightspeed when he passed Earth, and kept going right on by Alpha Centauri, all the while broadcasting "Lost," Alpha Centaurians could watch without a slowdown.

If a transmitter were moving at the speed of light towards a target, then the target would receive the entire transmission at once, as the transmitter arrived.

But since we were discussing time dilation, a transmitter moving away from the receiver, such as Voyager I or II, will have a slightly more “spread out” signal to the receiver, without relativistic effects. However, due to time dilation, we can expect to receive it in even more “slow motion”. I’m sure that we could look this up on the inter webs to verify.

[Martin Hash]

It's okay to say "Lost" would play slower & slower on Earth while it was being broadcast by the astronaut, just as it would play faster on Alpha Centauri.

On Earth it would play slower and slower and finally finish in 10 years: the 6 years during the astronaut's transit, plus 4 years from playing the last second of the last episode of season 6 while arriving at Alpha Centauri. On-the-other-hand, the Alpha Centaurians would have had to wait 4 years for the first season to start then it would play too fast for 2 years until it ended when the astronaut arrived.

Earth: 10 years to finish show
AC: 2 years to finish show
The average of these is 6 years, the number of seasons in "Lost," hence, no time travel.

[Martin Hash]

If there was kooky time travel, it would take 12 years for "Lost" to finish its 6 season run: the progressively slower 6 years while the astronaut was in transit, plus the 4 years for the last second of the last episode of season 4, which is all the astronaut had time for since he was time traveling 4 years into 6, plus 2 more years of normal speed while the astronaut played the last two seasons from Alpha Centauri.

On the Alpha Centauri side: they would have to wait 4 years for "Lost" to start, then start out playing too slow because the astronaut was time traveling, but it would have to play faster & faster to get all the way to the end of season 4 when the astronaut arrived, then finish off the last two seasons watching the show with the astronaut at normal speed, for a total of 4 years.

Earth: 12 years to finish show.
AC: 4 years to finish show.
The average of these is 8, hence, time travel.