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Comment by sschueller | Hacker News Reader

I don't always want to be the party pooper and this tech does have a lot of benefits when trying to transmit large items. However, you ain't ging to be video conferring to the moon or Mars with it. Not a single word about latency in the article.

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For those curious, I went and looked it up, and the one way (not round trip!) light travel time to the moon is about 1.3 seconds, and one way light travel time to mars is 3-22 minutes or so, depending on how far they are at the time.

So maaaaaybe you could have a really painful conversation with someone the moon, but not Mars.

edit: This is WITHOUT any latency introduced by the link/protocol, or if you have to then route the message from one side of the earth to the other, just time-of-flight distance calculations, so the absolute minimum possible latency.

1.3 seconds delay for conversation is mildly inconvenient, not painful.

Just another bad day on Cisco Webex™

Really? I'd be driven crazy by a 1.3 second delay. 300ms is bad enough.

You'd be continually talking over the other person.

That’s the speed of light, an aspect we can’t improve. The article is about bandwidth, an area we are able to affect.

You can send the data through a different medium to improve latency which satellite optical links could help with.

In space, latency will be dominated by distance. In low orbits, lasers will have low latency, good enough for interactive applications. Geosynchronous, Moon, and farther can't be helped.

Speed of light is still a limit, fastest possible roundtrip time between the Earth and moon is 2.5 seconds. Round trip between the Earth and Mars would be over 6 minutes when Mars is at its very closest to Earth.

in space its the distance, light has a speed limit

This is already sending data via lasers traveling through free space (and air, which has nearly the same speed of light as free space). You're not going to get a medium with a faster speed of light than free space unless you get into space-warping theoretical stuff. Even if you managed to run a fiber optic cable between a satellite and the earth, it would be around a third slower than lasers through space.

> latency

Well, the Moon's semi-major axis is about 380000 km, which means latency is lower-bounded to about 1 s.

Similarly, Mars' closest approach is 54.6 million km. That means a latency lower bound of 3 minutes.

The moon is only a second away. That's awkward for conversation, but perfectly possible for a structured meeting setting.

Laser link (not RF) implies a whole bunch of things:

1. speed of light through atmosphere, so basically c 2. line-of-sight is required, likely stationary base stations. Probably also subject to atmospheric and weather conditions

Just to clarify, item 1 is exactly the same for RF.

Humans wil adapt. If you want to call mars an ai will support you what the question/following sentence will be so you can answer the predicted question in one swoop. Problem solved.

They did that recently on the TV show Avenue 5.

Or you could write an email? I don't see how that works at all, you'd still be sitting in silence for minutes while the response loops around.

The satellite is only 300 miles up. The processing power on the satellite itself probably matters more for latency. At 200Gbps max (2x100), it's probably no slouch.

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