Stop giving the manufacturers ideas...
Stop giving the manufacturers ideas...
We've almost reached the limits of physics
So you mean I can have a computer that is approaching the limits ofLandauer's principle. Where does one find these mythical machines as I would love one that has the computational power of my desktop yet runs for years off of a single AA battery.
If it bleeds it leads.
has been around for a long time.
One of the consequences of the second law of thermodynamics is that a certain amount of energy is necessary to represent information. To record a single bit by changing the state of a system requires an amount of energy no less than kT, where T is the absolute temperature of the system and k is the Boltzman constant. (Stick with me; the physics lesson is almost over.)
Given that k = 1.38×10^-16 erg/Kelvin, and that the ambient temperature of the universe is 3.2 Kelvin, an ideal computer running at 3.2K would consume 4.4×10^-16 ergs every time it set or cleared a bit. To run a computer any colder than the cosmic background radiation would require extra energy to run a heat pump.
Now, the annual energy output of our sun is about 1.21×10^41 ergs. This is enough to power about 2.7×10^56 single bit changes on our ideal computer; enough state changes to put a 187-bit counter through all its values. If we built a Dyson sphere around the sun and captured all its energy for 32 years, without any loss, we could power a computer to count up to 2^192. Of course, it wouldn't have the energy left over to perform any useful calculations with this counter.
But that's just one star, and a measly one at that. A typical supernova releases something like 10^51 ergs. (About a hundred times as much energy would be released in the form of neutrinos, but let them go for now.) If all of this energy could be channeled into a single orgy of computation, a 219-bit counter could be cycled through all of its states.
These numbers have nothing to do with the technology of the devices; they are the maximums that thermodynamics will allow. And they strongly imply that brute-force attacks against 256-bit keys will be infeasible until computers are built from something other than matter and occupy something other than space.
I want crypto that has a good chance of outlasting the heat death of the universe even with a quantum computer. For symmetric key crypto this means you would need somewhere around a 601 bit keyspace IIRC before you exceed the mass energy of the universe.
Name one study offering a credible alternative explanation for observed phenomena.
As AC said, not necessarily for things evolved to survive in it. Tardigrades for example can handle fairly large doses just fine.
The planets are also likely tidally locked, and solar radiation would be a complete non-issue for anything on the dark side of the planet. Life has no need for light after all, it had been thriving on Earth for millions of years before the first bacteria evolved a light-sensitive protein that let them detect daylight and flee to deeper, safer water. And many millions of years more before one evolved the ability to harness light for energy.
But I already answered. Even assuming it's only 2.5% of the total atmospheric insulation, we'd be talking about 3.2F of heating, before even considering knock-on effects
We're talking about space science - "someday" is usually presumed to be many decades or centuries in the future.
And is that all? Really? That's not too bad. Child's play once we get serious about astronomy and start building gravitational telescopes using our sun as the lens. What could you resolve with a 550-700AU focal length?
No, rotation isn't required for tidal forces, just for those forces to substantially "massage" a planet. Just squeezing the planet doesn't add heat, the squeeze needs to be changing to generate substantial heat.
It's true you'll still get some tidal effects due to eccentricity, but they'll be far smaller than if the planet was rotating - if you imagine the tides squeezing a stress-ball into more of a football shape, rotation means the bulges are traveling around the planet once per day. Without rotation you'll get just a slight change in how tight you're squeezing as the planet move closer and further from its primary, as well as some very slight oscillation of the bulge across the surface due to the associated libration.
I suppose though if we're talking about tight orbits around a huge primary, even a tiny fraction of the original tidal effects could still be quite large.
Hmm, and there will be another effect as well - that of the pulsating "tides" from the other planets - after all the distance between their orbits ranges between only about 2x and 4x that between the Earth and Moon, except for the outermost at ~6x the distance. That would be a factor with Jupiter's moons as well. I wonder how the magnitude of the effect would compare?
"There... I've run rings 'round you logically" -- Monty Python's Flying Circus