Recent comments in /f/space

UmbralRaptor t1_j2bsqdb wrote

Water (in the form of ice) is quite common in the outer solar system. Water shortages in the present/near future are more about clean water.

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wokeupatapicnic t1_j2brwdu wrote

Pretty sure you just described the Firewall theory. I think Hawking proved that or at least was able to suggest that, this is not the case, but it’s worth looking into on your own if you’re interested!

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Yippeethemagician t1_j2brv7a wrote

Yes it is. Because alot of people incorrectly believe that there is something magical about nuclear power. It just boils water. That waste stays for a long time, in the thousands of years. They aren't able to deal with it now, and I don't see anyone being able to deal with it later. Hangout at a nuke plant sometime. Be amazed and horrified with how much the Simpsons got right.

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wokeupatapicnic t1_j2br80d wrote

Mostly correct. You’d see the universe progressively move fast and faster towards infinite motion until the “light-death” of the universe. Again, that is provided you were able to perceive and maintain thought during the process. But yes, you would not feel like you were moving in slowmo or anything, but everything outside of the BH would begin happening faster and faster and faster as you blinked out of existence

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incarnuim t1_j2bqwv2 wrote

The probe wouldn't notice a significant change. In fact it would be really tough for the probe to pinpoint when or even IF it had actually crossed the EH.

But you wouldn't get the probe back, you wouldn't get any signals, and you wouldn't feel any significant change in forces. The probe would just be gone (from your PoV). Meanwhile the probe would think it was still attached and sending back data, but the data never gets there....

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jaydfox t1_j2bqat6 wrote

Haha, no, but I do watch a fair amount or space channels (PBS Space Time, Dr. Becky, Anton Petrov, etc.).

One thing worth mentioning is that you'll eventually be spaghettified, no matter how big the black hole is. If a stellar mass black hole has an event horizon of about 3 km (I think, not positive), then a 1 million stellar mass black hole would have an event horizon of about 3 million km. But only when you get within 300 km of the singularity, would the tidal forces be as strong as at the event horizon of the stellar mass black hole. For the largest known black hole (66 billion solar masses, off the top of my head, but maybe there's a bigger one), the event horizon would be about 200 billion km in radius, about 2% of a light-year (so 0.04 light-years in diameter). But the tidal forces wouldn't be as strong as at the event horizon of a stellar mass black hole, until you were about 12,000 km from the singularity. This is due to the rapid decay of tidal forces with distance.

So in that sense, the person you were replying to was right. You will be spaghettified before you get anywhere near the hypothetical singularity, no matter how big. But with a big enough black hole, you'd get pretty deep into the black hole before you get ripped apart. Long enough to make interesting observations. Which is what the OP was asking about. What would you see if you fell into a large enough black hole? Long after you've crossed the event horizon, and long before you get close enough to the singularity to be ripped apart by tidal forces. I assume you would see stuff that fell in right after you, and stuff that fell in right before you. (If not, that implies you wouldn't even see your feet after they went in, if you went in feet first. And I seem to recall several different authors saying you would hardly notice yourself pass through the event horizon.) How much longer before and after? I assume the cosmic background radiation behind / above you would be blue shifted from microwave into infrared, visible, eventually ultraviolet, xrays, etc. Whether you get ripped apart before witnessing that, I don't know. I'd like to know.

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capmap t1_j2bq8ln wrote

For a black hole of sufficient size such as a SMBH, GR states there's a gentle fall (at light speed, lol) until the inner event horizon. QM states you're destroyed at the event horizon by a firewall of radiation.

I'm not going to profer which one is accurate and then go on a riff on that one theory when any matter have already been vaporized.

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