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Comment by analog31 | Hacker News Reader

This issue is raised whenever there's a discussion of things happening at a great distance. In my view, a convention of reporting the time when something is observed on earth, and maybe the distance if it's not commonly known, is a reasonable one. Anybody is free to convert the number to their preferred reference frame.

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It is always mind-blowing to remember that in the astronomical scale, it is impossible to know things that are happening right now or relatively recently by our standards unless there is information traveling faster than the speed of light, which is something that at this point remains purely in the realm of science fiction as far as we know.

A new conspiracy theory claims that the government or whatever is lying about the distance from the earth to the sun. I think for less intelligent people the size of the universe and its objects is too much to handle

I think it could be argued that in certain specific scenarios, this shortcoming (in normal scenarios) can be advantageous, such as thinking outside the boundaries or constraints of a box, where the constraints happen to be incorrect but culturally axiomatic and are thus insurmountable for normal, "proper" thinking people.

Having observed many thousands of discussions about "conspiracy theory" or "just wrong" (but the normal person can't explain why it is wrong, in fact) topics, I am very confident in this belief. And now having also had some similar conversations with ChatGPT, which is able to overcome with ease many mistakes that humans make, yet cannot overcome others, I am even more convinced.

Thinking outside the box sounds like coming up with new ways of doing things or being creative. I don't see how this is related to conspiracy theories, people are just mostly just hearing them from other people

Here’s NASA misstating the distance between the Earth and the Sun: https://www.nasa.gov/sites/default/files/files/YOSS_Act1.pdf

Obviously the Earth’s orbit is noncircular. Is that what you mean?

At some astronomical scales numbers like this don’t matter. Sure, if you’re doing parallax calculations you need precise orbits, but most of the time you can assume π = 3.

Misstatement is different from lying, no?

This says the distance is 93m miles. That's about what the distance is

I'm referring to people who think it's like a few thousand feet above the earth.

It's even more mind-blowing to remember that on that scale, the concept of "things happening at the same time" does not exist, because the reference frames don't allow for it.

That's so bizarre: Stand here, thing A happened before thing B. Stand over there, thing B happened before thing A. Stand at this other place, now they did happen at the same time, but only for you! Nobody's more right than the other. Universally, "same-timeness" (simultaneity) does not exist.

So, by asking for:

> to know things that are happening right now or relatively recently by our standards

You're really only asking for your particular flavor of "right now or relatively recently".

Where they stand does not matter. If those three observers do not move in relation one to another, they will see events in the same order.

You're right. I meant they are each standing in their own reference frame, so effectively they are moving with reference to each other, but I guess that wasn't entirely clear. For example: One observer is on Earth, the other on another planet outside the solar system.

This is actually not true. Look at the following constellation:

A--1--B--2--C

Imagine 1 and 2 are satellites and observer B launches a rocket at both of them at the same time. From B's perspective, both satellites explode at the same time.

A, however, will see 1 explode before 2. C, on the other hand, will see the reverse, that 2 explodes first.

There's no right ordering here, just different reference frames.

If Alice, Bob, and Charlie knows distance to satellites, then they can calculate the true timestamps of events. Alice will register explosion of satellite 1 at time Ta1 and distance Da1, satellite 2 at time Ta2 and distance Da2, and so on, then Alice will subtract time of propagation to receive true timestamps and will see that `Ta1 - Da1/c = Ta2 - Da2/c`.

The key idea is that there is no true timestamp. This is really hard to get across in simple examples, because we almost always describe the example from an objective, external viewpoint, and then start discussing how things appear from different perspectives in the example. But the supposedly "objective" viewpoint is just a different viewpoint that we've invented, it is no more accurate than either of the other ones.

So yes, Alice, Bob, and Charlie can all calculate the timestamps relative to the other positions, and they could collectively decide together that one of those options will count as the "true" measuring point. But this is still a measurement decision that they have made.

True, and any other "true" measuring point would be just as right. Hence, no simultaneity in the universe.

It's always possible to create shared clock between two points and keep it accurate, then measure time of events A and B according to the clock.

That’s some beautiful hand waving in regards to creating a shared clock.

I’m an idiot and would love to know how this would be possible.

Then you reunite the clocks and discover they show completely different time!

For this reason, I also don’t see how we could ever travel at faster than light speeds because we wouldn’t have the information that we won’t crash into something at the other end.

Yes, but I think once we reach that point we'd also be sending out some sort of mapping probes to gather data so you know where obstructions are. And since lots of things don't just sit still, they'd have to be constantly reevaluated somehow. Maybe sensors sending out data of what lies ahead kind of like our GPS. It will be an interesting issue to solve if we make it that long. But looking at how we're doing in our infancy with "self driving," we quite a long ways off lol.

In the Dune novel, the solution for this was a kind of evolved/specialized human kind that was able to see a bit into the future (with the help of a "drug", the Spice). Only this kind of "human" could be a pilot of a faster-than-light spaceships.

FTL rocket will be able to hit photons emitted from objects, thus it will be able to see in the direction of movement. Headlight will not work, of course.

It's mind boggling for me too, and I even took special relativity in college. The only reassurance is that for now, it's not of too much practical importance. The limitation of traveling at the speed of light is not a technological barrier for us yet, likewise the posted speed limits are not a limitation when I'm on my bicycle.

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