I have to wonder how this slowing down of time affected the Universe when it was still an inconceivably dense point that suddenly went into inflation mode, where and when time dilation must have been nearly as extreme as in the immediate proximity of an event horizon.
And how has any black hole in the Universe grown in mass at all in the past 13 billion years if time stops there? Any matter within the event horizon should be falling towards the singularity but frozen in time, frozen in its’ fall, never quite making it there.
How does any supernova ever even finish collapsing into a singularity?
The way I understood it way back when I was taking basic physics in college was thus (simplified): Time for the particle at relativistic speeds / gravities moves slower compared to a far away observer unbound by such influences. Like the twin siblings paradox. So a particle past the event horizon of a black hole would basically cease to experience time, but if we could see it, it would move otherworldly fast into it.
I have several astronomer friends from Spain, from where I’m standing it’s one of the world’s great academic “hot spots” for good astronomy.
Not only that, but one of these friends specializes in Active Galactic Nuclei and Blazars, I even entered the article hoping it was my friend. Cue Ron Howard narration voice: “It wasn’t.”
It’s interesting how the article you linked presents the conclusion
microbial life is not ruled out by the new results; but the fact is that the original Labeled Release results make sense with the chemistry of Martian soil as it’s now understood, no microbial life needed.
the chlorine component of the chlorobenzene is martian, and the carbon molecule of the chlorobenzene is consistent with a martian origin, though we cannot fully rule out instrument contamination.
Which would seem to be the same thing but with opposite probability biases. Your link is twisting its source material.
If there was life there 50 years ago there's good chances it has survived til today. Afaik there hasn't been any change in mars that would eradicate whatever life there is. We mightve killed the single organism we found but if we found one we can find more.
At first, the title of the post made me think that we killed all (possible) life on Mars, not just in the samples taken, just by having landed there and contaminated the planet. Now that would have been a true tragedy.
Some pretty interesting ideas. I was unaware that anything was living in the Atacama salt deposits, which certainly lends some credence to the idea that something could be pulling moisture out of the air on Mars, thin as it is.
I remember reading some article about deserts, and how, even when they seem completely empty of life, they actually have entire tiny fragile ecosystems living just under the sand. The article was in favor of imposing restrictions on dune buggies in a couple deserts where the activity was growing out of hand, because wherever the buggies went, that fragile ecosystem was just wiped out. And with the harsh conditions, it takes a really long time for them to recover.
Yeah, cryptobiotic crust! I’ve seen it in the Sonoran desert. It doesn’t look like much, I think if I hadn’t been warned ahead of time not to step on it I might have just done it without thinking. Given that just footprints can take on the order of decades to heal I think a dune buggy ban makes sense in areas where it grows.
I’m still surprised to learn about the microbes in the Atacama: it’s the driest place on earth, and I would have expected the salt deposits to make it even harder for anything to live there. Yknow what they say I guess: “Life, uh, finds a way.”
I can’t even fathom something like this. There’s so much energy involved. Can you imagine how bright matter around the black hole is? And there’s people who believe reaching relativistic speeds will be possible soon…
Black holes aren’t luminous except when matter is falling into the event horizon. So unless one of these was tearing through a nebula we probably wouldn’t see it.
So: they thought the discrepancy had to do with possible errors in the measurement of Cepheid Variables as standard candles, when extrapolated with the more luminous and usually distant Type Ia Supernovas as standard candles, but JWST just confirmed that previous measurements of Cepheid Variables have in fact been correct and reliable.
Is this an accurate summary of the article?
Over the last several years, cosmologists have had to grapple with an unyielding conundrum. The expansion rate of the universe, also known as the Hubble’s constant (H0), has two different values depending on how you measure it, either with the echo of the Big Bang or with stars and galaxies. Researchers have now improved the precision of the second method, making the tension so much worse.
One of the key elements of the measurements is the calibration of Cepheids stars. The true luminosity of these stars fluctuates over a defined period, so by measuring said period and the brightness we see, it is possible to work out the distance of these objects. You could do the same with a distant lightbulb as long as you knew what wattage it was.
The method using the Cepheids is known as the cosmic distance ladder, and it has an estimated value of 73 kilometers per second per megaparsec (a megaparsec is equivalent to 3.26 million light-years). This means that if two galaxies are 1 megaparsec apart, they would appear to be moving away from each other at a speed of 73 kilometers (45 miles) per second.
“Our study confirms the 73 km/s/Mpc expansion rate, but more importantly, it also provides the most precise, reliable calibrations of Cepheids as tools to measure distances to date,” senior author, Richard Anderson, from the Ecole Polytechnique Federale de Lausanne, said in a statement.
By using the cosmic microwave background, as measured by the European Space Agency’s Planck space telescope, the expansion rate is 67.4 ± 0.5 km/s/Mpc. The discrepancy of 5.6 km/s/Mpc could either signify that there is an issue with the way we measure things, or that there is something deeply wrong with our understanding of the universe.
"Suppose you wanted to build a tunnel by digging into two opposite sides of a mountain. If you’ve understood the type of rock correctly and if your calculations are correct, then the two holes you’re digging will meet in the center. But if they don’t, that means you’ve made a mistake – either your calculations are wrong or you’re wrong about the type of rock,” explained Anderson.
“That’s what’s going on with the Hubble constant. The more confirmation we get that our calculations are accurate, the more we can conclude that the discrepancy means our understanding of the universe is mistaken, that the universe isn’t quite as we thought.”
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