3 ms·

And unlike your standard light bulb, there's no need to worry about it getting dimmer with time - this one'll keep getting brighter until it disappears entirely

And unlike your standard light bulb, there's no need to worry about it getting dimmer with time - this one'll keep getting brighter until it disappears entirely!

sbierwagen 7y ago
Manufacturer's notice: the event horizon temperature goes up as well. By the time it has just five thousand years left, it'll be radiating super-energetic x-rays at (an average) 1.57 giga-electronvolts each. https://arxiv.org/pdf/0908.1803v1.pdf#15 https://arxiv.org/pdf/0908.1803v1.pdf#15
- perl4ever 7y ago
  Yeah, but that's after about ten trillion times the current age of the universe. For the next few billion years, it's going to remain 60 watts.
  - Roboprog 7y ago
    How would you detect something like that? A primordial black hole the mass of a small asteroid with a tiny absolute magnitude? If such a thing existed, there would likely be more than 1. How long would it take such an object to consume a star like our sun if it grazed or hit the star, vs a harmless hyperbolic flyby?
    - sbierwagen 7y ago
      Here's a Hawking radiation calculator that you can use to get an idea of some of the numbers involved: https://www.vttoth.com/CMS/physics-notes/311-hawking-radiation-calculator https://www.vttoth.com/CMS/physics-notes/311-hawking-radiati... Using this calculator, we find that a black hole with the mass of 433 Eros, 6.687E15 kg, would be quite hot, some 18 million kelvin, but emitting just 8 watts of power, and be 0.009 nanometres in radius. Pretty hard to find. Let's try something smaller. 162173 Ryugu, the rock that Hayabusa2 landed on, is only 4.5E11 kg. This gives you a much brighter hole: 1758 megawatts at 2.72657E11 kelvin. Interestingly, this may make it harder to detect! Its blackbody emission peak is at 9,211 KeV, and the Chandra X-Ray observatory only goes up to 10 KeV. (Focusing very-high-energy photons is not easy) You'd have to detect it from the fraction of total power it emits lower down in the spectrum.
- samus 7y ago
  Maybe some gamma-ray bursts are primordial black holes having their final death cry, with their emission spectrum moving into higher and higher frequencies?

And unlike your standard light bulb, there's no need to worry about it getting dimmer with time - this one'll keep getting brighter until it disappears entirely!

sbierwagen 7y ago

Manufacturer's notice: the event horizon temperature goes up as well. By the time it has just five thousand years left, it'll be radiating super-energetic x-rays at (an average) 1.57 giga-electronvolts each. https://arxiv.org/pdf/0908.1803v1.pdf#15 https://arxiv.org/pdf/0908.1803v1.pdf#15

perl4ever 7y ago
Yeah, but that's after about ten trillion times the current age of the universe. For the next few billion years, it's going to remain 60 watts.
- Roboprog 7y ago
  How would you detect something like that? A primordial black hole the mass of a small asteroid with a tiny absolute magnitude? If such a thing existed, there would likely be more than 1. How long would it take such an object to consume a star like our sun if it grazed or hit the star, vs a harmless hyperbolic flyby?
  - sbierwagen 7y ago
    Here's a Hawking radiation calculator that you can use to get an idea of some of the numbers involved: https://www.vttoth.com/CMS/physics-notes/311-hawking-radiation-calculator https://www.vttoth.com/CMS/physics-notes/311-hawking-radiati... Using this calculator, we find that a black hole with the mass of 433 Eros, 6.687E15 kg, would be quite hot, some 18 million kelvin, but emitting just 8 watts of power, and be 0.009 nanometres in radius. Pretty hard to find. Let's try something smaller. 162173 Ryugu, the rock that Hayabusa2 landed on, is only 4.5E11 kg. This gives you a much brighter hole: 1758 megawatts at 2.72657E11 kelvin. Interestingly, this may make it harder to detect! Its blackbody emission peak is at 9,211 KeV, and the Chandra X-Ray observatory only goes up to 10 KeV. (Focusing very-high-energy photons is not easy) You'd have to detect it from the fraction of total power it emits lower down in the spectrum.
samus 7y ago
Maybe some gamma-ray bursts are primordial black holes having their final death cry, with their emission spectrum moving into higher and higher frequencies?