wait and see
lol. I'll be dead. I don't want to wait and see. But here are my 2 cents.
Who is in Mars that we need to communicate with? Darth Vader?
Light maybe 40% faster in vacuum but to go up to outer space and back has 2 factors to consider: latency and weather.
Finally, based on Shannon–Hartley theorem, bandwidth is limited to megabits for satellite transmissions. So, I am not sure if he knows what he is talking about. Powerful light beams? That is also subject to weather and clouds. It needs clear line of sight.
All I'd say is good luck. I won't be around if it ever happens at all, for sure.
Edit: One more thing. Bandwidth spectrum is a limited commodity.
I can appreciate your thoughts but trust me, it's not everyday that you get to challenge a man of his calibre. When he talks about technology and internet, he knows a thing or two(co-founded zip2 and paypal, remember?), when he talks about space, science and engineering he also seems to know a thing or two, being the founder, CEO and CTO of a private company who builds rockets for a living(and makes money out of it by delivering cargo for NASA) and at the same time being CEO of a company who builds probably the most advanced cars in the world. All this(and the satellite part) is actually part of a grand vision he has and through which he pushes step by step - to help speed up the advent of sustainable production and consumption of energy(in the case of cars) and advance civilization to a multi-planetary species(in the case of rockets).
So my suggestion would be to do your homework and see what this guys is really upto before you even think of laying out arguments against something you lack info of. He might really surprise you actually.
P.S. Here is an older yet interesting video worth the watch:
http://www.ted.com/talks/elon_musk_the_mind_behind_tesla_spacex_solarcity?language=enAnyway lets get back to NEM.
If you have read what that article was about, we were in the context of "High speed Space Internet" and not about rockets or cars.
It is not as if I spent one moment to think about this. No one has proven and can prove or show that satellite is the panacea to our Internet problems. He may be a great entrepreneur, leader and what not. But remember, science is a proven fact. I quoted Shannon–Hartley theorem. If your read about that and you understand Engineering and Physics, which is my background, that cannot be disputed. Further if you understand Bandwidth Spectrum and how it is a scarce commodity plus how it is being allocated and use, you will also understand how this can pose to be a big problem.
Building rockets is a different story. It has nothing to do with electromagnetic radiation. Electromagnetic radiation is almost fully utilised in the lower bands on earth.
c = fλ is the very basis of electromagnetic radiation. It is a known fact that high frequency bands have more photonic energy. For outerspace propagation, one can possibly use high frequency transmission. But as soon as it enters earth's atmosphere, this will get dispersed by the large molecules of water and pollutants and will render these high frequency transmission useless. High frequency propagation is therefore used for short distances of a few kilometres at most because of its high interactivity with water molecules in the air.
Shannon effect cannot be ignored too. It basically says that the number of bits per second is proportional to the channel bandwidth. If we are to carry gigabits like fibre, this will mean lower frequencies is a non starter. Further, low frequency radio waves will interfere with an overcrowded space on earth which will introduce noise and interference to these signals. With decreased signal to noise ratio, error rates will increase thereby rendering the data signal unusable.
We therefore cannot use low frequency bands nor can we use high frequency bands. What else can we use then? Nothing! Unless Elon is saying that Einstein or Max Planck and quantum physics are all crap and that he has his own science which hitherto is not known to mankind. Otherwise, based on the above facts, he cannot possibly do anything.
Finally, don't forget that there is also latency to beam from earth to the satellite and back. For LEO and to avoid orbital decay, this can be as far away as 2000 km. The latency is already 13.33 ms handicap for a start vis-a-vis fibre optics.
One last thing before I close my case. Ever wondered why we cannot receive satellite TV when there is a thunderstorm? Talking about communicating with Mars for a start is already preposterous. Who the heaven in Elon's lifetime will want to live or can live in Mars. Not unless Elon wants to leave a precursor to a legacy behind.
Good luck Elon! Maybe he has an "e" to his name that I don't.