Well, from the perspective of the photons, the explosion happened just an instant before they hit the telescope, and they barely even travelled a single Planck length to get from the exploding star to the telescope. Events that are so far apart in space and time don't have fixed periods (or distances).
To observers in other galaxies that are moving fast relative to both us and the star, the time between the explosion and our detection of it (were they able to perceive both) would also vary.
Are you saying that if I’m in a spaceship, and I travel at the speed of light as I leave that star at that moment, and then I arrive here at earth, with my fellow photons traveling next to me, that I will have arrived at earth instantly without observing any time spent in transit?
Obviously, given that, you would have no way of stopping, so your arrival would be abrupt (ignoring whatever magical affects would be necessary to accelerate a massive object to light speed).
So in other words, if you can travel at the speed of light, you can be anywhere in the universe instantly, and never have to wait to get anywhere? I will say, that certainly makes no sense to me.
it's a big "if"; it's not possible for objects with mass to accelerate to light speed.
If you were able to do so, yes you could "get" anywhere in zero subjective time - as mentioned earlier, since no time passes for you, there would be no way for you to decide that you wanted to stop travelling at light speed - you would end your existence by impacting something.
> that certainly makes no sense to me
Humans, as a species, aren't experienced with relavitistic effects; we have no useful inherent intuition as to how things behave at these sorts of speeds. Most of us have to accept the maths and the experiements that demonstrate that our understanding of this behaviour is accurate.
And you having a rest mass cannot ever reach the actual speed of light, only a factor of <1.
If you were to travel with 95% of the speed of light your rest mass would increase by 3.2x ... at 99% by 7.1x at 99.9% by 22.4x and at 99.99999% by 2240x and so on. The Lorentz factor is infinite for the speed of light. Time "stops" and the object contracts to "zero" at c.
If you move fast enough, weird things happen in special (or general) relativity.
Similarly, if you somehow managed to send something even slightly faster than the speed of light, there's a frame of reference in which you have send it backwards in time.
Perhaps one of their planets released a probe that will attach to a future intelligent life form and tell their story. [1] How many years until we potentially find it?
We see supernovae regularly and observe the aftermath within days of the event. What is special about this one is that TESS happened to be observing it before the explosion.
Some sources claim that about one star per year in Milky Way dies. We have about 100 billion visible galaxies, so roughly 3000 stars per second die in our visible universe - however, most of those are small stars which aren't really visible to our instruments.
Headline is a physical impossibility to occur (if we assume astronomers in our solar system), or a practical impossibility to know about (if we assume otherwise).
Pedantically, we can't actually witness anything at the same moment it happens for the same reasons. Our brains trick us into thinking we are... but it turns out all of us are behind the times.
I think the headline provides the necessary punch of what was so cool about this observation; "We" watched it evolve instead of just looking at the aftermath.
>Pedantically, we can't actually witness anything at the same moment it happens for the same reasons.
the best kind of antically, when I first read the title I snorted as everyone else and rushed in to observe the obvious (ironic given the subject) but your observation brought me up short - then again observations that are only milliseconds in remove from the occurrence as opposed to millions of light years may be given a pass about the 'same time' crack.
