I recently re-watched Contact for the first time since my childhood, and while I thoroughly enjoyed it, I realized that there was something I'd never understood: why couldn't they corroborate Ellie's account of her journey?

As far as I could tell, the pod fell harmlessly through the machine. That is, it didn't break anything, and the machine wasn't destroyed. I don't recall any dialogue about circuits being fried or the system shutting down, so presumably it wouldn't be hard to simply hoist the pod up and go again. I imagine the energy draw was substantial on the local Japanese power grid, but given the amount of effort and money already invested in the machine, surely "Round 2" wasn't out of the question? I mean, they almost certainly expected that this machine would get more than one good use out of it, anyway!

So given Ellie's vehement insistence that the machine had worked, the public nature of the controversy surrounding her testimony, and the government's (secret) findings that her device had recorded 18 hours of static, why wasn't it the obvious choice to have someone else suiting up the next day, ready to drop through the machine and corroborate her story?

3 Answers 3


The source novel and the original screenplay for the film approach this from slightly different angles. In both the book and the early screenplay, however the machine wasn't a 'drop' but a thingy made of a sort of crystal that sat inside a series of spinning thingies. You entered the machine through a transparent panel in the side.


We don't learn the fate of the machine, but it was made abundantly clear that it simply wouldn't work a second time. It can be "spun up" but there won't be a connecting wormhole. Presumably any further attempt to use it would simply be aborted. Note also that the machine is fabulously expensive to use so it's likely it would (at some point) be tried again but just not work.

The tunnel from Honshu to Hokkaido was open again, but the passageway from Earth to Vega was closed. They hadn’t actually tested this proposition — Ellie wondered whether, when the Five finally left the site, the project would try to spin up the benzels again—but she believed what she had been told: The Machine would not work again; there would be no further access to the tunnels for the beings of Earth. We could make little indentations in space-time as much as we liked; it would do us no good if no one hooked up from the other side. We had been given a glimpse, she thought, and then were left to save ourselves. If we could.


In the earlier draft screenplay the government declared the project an apparent failure. The entryway to the machine becomes impervious to entry and the decision is taken to simply encase the entire thing in concrete in case it causes further problems, literally burying it.

PRESIDENT LASKER (V.O.): Put him through.

KITZ (V.O.): Nothing. Apparently the surface began to ossify immediately after she emerged; all subsequent attempts to re-enter the machine have failed...

The sedan approaches the Capitol Building. The steps are mobbed with a surreal menagerie of the fanatical and the dispossessed. A huge bonfire has been built; images of Ellie on the cross...

KITZ (V.O.): ... as have all attempts at internal analysis. We've tried sonargrams, magnetic resonance, gamma rays; it's completely impenetrable.

PRESIDENT LASKER (V.O.): Recommendations?

KITZ (V.O.) I don't know. Maybe we built the damn thing wrong. Maybe it was all a hoax...
The safest thing would probably be to do a Chernobyl; encase it in concrete.

... (later)


[The entombment of the machine has begun. Scaffolding on all sides, swarming with workers in quarantine suits. Helicopters fly overhead, dumping load after load of concrete.]

There's really no good reason to assume that the film machine suffered a different fate.


While nobody could corroborate Ellie's personal experiences, anybody could prove the signal was impossible to fake. The simple one word reason is parallax.

Let's say you try to fake a signal from Vega. That's 26 light years away, so close enough to detect parallax easily.

You can put a satellite in orbit around Earth and make your satellite transmit a signal, and pretend the signal is from Vega. A radio dish could pick up the signal when your satellite is in the same position in the sky as Vega. All a radio astronomer has to do is ask a technician at a different radio telescope a few thousand miles away to point their dish at Vega. When the other dish points at Vega, it won't be pointing at your satellite, so it won't get the fake message from your satellite.

It's a simple parallax test.

Radio astronomers do this all the time. Every day. They might get some transient signal. The signal is not necessarily an artificial signal, but something from either a nearby source on Earth, something in orbit around Earth, some automated unmanned aircraft flying over their dish's controlled airspace, or perhaps a weird natural phenomenon hundreds of light years away. How do they filter out Earth based (or Earth orbiting) signals from astronomical events? They just ask their buddies at a different radio telescope to do a quick check. This check only takes a few minutes. If their buddy a few thousand miles away gets the same signal, they know the source is not from Earth. If their buddy does not get the signal, they know the source is Earth based.

I'm surprised the main character, Eleanor Arroway, did not mention this very simple test at the end of the movie when National Security Director, Michael Kitz, asked if Hadden could have faked the signal.

I am also surprised that anybody doubted the authenticity of the signal, or that Kitz even mentioned the possibility that the signal could be fake. The consensus by astronomers all over the world within the first few hours would be "this is real!"

While a good movie maker sometimes wants to leave doubt in the minds of the viewers that alternative interpretations are possible, a good scientist would say that no doubt is possible on some questions because the evidence is conclusive.

How do I know this? I've been an astronomer. I published peer-reviewed articles in astronomical science journals. There is a reason why my profile picture shows a radio dish.

There are 3 independent lines of evidence to support her story, so I think that people would eventually come around to believing her.

  1. The signal is real because you can't fake parallax.
  2. The recording devices contain 18 hours of static evidence, which supports her claim of being gone for many hours.
  3. Once her computers dig deep enough into the digits of Pi, the computers will eventually find "evidence" of a message hidden in Pi by the "creator" of the universe. This would show she was given knowledge which was not previously known to humanity, which anybody with a computer could independently confirm.
  • I think this in fact has been proven in the novel. The question isn't about the signal though, it's about the act of traveling. Mar 4, 2017 at 18:20
  • @Gallifreyan Given that the signal is real, that the "18 hours of static" evidence supports her claim of being gone for many hours, and the eventual "evidence" of a hidden message in Pi, I think that people would eventually come around to believing her. (I for one doubt anybody could hide a message in a number like Pi, and I am surprised Carl Sagan even put that in the novel. He is too much of a skeptic to try and make people believe something which is easily disproved.)
    – RichS
    Mar 4, 2017 at 18:25
  • Well, if memory serves it is implied at the end of the novel that Ellie would prove her experience was real. Regarding your last part, but the typing monkey "theory" it is perfectly possible that there is in fact a "message" in Pi, though maybe not in the first whatever-million digits Ellie finds it (in base 11). Also, mandatory XKCD Mar 4, 2017 at 18:28
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    @Gallifreyan I updated my answer to better address the question. :-)
    – RichS
    Mar 4, 2017 at 19:21
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    @Valorum Those two satellites might be the right distance apart for two specific radio dishes on Earth for a fleeting moment, but you can't put enough satellites in orbit to fake parallax for every radio dish for every minute. As Abraham Lincoln said, "You can fool some of the people some of the time, but you can't fool all the people all the time."
    – RichS
    Mar 5, 2017 at 16:39

Humans are not able to produce enough energy to open a wormhole. All the machine does is create a very small disturbance the aliens can detect. Once they detect the disturbance, they 'hook up' to it, and open up the wormhole from the other side.

  • No, but humans are able to produce enough energy to move the giant circular arms, run the command center, etc. That's what I meant by the "substantial draw on the local power grid."
    – Nerrolken
    Jul 28, 2015 at 16:04

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