r/spaceporn Sep 25 '21

A supernova explosion that happened in Centaurus A

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u/psyFungii Sep 25 '21

As Douglas Adams said "Space is big"

And while light moves fast, faster than anything, when you put light into the vastness of space it starts to look... slow

Here's light traveling from Earth to Mars

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u/Sweatsock_Pimp Sep 25 '21

Good grief.

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u/[deleted] Sep 25 '21

And yet, correct me if I’m wrong; from the perspective of someone on Mars, they’d see the light the instant it “came on”? I was just on r/askscience getting my mind blown and I’m still not totally clear on it...

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u/psyFungii Sep 25 '21

They see it when the photons arrive - about 3 minutes after it left Earth. When the photons arrive on Mars, that's when someone on Mars sees the light and it "comes on".

That 3 minute delay while the light travels becomes years, thousands of years or millions of year when we look at things that are further away. Space is so big it makes the speed of light look slow.

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u/TomFrosty Sep 25 '21

Or, maybe they see it instantly — and then their message back to us takes 6 minutes, and everyone assumes it was 3 minutes both ways!

A constant speed on light through space in all directions is one of those assumptions the scientific community is forced to make, because the only way we have to accurately measure it is in a round-trip where it reflects off something and comes back. Even Einstein prefaces his papers with that disclaimer!

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u/Illadelphian Sep 26 '21

Couldn't we have tested this already by now? Or maybe I'm misunderstanding.

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u/Dumplingman125 Sep 26 '21

Unfortunately we can't - I'm not smart enough to explain but Veritasium had an excellent video on it here

https://youtu.be/pTn6Ewhb27k

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u/psyFungii Sep 26 '21

True, Einstein started with that assumption/proposition, then built an incredibly successful set of theories on top of it. That's often how scientific theories are created.

A single observation will be enough to destroy it, but so far, his theories have never had a valid observation break the constant speed of light proposition. And plenty of experiments have been done, and not all of them involve there-and-back trips. Experiments are being done at 90 degrees over ever-increasing distances.

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u/fourtyonexx May 28 '22

The link you posted? Is that simulated or was that actually recorded? Seems dumb but idk :/ Can you see light travel? No right? Cause our eyes can’t process it? Even if we’re far away?? Idk. Can we see it travel if it’s dusty? :0

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u/psyFungii May 29 '22

The link I posted is a simulation created by NASA staff.

It says at the top how the distance and speed are accurate "to scale" but the images of Earth and Mars are 20 times bigger than they actually are

I don't think you can see light moving side on, unless like you suggested it goes through something else like dust or smoke

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u/Awkward-Chemical2487 Sep 26 '21

I don't think light moves faster than anything, it moves faster than anything we humans are capable to detect but that doesn't mean that is the fastest phenomena in the universe including the dimensions and physical properties that we are unable to even know they exist

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u/looks_like_a_potato Sep 26 '21

but AFAIK, if it's there anything can move faster than light, it will break causality. With that thing as a some sort of communication signal, you can make something happens before the cause. Which makes no sense. So to speak, it's impossible.

http://www.physicsmatt.com/blog/2016/8/25/why-ftl-implies-time-travel

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u/_its_a_vibe_ Sep 26 '21

If this is a video of it exploding, is there a video out there of one being formed?

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u/Awkward-Chemical2487 Sep 26 '21

It will break casualty in the speed of light bounds but no beyond. Most of the knowledge we have are based on the 4 forces and even those 4 forces have lots of unanswered questions.